FMCSA-RRA-07-012

DOT-VNTSC-FMCSA-07-02

Human Factors Division (RTV-4G)

Office of Aviation Programs

John A. Volpe National Transportation Systems Center

**Emissions Impacts on Driver Safety**

**Prepared by:**

Dr. Michelle Yeh, RITA/RTV-4G

John K. Pollard, RITA/RTV-4G

U.S. Department of Transportation

Research and Innovative Technology Administration

John A. Volpe National Transportation Systems Center

Cambridge, MA 02142

**Prepared for:**

Michael Johnsen

Federal Motor Carrier Safety Administration

Washington, DC. 20590

July 2007

![](media/image1.jpeg){width="2.625in" height="0.7388888888888889in"}

Final Report

+-----------------------------------------------------------------------+
| > Notice                                                              |
|                                                                       |
| This document is disseminated under the sponsorship of the Department |
| of Transportation in the interest of information exchange. The United |
| States Government assumes no liability for its contents or use        |
| thereof.                                                              |
+-----------------------------------------------------------------------+
|                                                                       |
+-----------------------------------------------------------------------+
| > Notice                                                              |
|                                                                       |
| The United States Government does not endorse products or             |
| manufacturers. Trade or manufacturers' names appear herein solely     |
| because they are considered essential to the objective of this        |
| report.                                                               |
+-----------------------------------------------------------------------+

+-------------------+-----+----------+------------+---+-----------------+
| # REPORT          |     |          |            | * |                 |
|  DOCUMENTATION PA |     |          |            | F |                 |
| GE {#report-docum |     |          |            | o |                 |
| entation-page .Do |     |          |            | r |                 |
| cHdg .unnumbered} |     |          |            | m |                 |
|                   |     |          |            | A |                 |
|                   |     |          |            | p |                 |
|                   |     |          |            | p |                 |
|                   |     |          |            | r |                 |
|                   |     |          |            | o |                 |
|                   |     |          |            | v |                 |
|                   |     |          |            | e |                 |
|                   |     |          |            | d |                 |
|                   |     |          |            | * |                 |
|                   |     |          |            |   |                 |
|                   |     |          |            | * |                 |
|                   |     |          |            | O |                 |
|                   |     |          |            | M |                 |
|                   |     |          |            | B |                 |
|                   |     |          |            | N |                 |
|                   |     |          |            | o |                 |
|                   |     |          |            | . |                 |
|                   |     |          |            | 0 |                 |
|                   |     |          |            | 7 |                 |
|                   |     |          |            | 0 |                 |
|                   |     |          |            | 4 |                 |
|                   |     |          |            | - |                 |
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|                   |     |          |            | 1 |                 |
|                   |     |          |            | 8 |                 |
|                   |     |          |            | 8 |                 |
|                   |     |          |            | * |                 |
+-------------------+-----+----------+------------+---+-----------------+
| Public reporting  |     |          |            |   |                 |
| burden for this   |     |          |            |   |                 |
| collection of     |     |          |            |   |                 |
| information is    |     |          |            |   |                 |
| estimated to      |     |          |            |   |                 |
| average 1 hour    |     |          |            |   |                 |
| per response,     |     |          |            |   |                 |
| including the     |     |          |            |   |                 |
| time for          |     |          |            |   |                 |
| reviewing         |     |          |            |   |                 |
| instructions,     |     |          |            |   |                 |
| searching         |     |          |            |   |                 |
| existing data     |     |          |            |   |                 |
| sources,          |     |          |            |   |                 |
| gathering and     |     |          |            |   |                 |
| maintaining the   |     |          |            |   |                 |
| data needed, and  |     |          |            |   |                 |
| completing and    |     |          |            |   |                 |
| reviewing the     |     |          |            |   |                 |
| collection of     |     |          |            |   |                 |
| information. Send |     |          |            |   |                 |
| comments          |     |          |            |   |                 |
| regarding this    |     |          |            |   |                 |
| burden estimate   |     |          |            |   |                 |
| or any other      |     |          |            |   |                 |
| aspect of this    |     |          |            |   |                 |
| collection of     |     |          |            |   |                 |
| information,      |     |          |            |   |                 |
| including         |     |          |            |   |                 |
| suggestions for   |     |          |            |   |                 |
| reducing this     |     |          |            |   |                 |
| burden, to        |     |          |            |   |                 |
| Washington        |     |          |            |   |                 |
| Headquarters      |     |          |            |   |                 |
| Services,         |     |          |            |   |                 |
| Directorate for   |     |          |            |   |                 |
| Information       |     |          |            |   |                 |
| Operations and    |     |          |            |   |                 |
| Reports, 1215     |     |          |            |   |                 |
| Jefferson Davis   |     |          |            |   |                 |
| Highway, Suite    |     |          |            |   |                 |
| 1204, Arlington,  |     |          |            |   |                 |
| VA 22202-4302,    |     |          |            |   |                 |
| and to the Office |     |          |            |   |                 |
| of Management and |     |          |            |   |                 |
| Budget, Paperwork |     |          |            |   |                 |
| Reduction Project |     |          |            |   |                 |
| (0704-0188),      |     |          |            |   |                 |
| Washington, DC    |     |          |            |   |                 |
| 20503.            |     |          |            |   |                 |
+-------------------+-----+----------+------------+---+-----------------+
| 1\. AGENCY USE    |     | 2\.      |            | 3 |                 |
| ONLY (Leave       |     | REPORT   |            | \ |                 |
| blank)            |     | DATE     |            | . |                 |
|                   |     |          |            | R |                 |
|                   |     | July     |            | E |                 |
|                   |     | 2007     |            | P |                 |
|                   |     |          |            | O |                 |
|                   |     |          |            | R |                 |
|                   |     |          |            | T |                 |
|                   |     |          |            | T |                 |
|                   |     |          |            | Y |                 |
|                   |     |          |            | P |                 |
|                   |     |          |            | E |                 |
|                   |     |          |            | A |                 |
|                   |     |          |            | N |                 |
|                   |     |          |            | D |                 |
|                   |     |          |            | D |                 |
|                   |     |          |            | A |                 |
|                   |     |          |            | T |                 |
|                   |     |          |            | E |                 |
|                   |     |          |            | S |                 |
|                   |     |          |            | C |                 |
|                   |     |          |            | O |                 |
|                   |     |          |            | V |                 |
|                   |     |          |            | E |                 |
|                   |     |          |            | R |                 |
|                   |     |          |            | E |                 |
|                   |     |          |            | D |                 |
|                   |     |          |            |   |                 |
|                   |     |          |            | F |                 |
|                   |     |          |            | i |                 |
|                   |     |          |            | n |                 |
|                   |     |          |            | a |                 |
|                   |     |          |            | l |                 |
|                   |     |          |            | R |                 |
|                   |     |          |            | e |                 |
|                   |     |          |            | p |                 |
|                   |     |          |            | o |                 |
|                   |     |          |            | r |                 |
|                   |     |          |            | t |                 |
|                   |     |          |            | , |                 |
|                   |     |          |            | J |                 |
|                   |     |          |            | u |                 |
|                   |     |          |            | l |                 |
|                   |     |          |            | y |                 |
|                   |     |          |            | 2 |                 |
|                   |     |          |            | 0 |                 |
|                   |     |          |            | 0 |                 |
|                   |     |          |            | 7 |                 |
+-------------------+-----+----------+------------+---+-----------------+
| 4\. TITLE AND     |     |          |            |   | 5\. FUNDING     |
| SUBTITLE          |     |          |            |   | NUMBERS         |
|                   |     |          |            |   |                 |
| Emissions Impacts |     |          |            |   | SA0T/DV805      |
| on Driver Safety  |     |          |            |   |                 |
+-------------------+-----+----------+------------+---+-----------------+
| 6\. AUTHOR(S)     |     |          |            |   |                 |
|                   |     |          |            |   |                 |
| Michelle Yeh and  |     |          |            |   |                 |
| John K. Pollard   |     |          |            |   |                 |
+-------------------+-----+----------+------------+---+-----------------+
| 7\. PERFORMING    |     |          |            |   | 8\. PERFORMING  |
| ORGANIZATION      |     |          |            |   | ORGANIZATION    |
| NAME(S) AND       |     |          |            |   | REPORT NUMBER   |
| ADDRESS(ES)       |     |          |            |   |                 |
|                   |     |          |            |   | DOT-VN          |
| U.S. Department   |     |          |            |   | TSC-FMCSA-07-02 |
| of Transportation |     |          |            |   |                 |
|                   |     |          |            |   |                 |
| John A. Volpe     |     |          |            |   |                 |
| National          |     |          |            |   |                 |
| Transportation    |     |          |            |   |                 |
| Systems Center    |     |          |            |   |                 |
|                   |     |          |            |   |                 |
| Research and      |     |          |            |   |                 |
| Innovative        |     |          |            |   |                 |
| Technology        |     |          |            |   |                 |
| Administration    |     |          |            |   |                 |
|                   |     |          |            |   |                 |
| Cambridge, MA     |     |          |            |   |                 |
| 02142-1093        |     |          |            |   |                 |
+-------------------+-----+----------+------------+---+-----------------+
| 9\.               |     |          |            |   | 10\.            |
| SPON              |     |          |            |   | SPONSO          |
| SORING/MONITORING |     |          |            |   | RING/MONITORING |
| AGENCY NAME(S)    |     |          |            |   | AGENCY REPORT   |
| AND ADDRESS(ES)   |     |          |            |   | NUMBER          |
|                   |     |          |            |   |                 |
| U.S. Department   |     |          |            |   | F               |
| of Transportation |     |          |            |   | MCSA-RRA-07-012 |
|                   |     |          |            |   |                 |
| Federal Motor     |     |          |            |   |                 |
| Carrier Safety    |     |          |            |   |                 |
| Administration    |     |          |            |   |                 |
|                   |     |          |            |   |                 |
| Washington, DC.   |     |          |            |   |                 |
| 20590             |     |          |            |   |                 |
+-------------------+-----+----------+------------+---+-----------------+
| 11\.              |     |          |            |   |                 |
| SUPPLEMENTARY     |     |          |            |   |                 |
| NOTES             |     |          |            |   |                 |
+-------------------+-----+----------+------------+---+-----------------+
| 12a.              |     |          |            |   | 12b.            |
| DISTRIBU          |     |          |            |   | DISTRIBUTION    |
| TION/AVAILABILITY |     |          |            |   | CODE            |
| STATEMENT         |     |          |            |   |                 |
+-------------------+-----+----------+------------+---+-----------------+
| 13\. ABSTRACT     |     |          |            |   |                 |
| (Maximum 200      |     |          |            |   |                 |
| words)            |     |          |            |   |                 |
|                   |     |          |            |   |                 |
| The Federal Motor |     |          |            |   |                 |
| Carriers Safety   |     |          |            |   |                 |
| Administration    |     |          |            |   |                 |
| (FMCSA) is        |     |          |            |   |                 |
| concerned that    |     |          |            |   |                 |
| truck drivers'    |     |          |            |   |                 |
| exposure to high  |     |          |            |   |                 |
| levels of air     |     |          |            |   |                 |
| pollutants and    |     |          |            |   |                 |
| mobile air toxics |     |          |            |   |                 |
| for potentially   |     |          |            |   |                 |
| long periods of   |     |          |            |   |                 |
| time, may lead to |     |          |            |   |                 |
| acute and/or long |     |          |            |   |                 |
| term cognitive    |     |          |            |   |                 |
| impairments as a  |     |          |            |   |                 |
| result. The goal  |     |          |            |   |                 |
| of this project   |     |          |            |   |                 |
| was to compile    |     |          |            |   |                 |
| existing          |     |          |            |   |                 |
| information       |     |          |            |   |                 |
| addressing the    |     |          |            |   |                 |
| following         |     |          |            |   |                 |
| question: *Does   |     |          |            |   |                 |
| exposure to       |     |          |            |   |                 |
| diesel exhaust at |     |          |            |   |                 |
| levels found in   |     |          |            |   |                 |
| cabs affect       |     |          |            |   |                 |
| driver safety     |     |          |            |   |                 |
| performance by    |     |          |            |   |                 |
| affecting driver  |     |          |            |   |                 |
| sleep, alertness, |     |          |            |   |                 |
| reaction time,    |     |          |            |   |                 |
| fatigue levels,   |     |          |            |   |                 |
| or                |     |          |            |   |                 |
| judgment-making   |     |          |            |   |                 |
| abilities?* To    |     |          |            |   |                 |
| determine whether |     |          |            |   |                 |
| such an effect    |     |          |            |   |                 |
| exists, the Volpe |     |          |            |   |                 |
| National          |     |          |            |   |                 |
| Transportation    |     |          |            |   |                 |
| Systems Center    |     |          |            |   |                 |
| conducted expert  |     |          |            |   |                 |
| interviews to     |     |          |            |   |                 |
| obtain insight    |     |          |            |   |                 |
| into the question |     |          |            |   |                 |
| and searched the  |     |          |            |   |                 |
| environmental and |     |          |            |   |                 |
| medical           |     |          |            |   |                 |
| literature. The   |     |          |            |   |                 |
| results of these  |     |          |            |   |                 |
| activities are    |     |          |            |   |                 |
| reported here.    |     |          |            |   |                 |
|                   |     |          |            |   |                 |
| The results of    |     |          |            |   |                 |
| the expert        |     |          |            |   |                 |
| interviews and    |     |          |            |   |                 |
| literature search |     |          |            |   |                 |
| highlighted the   |     |          |            |   |                 |
| fact that very    |     |          |            |   |                 |
| little is known   |     |          |            |   |                 |
| regarding the     |     |          |            |   |                 |
| cognitive impact  |     |          |            |   |                 |
| of exposure to    |     |          |            |   |                 |
| diesel exhaust    |     |          |            |   |                 |
| emissions.        |     |          |            |   |                 |
| Certainly, the    |     |          |            |   |                 |
| potential for an  |     |          |            |   |                 |
| effect exists,    |     |          |            |   |                 |
| but cognitive     |     |          |            |   |                 |
| ability is        |     |          |            |   |                 |
| generally         |     |          |            |   |                 |
| confounded with   |     |          |            |   |                 |
| other "lifestyle" |     |          |            |   |                 |
| factors for truck |     |          |            |   |                 |
| drivers (e.g.,    |     |          |            |   |                 |
| fatigue, shift    |     |          |            |   |                 |
| work).            |     |          |            |   |                 |
| Consequently, the |     |          |            |   |                 |
| question will be  |     |          |            |   |                 |
| difficult to      |     |          |            |   |                 |
| answer.           |     |          |            |   |                 |
| Challenges for    |     |          |            |   |                 |
| future research   |     |          |            |   |                 |
| are identified.   |     |          |            |   |                 |
+-------------------+-----+----------+------------+---+-----------------+
| 14\. SUBJECT      |     |          |            |   | 15\. NUMBER OF  |
| TERMS             |     |          |            |   | PAGES           |
|                   |     |          |            |   |                 |
| Diesel exhaust,   |     |          |            |   | 59              |
| emissions, driver |     |          |            |   |                 |
| safety, truck     |     |          |            |   |                 |
| drivers,          |     |          |            |   |                 |
| cognition, driver |     |          |            |   |                 |
| alertness,        |     |          |            |   |                 |
| reaction time,    |     |          |            |   |                 |
| fatigue, decision |     |          |            |   |                 |
| making            |     |          |            |   |                 |
+-------------------+-----+----------+------------+---+-----------------+
|                   |     |          |            |   | 16\. PRICE CODE |
+-------------------+-----+----------+------------+---+-----------------+
| 17\. SECURITY     | 1   |          | 19\.       |   | 20\. LIMITATION |
| CLASSIFICATION\   | 8\. |          | SECURITY   |   | OF ABSTRACT     |
| OF REPORT         | SE  |          | CLASS      |   |                 |
|                   | CUR |          | IFICATION\ |   |                 |
| Unclassified      | ITY |          | OF         |   |                 |
|                   | CLA |          | ABSTRACT   |   |                 |
|                   | SSI |          |            |   |                 |
|                   | FIC |          | Un         |   |                 |
|                   | ATI |          | classified |   |                 |
|                   | ON\ |          |            |   |                 |
|                   | OF  |          |            |   |                 |
|                   | T   |          |            |   |                 |
|                   | HIS |          |            |   |                 |
|                   | P   |          |            |   |                 |
|                   | AGE |          |            |   |                 |
|                   |     |          |            |   |                 |
|                   | Unc |          |            |   |                 |
|                   | las |          |            |   |                 |
|                   | sif |          |            |   |                 |
|                   | ied |          |            |   |                 |
+-------------------+-----+----------+------------+---+-----------------+

NSN 7540-01-280-5500 Standard Form 298 (Rev. 2-89)

Prescribed by ANSI Std. 239-18

298-102

METRIC/ENGLISH CONVERSION FACTORS

<table style="width:100%;">
<colgroup>
<col style="width: 23%" />
<col style="width: 1%" />
<col style="width: 0%" />
<col style="width: 23%" />
<col style="width: 0%" />
<col style="width: 23%" />
<col style="width: 0%" />
<col style="width: 1%" />
<col style="width: 0%" />
<col style="width: 0%" />
<col style="width: 24%" />
</colgroup>
<thead>
<tr class="header">
<th colspan="5"><strong>ENGLISH TO METRIC</strong></th>
<th colspan="6"><strong>METRIC TO ENGLISH</strong></th>
</tr>
<tr class="odd">
<th colspan="5"><strong>LENGTH (APPROXIMATE)</strong></th>
<th colspan="6"><strong>LENGTH (APPROXIMATE)</strong></th>
</tr>
</thead>
<tbody>
<tr class="odd">
<td>1 inch (in)</td>
<td><strong>=</strong></td>
<td colspan="2"><strong>2.5 centimeters (cm)</strong></td>
<td colspan="2"><strong>1 millimeter (mm)</strong></td>
<td colspan="3"><strong>=</strong></td>
<td colspan="2"><strong>0.04 inch (in)</strong></td>
</tr>
<tr class="even">
<td><strong>1 foot (ft)</strong></td>
<td><strong>=</strong></td>
<td colspan="2"><strong>30 centimeters (cm)</strong></td>
<td colspan="2"><strong>1 centimeter (cm)</strong></td>
<td colspan="3"><strong>=</strong></td>
<td colspan="2"><strong>0.4 inch (in)</strong></td>
</tr>
<tr class="odd">
<td><strong>1 yard (yd)</strong></td>
<td><strong>=</strong></td>
<td colspan="2"><strong>0.9 meter (m)</strong></td>
<td colspan="2"><strong>1 meter (m)</strong></td>
<td colspan="3"><strong>=</strong></td>
<td colspan="2"><strong>3.3 feet (ft)</strong></td>
</tr>
<tr class="even">
<td><strong>1 mile (mi)</strong></td>
<td><strong>=</strong></td>
<td colspan="2"><strong>1.6 kilometers (km)</strong></td>
<td colspan="2"><strong>1 meter (m)</strong></td>
<td colspan="3"><strong>=</strong></td>
<td colspan="2"><strong>1.1 yards (yd)</strong></td>
</tr>
<tr class="odd">
<td></td>
<td></td>
<td colspan="2"></td>
<td colspan="2"><strong>1 kilometer (km)</strong></td>
<td colspan="3"><strong>=</strong></td>
<td colspan="2"><strong>0.6 mile (mi)</strong></td>
</tr>
<tr class="even">
<td colspan="5"><strong>AREA (APPROXIMATE)</strong></td>
<td colspan="6"><strong>AREA (APPROXIMATE)</strong></td>
</tr>
<tr class="odd">
<td><strong>1 square inch (sq in, in<sup>2</sup>)</strong></td>
<td><strong>=</strong></td>
<td colspan="2"><strong>6.5 square centimeters
(cm<sup>2</sup>)</strong></td>
<td colspan="2"><strong>1 square centimeter
(cm<sup>2</sup>)</strong></td>
<td colspan="3"><strong>=</strong></td>
<td colspan="2"><strong>0.16 square inch (sq in,
in<sup>2</sup>)</strong></td>
</tr>
<tr class="even">
<td><strong>1 square foot (sq ft, ft<sup>2</sup>)</strong></td>
<td><strong>=</strong></td>
<td colspan="2"><strong>0.09 square meter (m<sup>2</sup>)</strong></td>
<td colspan="2"><strong>1 square meter (m<sup>2</sup>)</strong></td>
<td colspan="3"><strong>=</strong></td>
<td colspan="2"><strong>1.2 square yards (sq yd,
yd<sup>2</sup>)</strong></td>
</tr>
<tr class="odd">
<td><strong>1 square yard (sq yd, yd<sup>2</sup>)</strong></td>
<td><strong>=</strong></td>
<td colspan="2"><strong>0.8 square meter (m<sup>2</sup>)</strong></td>
<td colspan="2"><strong>1 square kilometer
(km<sup>2</sup>)</strong></td>
<td colspan="3"><strong>=</strong></td>
<td colspan="2"><strong>0.4 square mile (sq mi,
mi<sup>2</sup>)</strong></td>
</tr>
<tr class="even">
<td><strong>1 square mile (sq mi, mi<sup>2</sup>)</strong></td>
<td><strong>=</strong></td>
<td colspan="2"><strong>2.6 square kilometers
(km<sup>2</sup>)</strong></td>
<td colspan="2"><strong>10,000 square meters
(m<sup>2</sup>)</strong></td>
<td colspan="3"><strong>=</strong></td>
<td colspan="2"><strong>1 hectare (ha) = 2.5 acres</strong></td>
</tr>
<tr class="odd">
<td><strong>1 acre = 0.4 hectare (he)</strong></td>
<td><strong>=</strong></td>
<td colspan="2"><strong>4,000 square meters
(m<sup>2</sup>)</strong></td>
<td colspan="2"></td>
<td colspan="3"></td>
<td colspan="2"></td>
</tr>
<tr class="even">
<td colspan="5"><strong>MASS - WEIGHT (APPROXIMATE)</strong></td>
<td colspan="6"><strong>MASS - WEIGHT (APPROXIMATE)</strong></td>
</tr>
<tr class="odd">
<td><strong>1 ounce (oz)</strong></td>
<td><strong>=</strong></td>
<td colspan="2"><strong>28 grams (gm)</strong></td>
<td colspan="2"><strong>1 gram (gm)</strong></td>
<td colspan="2"><strong>=</strong></td>
<td colspan="3"><strong>0.036 ounce (oz)</strong></td>
</tr>
<tr class="even">
<td><strong>1 pound (lb)</strong></td>
<td><strong>=</strong></td>
<td colspan="2"><strong>0.45 kilogram (kg)</strong></td>
<td colspan="2"><strong>1 kilogram (kg)</strong></td>
<td colspan="2"><strong>=</strong></td>
<td colspan="3"><strong>2.2 pounds (lb)</strong></td>
</tr>
<tr class="odd">
<td><strong>1 short ton = 2,000 pounds (lb)</strong></td>
<td><strong>=</strong></td>
<td colspan="2"><strong>0.9 tonne (t)</strong></td>
<td colspan="2"><strong>1 tonne (t)</strong></td>
<td colspan="2"><p><strong>=</strong></p>
<p><strong>=</strong></p></td>
<td colspan="3"><p><strong>1,000 kilograms (kg)</strong></p>
<p><strong>1.1 short tons</strong></p></td>
</tr>
<tr class="even">
<td colspan="5"><strong>VOLUME (APPROXIMATE)</strong></td>
<td colspan="6"><strong>VOLUME (APPROXIMATE)</strong></td>
</tr>
<tr class="odd">
<td><strong>1 teaspoon (tsp)</strong></td>
<td colspan="2"><strong>=</strong></td>
<td colspan="2"><strong>5 milliliters (ml)</strong></td>
<td colspan="2"><strong>1 milliliter (ml)</strong></td>
<td colspan="3"><strong>=</strong></td>
<td><strong>0.03 fluid ounce (fl oz)</strong></td>
</tr>
<tr class="even">
<td><strong>1 tablespoon (tbsp)</strong></td>
<td colspan="2"><strong>=</strong></td>
<td colspan="2"><strong>15 milliliters (ml)</strong></td>
<td colspan="2"><strong>1 liter (l)</strong></td>
<td colspan="3"><strong>=</strong></td>
<td><strong>2.1 pints (pt)</strong></td>
</tr>
<tr class="odd">
<td><strong>1 fluid ounce (fl oz)</strong></td>
<td colspan="2"><strong>=</strong></td>
<td colspan="2"><strong>30 milliliters (ml)</strong></td>
<td colspan="2"><strong>1 liter (l)</strong></td>
<td colspan="3"><strong>=</strong></td>
<td><strong>1.06 quarts (qt)</strong></td>
</tr>
<tr class="even">
<td><strong>1 cup (c)</strong></td>
<td colspan="2"><strong>=</strong></td>
<td colspan="2"><strong>0.24 liter (l)</strong></td>
<td colspan="2"><strong>1 liter (l)</strong></td>
<td colspan="3"><strong>=</strong></td>
<td><strong>0.26 gallon (gal)</strong></td>
</tr>
<tr class="odd">
<td><strong>1 pint (pt)</strong></td>
<td colspan="2"><strong>=</strong></td>
<td colspan="2"><strong>0.47 liter (l)</strong></td>
<td colspan="2"></td>
<td colspan="3"></td>
<td></td>
</tr>
<tr class="even">
<td><strong>1 quart (qt)</strong></td>
<td colspan="2"><strong>=</strong></td>
<td colspan="2"><strong>0.96 liter (l)</strong></td>
<td colspan="2"></td>
<td colspan="3"></td>
<td></td>
</tr>
<tr class="odd">
<td><strong>1 gallon (gal)</strong></td>
<td colspan="2"><strong>=</strong></td>
<td colspan="2"><strong>3.8 liters (l)</strong></td>
<td colspan="2"></td>
<td colspan="3"></td>
<td></td>
</tr>
<tr class="even">
<td><strong>1 cubic foot (cu ft, ft<sup>3</sup>)</strong></td>
<td colspan="2"><strong>=</strong></td>
<td colspan="2"><strong>0.03 cubic meter (m<sup>3</sup>)</strong></td>
<td colspan="2"><strong>1 cubic meter (m<sup>3</sup>)</strong></td>
<td colspan="3"><strong>=</strong></td>
<td><strong>36 cubic feet (cu ft, ft<sup>3</sup>)</strong></td>
</tr>
<tr class="odd">
<td><strong>1 cubic yard (cu yd, yd<sup>3</sup>)</strong></td>
<td colspan="2"><strong>=</strong></td>
<td colspan="2"><strong>0.76 cubic meter (m<sup>3</sup>)</strong></td>
<td colspan="2"><strong>1 cubic meter (m<sup>3</sup>)</strong></td>
<td colspan="3"><strong>=</strong></td>
<td><strong>1.3 cubic yards (cu yd, yd<sup>3</sup>)</strong></td>
</tr>
<tr class="even">
<td colspan="5"><strong>TEMPERATURE (EXACT)</strong></td>
<td colspan="6"><strong>TEMPERATURE (EXACT)</strong></td>
</tr>
<tr class="odd">
<td><strong>[(x-32)(5/9)] F</strong></td>
<td colspan="2"><strong>=</strong></td>
<td colspan="2"><strong>y C</strong></td>
<td colspan="2"><strong>[(9/5) y + 32] C</strong></td>
<td colspan="2"><strong>=</strong></td>
<td colspan="2"><strong>x F</strong></td>
</tr>
</tbody>
</table>

![](media/image3.wmf)

![](media/image4.wmf)

For more exact and or other conversion factors, see NIST Miscellaneous
Publication 286, Units of Weights and Measures. Price \$2.50 SD Catalog
No. C13 10286 **Updated 6/17/98**

Preface

This report was prepared by the Human Factors Division of the Office of
Aviation Programs at the John A. Volpe National Transportation Systems
Center, United States Department of Transportation. This research was
conducted with funding from the Federal Motor Carriers Safety
Administration (FMCSA); Michael Johnsen served as the project manager.
The authors wish to thank Michael Johnsen, Jose Mantilla, and Paul Zebe
for their direction and guidance in the development of this report.
Special thanks also go to Christopher Zevitas for his help identifying
experts to interview, to the researchers who participated in the
interviews, and to Marilyn Gross for her assistance in conducting the
literature review.

The views expressed herein are those of the authors and do not
necessarily reflect the views of the Volpe National Transportation
Systems Center, the Research and Innovative Technology Administration,
or the United States Department of Transportation.

Feedback on this document can be sent to Michelle Yeh
(Michelle.Yeh@volpe.dot.gov) or JK Pollard
(John.K.Pollard@volpe.dot.gov).

Table of Contents

[1 Introduction 1](#introduction)

[2 Expert Interviews 2](#expert-interviews)

[2.1 Participants 2](#participants)

[2.2 Method 2](#method)

[2.3 Results 3](#results)

[2.4 Conclusions 4](#conclusions)

[3 Literature Review 5](#literature-review)

[3.1 Method 5](#method-1)

[3.2 Results 5](#results-1)

[3.2.1 Diesel Emissions Exposure 6](#diesel-emissions-exposure)

[3.2.2 Carbon Monoxide Exposure 7](#carbon-monoxide-exposure)

[3.3.3 Similar Substances 7](#other-substances)

[3.3 Summary 8](#summary)

[4 Summary and Challenges for Future Research
9](#summary-and-challenges-for-future-research)

[4.1 Summary 9](#summary-1)

[4.2 Research Challenges 9](#research-challenges)

[4.3 Conclusion 10](#conclusion)

[References 12](#references)

[Appendix A. Notes from Expert Interviews
17](#notes-from-expert-interviews)

[Appendix B. Annotated Bibliography 24](#annotated-bibliography)

[B.1 Cognitive Effects of Diesel Exposure
25](#cognitive-effects-of-diesel-exposure)

[B.2 Cognitive Effects of Carbon Monoxide Exposure
28](#cognitive-effects-of-carbon-monoxide-exposure)

[B.3 Cognitive Effects of Exposure to Jet Fuel Vapors
37](#cognitive-effects-of-exposure-to-jet-fuel-vapors)

[B.4 Other Health Effects of Diesel Exposure
43](#other-health-effects-of-diesel-exposure)

[B.5 Measuring Air Quality 47](#measuring-air-quality)

Executive Summary

The goal of this project was to compile existing information regarding
whether driver performance is affected by exposure to diesel exhaust
emissions at levels found in cabs. The health effects of exposure on the
cardiovascular and pulmonary systems are well documented, but there is a
lack of understanding regarding the potential cognitive effects of
diesel exhaust emissions exposure. The Federal Motor Carriers Safety
Administration (FMCSA) is concerned that truck drivers' exposure to high
levels of air pollutants and mobile air toxics for potentially long
periods of time, could influence their safety and affect their sleep,
alertness, or judgment. To address this issue, the Volpe National
Transportation Systems Center conducted expert interviews to obtain
insight into the issue and searched the environmental and medical
literature for relevant research. The results of these two activities
are reported here. Challenges to future research are also noted.

**Expert Interviews**

Ten researchers from the Environmental Protection Agency (EPA), Harvard
School of Public Health, and Wright Patterson Air Force Base
participated in the interviews. The researchers noted that there is a
dearth of literature addressing the cognitive effects of diesel
emissions. Instead, human studies have generally addressed the effects
of diesel exhaust on pulmonary and cardiovascular health, and animal
studies have typically focused on the neurotoxic effects of exposure.
Most researchers acknowledged that there is a cause for concern; several
studies have shown high concentrations of particles at hot spots such as
truck stops and major freeways. However, little is known whether
cognitive ability would be impaired as a consequence, and the consensus
reached by the researchers interviewed was that such a question would be
difficult to answer.

**Literature Review**

A review of the environmental and medical literature identified only
three studies that directly examined the cognitive impacts of diesel
exhaust exposure. Two of these studies focused on the chronic effects of
exposure to diesel exhaust emissions and reported impairments in
cognitive ability -- as indicated by decrements in memory, problem
solving, and reaction time -- as a consequence. However, the level of
exposure leading to the impairment was not measured, and the extent of
the impairment (i.e., whether it is long-lasting or temporary) was not
clear. Only one study measured and controlled for exposure, but its
focus was on the health effects of acute, short-term exposure,
particularly for those with sensitivity to chemicals. The results showed
no effect on cognitive ability due to exposure between those who were
chemically sensitive versus those who were not, although the former
group reported more symptoms (e.g., dizziness, nausea, fatigue) than the
latter group. However, performance differences within a group before,
during, and after exposure were not compared as part of the study.

The literature search was expanded to include research that examined the
cognitive impacts to chemicals in diesel exhaust or substances that
could have similar cognitive effects as diesel exhaust, but no clear
conclusions could be drawn from these studies. With respect to the
literature on the cognitive effects of chemicals in diesel exhaust, the
only studies found addressed the effects of carbon monoxide exposure. In
these studies, exposure was generally acute and short-term. The
cognitive impact of carbon monoxide exposure varied depending on the
task; performance on vigilance and tracking tasks showed no effect of
exposure and time estimation was impaired slightly, but performance on
complex tasks requiring abstract thinking and manual dexterity or
performing two tasks concurrently was impaired. Consequently, carbon
monoxide could impair driver judgments at high levels of exposure, but
it is not clear whether such levels are encountered in the typical
driving environment. It is also important to consider that the level of
carbon monoxide to which drivers are exposed fluctuates greatly due to
weather and traffic.

With respect to the literature for substances that could have similar
cognitive consequences as diesel exhaust, a body of research addressing
the cognitive effects of exposure to jet fuel vapors was considered
potentially relevant, since both jet fuel and diesel are fuel oils and
hence, closely related. Much of this research was the result of the
military's concern that such exposure could lead to errors by pilots in
navigation and communication. Studies addressing this issue focused on
the chronic, long-term effects of exposure, i.e., over weeks in the case
of animal studies and years for human studies. While animal studies
examining the neurobehavioral consequences of jet fuel vapor exposure
showed only short-term effects of exposure on behavior and brain
development, the results of human studies examining the consequences of
occupational exposure to jet fuel showed more lasting effects. Exposed
workers had more variable performance on complex tasks compared to
non-exposed workers and greater performance decrements on simple tasks.
However, the degree to which exposure to diesel emissions has similar
consequences as exposure to jet fuel vapors is unknown.

**Challenges to Future Research**

The results of the expert interviews and literature search highlight the
fact that very little is known regarding the cognitive impact of
exposure to diesel exhaust emissions. One reason for this is that the
question is a difficult one to answer.

First, cognitive ability is influenced by external stressors; for the
truck driver, lifestyle factors (e.g., long hours, shift work) have
significant impacts on cognitive functioning. Consequently, the specific
impacts of diesel exhaust emissions exposure could be difficult to
isolate and measure. Second, a good metric of cognitive ability that
would be sensitive to the effects is needed. Results from the literature
examining the effects of carbon monoxide exposure show varying levels of
cognitive impairment depending on task complexity.

Third, a dose-response effect of exposure on cognition would be
difficult to determine. To measure the effects of acute, short-term
exposure, cognitive tests would need to be administered at the time of
exposure, but there are no easy methods to track drivers' exposure in
real-time, and capturing drivers at the time of exposure would be
methodologically challenging. To measure the chronic effects of
long-term exposure, an estimate of the level of diesel exhaust emissions
to which drivers are exposed over time would be needed. Developing a
model to determine these estimates would require a large data collection
effort to consider all factors that moderate exposure (e.g., commodity,
length of haul).

One interesting approach is to examine whether there are any biological
indicators (e.g., blood markers) of cognition. No such markers have yet
been identified, and establishing the relationship between biological
markers and cognitive ability would be a significant task.

While controlled laboratory studies and animal studies offer an
alternative to occupational studies in a complex real-world environment,
it is not clear whether the results from these basic research studies
would generalize to the truck driving population. The results of human
laboratory studies would still need to be considered with other
important lifestyle factors that influence cognitive ability, and animal
studies would be limited to addressing the effects of diesel emissions
exposure on basic cognition, whereas much of the skills required in
driving in order to maintain safety require a high level of cognitive
functioning.

Thus, any research to be conducted would be costly, difficult to
implement, and any effects difficult to measure. Although the potential
for an effect exists, it is important to note that the harmful effects
of emissions are being addressed in other ways. The EPA is establishing
a comprehensive national clean diesel initiative to reduce emissions
from diesel engines in the heavy-duty commercial motor vehicle fleet
through the use of high-efficiency catalytic exhaust emission control
devices or comparably effective advanced technologies. It is hoped that
when the program is fully implemented and the fleet of older engines has
fully turned over (by 2030), the benefits of this initiative will be
evidenced by the improved health and safety of all drivers.

# Introduction

The Federal Motor Carriers Safety Administration (FMCSA) is concerned
that truck drivers, who are exposed to diesel emissions for potentially
long periods of time and over many years, may suffer acute and/or long
term cognitive impairments as a result. Measurements of diesel exhaust
in cabs of idling trucks and in "hot spots" where many trucks idle
(e.g., overnight at truck stops or waiting at a border crossing) show
levels of air pollutants and mobile air toxics that exceed federal
health standards. The health impacts of diesel exhaust exposure have
generally focused on its cancer-related effects and impact on
cardiovascular and pulmonary function. Less is known regarding the
impact of diesel exhaust exposure on cognition. Thus, FMCSA sponsored
the Volpe National Transportation Systems Center (Volpe Center) to
compile existing information that addressed the role (if any) of these
pollutants in affecting 1) driver alertness, reaction time, and fatigue;
and 2) the quality of sleep drivers experience in cabs with elevated
levels of emissions. Specifically, the question of interest addressed
was: *Does exposure to diesel exhaust at levels found in cabs affect
driver safety performance by affecting driver sleep, alertness, reaction
time, fatigue levels, or judgment-making abilities?*

The Volpe Center conducted two tasks. One task was a series of *expert
interviews* to obtain insight into the question. The other task was a
*literature search* of environmental and medical literature to determine
whether any studies were conducted that examined the cognitive impacts
of diesel exposure. The literature search included neurological studies,
studies related to specific chemicals found in diesel exhaust, and
studies examining the cognitive effects of substances that could have
similar effects as diesel exhaust (e.g., jet fuel).

This report presents the results of this effort. Section 2 provides a
summary of the expert interviews and Section 3 presents an overview of
the literature review findings. Detailed notes from each interview and
an annotated bibliography of the literature identified in the review are
provided in Appendix A and Appendix B, respectively. A summary of the
findings and challenges for future research are identified in Section 4.

# Expert Interviews

The Volpe Center conducted interviews with neurotoxicologists,
engineers, and medical professionals for their insight regarding the
cognitive effects of diesel exhaust exposure. This section describes the
methodology for the interviews and presents a summary of the interview
discussions. Notes from each interview are provided in Appendix A.

## Participants

Ten subject matter experts participated in the interviews, as listed
below:

-   EPA: Vernon Benignus, William Boyes, Ian Gilmour, Chad Bailey

-   Harvard School of Public Health: Tom Smith, Eric Garshick, Jaime
    Hart

-   United States (U.S.) Air Force, Wright Patterson Air Force
    Base/Science Applications International Corporation (SAIC): Gail
    Chapman, Palur Gunasekar, Shawn McInturf, and Haviland Steele

The participants were identified through recommendations from the
Environmental Protection Agency (EPA), FMCSA, and the Volpe Center, as
well as through a review of the relevant literature (see Section 3).

The first interviews were conducted with researchers at the U.S.
Environmental Protection Agency (EPA). FMCSA identified three experts as
a starting point: Vernon Benignus, William Boyes, and Chad Bailey.
Vernon Benignus and William Boyes are neurotoxicologists with knowledge
regarding the neurobehavioral effects of organic compounds and solvents.
They recruited Ian Gilmour, a research biologist, to participate in the
discussion to provide input on the health effects of air pollutants.
Chad Bailey is an environmental scientist with knowledge on the health
effects of diesel emissions.

During the course of the EPA interviews, it was recommended that the
Volpe Center contact researchers at the Harvard School of Public Health
to discuss their large-scale cohort study examining the occupational
health effects of diesel exhaust emissions on truck drivers. It was not
known whether the Harvard study addressed cognitive ability, however.
Environmentalists at the Volpe Center also felt that researchers at
Harvard would have insight into the problem and provided the initial
contacts for Tom Smith, a Professor of Industrial Hygiene in the
Department of Environmental Health, and Eric Garshick, an Assistant
Professor at Harvard Medical School, both involved in the cohort study.

Finally, the results of the literature review, conducted concurrently
with the interviews, indicated that research sponsored by the military
might shed some light on the problem. In particular, the U.S. Air Force
had conducted studies examining the neurobehavioral effects of exposure
to jet fuel vapors. Because diesel exhaust and jet fuel are closely
related, it was of interest to determine if the effects of exposure from
jet fuel vapors might be similar to that expected from exposure to
diesel exhaust emissions.

## Method

To structure the interviews, six questions of interest were identified
by the Volpe Center in conjunction with FMCSA:

1.  Are you aware of any research on the effects of diesel emissions
    (preferably at levels a driver might be exposed to) on alertness,
    decision-making, or sleeping, or any other impacts that could affect
    a driver's ability to drive safely?

2.  Do you think there is any chance that there could be an effect such
    as this?

3.  Some existing research suggests that there are elevated levels of
    emissions in truck cabs that exceed Federal agency standards. Are
    you aware of any research that has examined ambient air quality in
    \'hot spots\' where trucks might park or inside truck cabs?

4.  If primary research needs to be conducted (in the absence of
    existing research) what vehicle would be appropriate (Federal agency
    or organization with expertise in this field)?

5.  What factors should be considered in this research?

6.  Can you recommend anyone else we should contact regarding this
    research?

The interviews were generally conducted as informal discussions. During
the interview, experts were asked to discuss their research examining
the health effects of diesel exhaust or similar substances or to discuss
their interest in the topic.

## Results

The researchers interviewed noted that there is a paucity of literature
examining the cognitive effects of diesel emissions. Only two studies
were known to be of potential relevance: one that examined the
neurobehavioral effects of occupational exposure by railroad workers and
electricians to diesel exhaust (see Kilburn, 2000; note that this study
was identified by FMCSA in their earlier review) and one that considered
the likelihood of reporting Gulf War syndrome symptoms after exposure to
diesel fuel vapors (see Fiedler, et al., 2004). A third study noted by
some researchers to be of interest, although not directly relevant to
cognitive functioning, was a recent finding that particulate matter can
migrate from nasal passages to the brain when it is inhaled (in
particular, manganese). However, it was not clear from the research
whether these particulates would have any impact on neurological
functions.

Other research examining the health effects of diesel exhaust emissions
has tended to focus on the cardiovascular or pulmonary effects. In the
laboratory setting, these studies are conducted with healthy young
adults or mild asthmatics, who inhale low levels of diesel exhaust fumes
and then perform physical tasks. In the field, several occupational
studies have measured the level of diesel emissions in vehicles and
examined its effect on drivers. In one study, for example, the level of
diesel emissions in patrol cars of North Carolina state troopers was
measured and the health effects were evaluated with respect to the state
troopers' blood profiles, blood pressure and heart rate. The results of
the study identified cardiac consequences of the troopers' occupational
exposure to diesel emissions (see Riediker, et al., 2003, 2004).

With respect to the trucking industry, the Harvard School of Public
Health is conducting a large study addressing the health effects of
occupational exposure to diesel emissions. Specifically, the study
examines the relationship between lung cancer and diesel and vehicle
emissions exposure. Researchers have collected measurements for
particulates at various trucking terminals, and a database is being
developed so that exposure can be estimated based on workers' job title,
work location, and terminal site. The results of the study so far have
shown that there is an increased risk of lung cancer, cardiac mortality,
and accidental death.

The discussions highlighted the fact that exposure to diesel emissions
can occur in several ways. Of particular concern to FMCSA is the air
quality in "hot spots", where trucks may park for an extended period of
time with their engines idling. Several research studies have focused on
one interchange in Tennessee along Interstate-40 and Watt Road, where
there are three truck stops with an overall capacity for 700 overnight
trucks. As part of the studies, the air quality at these truck stops and
in cabs have been measured and modeled. The measurements showed high
concentrations of particulate matter during the nighttime hours when
there were more diesel trucks idling and the atmosphere was at its
meteorological low, and during the winter months. Models of air quality
show that truck stops represent islands of high concentration among low
background areas. There is also a consistent finding showing that the
concentration of very fine particles coming out of exhaust tailpipes is
ten times higher along major freeways compared to urban background air.
Other studies examining the levels of different particulate mixture
components (i.e., soot, carbon) also show a steep gradient along major
freeways.

Researchers were divided regarding whether there could be a cognitive
effect of diesel emissions. Neurotoxicologists interviewed generally
thought that an effect was possible; in fact, the EPA is proposing a
series of animal studies to examine the neurophysiological and cognitive
effects of diesel exposure. Animal studies provide a means for drawing
clear conclusions between a neurotoxin and behavior, without influences
by external sources. However, medical researchers were more cautious,
acknowledging that cognitive issues are generally confounded with
"lifestyle" factors for truck drivers (e.g., poor sleep). As a result,
if cognitive impairments were found, it would not be clear whether the
impairment was the result of exposure to diesel exhaust emissions or
other external stressors.

## Conclusions

If any research were to be conducted for FMCSA on the cognitive impact
of diesel emissions, it would be important to consider factors that
could be measured empirically and variables that could moderate the
results. Both real-time exposure and cognitive ability are difficult to
measure. A series of studies would be needed to identify markers of
exposure and biological indicators of neurocognitive functioning.
Additionally, it would be important to consider the method of exposure;
inhalation is only one form and drivers may absorb diesel through the
hands. The dose and level of exposure could vary depending on the
source, magnitude and length of time of exposure.

Several agencies are interested and in a position to conduct this kind
of research should new studies be proposed by FMCSA. The EPA and
military are best suited for conducting animal studies. For human
studies, the Harvard School of Public Health has established
relationships with trucking companies, unions, and management, and could
expand their current study to measure the cognitive impacts of diesel
exhaust exposure.

# Literature Review

A literature review was conducted on neurological studies and studies
relating to the specific chemicals found in diesel exhaust that examined
the *cognitive* impacts of diesel exhaust exposure (e.g., driver
alertness, reaction time, fatigue levels, sleep-disruption, or
judgment-making abilities). Literature addressing the potential cancer
risks of diesel exhaust emissions exposure or its cardiovascular or
pulmonary effects was not included in the scope of the review. The
methodology for the literature search and a summary of the findings are
presented in this section. An annotated bibliography, providing details
for each of the studies discussed, is included as Appendix B. Note that
while the literature review focused only on the those studies that
addressed the cognitive effects of diesel exhaust emissions exposure,
Appendix B presents a larger view of the problem and includes references
for studies that addressed the non-cognitive health effects of diesel
exhaust exposure and for studies that measured air quality in general
traffic and "hot spots" since it was expected that this research might
also be of interest to the reader.

## Method

The review searched the environmental and medical literature and
included the following nine sources:

1)  Transportation Research Information Service (TRIS)/National
    Transportation Library (NTL)

2)  Defense Technical Information Center (DTIC)

3)  Center for Disease Control (CDC)/National Institute of Occupational
    Safety & Health (NIOSH)

4)  Medline

5)  National Institute of Environmental Health Sciences

6)  EPA

7)  EbscoHost and InfoTrac (indexes to a variety of journals)

8)  Health Effects Institute

9)  Assorted links from Internet search engines (e.g., Google)

The focus was on those studies examining the *cognitive* effects of
diesel exposure rather than examination of cancer risks or
cardiovascular or pulmonary functions.

## Results

The results of the literature search consisted of neurological studies
and research related to chemicals found in diesel exhaust and similar
substances. An overview of the findings is presented in the three
following sections. Section 3.2.1 addresses research on diesel exhaust
exposure. Because so little literature specifically addressing the
cognitive impact of diesel exhaust exposure was found, the literature
search was expanded to consider research examining the cognitive impacts
of exposure to chemicals found in diesel exhaust, based on the "Partial
List of Chemicals Associated with Diesel Exhaust" specified by the U.S.
Department of Labor (see
[www.osha.gov/SLTC/dieselexhaust/chemical.html](http://www.osha.gov/SLTC/dieselexhaust/chemical.html)).
Of these chemicals, only studies were found addressing the cognitive
effects of carbon monoxide exposure, and an overview of these findings
are provided in Section 3.2.2. Finally, the literature search also
considered the cognitive effects of substances that could have similar
effects to diesel exhaust. In particular, the literature review
identified a body of research addressing the cognitive effects of
exposure to jet fuel vapors. Both jet fuel and diesel are fuel oils, so
the two were considered to be closely related. Additionally, because
diesel vapors from unburned fuel can be a component of diesel exhaust,
findings from the literature regarding the cognitive impairments due to
jet fuel vapors were expected to be potentially relevant. This is
discussed in Section 3.3.3.

### Diesel Emissions Exposure

The literature review identified only three studies that directly
examined the cognitive impacts of diesel exhaust exposure, none of which
were focused specifically on truck drivers. Two of these studies
addressed the chronic effects of long-term exposure and reported
impairments in cognitive ability. In the first study, Kilburn (2000)
examined whether diesel exhaust-exposed workers had more impairment in
central nervous system functions than non-exposed workers. Performance
on neurophysiological and neuropsychological tests for 10 railroad
workers and six electricians (the chemically-exposed workers) was
compared to a control group with no known history of exposure. The
results showed impairments in neurobehavioral functions for the
diesel-exposed workers relative to the control group and suggested that
a link between diesel-exhaust exposure and impairment to the central
nervous system (including cognitive functioning) may be present.
Specifically, diesel-exhaust exposure led to cognitive decrements in
memory, problem solving, reaction time and neurological impairments in
vision and balance.

In the other study, Maruff, et al. (1998) addressed the neurological and
cognitive consequences of chronic petrol sniffing. Blood tests,
neurological tests, and psychological tests were performed on 34
*non-sniffers* who had never sniffed petrol, 33 *current sniffers* who
had sniffed petrol for at least six months and were currently and
actively sniffing; and 30 *ex-sniffers*, who had sniffed petrol for at
least six months but had not sniffed petrol in the six -month period
prior to the study. The psychological test results showed better
performance for non-sniffers on pattern and spatial recognition and
paired association learning, particularly as the number of patterns
increased, relative to current sniffers and ex-sniffers. Additionally,
non-sniffers showed higher performance than current sniffers on visual
search as the number of distractors increased. The findings suggest that
petrol sniffing may compromise neurological and cognitive functions but
that their effects may be reduced over time with abstinence.

While chronic exposure to diesel exhaust emissions has been found to
impair cognitive functioning, less known are the effects of acute,
short-term exposure. This was the focus of a study by Fiedler, et al.
(2004), which assessed the health effects of acute exposure to diesel
vapors with acetaldehyde on Gulf War veterans under stressful and
non-stressful conditions. Participants were classified as being *ill*,
based on criteria for chronic fatigue syndrome and self-reported
chemical sensitivity, or *healthy*. They were exposed for 50 minutes in
a controlled environment facility to 5 parts per million (ppm) diesel
vapor, simulating typical exposure concentrations in garages where
diesel and other fuels are used, with 0.5 ppm concentration of
acetaldehyde added to simulate the soldiers' environmental conditions.
Subjective reports of symptoms and performance on a dual-task driving
task, with and without stressors, were compared for the two groups of
Gulf War veterans before, during, and after exposure. The results
indicated that although ill Gulf War veterans reported more severe
symptoms than healthy Gulf War veterans as a result of the exposure
(e.g., difficulty concentrating, disorientation, dizziness, and
headaches), there was no performance difference attributable to
cognitive ability between the two groups, as measured by the dual-task
driving simulation test. However, it is important to note that there was
no control group (i.e., a "no exposure" condition), nor was performance
within a group compared before, during, or after exposure.

Thus, the results of the literature review suggest that cognitive
impairment may result from chronic exposure to diesel exhaust emissions
(Kilburn, 2000 and Maruff, et al., 1998), but the level of exposure
leading to the impairment was not known, and the extent of the
impairment (i.e., whether it is temporary or not) is not clear. The one
study that did measure and control for exposure showed that
chemically-sensitive participants were more likely to report symptoms
than healthy participants after acute exposure, but reported no
difference attributable to cognitive ability between the two groups
(Fiedler, et al., 2004). However, it was not clear whether there were
performance differences within a group as a consequence of exposure.

### Carbon Monoxide Exposure

Studies addressing the cognitive effects of carbon monoxide exposure
were primarily conducted in controlled laboratory environments. In the
studies, exposure was considered with respect to its short-term, acute
effects and measured as a function of the concentration level (in parts
per million, ppm) and/or via participants' carboxyhemoglobin (COHb)
levels, a measure of the amount of carbon monoxide and hemoglobin in red
blood cells when carbon monoxide is inhaled. The concentration levels
tested vary from 0 ppm to 200 ppm, with COHb levels ranging from less
than 1% (with no exposure) to 10% and higher. Subjectively, participants
reported symptoms such as headaches at high levels of exposure (Stewart,
et al., 1970; Stewart, et al., 1973). Objectively, the results of these
studies generally showed no effects on monitoring (Horvath, Dahms, and
O'Hanlon, 1971) and tracking (Hanks, 1970; Mikulka, et al., 1970;
O'Donnell, et al., 1971) tasks and small effects on time estimation
abilities (Beard and Wertheim, 1967; Bunnell and Horvath, 1988). Of
concern, however, are studies that show the potential for memory
deficits and impaired cognitive functioning on more complex tasks such
as abstract thinking and manual dexterity (Amitai, et al., 1998; Ryan,
1990; Stewart, et al., 1970) and dual task performance (Milhevic,
Gliner, and Horvath, 1983).

With respect to driving performance, the effects of carbon monoxide
exposure are not as clear. Wright, Randell, and Shephard (1973) showed
that a 3.4% increase in COHb levels (achieved through carbon monoxide
exposure at levels of 100 ppm for 2 hours) could impair judgments while
driving. Additionally, COHb levels upwards of 11% created some "tunnel
vision", with drivers focusing more on information in the forward field
of view and less on information at the periphery (McFarland, 1973).
However, it is not clear whether the levels of carbon monoxide to which
drivers are exposed while on the road are equivalent to those used in
the studies. In fact, one report that noted the carbon monoxide level in
cars indicated levels of less than 25 ppm (Mayron and Winterhaller,
1976), although the level of exposure fluctuates due to weather and
traffic.

It is worth noting that there were no negative consequences of carbon
monoxide exposure on sleep (O'Donnell, Chikos, and Theodore, 1971);
participants exposed to carbon monoxide experienced more "deep sleep"
than those who were not exposed, with no impact on cognitive
functioning.

### Other Substances

Anecdotal reports by pilots complaining of nausea, poor coordination,
short-term memory loss, and "slow thinking" after short-term acute
exposure to jet fuel led to concerns that exposure to jet fuel vapors
could result in pilot errors in navigation and communication (Davies,
1964; Porter, 1990; Smith, et al., 1997). Basic research investigating
the consequences of exposure to jet-fuel vapors has generally focused on
the consequences of chronic exposure, measured in weeks for controlled
animal studies and years for human studies. The results of animal
studies indicated short-term neurological and behavioral effects (e.g.,
during exposure or initially during postnatal development) without any
long-term consequences (Mattie, et al., 2001; Nordholm, 1998). However,
human studies suggest more permanent neurological effects. Three studies
directly examined the prevalence of cognitive deficits on aircraft
factory workers with long-term exposure to jet fuel (Knave, Mindus, and
Struwe, 1979; Knave, Persson, Goldberg, and Westerholm, 1976; Knave, et
al., 1978), the results of which suggest a link between exposure and
cerebellar functioning (Ritchie, et al., 2001). The results show more
symptoms of exposure (e.g., dizziness, headache, nausea, respiratory
tract inflammation, chest palpitations) reported by workers with high
exposure compared to workers with lower levels or no exposure. Exposed
workers showed greater variability in performance on psychological tests
of complex reaction time and greater performance decrements on tasks of
simple reaction time and perceptual speed (Knave, Mindus, and Struwe,
1979; Knave, et al., 1978). Neurological tests on workers with high and
low levels of exposure showed no differences due to level of exposure
(Knave, Persson, Goldberg, and Westerholm, 1976). The extent to which
jet fuel vapors and diesel exhaust have similar effects is not known,
however.

## Summary

The review of the environmental and medical literature identified only
three studies that directly examined the cognitive impacts of diesel
exhaust exposure. Two of the three studies reported impairments in
cognitive ability as a result of *chronic* exposure, but the level of
exposure resulting in the impairment was not measurable, and whether the
impairment was temporary or long lasting is not clear. Only one study
controlled for exposure, but its focus was on determining the effects of
*acute* diesel emissions exposure, particularly for those with chemical
sensitivity. The results of the study showed no difference in cognitive
ability due to exposure between chemically-sensitive participants and
healthy participants, but no comparison of cognitive performance before,
during, or after exposure within a group was conducted.

The literature search was expanded to include research that examined the
cognitive effects to chemicals in diesel exhaust or substances that
could have similar cognitive effects as diesel exhaust. With respect to
the former, only studies addressing the cognitive effects of carbon
monoxide exposure were identified. While carbon monoxide may impair
driver judgments, it is not clear whether the level of carbon monoxide
to which drivers are exposed is significant enough to cause such
impairments. With respect to the latter, research examining the
cognitive effects of exposure to jet fuel vapors was considered to be
potentially relevant since both jet fuel and diesel are components and
fuel oil and diesel exhaust emissions also contain a mixture of gases
and vapors. The results of these studies showed no long-term
neurobehavioral consequences of chronic exposure to jet fuel vapors in
animals but more lasting effects in humans. However, the degree to which
jet fuel vapors and diesel exhaust vapors have similar effects is not
known.

# Summary and Challenges for Future Research

The goal of this project was to determine whether truck drivers'
exposure to diesel exhaust emissions at levels found in cabs affects
cognitive ability. A series of expert interviews was conducted and the
environmental and medical literature was reviewed to answer this
question. Unfortunately, no conclusive answer was found; the potential
for an effect exists, but the question is difficult to answer
empirically. The results are summarized below and challenges to future
research are discussed.

## Summary

The consensus of the experts interviewed was that the effects of diesel
exhaust emissions exposure on the cardiovascular and pulmonary system
are well-known, but it is not clear whether a cognitive impact exists.
While an effect is possible, a clear link between the two would be
difficult to measure empirically. This may account for the lack of
literature that directly addressed the cognitive effects of diesel
emissions exposure. The literature review identified only three studies.
While the results of those studies suggested that chronic exposure to
diesel exhaust could affect memory, problem solving, and reaction time,
the level of exposure resulting in the impairment and the severity of
the impairment, was not defined.

Research examining the cognitive effects of exposure to chemical
components of diesel exhaust (i.e., carbon monoxide) and to substances
that could have similar effects as diesel exhaust emissions (i.e., jet
fuel vapors) was also considered. The literature addressing the
cognitive-related health effects of chemical components in diesel
exhaust was limited to research on carbon monoxide exposure. Carbon
monoxide impaired performance only slightly on simple tasks (e.g.,
vigilance and tracking tasks), but more significantly on complex tasks,
such as abstract thinking. However, the studies addressing carbon
monoxide exposure were generally conducted in controlled laboratory
environments, and whether levels of exposure in the typical driving
environment are as high as those used was not clear. The literature
examining the cognitive effects of exposure to jet fuel vapors was
considered to be potentially relevant since diesel and jet fuel are
closely related. Controlled animal studies and occupational studies on
human participants showed contradictory results; the effect of exposure
on animals had only short-term neurological effects, which dissipated
once exposure ceased, but the results of human research studies showed
long-term impairments.

## Research Challenges

The expert interviews and literature search highlighted the fact that
little is known regarding the cognitive effects of diesel exhaust
emissions exposure. The results identified several challenges to
conducting further research. Specifically, any research to address this
issue would be costly and difficult to implement and any effects
difficult to measure for a number of reasons.

First, it is difficult to isolate the cognitive effects due to diesel
emissions exposure from the cognitive effects of other stressors, such
as lifestyle (e.g., long hours, shift work). Second, a good metric of
cognitive ability that would be sensitive to the effects is needed.
Research addressing the cognitive impacts of carbon monoxide exposure
showed varying results depending on the difficulty of the task.

Third, a good dose-response effect of diesel emissions exposure on
cognition would be methodologically difficult to collect. To measure the
effects of acute, high-dosage exposure, cognitive tests would need to be
administered at times of exposure, but the level of exposure is variable
due to factors such as the traffic, weather, and time of day. There are
no easy methods to track drivers' exposure to concentration of particles
over time, and capturing drivers at the time of exposure to evaluate
their cognitive ability would be a challenge. To measure the chronic
effects of long-term exposure, an estimate of the level of diesel
exhaust emissions to which drivers are exposed over time would be
needed. Developing a model to determine these estimates would require a
large data collection effort to consider factors that moderate exposure
(e.g., commodity, length of haul).

One interesting approach for future research is to examine whether there
are any biological indicators (e.g., blood markers) of cognition. That
is, inflammatory markers in the blood that might indicate cognitive
impairments. The Harvard School of Public Health is currently collecting
biological data from truck drivers as part of a cohort study examining
the non-cognitive health effects of diesel emissions exposure on the
population. Although no biological markers for cognition have yet been
identified, the Harvard School of Public Health could begin to examine
whether such a marker exists and establish a relationship between a
specific inflammatory marker and cognitive ability. This would be a
significant task, however.

Additionally, the results from the cohort study conducted by the Harvard
School of Public Health could be used to estimate drivers' level of
exposure over time. Researchers are measuring concentrations of
particulate matter at trucking terminals and in cabs (with body worn
monitors). This data could be used to develop a model of exposure, and
the model considered with respect to the overall cognitive effects of
the truck driver lifestyle. Further refinements to the model could
examine the contribution of other moderating variables; for example, the
combined effects of aging and exposure by comparing data on cognitive
ability collected from truck drivers with cognitive data collected from
gerontology studies. Similar to the previous proposal, developing such a
model and deriving any valuable data would be a long-term effort.

Several other options for basic research should be noted, although it is
also important to consider that results from these controlled laboratory
studies may not generalize to the truck driving population. A laboratory
study is feasible; healthy participants can be exposed to diesel exhaust
emissions at levels that would be representative of that encountered at
truck stops and complete a series of tasks. The level of impairment and
the extent of the impairments (i.e., how long it lasts) could be
measured. However, the results would still need to be considered with
respect to other important lifestyle factors that influence cognitive
ability. Animal studies are also possible and could serve as a starting
point for determining whether a clear link between cognition and diesel
exposure exists. However, animal studies could measure only performance
on simple tasks, and much of the skills required in driving in order to
maintain safety require a high level of cognitive functioning.
Consequently, the question of whether or not the results would
generalize remains. It is possible that these basic human and animal
studies could provide the basis for a model that examines the
contribution of acute and chronic exposure to diesel exhaust to
cognitive ability.

If FMCSA determines that additional research is needed, several
organizations would be interested in assisting in the effort. The
Harvard School of Public Health could expand their current occupational
study to address whether a cognitive effect of diesel exhaust emissions
exposure exists. Harvard researchers have established relationships with
several trucking companies and are traveling to terminals to collect
information on exposure levels and biological data from truck drivers.
As noted above, they could begin to examine whether a biological marker
for cognitive ability exists and determine what tasks to administer to
measure neurocognitive functioning. For basic research, the EPA is well
suited to conducted animal studies; in fact, the EPA's 5-year plan
proposes animal studies to examine the effect of diesel emissions
exposure.

## Conclusion

Unfortunately, the question regarding whether diesel exhaust emissions
exposure affects cognition will remain unanswered for a while to come.
The potential for an effect exists, but a clear answer is difficult to
obtain. The harmful effects of emissions are being addressed in other
ways, however. The EPA is establishing a comprehensive national clean
diesel initiative to reduce emissions from the over 11 million diesel
engines in the heavy-duty commercial motor vehicle fleet. Standards set
forth by this initiative are anticipated to reduce nitrous oxide (NO~X~)
and particulate matter emissions from heavy duty engines by 90% and 95%
below current standard levels, respectively, through the use of
high-efficiency catalytic exhaust emission control devices or comparably
effective advanced technologies. These new standards will significantly
reduce drivers' exposure to emissions as they are phased in between
2007-2010. The public health and environmental benefits of the program
will come at an average cost increase of about \$2,000 to \$3,200 per
new vehicle in the near term and about \$1,200 to \$1,900 per new
vehicle in the long term.

However, these standards may only offer a short-term solution. Estimates
show an increasing trend of truck vehicle miles traveled (TVMT). In
2005, the Energy Information Administration estimated that truck drivers
traveled an average of 230 million miles, with an annual growth rate of
2.2%. Consequently, it is not known whether the benefits from the EPA's
clean diesel initiative will be offset by an increase in the number of
heavy-duty commercial motor vehicles in the long-term. It is hoped that
when the program is fully implemented and the fleet of older engines has
fully turned over (by 2030), the reduction in NO~X~, non-methane
hydrocarbon and particulate matter emissions will be evidenced through
the improved health and safety of all drivers.

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  \[B.2\]   Ryan, C.M. (1990). Memory disturbances following chronic,
            low-level carbon monoxide exposure. *Archives of Clinical
            Neuropsychology*, 5, 59-67.

  \[B.5\]   Sapkota, A. and Buckley, T.J. (2003). The mobile source effect on
            curbside 1,3-butadiene, benzene, and particle-bound polycyclic
            aromatic hydrocarbons assessed at a tollbooth. *Journal of the
            Air and Waste Management Association*, 53, 740-748.

  \[B.5\]   Seshagiri, B. (2003). Exposure to Diesel Exhaust Emissions on
            Board Locomotives. *American Industrial Hygiene Association
            Journal*, 64, 678-683.

  \[B.5\]   Smith, T.J., Davis, M.E., Reaser, P., Natkin, J., Hart, J.E.,
            Laden, F., Heff, A., and Garshick, E. (2006). Overview of
            particulate exposure in the U.S. trucking industry. *Journal of
            Environmental Monitoring*, 8, 711-720.

  \[B.2\]   Stewart, R.D., Fisher, T.N., Baretta, E.D., and Herrmann, A.A.
            (1973). Experimental human exposure to high concentrations of
            carbon monoxide. *Archives of Environmental Health*, 26, 1-7.

  \[B.2\]   Stewart, R.D., Peterson, J.E., Baretta, E.D., Bachand, R.T.,
            Hosco, M.J., and Herrmann, A.A. (1970). Experimental human
            exposure to carbon monoxide. *Archives of Environmental Health*,
            21, 154-164.

  \[B.5\]   Smith, L.B., Bhattacharya, A., Lemasters, G., Succop, P., Puhala
            II, E., Medvedovic, M., and Joyce, J. (1997). Effect of chronic
            low-level exposure to jet fuel on postural balance of U.S. Air
            Force Personnel. *Journal of Occupational and Environmental
            Medicine*, 39(7), 623-632.

  \[B.5\]   Storey, J.M.E., Lewis Sr., S.A., Zietsman, J., Villa, J.C., and
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  \[B.5\]   Storey, J.M.E., Thomas, J.F., Lewis Sr., S.A., Dam, T.Q.,
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  \[B.5\]   Verma, D.K., Cheng, W.K., Shaw, D.S., Shaw, M.L., Verma, P.,
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            Occupational and Environmental Hygiene*, 1, 725-737.

  \[B.5\]   Verma, D.K., Finkelstein, M.M., Kurtz, L., Smolynec, K., and
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  \[B.5\]   Verma, D.K., Shaw, L., Julian, J., Smolynek, K., Wood, C., and
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  \[B.4\]   Wade III, J.F. and Newman, L.S. (1993). Diesel asthma: Reactive
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  \[B.2\]   Wright, G., Randell, P., and Shephard, R.J. (1973). Carbon
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  \[B.5\]   Zhu, Y., Kuhn, T., Mayo, P., and Hinds, W.C. (2006). Comparison
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  \[B.5\]   Ziskind, R., Carlin, T., Axelrod, M., Allen, R.W., and Schwartz,
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            Washington, D.C.
  --------- -----------------------------------------------------------------

#  Notes from Expert Interviews {#notes-from-expert-interviews .Appendix-Heading-1}

+-----------+------------------------------------+-------+------------+
| *         | Vernon Benignus, William Boyes,    | **Da  | March 6,   |
| *Intervie | Ian Gilmour                        | te**: | 2007       |
| wee(s):** |                                    |       |            |
+===========+====================================+=======+============+
| 1.  **Are |                                    |       |            |
|     you   |                                    |       |            |
|     aware |                                    |       |            |
|     of    |                                    |       |            |
|     any   |                                    |       |            |
|           |                                    |       |            |
|  research |                                    |       |            |
|     on    |                                    |       |            |
|     the   |                                    |       |            |
|           |                                    |       |            |
|   effects |                                    |       |            |
|     of    |                                    |       |            |
|           |                                    |       |            |
|    diesel |                                    |       |            |
|           |                                    |       |            |
| emissions |                                    |       |            |
|     (p    |                                    |       |            |
| referably |                                    |       |            |
|     at    |                                    |       |            |
|           |                                    |       |            |
|    levels |                                    |       |            |
|     a     |                                    |       |            |
|           |                                    |       |            |
|    driver |                                    |       |            |
|     might |                                    |       |            |
|     be    |                                    |       |            |
|           |                                    |       |            |
|   exposed |                                    |       |            |
|     to)   |                                    |       |            |
|     on    |                                    |       |            |
|     a     |                                    |       |            |
| lertness, |                                    |       |            |
|           |                                    |       |            |
|   decisio |                                    |       |            |
| n-making, |                                    |       |            |
|     or    |                                    |       |            |
|           |                                    |       |            |
| sleeping, |                                    |       |            |
|     or    |                                    |       |            |
|     any   |                                    |       |            |
|     other |                                    |       |            |
|           |                                    |       |            |
|   impacts |                                    |       |            |
|     that  |                                    |       |            |
|     could |                                    |       |            |
|           |                                    |       |            |
|    affect |                                    |       |            |
|     a     |                                    |       |            |
|           |                                    |       |            |
|  driver's |                                    |       |            |
|           |                                    |       |            |
|   ability |                                    |       |            |
|     to    |                                    |       |            |
|     drive |                                    |       |            |
|           |                                    |       |            |
| safely?** |                                    |       |            |
|           |                                    |       |            |
| No. Will  |                                    |       |            |
| Boyes has |                                    |       |            |
| examined  |                                    |       |            |
| the       |                                    |       |            |
| effects   |                                    |       |            |
| of air    |                                    |       |            |
| pollution |                                    |       |            |
| on        |                                    |       |            |
| animals   |                                    |       |            |
| with      |                                    |       |            |
| p         |                                    |       |            |
| articular |                                    |       |            |
| focus on  |                                    |       |            |
| the       |                                    |       |            |
| effects   |                                    |       |            |
| of the    |                                    |       |            |
| organic   |                                    |       |            |
| c         |                                    |       |            |
| ompounds. |                                    |       |            |
| He is     |                                    |       |            |
| aware of  |                                    |       |            |
| primarily |                                    |       |            |
| animal    |                                    |       |            |
| studies   |                                    |       |            |
| looking   |                                    |       |            |
| at the    |                                    |       |            |
| n         |                                    |       |            |
| eurotoxic |                                    |       |            |
| effects   |                                    |       |            |
| of        |                                    |       |            |
| diesel,   |                                    |       |            |
| rather    |                                    |       |            |
| than the  |                                    |       |            |
| cognitive |                                    |       |            |
| effects.  |                                    |       |            |
| Recent    |                                    |       |            |
| studies   |                                    |       |            |
| looking   |                                    |       |            |
| at the    |                                    |       |            |
| effects   |                                    |       |            |
| of        |                                    |       |            |
| exposure  |                                    |       |            |
| on humans |                                    |       |            |
| have      |                                    |       |            |
| included  |                                    |       |            |
| a         |                                    |       |            |
| meta      |                                    |       |            |
| -analysis |                                    |       |            |
| examining |                                    |       |            |
| the       |                                    |       |            |
| neu       |                                    |       |            |
| rological |                                    |       |            |
| effects   |                                    |       |            |
| of        |                                    |       |            |
| exposure  |                                    |       |            |
| to        |                                    |       |            |
| specific  |                                    |       |            |
| organic   |                                    |       |            |
| c         |                                    |       |            |
| ompounds. |                                    |       |            |
| While     |                                    |       |            |
| these     |                                    |       |            |
| studies   |                                    |       |            |
| have not  |                                    |       |            |
| spe       |                                    |       |            |
| cifically |                                    |       |            |
| examined  |                                    |       |            |
| the       |                                    |       |            |
| effect of |                                    |       |            |
| diesel,   |                                    |       |            |
| the       |                                    |       |            |
| hyd       |                                    |       |            |
| rocarbons |                                    |       |            |
| in the    |                                    |       |            |
| fluids    |                                    |       |            |
| tested    |                                    |       |            |
| may have  |                                    |       |            |
| similar   |                                    |       |            |
| effects   |                                    |       |            |
| on the    |                                    |       |            |
| central   |                                    |       |            |
| nervous   |                                    |       |            |
| system    |                                    |       |            |
| (CNS) as  |                                    |       |            |
| the       |                                    |       |            |
| hyd       |                                    |       |            |
| rocarbons |                                    |       |            |
| in diesel |                                    |       |            |
| exhaust,  |                                    |       |            |
| e.g.,     |                                    |       |            |
| CNS-d     |                                    |       |            |
| epressant |                                    |       |            |
| pr        |                                    |       |            |
| operties. |                                    |       |            |
| A recent  |                                    |       |            |
| finding   |                                    |       |            |
| is that   |                                    |       |            |
| pa        |                                    |       |            |
| rticulate |                                    |       |            |
| matter    |                                    |       |            |
| may be    |                                    |       |            |
| able to   |                                    |       |            |
| migrate   |                                    |       |            |
| from      |                                    |       |            |
| nasal     |                                    |       |            |
| passages  |                                    |       |            |
| (when     |                                    |       |            |
| inhaled)  |                                    |       |            |
| into the  |                                    |       |            |
| brain.    |                                    |       |            |
| This      |                                    |       |            |
| research  |                                    |       |            |
| has been  |                                    |       |            |
| done      |                                    |       |            |
| primarily |                                    |       |            |
| on        |                                    |       |            |
| specific  |                                    |       |            |
| metals,   |                                    |       |            |
| e.g.,     |                                    |       |            |
| m         |                                    |       |            |
| anganese. |                                    |       |            |
|           |                                    |       |            |
| Ian       |                                    |       |            |
| Gilmour   |                                    |       |            |
| discussed |                                    |       |            |
| new       |                                    |       |            |
| research  |                                    |       |            |
| that has  |                                    |       |            |
| examined  |                                    |       |            |
| the       |                                    |       |            |
| specific  |                                    |       |            |
| effects   |                                    |       |            |
| of the    |                                    |       |            |
| different |                                    |       |            |
| chemical  |                                    |       |            |
| c         |                                    |       |            |
| omponents |                                    |       |            |
| in diesel |                                    |       |            |
| exhaust   |                                    |       |            |
| on        |                                    |       |            |
| pulmonary |                                    |       |            |
| health    |                                    |       |            |
| (spec     |                                    |       |            |
| ifically, |                                    |       |            |
| asthma).  |                                    |       |            |
| He noted  |                                    |       |            |
| that      |                                    |       |            |
| there are |                                    |       |            |
| eight     |                                    |       |            |
| labs that |                                    |       |            |
| are       |                                    |       |            |
| c         |                                    |       |            |
| onducting |                                    |       |            |
| hum       |                                    |       |            |
| an-diesel |                                    |       |            |
| i         |                                    |       |            |
| nhalation |                                    |       |            |
| studies   |                                    |       |            |
| but these |                                    |       |            |
| studies   |                                    |       |            |
| are       |                                    |       |            |
| focused   |                                    |       |            |
| on the    |                                    |       |            |
| effects   |                                    |       |            |
| of diesel |                                    |       |            |
| on the    |                                    |       |            |
| pulmonary |                                    |       |            |
| and       |                                    |       |            |
| cardi     |                                    |       |            |
| ovascular |                                    |       |            |
| systems.  |                                    |       |            |
| These     |                                    |       |            |
| studies   |                                    |       |            |
| are       |                                    |       |            |
| conducted |                                    |       |            |
| with      |                                    |       |            |
| healthy   |                                    |       |            |
| young     |                                    |       |            |
| adults or |                                    |       |            |
| with mild |                                    |       |            |
| a         |                                    |       |            |
| sthmatics |                                    |       |            |
| who are   |                                    |       |            |
| asked to  |                                    |       |            |
| inhale    |                                    |       |            |
| diesel    |                                    |       |            |
| (in the   |                                    |       |            |
| amount    |                                    |       |            |
| that may  |                                    |       |            |
| be        |                                    |       |            |
| typical   |                                    |       |            |
| of daily  |                                    |       |            |
| exposure) |                                    |       |            |
| and asked |                                    |       |            |
| to        |                                    |       |            |
| perform   |                                    |       |            |
| physical  |                                    |       |            |
| tasks.    |                                    |       |            |
| Re        |                                    |       |            |
| searchers |                                    |       |            |
| then      |                                    |       |            |
| examine   |                                    |       |            |
| lung      |                                    |       |            |
| function, |                                    |       |            |
| cardiac   |                                    |       |            |
| output,   |                                    |       |            |
| heart     |                                    |       |            |
| rate,     |                                    |       |            |
| etc. No   |                                    |       |            |
| studies   |                                    |       |            |
| have      |                                    |       |            |
| spe       |                                    |       |            |
| cifically |                                    |       |            |
| looked at |                                    |       |            |
| the       |                                    |       |            |
| cognitive |                                    |       |            |
| effects   |                                    |       |            |
| on sleep. |                                    |       |            |
|           |                                    |       |            |
| Other     |                                    |       |            |
| studies:  |                                    |       |            |
| M         |                                    |       |            |
| onitoring |                                    |       |            |
| of North  |                                    |       |            |
| Carolina  |                                    |       |            |
| state     |                                    |       |            |
| troopers  |                                    |       |            |
| and air   |                                    |       |            |
| pollution |                                    |       |            |
| levels in |                                    |       |            |
| the       |                                    |       |            |
| patrol    |                                    |       |            |
| cars and  |                                    |       |            |
| a         |                                    |       |            |
| ssociated |                                    |       |            |
| the two   |                                    |       |            |
| with      |                                    |       |            |
| cardiac   |                                    |       |            |
| and       |                                    |       |            |
| re        |                                    |       |            |
| spiratory |                                    |       |            |
| f         |                                    |       |            |
| unctions. |                                    |       |            |
|           |                                    |       |            |
| 2.  **Do  |                                    |       |            |
|     you   |                                    |       |            |
|     think |                                    |       |            |
|     there |                                    |       |            |
|     is    |                                    |       |            |
|     any   |                                    |       |            |
|           |                                    |       |            |
|    chance |                                    |       |            |
|     that  |                                    |       |            |
|     there |                                    |       |            |
|     could |                                    |       |            |
|     be an |                                    |       |            |
|           |                                    |       |            |
|    effect |                                    |       |            |
|     such  |                                    |       |            |
|     as    |                                    |       |            |
|           |                                    |       |            |
|   this?** |                                    |       |            |
|           |                                    |       |            |
| Yes. In   |                                    |       |            |
| the EPA's |                                    |       |            |
| 5-year    |                                    |       |            |
| research  |                                    |       |            |
| plan,     |                                    |       |            |
| there is  |                                    |       |            |
| an item   |                                    |       |            |
| to        |                                    |       |            |
| conduct   |                                    |       |            |
| animal    |                                    |       |            |
| studies   |                                    |       |            |
| to        |                                    |       |            |
| examine   |                                    |       |            |
| the       |                                    |       |            |
| neurop    |                                    |       |            |
| hysiology |                                    |       |            |
| or        |                                    |       |            |
| cognitive |                                    |       |            |
| deficits  |                                    |       |            |
| with      |                                    |       |            |
| exposure  |                                    |       |            |
| to        |                                    |       |            |
| diesel,   |                                    |       |            |
| e.g., by  |                                    |       |            |
| placing   |                                    |       |            |
| trained   |                                    |       |            |
| rats into |                                    |       |            |
| Skinner   |                                    |       |            |
| boxes in  |                                    |       |            |
| i         |                                    |       |            |
| nhalation |                                    |       |            |
| chambers  |                                    |       |            |
| where     |                                    |       |            |
| volatiles |                                    |       |            |
| are       |                                    |       |            |
| trapped   |                                    |       |            |
| and       |                                    |       |            |
| testing   |                                    |       |            |
| their     |                                    |       |            |
| cognitive |                                    |       |            |
| and       |                                    |       |            |
| neu       |                                    |       |            |
| rological |                                    |       |            |
| f         |                                    |       |            |
| unctions. |                                    |       |            |
|           |                                    |       |            |
| 3         |                                    |       |            |
| .  **Some |                                    |       |            |
|           |                                    |       |            |
|  existing |                                    |       |            |
|           |                                    |       |            |
|  research |                                    |       |            |
|           |                                    |       |            |
|  suggests |                                    |       |            |
|     that  |                                    |       |            |
|     there |                                    |       |            |
|     are   |                                    |       |            |
|           |                                    |       |            |
|  elevated |                                    |       |            |
|           |                                    |       |            |
|    levels |                                    |       |            |
|     of    |                                    |       |            |
|           |                                    |       |            |
| emissions |                                    |       |            |
|     in    |                                    |       |            |
|     truck |                                    |       |            |
|     cabs  |                                    |       |            |
|     that  |                                    |       |            |
|           |                                    |       |            |
|    exceed |                                    |       |            |
|           |                                    |       |            |
|   Federal |                                    |       |            |
|           |                                    |       |            |
|    agency |                                    |       |            |
|     s     |                                    |       |            |
| tandards. |                                    |       |            |
|     Are   |                                    |       |            |
|     you   |                                    |       |            |
|     aware |                                    |       |            |
|     of    |                                    |       |            |
|     any   |                                    |       |            |
|           |                                    |       |            |
|  research |                                    |       |            |
|     that  |                                    |       |            |
|     has   |                                    |       |            |
|           |                                    |       |            |
|  examined |                                    |       |            |
|           |                                    |       |            |
|   ambient |                                    |       |            |
|     air   |                                    |       |            |
|           |                                    |       |            |
|   quality |                                    |       |            |
|     in    |                                    |       |            |
|     \'hot |                                    |       |            |
|           |                                    |       |            |
|   spots\' |                                    |       |            |
|     where |                                    |       |            |
|           |                                    |       |            |
|    trucks |                                    |       |            |
|     might |                                    |       |            |
|     park  |                                    |       |            |
|     or    |                                    |       |            |
|           |                                    |       |            |
|    inside |                                    |       |            |
|     truck |                                    |       |            |
|           |                                    |       |            |
|   cabs?** |                                    |       |            |
|           |                                    |       |            |
| There are |                                    |       |            |
| several   |                                    |       |            |
| in        |                                    |       |            |
| itiatives |                                    |       |            |
| underway  |                                    |       |            |
| to look   |                                    |       |            |
| at "hot   |                                    |       |            |
| spots" at |                                    |       |            |
| or near   |                                    |       |            |
| roadways  |                                    |       |            |
| and       |                                    |       |            |
| highways  |                                    |       |            |
| and to    |                                    |       |            |
| look at   |                                    |       |            |
| c         |                                    |       |            |
| hildren's |                                    |       |            |
| exposure  |                                    |       |            |
| to diesel |                                    |       |            |
| exhaust   |                                    |       |            |
| as a      |                                    |       |            |
| cause of  |                                    |       |            |
| asthma.   |                                    |       |            |
|           |                                    |       |            |
| 4.  **If  |                                    |       |            |
|           |                                    |       |            |
|   primary |                                    |       |            |
|           |                                    |       |            |
|  research |                                    |       |            |
|     needs |                                    |       |            |
|     to be |                                    |       |            |
|           |                                    |       |            |
| conducted |                                    |       |            |
|     (in   |                                    |       |            |
|     the   |                                    |       |            |
|           |                                    |       |            |
|   absence |                                    |       |            |
|     of    |                                    |       |            |
|           |                                    |       |            |
|  existing |                                    |       |            |
|           |                                    |       |            |
| research) |                                    |       |            |
|     what  |                                    |       |            |
|           |                                    |       |            |
|   vehicle |                                    |       |            |
|     would |                                    |       |            |
|     be    |                                    |       |            |
|     ap    |                                    |       |            |
| propriate |                                    |       |            |
|           |                                    |       |            |
|  (Federal |                                    |       |            |
|           |                                    |       |            |
|    agency |                                    |       |            |
|     or    |                                    |       |            |
|     org   |                                    |       |            |
| anization |                                    |       |            |
|     with  |                                    |       |            |
|           |                                    |       |            |
| expertise |                                    |       |            |
|     in    |                                    |       |            |
|     this  |                                    |       |            |
|           |                                    |       |            |
| field)?** |                                    |       |            |
|           |                                    |       |            |
| Federal   |                                    |       |            |
| agencies  |                                    |       |            |
| should    |                                    |       |            |
| conduct   |                                    |       |            |
| the       |                                    |       |            |
| programs  |                                    |       |            |
| to        |                                    |       |            |
| leverage  |                                    |       |            |
| with      |                                    |       |            |
| existing  |                                    |       |            |
| research  |                                    |       |            |
| programs. |                                    |       |            |
| The       |                                    |       |            |
| Health    |                                    |       |            |
| Effects   |                                    |       |            |
| Institute |                                    |       |            |
| was       |                                    |       |            |
| noted.    |                                    |       |            |
| This      |                                    |       |            |
| org       |                                    |       |            |
| anization |                                    |       |            |
| receives  |                                    |       |            |
| funding   |                                    |       |            |
| from EPA  |                                    |       |            |
| and       |                                    |       |            |
| a         |                                    |       |            |
| utomotive |                                    |       |            |
| and       |                                    |       |            |
| trucking  |                                    |       |            |
| in        |                                    |       |            |
| dustries. |                                    |       |            |
|           |                                    |       |            |
| 5         |                                    |       |            |
| .  **What |                                    |       |            |
|           |                                    |       |            |
|   factors |                                    |       |            |
|           |                                    |       |            |
|    should |                                    |       |            |
|     be    |                                    |       |            |
|     c     |                                    |       |            |
| onsidered |                                    |       |            |
|     in    |                                    |       |            |
|     this  |                                    |       |            |
|     re    |                                    |       |            |
| search?** |                                    |       |            |
|           |                                    |       |            |
| Research  |                                    |       |            |
| may be    |                                    |       |            |
| conducted |                                    |       |            |
| using a   |                                    |       |            |
| c         |                                    |       |            |
| ontrolled |                                    |       |            |
| exposure  |                                    |       |            |
| (i.e., a  |                                    |       |            |
| l         |                                    |       |            |
| aboratory |                                    |       |            |
| study     |                                    |       |            |
| including |                                    |       |            |
| control   |                                    |       |            |
| groups)   |                                    |       |            |
| to        |                                    |       |            |
| determine |                                    |       |            |
| the       |                                    |       |            |
| specific  |                                    |       |            |
| effect of |                                    |       |            |
| chemicals |                                    |       |            |
| or a      |                                    |       |            |
| field     |                                    |       |            |
| study in  |                                    |       |            |
| which     |                                    |       |            |
| occ       |                                    |       |            |
| upational |                                    |       |            |
| par       |                                    |       |            |
| ticipants |                                    |       |            |
| are       |                                    |       |            |
| monitored |                                    |       |            |
| in their  |                                    |       |            |
| work      |                                    |       |            |
| env       |                                    |       |            |
| ironments |                                    |       |            |
| and       |                                    |       |            |
| compared  |                                    |       |            |
| with      |                                    |       |            |
| workers   |                                    |       |            |
| in        |                                    |       |            |
| similar   |                                    |       |            |
| oc        |                                    |       |            |
| cupations |                                    |       |            |
| who have  |                                    |       |            |
| only      |                                    |       |            |
| normal    |                                    |       |            |
| exposure  |                                    |       |            |
| to diesel |                                    |       |            |
| exhaust.  |                                    |       |            |
|           |                                    |       |            |
| 6.  **Can |                                    |       |            |
|     you   |                                    |       |            |
|           |                                    |       |            |
| recommend |                                    |       |            |
|           |                                    |       |            |
|    anyone |                                    |       |            |
|     else  |                                    |       |            |
|     we    |                                    |       |            |
|           |                                    |       |            |
|    should |                                    |       |            |
|           |                                    |       |            |
|   contact |                                    |       |            |
|           |                                    |       |            |
| regarding |                                    |       |            |
|     this  |                                    |       |            |
|     re    |                                    |       |            |
| search?** |                                    |       |            |
|           |                                    |       |            |
|           |                                    |       |            |
|   -   For |                                    |       |            |
|           |                                    |       |            |
|        in |                                    |       |            |
| formation |                                    |       |            |
|           |                                    |       |            |
|        on |                                    |       |            |
|           |                                    |       |            |
|     human |                                    |       |            |
|           |                                    |       |            |
|  studies: |                                    |       |            |
|           |                                    |       |            |
|       Bob |                                    |       |            |
|           |                                    |       |            |
|    Devlin |                                    |       |            |
|           |                                    |       |            |
|   (<devli |                                    |       |            |
| n.robert@ |                                    |       |            |
| epa.gov>, |                                    |       |            |
|           |                                    |       |            |
|     919.9 |                                    |       |            |
| 66.6255); |                                    |       |            |
|           |                                    |       |            |
|   Michael |                                    |       |            |
|           |                                    |       |            |
|    Madden |                                    |       |            |
|           |                                    |       |            |
|     (919. |                                    |       |            |
| 966.6257) |                                    |       |            |
|           |                                    |       |            |
|           |                                    |       |            |
|  -   Eric |                                    |       |            |
|           |                                    |       |            |
| Garshick, |                                    |       |            |
|           |                                    |       |            |
|   Harvard |                                    |       |            |
|           |                                    |       |            |
|    School |                                    |       |            |
|           |                                    |       |            |
|        of |                                    |       |            |
|           |                                    |       |            |
|    Public |                                    |       |            |
|           |                                    |       |            |
|   Health. |                                    |       |            |
|           |                                    |       |            |
|    Epidem |                                    |       |            |
| iological |                                    |       |            |
|           |                                    |       |            |
|   studies |                                    |       |            |
|           |                                    |       |            |
| examining |                                    |       |            |
|           |                                    |       |            |
|   whether |                                    |       |            |
|           |                                    |       |            |
|     there |                                    |       |            |
|           |                                    |       |            |
|        is |                                    |       |            |
|         a |                                    |       |            |
|           |                                    |       |            |
|      link |                                    |       |            |
|           |                                    |       |            |
|   between |                                    |       |            |
|           |                                    |       |            |
|    diesel |                                    |       |            |
|           |                                    |       |            |
|  exposure |                                    |       |            |
|           |                                    |       |            |
|       and |                                    |       |            |
|           |                                    |       |            |
|   cancer. |                                    |       |            |
+-----------+------------------------------------+-------+------------+

+-----------+------------------------------------+-------+------------+
| *         | Chad Bailey                        | **Da  | March 6,   |
| *Intervie |                                    | te:** | 2007       |
| wee(s):** |                                    |       |            |
+===========+====================================+=======+============+
| 1.  **Are |                                    |       |            |
|     you   |                                    |       |            |
|     aware |                                    |       |            |
|     of    |                                    |       |            |
|     any   |                                    |       |            |
|           |                                    |       |            |
|  research |                                    |       |            |
|     on    |                                    |       |            |
|     the   |                                    |       |            |
|           |                                    |       |            |
|   effects |                                    |       |            |
|     of    |                                    |       |            |
|           |                                    |       |            |
|    diesel |                                    |       |            |
|           |                                    |       |            |
| emissions |                                    |       |            |
|     (p    |                                    |       |            |
| referably |                                    |       |            |
|     at    |                                    |       |            |
|           |                                    |       |            |
|    levels |                                    |       |            |
|     a     |                                    |       |            |
|           |                                    |       |            |
|    driver |                                    |       |            |
|     might |                                    |       |            |
|     be    |                                    |       |            |
|           |                                    |       |            |
|   exposed |                                    |       |            |
|     to)   |                                    |       |            |
|     on    |                                    |       |            |
|     a     |                                    |       |            |
| lertness, |                                    |       |            |
|           |                                    |       |            |
|   decisio |                                    |       |            |
| n-making, |                                    |       |            |
|     or    |                                    |       |            |
|           |                                    |       |            |
| sleeping, |                                    |       |            |
|     or    |                                    |       |            |
|     any   |                                    |       |            |
|     other |                                    |       |            |
|           |                                    |       |            |
|   impacts |                                    |       |            |
|     that  |                                    |       |            |
|     could |                                    |       |            |
|           |                                    |       |            |
|    affect |                                    |       |            |
|     a     |                                    |       |            |
|           |                                    |       |            |
|  driver's |                                    |       |            |
|           |                                    |       |            |
|   ability |                                    |       |            |
|     to    |                                    |       |            |
|     drive |                                    |       |            |
|           |                                    |       |            |
| safely?** |                                    |       |            |
|           |                                    |       |            |
| No, but   |                                    |       |            |
| there     |                                    |       |            |
| have been |                                    |       |            |
| several   |                                    |       |            |
| other     |                                    |       |            |
| studies   |                                    |       |            |
| looking   |                                    |       |            |
| at the    |                                    |       |            |
| cardiac   |                                    |       |            |
| and       |                                    |       |            |
| pulmonary |                                    |       |            |
| effects   |                                    |       |            |
| of diesel |                                    |       |            |
| exposure  |                                    |       |            |
| (e.g.,    |                                    |       |            |
| lung      |                                    |       |            |
| cancer,   |                                    |       |            |
| asthma)   |                                    |       |            |
| in        |                                    |       |            |
| trucking  |                                    |       |            |
| t         |                                    |       |            |
| erminals, |                                    |       |            |
| truck     |                                    |       |            |
| yards,    |                                    |       |            |
| truck     |                                    |       |            |
| stops and |                                    |       |            |
| in the    |                                    |       |            |
| railroad  |                                    |       |            |
| industry  |                                    |       |            |
| examining |                                    |       |            |
| exposure  |                                    |       |            |
| in        |                                    |       |            |
| l         |                                    |       |            |
| ocomotive |                                    |       |            |
| cabs.     |                                    |       |            |
|           |                                    |       |            |
| -   The   |                                    |       |            |
|           |                                    |       |            |
|   Harvard |                                    |       |            |
|     U     |                                    |       |            |
| niversity |                                    |       |            |
|           |                                    |       |            |
|    School |                                    |       |            |
|     of    |                                    |       |            |
|           |                                    |       |            |
|    Public |                                    |       |            |
|           |                                    |       |            |
|    Health |                                    |       |            |
|           |                                    |       |            |
| conducted |                                    |       |            |
|     an    |                                    |       |            |
|           |                                    |       |            |
|    epidem |                                    |       |            |
| iological |                                    |       |            |
|     study |                                    |       |            |
|     syste |                                    |       |            |
| matically |                                    |       |            |
|     e     |                                    |       |            |
| valuating |                                    |       |            |
|           |                                    |       |            |
| emissions |                                    |       |            |
|           |                                    |       |            |
|  exposure |                                    |       |            |
|     of    |                                    |       |            |
|     truck |                                    |       |            |
|           |                                    |       |            |
|   drivers |                                    |       |            |
|     at    |                                    |       |            |
|     the   |                                    |       |            |
|     five  |                                    |       |            |
|           |                                    |       |            |
|   largest |                                    |       |            |
|           |                                    |       |            |
| unionized |                                    |       |            |
|           |                                    |       |            |
|  trucking |                                    |       |            |
|     firms |                                    |       |            |
|     and   |                                    |       |            |
|     the   |                                    |       |            |
|     rate  |                                    |       |            |
|     of    |                                    |       |            |
|     lung  |                                    |       |            |
|           |                                    |       |            |
|   cancer. |                                    |       |            |
|     A     |                                    |       |            |
|           |                                    |       |            |
|   similar |                                    |       |            |
|     study |                                    |       |            |
|     was   |                                    |       |            |
|           |                                    |       |            |
| conducted |                                    |       |            |
|           |                                    |       |            |
|   looking |                                    |       |            |
|     at    |                                    |       |            |
|     the   |                                    |       |            |
|           |                                    |       |            |
|  exposure |                                    |       |            |
|     risk  |                                    |       |            |
|     to    |                                    |       |            |
|     rail  |                                    |       |            |
|           |                                    |       |            |
|  workers. |                                    |       |            |
|           |                                    |       |            |
| -   A     |                                    |       |            |
|     study |                                    |       |            |
|           |                                    |       |            |
| conducted |                                    |       |            |
|     in    |                                    |       |            |
|     the   |                                    |       |            |
|     state |                                    |       |            |
|     of    |                                    |       |            |
|     North |                                    |       |            |
|           |                                    |       |            |
|  Carolina |                                    |       |            |
|           |                                    |       |            |
|  examined |                                    |       |            |
|     the   |                                    |       |            |
|           |                                    |       |            |
|   effects |                                    |       |            |
|     of    |                                    |       |            |
|           |                                    |       |            |
|    diesel |                                    |       |            |
|           |                                    |       |            |
|  exposure |                                    |       |            |
|     on    |                                    |       |            |
|     state |                                    |       |            |
|           |                                    |       |            |
| troopers. |                                    |       |            |
|     Re    |                                    |       |            |
| searchers |                                    |       |            |
|           |                                    |       |            |
|  measured |                                    |       |            |
|     the   |                                    |       |            |
|           |                                    |       |            |
| troopers' |                                    |       |            |
|     blood |                                    |       |            |
|           |                                    |       |            |
|  pressure |                                    |       |            |
|     and   |                                    |       |            |
|     heart |                                    |       |            |
|           |                                    |       |            |
|    rhythm |                                    |       |            |
|     and   |                                    |       |            |
|           |                                    |       |            |
| collected |                                    |       |            |
|     blood |                                    |       |            |
|     draws |                                    |       |            |
|           |                                    |       |            |
|    before |                                    |       |            |
|     and   |                                    |       |            |
|     after |                                    |       |            |
|     their |                                    |       |            |
|           |                                    |       |            |
|    shifts |                                    |       |            |
|     and   |                                    |       |            |
|     found |                                    |       |            |
|           |                                    |       |            |
| increased |                                    |       |            |
|     heart |                                    |       |            |
|     rate  |                                    |       |            |
|     va    |                                    |       |            |
| riability |                                    |       |            |
|     in    |                                    |       |            |
|     young |                                    |       |            |
|           |                                    |       |            |
|    police |                                    |       |            |
|           |                                    |       |            |
| officers, |                                    |       |            |
|     and   |                                    |       |            |
|     in    |                                    |       |            |
|     cars  |                                    |       |            |
|     with  |                                    |       |            |
|           |                                    |       |            |
|    higher |                                    |       |            |
|     conc  |                                    |       |            |
| entration |                                    |       |            |
|     of    |                                    |       |            |
|           |                                    |       |            |
|    higher |                                    |       |            |
|     pa    |                                    |       |            |
| rticulate |                                    |       |            |
|           |                                    |       |            |
|   matter. |                                    |       |            |
|     Addi  |                                    |       |            |
| tionally, |                                    |       |            |
|     the   |                                    |       |            |
|     blood |                                    |       |            |
|           |                                    |       |            |
|   profile |                                    |       |            |
|           |                                    |       |            |
|    showed |                                    |       |            |
|     signs |                                    |       |            |
|     of    |                                    |       |            |
|     infl  |                                    |       |            |
| ammation, |                                    |       |            |
|     s     |                                    |       |            |
| uggesting |                                    |       |            |
|     that  |                                    |       |            |
|     there |                                    |       |            |
|     were  |                                    |       |            |
|           |                                    |       |            |
|   cardiac |                                    |       |            |
|     cons  |                                    |       |            |
| equences. |                                    |       |            |
|           |                                    |       |            |
| -         |                                    |       |            |
|   Kilburn |                                    |       |            |
|           |                                    |       |            |
| conducted |                                    |       |            |
|     a     |                                    |       |            |
|     small |                                    |       |            |
|     study |                                    |       |            |
|           |                                    |       |            |
| examining |                                    |       |            |
|     the   |                                    |       |            |
|           |                                    |       |            |
|   effects |                                    |       |            |
|     of    |                                    |       |            |
|           |                                    |       |            |
|    diesel |                                    |       |            |
|           |                                    |       |            |
|  exposure |                                    |       |            |
|     on 10 |                                    |       |            |
|           |                                    |       |            |
|  railroad |                                    |       |            |
|           |                                    |       |            |
|   workers |                                    |       |            |
|     and   |                                    |       |            |
|     six   |                                    |       |            |
|     ele   |                                    |       |            |
| ctricians |                                    |       |            |
|     and   |                                    |       |            |
|           |                                    |       |            |
| suggested |                                    |       |            |
|     that  |                                    |       |            |
|     there |                                    |       |            |
|     may   |                                    |       |            |
|     be    |                                    |       |            |
|           |                                    |       |            |
|    neurob |                                    |       |            |
| ehavioral |                                    |       |            |
|     im    |                                    |       |            |
| pairments |                                    |       |            |
|           |                                    |       |            |
| resulting |                                    |       |            |
|     from  |                                    |       |            |
|           |                                    |       |            |
|    diesel |                                    |       |            |
|           |                                    |       |            |
| exposure. |                                    |       |            |
|           |                                    |       |            |
| -         |                                    |       |            |
|   Another |                                    |       |            |
|     study |                                    |       |            |
|           |                                    |       |            |
|    looked |                                    |       |            |
|     at    |                                    |       |            |
|     the   |                                    |       |            |
|     l     |                                    |       |            |
| ikelihood |                                    |       |            |
|     of    |                                    |       |            |
|     Gulf  |                                    |       |            |
|     War   |                                    |       |            |
|           |                                    |       |            |
|  syndrome |                                    |       |            |
|           |                                    |       |            |
| resulting |                                    |       |            |
|     from  |                                    |       |            |
|           |                                    |       |            |
| breathing |                                    |       |            |
|     fuel  |                                    |       |            |
|           |                                    |       |            |
|   vapors. |                                    |       |            |
|           |                                    |       |            |
| -   NIOSH |                                    |       |            |
|     has   |                                    |       |            |
|           |                                    |       |            |
| conducted |                                    |       |            |
|           |                                    |       |            |
|  worksite |                                    |       |            |
|           |                                    |       |            |
|    health |                                    |       |            |
|           |                                    |       |            |
|    hazard |                                    |       |            |
|     eva   |                                    |       |            |
| luations, |                                    |       |            |
|     e.g., |                                    |       |            |
|     a     |                                    |       |            |
|           |                                    |       |            |
| long-term |                                    |       |            |
|     miner |                                    |       |            |
|     study |                                    |       |            |
|           |                                    |       |            |
|   looking |                                    |       |            |
|     at    |                                    |       |            |
|     lung  |                                    |       |            |
|           |                                    |       |            |
|   cancer. |                                    |       |            |
|           |                                    |       |            |
| -         |                                    |       |            |
|    Vernon |                                    |       |            |
|           |                                    |       |            |
|  Benignus |                                    |       |            |
|     and   |                                    |       |            |
|     Will  |                                    |       |            |
|     Boyes |                                    |       |            |
|           |                                    |       |            |
| published |                                    |       |            |
|     a     |                                    |       |            |
|     paper |                                    |       |            |
|     a     |                                    |       |            |
| ddressing |                                    |       |            |
|           |                                    |       |            |
|   toluene |                                    |       |            |
|           |                                    |       |            |
| exposure. |                                    |       |            |
|           |                                    |       |            |
|  Although |                                    |       |            |
|           |                                    |       |            |
|   toluene |                                    |       |            |
|     is    |                                    |       |            |
|     not   |                                    |       |            |
|     in    |                                    |       |            |
|           |                                    |       |            |
|    diesel |                                    |       |            |
|           |                                    |       |            |
|  exhaust, |                                    |       |            |
|     if a  |                                    |       |            |
|     fuel  |                                    |       |            |
|     truck |                                    |       |            |
|           |                                    |       |            |
|  operator |                                    |       |            |
|     is    |                                    |       |            |
|           |                                    |       |            |
| routinely |                                    |       |            |
|           |                                    |       |            |
| unloading |                                    |       |            |
|     fuel  |                                    |       |            |
|     from  |                                    |       |            |
|     a     |                                    |       |            |
|     tank  |                                    |       |            |
|           |                                    |       |            |
|    truck, |                                    |       |            |
|     it's  |                                    |       |            |
|           |                                    |       |            |
|  possible |                                    |       |            |
|     that  |                                    |       |            |
|     s/he  |                                    |       |            |
|     could |                                    |       |            |
|     be    |                                    |       |            |
|           |                                    |       |            |
|   exposed |                                    |       |            |
|     early |                                    |       |            |
|     on,   |                                    |       |            |
|     and   |                                    |       |            |
|     this  |                                    |       |            |
|     could |                                    |       |            |
|           |                                    |       |            |
| influence |                                    |       |            |
|           |                                    |       |            |
|    choice |                                    |       |            |
|           |                                    |       |            |
|  reaction |                                    |       |            |
|     time. |                                    |       |            |
|           |                                    |       |            |
| -   Other |                                    |       |            |
|           |                                    |       |            |
|   studies |                                    |       |            |
|     have  |                                    |       |            |
|           |                                    |       |            |
|  examined |                                    |       |            |
|     the   |                                    |       |            |
|           |                                    |       |            |
| chemicals |                                    |       |            |
|     to    |                                    |       |            |
|     which |                                    |       |            |
|           |                                    |       |            |
|    people |                                    |       |            |
|     in    |                                    |       |            |
|           |                                    |       |            |
| petroleum |                                    |       |            |
|     dis   |                                    |       |            |
| tribution |                                    |       |            |
|     chain |                                    |       |            |
|     are   |                                    |       |            |
|           |                                    |       |            |
|  exposed, |                                    |       |            |
|     e.g., |                                    |       |            |
|     Dave  |                                    |       |            |
|     Verma |                                    |       |            |
|     at    |                                    |       |            |
|           |                                    |       |            |
|  McMaster |                                    |       |            |
|     U     |                                    |       |            |
| niversity |                                    |       |            |
|           |                                    |       |            |
|    looked |                                    |       |            |
|     at    |                                    |       |            |
|     tank  |                                    |       |            |
|     truck |                                    |       |            |
|           |                                    |       |            |
|  drivers' |                                    |       |            |
|           |                                    |       |            |
|  exposure |                                    |       |            |
|     to    |                                    |       |            |
|           |                                    |       |            |
|   vapors. |                                    |       |            |
|           |                                    |       |            |
| 2.  **Do  |                                    |       |            |
|     you   |                                    |       |            |
|     think |                                    |       |            |
|     there |                                    |       |            |
|     is    |                                    |       |            |
|     any   |                                    |       |            |
|           |                                    |       |            |
|    chance |                                    |       |            |
|     that  |                                    |       |            |
|     there |                                    |       |            |
|     could |                                    |       |            |
|     be an |                                    |       |            |
|           |                                    |       |            |
|    effect |                                    |       |            |
|     such  |                                    |       |            |
|     as    |                                    |       |            |
|           |                                    |       |            |
|   this?** |                                    |       |            |
|           |                                    |       |            |
| Yes.      |                                    |       |            |
|           |                                    |       |            |
| 3         |                                    |       |            |
| .  **Some |                                    |       |            |
|           |                                    |       |            |
|  existing |                                    |       |            |
|           |                                    |       |            |
|  research |                                    |       |            |
|           |                                    |       |            |
|  suggests |                                    |       |            |
|     that  |                                    |       |            |
|     there |                                    |       |            |
|     are   |                                    |       |            |
|           |                                    |       |            |
|  elevated |                                    |       |            |
|           |                                    |       |            |
|    levels |                                    |       |            |
|     of    |                                    |       |            |
|           |                                    |       |            |
| emissions |                                    |       |            |
|     in    |                                    |       |            |
|     truck |                                    |       |            |
|     cabs  |                                    |       |            |
|     that  |                                    |       |            |
|           |                                    |       |            |
|    exceed |                                    |       |            |
|           |                                    |       |            |
|   Federal |                                    |       |            |
|           |                                    |       |            |
|    agency |                                    |       |            |
|     s     |                                    |       |            |
| tandards. |                                    |       |            |
|     Are   |                                    |       |            |
|     you   |                                    |       |            |
|     aware |                                    |       |            |
|     of    |                                    |       |            |
|     any   |                                    |       |            |
|           |                                    |       |            |
|  research |                                    |       |            |
|     that  |                                    |       |            |
|     has   |                                    |       |            |
|           |                                    |       |            |
|  examined |                                    |       |            |
|           |                                    |       |            |
|   ambient |                                    |       |            |
|     air   |                                    |       |            |
|           |                                    |       |            |
|   quality |                                    |       |            |
|     in    |                                    |       |            |
|     \'hot |                                    |       |            |
|           |                                    |       |            |
|   spots\' |                                    |       |            |
|     where |                                    |       |            |
|           |                                    |       |            |
|    trucks |                                    |       |            |
|     might |                                    |       |            |
|     park  |                                    |       |            |
|     or    |                                    |       |            |
|           |                                    |       |            |
|    inside |                                    |       |            |
|     truck |                                    |       |            |
|           |                                    |       |            |
|   cabs?** |                                    |       |            |
|           |                                    |       |            |
| Exposure  |                                    |       |            |
| to diesel |                                    |       |            |
| emissions |                                    |       |            |
| can occur |                                    |       |            |
| in a      |                                    |       |            |
| variety   |                                    |       |            |
| of        |                                    |       |            |
| s         |                                    |       |            |
| cenarios. |                                    |       |            |
| For       |                                    |       |            |
| example,  |                                    |       |            |
| for a     |                                    |       |            |
| l         |                                    |       |            |
| ess-than- |                                    |       |            |
| truckload |                                    |       |            |
| company,  |                                    |       |            |
| exposure  |                                    |       |            |
| can occur |                                    |       |            |
| at the    |                                    |       |            |
| truck     |                                    |       |            |
| terminals |                                    |       |            |
| at the    |                                    |       |            |
| origin    |                                    |       |            |
| and       |                                    |       |            |
| de        |                                    |       |            |
| stination |                                    |       |            |
| points    |                                    |       |            |
| where     |                                    |       |            |
| there is  |                                    |       |            |
| lots of   |                                    |       |            |
| diesel    |                                    |       |            |
| activity  |                                    |       |            |
| in the    |                                    |       |            |
| truck     |                                    |       |            |
| yard or   |                                    |       |            |
| from      |                                    |       |            |
| engines   |                                    |       |            |
| on the    |                                    |       |            |
| dock.     |                                    |       |            |
| Once the  |                                    |       |            |
| truck is  |                                    |       |            |
| moving,   |                                    |       |            |
| exposure  |                                    |       |            |
| can occur |                                    |       |            |
| on        |                                    |       |            |
| secondary |                                    |       |            |
| roads,    |                                    |       |            |
| freeways, |                                    |       |            |
| etc.,     |                                    |       |            |
| with the  |                                    |       |            |
| most      |                                    |       |            |
| direct    |                                    |       |            |
| exposure  |                                    |       |            |
| at        |                                    |       |            |
| overnight |                                    |       |            |
| locations |                                    |       |            |
| (e.g., a  |                                    |       |            |
| truck     |                                    |       |            |
| stop).    |                                    |       |            |
|           |                                    |       |            |
| Several   |                                    |       |            |
| studies   |                                    |       |            |
| have      |                                    |       |            |
| measured  |                                    |       |            |
| exposure  |                                    |       |            |
| to diesel |                                    |       |            |
| in        |                                    |       |            |
| Tennessee |                                    |       |            |
| along     |                                    |       |            |
| Inte      |                                    |       |            |
| rstate-40 |                                    |       |            |
| and Watt  |                                    |       |            |
| Road.     |                                    |       |            |
| There are |                                    |       |            |
| three     |                                    |       |            |
| truck     |                                    |       |            |
| stops     |                                    |       |            |
| here with |                                    |       |            |
| a         |                                    |       |            |
| capacity  |                                    |       |            |
| for 700   |                                    |       |            |
| overnight |                                    |       |            |
| trucks.   |                                    |       |            |
| As part   |                                    |       |            |
| of the    |                                    |       |            |
| Watt Road |                                    |       |            |
| Envi      |                                    |       |            |
| ronmental |                                    |       |            |
| L         |                                    |       |            |
| aboratory |                                    |       |            |
| In        |                                    |       |            |
| itiative, |                                    |       |            |
| the air   |                                    |       |            |
| quality   |                                    |       |            |
| at this   |                                    |       |            |
| truck     |                                    |       |            |
| stop and  |                                    |       |            |
| in truck  |                                    |       |            |
| cabs has  |                                    |       |            |
| been      |                                    |       |            |
| measured. |                                    |       |            |
| The       |                                    |       |            |
| results   |                                    |       |            |
| of these  |                                    |       |            |
| studies   |                                    |       |            |
| indicate  |                                    |       |            |
| that high |                                    |       |            |
| conc      |                                    |       |            |
| entration |                                    |       |            |
| of        |                                    |       |            |
| pa        |                                    |       |            |
| rticulate |                                    |       |            |
| matter    |                                    |       |            |
| was found |                                    |       |            |
| during    |                                    |       |            |
| the       |                                    |       |            |
| nighttime |                                    |       |            |
| hours,    |                                    |       |            |
| when      |                                    |       |            |
| there     |                                    |       |            |
| were more |                                    |       |            |
| diesel    |                                    |       |            |
| trucks    |                                    |       |            |
| idling    |                                    |       |            |
| and the   |                                    |       |            |
| a         |                                    |       |            |
| tmosphere |                                    |       |            |
| was at    |                                    |       |            |
| its       |                                    |       |            |
| meteo     |                                    |       |            |
| rological |                                    |       |            |
| low, and  |                                    |       |            |
| during    |                                    |       |            |
| the       |                                    |       |            |
| winter    |                                    |       |            |
| months,   |                                    |       |            |
| when more |                                    |       |            |
| trucks    |                                    |       |            |
| are       |                                    |       |            |
| idling.   |                                    |       |            |
|           |                                    |       |            |
| Addi      |                                    |       |            |
| tionally, |                                    |       |            |
| re        |                                    |       |            |
| searchers |                                    |       |            |
| from Oak  |                                    |       |            |
| Ridge     |                                    |       |            |
| National  |                                    |       |            |
| Labs      |                                    |       |            |
| (John     |                                    |       |            |
| Storey,   |                                    |       |            |
| Jim       |                                    |       |            |
| Parks)    |                                    |       |            |
| collected |                                    |       |            |
| a wide    |                                    |       |            |
| range of  |                                    |       |            |
| emissions |                                    |       |            |
| meas      |                                    |       |            |
| urements, |                                    |       |            |
| which     |                                    |       |            |
| Chad      |                                    |       |            |
| Bailey is |                                    |       |            |
| modeling. |                                    |       |            |
| The       |                                    |       |            |
| modeling  |                                    |       |            |
| results   |                                    |       |            |
| show that |                                    |       |            |
| truck     |                                    |       |            |
| stops     |                                    |       |            |
| represent |                                    |       |            |
| islands   |                                    |       |            |
| of high   |                                    |       |            |
| conc      |                                    |       |            |
| entration |                                    |       |            |
| among low |                                    |       |            |
| b         |                                    |       |            |
| ackground |                                    |       |            |
| areas.    |                                    |       |            |
| Other     |                                    |       |            |
| studies   |                                    |       |            |
| have      |                                    |       |            |
| looked at |                                    |       |            |
| typical   |                                    |       |            |
| conce     |                                    |       |            |
| ntrations |                                    |       |            |
| of air    |                                    |       |            |
| p         |                                    |       |            |
| ollutants |                                    |       |            |
| found on  |                                    |       |            |
| freeways  |                                    |       |            |
| and       |                                    |       |            |
| r         |                                    |       |            |
| oadsides; |                                    |       |            |
| data is   |                                    |       |            |
| being     |                                    |       |            |
| collected |                                    |       |            |
| in        |                                    |       |            |
| C         |                                    |       |            |
| alifornia |                                    |       |            |
| by USC    |                                    |       |            |
| and UCLA, |                                    |       |            |
| and in    |                                    |       |            |
| the New   |                                    |       |            |
| York area |                                    |       |            |
| by the    |                                    |       |            |
| U         |                                    |       |            |
| niversity |                                    |       |            |
| of        |                                    |       |            |
| R         |                                    |       |            |
| ochester, |                                    |       |            |
| Albany.   |                                    |       |            |
| There is  |                                    |       |            |
| a         |                                    |       |            |
| c         |                                    |       |            |
| onsistent |                                    |       |            |
| finding   |                                    |       |            |
| showing   |                                    |       |            |
| that      |                                    |       |            |
| along     |                                    |       |            |
| freeways, |                                    |       |            |
| the       |                                    |       |            |
| conc      |                                    |       |            |
| entration |                                    |       |            |
| of very   |                                    |       |            |
| fine      |                                    |       |            |
| particles |                                    |       |            |
| coming    |                                    |       |            |
| out of    |                                    |       |            |
| exhaust   |                                    |       |            |
| tailpipes |                                    |       |            |
| is a      |                                    |       |            |
| tenfold   |                                    |       |            |
| higher    |                                    |       |            |
| along     |                                    |       |            |
| major     |                                    |       |            |
| freeways  |                                    |       |            |
| compared  |                                    |       |            |
| to urban  |                                    |       |            |
| b         |                                    |       |            |
| ackground |                                    |       |            |
| air.      |                                    |       |            |
| Studies   |                                    |       |            |
| that have |                                    |       |            |
| looked at |                                    |       |            |
| other     |                                    |       |            |
| component |                                    |       |            |
| of        |                                    |       |            |
| pa        |                                    |       |            |
| rticulate |                                    |       |            |
| mixture   |                                    |       |            |
| (soot,    |                                    |       |            |
| carbon)   |                                    |       |            |
| also show |                                    |       |            |
| a steep   |                                    |       |            |
| gradient  |                                    |       |            |
| along     |                                    |       |            |
| major     |                                    |       |            |
| freeway.  |                                    |       |            |
|           |                                    |       |            |
| 4.  **If  |                                    |       |            |
|           |                                    |       |            |
|   primary |                                    |       |            |
|           |                                    |       |            |
|  research |                                    |       |            |
|     needs |                                    |       |            |
|     to be |                                    |       |            |
|           |                                    |       |            |
| conducted |                                    |       |            |
|     (in   |                                    |       |            |
|     the   |                                    |       |            |
|           |                                    |       |            |
|   absence |                                    |       |            |
|     of    |                                    |       |            |
|           |                                    |       |            |
|  existing |                                    |       |            |
|           |                                    |       |            |
| research) |                                    |       |            |
|     what  |                                    |       |            |
|           |                                    |       |            |
|   vehicle |                                    |       |            |
|     would |                                    |       |            |
|     be    |                                    |       |            |
|     ap    |                                    |       |            |
| propriate |                                    |       |            |
|           |                                    |       |            |
|  (Federal |                                    |       |            |
|           |                                    |       |            |
|    agency |                                    |       |            |
|     or    |                                    |       |            |
|     org   |                                    |       |            |
| anization |                                    |       |            |
|     with  |                                    |       |            |
|           |                                    |       |            |
| expertise |                                    |       |            |
|     in    |                                    |       |            |
|     this  |                                    |       |            |
|           |                                    |       |            |
| field)?** |                                    |       |            |
|           |                                    |       |            |
| Academia  |                                    |       |            |
| would be  |                                    |       |            |
| well      |                                    |       |            |
| -equipped |                                    |       |            |
| to        |                                    |       |            |
| conduct   |                                    |       |            |
| some of   |                                    |       |            |
| the       |                                    |       |            |
| research, |                                    |       |            |
| e.g.,     |                                    |       |            |
| through   |                                    |       |            |
| I         |                                    |       |            |
| ndustrial |                                    |       |            |
| Hygiene   |                                    |       |            |
| and       |                                    |       |            |
| Occ       |                                    |       |            |
| upational |                                    |       |            |
| Health    |                                    |       |            |
| de        |                                    |       |            |
| partments |                                    |       |            |
| at        |                                    |       |            |
| Harvard   |                                    |       |            |
| Un        |                                    |       |            |
| iversity, |                                    |       |            |
| U         |                                    |       |            |
| niversity |                                    |       |            |
| of        |                                    |       |            |
| Michigan, |                                    |       |            |
| UCLA, and |                                    |       |            |
| UC-       |                                    |       |            |
| Berkeley. |                                    |       |            |
| Other     |                                    |       |            |
| orga      |                                    |       |            |
| nizations |                                    |       |            |
| who might |                                    |       |            |
| be able   |                                    |       |            |
| to assist |                                    |       |            |
| are the   |                                    |       |            |
| Health    |                                    |       |            |
| Effects   |                                    |       |            |
| Institute |                                    |       |            |
| (HEI) and |                                    |       |            |
| N         |                                    |       |            |
| IOSH-CDC. |                                    |       |            |
| Other     |                                    |       |            |
| experts   |                                    |       |            |
| in the    |                                    |       |            |
| field are |                                    |       |            |
| Vern      |                                    |       |            |
| Benignus  |                                    |       |            |
| and Will  |                                    |       |            |
| Boyes.    |                                    |       |            |
|           |                                    |       |            |
| 5         |                                    |       |            |
| .  **What |                                    |       |            |
|           |                                    |       |            |
|   factors |                                    |       |            |
|           |                                    |       |            |
|    should |                                    |       |            |
|     be    |                                    |       |            |
|     c     |                                    |       |            |
| onsidered |                                    |       |            |
|     in    |                                    |       |            |
|     this  |                                    |       |            |
|     re    |                                    |       |            |
| search?** |                                    |       |            |
|           |                                    |       |            |
| 6.  **Can |                                    |       |            |
|     you   |                                    |       |            |
|           |                                    |       |            |
| recommend |                                    |       |            |
|           |                                    |       |            |
|    anyone |                                    |       |            |
|     else  |                                    |       |            |
|     we    |                                    |       |            |
|           |                                    |       |            |
|    should |                                    |       |            |
|           |                                    |       |            |
|   contact |                                    |       |            |
|           |                                    |       |            |
| regarding |                                    |       |            |
|     this  |                                    |       |            |
|     re    |                                    |       |            |
| search?** |                                    |       |            |
|           |                                    |       |            |
| -   Eric  |                                    |       |            |
|           |                                    |       |            |
| Garshick, |                                    |       |            |
|           |                                    |       |            |
|   Harvard |                                    |       |            |
|           |                                    |       |            |
|    School |                                    |       |            |
|     of    |                                    |       |            |
|           |                                    |       |            |
|    Public |                                    |       |            |
|           |                                    |       |            |
|   Health. |                                    |       |            |
|           |                                    |       |            |
|    Epidem |                                    |       |            |
| iological |                                    |       |            |
|           |                                    |       |            |
|   studies |                                    |       |            |
|           |                                    |       |            |
| examining |                                    |       |            |
|           |                                    |       |            |
|   whether |                                    |       |            |
|     there |                                    |       |            |
|     is a  |                                    |       |            |
|     link  |                                    |       |            |
|           |                                    |       |            |
|   between |                                    |       |            |
|           |                                    |       |            |
|    diesel |                                    |       |            |
|           |                                    |       |            |
|  exposure |                                    |       |            |
|     and   |                                    |       |            |
|           |                                    |       |            |
|   cancer. |                                    |       |            |
|           |                                    |       |            |
| -   Byron |                                    |       |            |
|           |                                    |       |            |
|    Bunker |                                    |       |            |
|     (     |                                    |       |            |
| emissions |                                    |       |            |
|     e     |                                    |       |            |
| ngineer): |                                    |       |            |
|     734   |                                    |       |            |
| .214.4155 |                                    |       |            |
|           |                                    |       |            |
| **Other   |                                    |       |            |
| d         |                                    |       |            |
| iscussion |                                    |       |            |
| topics**  |                                    |       |            |
|           |                                    |       |            |
| [What is  |                                    |       |            |
| the       |                                    |       |            |
| impact of |                                    |       |            |
| re        |                                    |       |            |
| gulations |                                    |       |            |
| that may  |                                    |       |            |
| be        |                                    |       |            |
| ena       |                                    |       |            |
| cted?]{.u |                                    |       |            |
| nderline} |                                    |       |            |
| The       |                                    |       |            |
| conc      |                                    |       |            |
| entration |                                    |       |            |
| of        |                                    |       |            |
| pa        |                                    |       |            |
| rticulate |                                    |       |            |
| mass and  |                                    |       |            |
| the       |                                    |       |            |
| numbers   |                                    |       |            |
| of        |                                    |       |            |
| particles |                                    |       |            |
| will      |                                    |       |            |
| decrease  |                                    |       |            |
| as a      |                                    |       |            |
| result of |                                    |       |            |
| these     |                                    |       |            |
| s         |                                    |       |            |
| tandards. |                                    |       |            |
| Reducing  |                                    |       |            |
| the       |                                    |       |            |
| sulfur in |                                    |       |            |
| the base  |                                    |       |            |
| fuel will |                                    |       |            |
| reduce    |                                    |       |            |
| ultrafine |                                    |       |            |
| matter.   |                                    |       |            |
| With      |                                    |       |            |
| respect   |                                    |       |            |
| to soot,  |                                    |       |            |
| the new   |                                    |       |            |
| standards |                                    |       |            |
| are       |                                    |       |            |
| expected  |                                    |       |            |
| to        |                                    |       |            |
| require   |                                    |       |            |
| manu      |                                    |       |            |
| facturers |                                    |       |            |
| to use    |                                    |       |            |
| particle  |                                    |       |            |
| traps, so |                                    |       |            |
| that      |                                    |       |            |
| emissions |                                    |       |            |
| may not   |                                    |       |            |
| be an     |                                    |       |            |
| issue.    |                                    |       |            |
+-----------+------------------------------------+-------+------------+

+-----------+------------------------------------+-------+------------+
| *         | Thomas Smith, Harvard University   | **Da  | April 4,   |
| *Intervie |                                    | te**: | 2007       |
| wee(s)**: |                                    |       |            |
+-----------+------------------------------------+-------+------------+
| The       |                                    |       |            |
| Harvard   |                                    |       |            |
| School of |                                    |       |            |
| Public    |                                    |       |            |
| Health is |                                    |       |            |
| c         |                                    |       |            |
| onducting |                                    |       |            |
| a cohort  |                                    |       |            |
| study to  |                                    |       |            |
| examine   |                                    |       |            |
| the       |                                    |       |            |
| rel       |                                    |       |            |
| ationship |                                    |       |            |
| between   |                                    |       |            |
| lung      |                                    |       |            |
| cancer    |                                    |       |            |
| and       |                                    |       |            |
| diesel    |                                    |       |            |
| and       |                                    |       |            |
| vehicle   |                                    |       |            |
| emissions |                                    |       |            |
| exposure  |                                    |       |            |
| in the    |                                    |       |            |
| trucking  |                                    |       |            |
| industry. |                                    |       |            |
| The       |                                    |       |            |
| cohort    |                                    |       |            |
| contains  |                                    |       |            |
| drivers,  |                                    |       |            |
| dock      |                                    |       |            |
| workers,  |                                    |       |            |
| m         |                                    |       |            |
| echanics, |                                    |       |            |
| hostlers, |                                    |       |            |
| and       |                                    |       |            |
| clerks    |                                    |       |            |
| from four |                                    |       |            |
| large     |                                    |       |            |
| trucking  |                                    |       |            |
| c         |                                    |       |            |
| ompanies. |                                    |       |            |
| As part   |                                    |       |            |
| of the    |                                    |       |            |
| study,    |                                    |       |            |
| over      |                                    |       |            |
| 4,000     |                                    |       |            |
| mea       |                                    |       |            |
| surements |                                    |       |            |
| of        |                                    |       |            |
| par       |                                    |       |            |
| ticulates |                                    |       |            |
| were      |                                    |       |            |
| collected |                                    |       |            |
| at        |                                    |       |            |
| various   |                                    |       |            |
| trucking  |                                    |       |            |
| terminals |                                    |       |            |
| with      |                                    |       |            |
| different |                                    |       |            |
| levels of |                                    |       |            |
| op        |                                    |       |            |
| erations. |                                    |       |            |
| This data |                                    |       |            |
| is being  |                                    |       |            |
| used to   |                                    |       |            |
| create a  |                                    |       |            |
| database  |                                    |       |            |
| of        |                                    |       |            |
| exposure  |                                    |       |            |
| to        |                                    |       |            |
| estimate  |                                    |       |            |
| exposure  |                                    |       |            |
| based on  |                                    |       |            |
| job       |                                    |       |            |
| title,    |                                    |       |            |
| work      |                                    |       |            |
| location, |                                    |       |            |
| and       |                                    |       |            |
| terminal  |                                    |       |            |
| site. The |                                    |       |            |
| results   |                                    |       |            |
| of the    |                                    |       |            |
| study so  |                                    |       |            |
| far have  |                                    |       |            |
| shown     |                                    |       |            |
| that      |                                    |       |            |
| there is  |                                    |       |            |
| an        |                                    |       |            |
| increased |                                    |       |            |
| risk of   |                                    |       |            |
| lung      |                                    |       |            |
| cancer,   |                                    |       |            |
| cardiac   |                                    |       |            |
| m         |                                    |       |            |
| ortality, |                                    |       |            |
| and       |                                    |       |            |
| a         |                                    |       |            |
| ccidental |                                    |       |            |
| death in  |                                    |       |            |
| this      |                                    |       |            |
| po        |                                    |       |            |
| pulation. |                                    |       |            |
|           |                                    |       |            |
| 1.  **Are |                                    |       |            |
|     you   |                                    |       |            |
|     aware |                                    |       |            |
|     of    |                                    |       |            |
|     any   |                                    |       |            |
|           |                                    |       |            |
|  research |                                    |       |            |
|     on    |                                    |       |            |
|     the   |                                    |       |            |
|           |                                    |       |            |
|   effects |                                    |       |            |
|     of    |                                    |       |            |
|           |                                    |       |            |
|    diesel |                                    |       |            |
|           |                                    |       |            |
| emissions |                                    |       |            |
|     (p    |                                    |       |            |
| referably |                                    |       |            |
|     at    |                                    |       |            |
|           |                                    |       |            |
|    levels |                                    |       |            |
|     a     |                                    |       |            |
|           |                                    |       |            |
|    driver |                                    |       |            |
|     might |                                    |       |            |
|     be    |                                    |       |            |
|           |                                    |       |            |
|   exposed |                                    |       |            |
|     to)   |                                    |       |            |
|     on    |                                    |       |            |
|     a     |                                    |       |            |
| lertness, |                                    |       |            |
|           |                                    |       |            |
|   decisio |                                    |       |            |
| n-making, |                                    |       |            |
|     or    |                                    |       |            |
|           |                                    |       |            |
| sleeping, |                                    |       |            |
|     or    |                                    |       |            |
|     any   |                                    |       |            |
|     other |                                    |       |            |
|           |                                    |       |            |
|   impacts |                                    |       |            |
|     that  |                                    |       |            |
|     could |                                    |       |            |
|           |                                    |       |            |
|    affect |                                    |       |            |
|     a     |                                    |       |            |
|           |                                    |       |            |
|  driver's |                                    |       |            |
|           |                                    |       |            |
|   ability |                                    |       |            |
|     to    |                                    |       |            |
|     drive |                                    |       |            |
|           |                                    |       |            |
| safely?** |                                    |       |            |
|           |                                    |       |            |
| No, much  |                                    |       |            |
| of their  |                                    |       |            |
| work has  |                                    |       |            |
| focused   |                                    |       |            |
| on        |                                    |       |            |
| measuring |                                    |       |            |
| exposure  |                                    |       |            |
| at        |                                    |       |            |
| different |                                    |       |            |
| work      |                                    |       |            |
| locations |                                    |       |            |
| for       |                                    |       |            |
| different |                                    |       |            |
| types of  |                                    |       |            |
| workers   |                                    |       |            |
| at        |                                    |       |            |
| various   |                                    |       |            |
| terminal  |                                    |       |            |
| sites.    |                                    |       |            |
|           |                                    |       |            |
| 2.  **Do  |                                    |       |            |
|     you   |                                    |       |            |
|     think |                                    |       |            |
|     there |                                    |       |            |
|     is    |                                    |       |            |
|     any   |                                    |       |            |
|           |                                    |       |            |
|    chance |                                    |       |            |
|     that  |                                    |       |            |
|     there |                                    |       |            |
|     could |                                    |       |            |
|     be an |                                    |       |            |
|           |                                    |       |            |
|    effect |                                    |       |            |
|     such  |                                    |       |            |
|     as    |                                    |       |            |
|           |                                    |       |            |
|   this?** |                                    |       |            |
|           |                                    |       |            |
| There     |                                    |       |            |
| could be  |                                    |       |            |
| an        |                                    |       |            |
| effect,   |                                    |       |            |
| but it is |                                    |       |            |
| much more |                                    |       |            |
| difficult |                                    |       |            |
| to        |                                    |       |            |
| quantify  |                                    |       |            |
| than      |                                    |       |            |
| disease.  |                                    |       |            |
|           |                                    |       |            |
| 3         |                                    |       |            |
| .  **Some |                                    |       |            |
|           |                                    |       |            |
|  existing |                                    |       |            |
|           |                                    |       |            |
|  research |                                    |       |            |
|           |                                    |       |            |
|  suggests |                                    |       |            |
|     that  |                                    |       |            |
|     there |                                    |       |            |
|     are   |                                    |       |            |
|           |                                    |       |            |
|  elevated |                                    |       |            |
|           |                                    |       |            |
|    levels |                                    |       |            |
|     of    |                                    |       |            |
|           |                                    |       |            |
| emissions |                                    |       |            |
|     in    |                                    |       |            |
|     truck |                                    |       |            |
|     cabs  |                                    |       |            |
|     that  |                                    |       |            |
|           |                                    |       |            |
|    exceed |                                    |       |            |
|           |                                    |       |            |
|   Federal |                                    |       |            |
|           |                                    |       |            |
|    agency |                                    |       |            |
|     s     |                                    |       |            |
| tandards. |                                    |       |            |
|     Are   |                                    |       |            |
|     you   |                                    |       |            |
|     aware |                                    |       |            |
|     of    |                                    |       |            |
|     any   |                                    |       |            |
|           |                                    |       |            |
|  research |                                    |       |            |
|     that  |                                    |       |            |
|     has   |                                    |       |            |
|           |                                    |       |            |
|  examined |                                    |       |            |
|           |                                    |       |            |
|   ambient |                                    |       |            |
|     air   |                                    |       |            |
|           |                                    |       |            |
|   quality |                                    |       |            |
|     in    |                                    |       |            |
|     \'hot |                                    |       |            |
|           |                                    |       |            |
|   spots\' |                                    |       |            |
|     where |                                    |       |            |
|           |                                    |       |            |
|    trucks |                                    |       |            |
|     might |                                    |       |            |
|     park  |                                    |       |            |
|     or    |                                    |       |            |
|           |                                    |       |            |
|    inside |                                    |       |            |
|     truck |                                    |       |            |
|           |                                    |       |            |
|   cabs?** |                                    |       |            |
|           |                                    |       |            |
| Mea       |                                    |       |            |
| surements |                                    |       |            |
| of air    |                                    |       |            |
| quality   |                                    |       |            |
| in truck  |                                    |       |            |
| cabs have |                                    |       |            |
| been      |                                    |       |            |
| collected |                                    |       |            |
| as part   |                                    |       |            |
| of their  |                                    |       |            |
| study. No |                                    |       |            |
| "hot      |                                    |       |            |
| spots"    |                                    |       |            |
| were      |                                    |       |            |
| found,    |                                    |       |            |
| per se,   |                                    |       |            |
| but       |                                    |       |            |
| mea       |                                    |       |            |
| surements |                                    |       |            |
| suggest   |                                    |       |            |
| that      |                                    |       |            |
| truck     |                                    |       |            |
| drivers'  |                                    |       |            |
| exposure  |                                    |       |            |
| is        |                                    |       |            |
| primarily |                                    |       |            |
| the       |                                    |       |            |
| result of |                                    |       |            |
| traffic   |                                    |       |            |
| emissions |                                    |       |            |
| from      |                                    |       |            |
| other     |                                    |       |            |
| cars.     |                                    |       |            |
| That is,  |                                    |       |            |
| a         |                                    |       |            |
| ddressing |                                    |       |            |
| the       |                                    |       |            |
| effects   |                                    |       |            |
| of        |                                    |       |            |
| exposure  |                                    |       |            |
| to        |                                    |       |            |
| traffic   |                                    |       |            |
| emissions |                                    |       |            |
| may be    |                                    |       |            |
| more      |                                    |       |            |
| feasible  |                                    |       |            |
| than      |                                    |       |            |
| a         |                                    |       |            |
| ddressing |                                    |       |            |
| the       |                                    |       |            |
| effects   |                                    |       |            |
| of        |                                    |       |            |
| exposure  |                                    |       |            |
| to        |                                    |       |            |
| diesel,   |                                    |       |            |
| spec      |                                    |       |            |
| ifically. |                                    |       |            |
| However,  |                                    |       |            |
| exposure  |                                    |       |            |
| levels    |                                    |       |            |
| are       |                                    |       |            |
| sporadic, |                                    |       |            |
| e.g.,     |                                    |       |            |
| occurring |                                    |       |            |
| only if   |                                    |       |            |
| the       |                                    |       |            |
| driver is |                                    |       |            |
| following |                                    |       |            |
| close to  |                                    |       |            |
| another   |                                    |       |            |
| car or    |                                    |       |            |
| truck.    |                                    |       |            |
| [Note     |                                    |       |            |
| that most |                                    |       |            |
| of the    |                                    |       |            |
| drivers   |                                    |       |            |
| in their  |                                    |       |            |
| study are |                                    |       |            |
| not       |                                    |       |            |
| long-haul |                                    |       |            |
| drivers   |                                    |       |            |
| and do    |                                    |       |            |
| not sleep |                                    |       |            |
| in their  |                                    |       |            |
| tr        |                                    |       |            |
| ucks.]{.u |                                    |       |            |
| nderline} |                                    |       |            |
|           |                                    |       |            |
| 4.  **If  |                                    |       |            |
|           |                                    |       |            |
|   primary |                                    |       |            |
|           |                                    |       |            |
|  research |                                    |       |            |
|     needs |                                    |       |            |
|     to be |                                    |       |            |
|           |                                    |       |            |
| conducted |                                    |       |            |
|     (in   |                                    |       |            |
|     the   |                                    |       |            |
|           |                                    |       |            |
|   absence |                                    |       |            |
|     of    |                                    |       |            |
|           |                                    |       |            |
|  existing |                                    |       |            |
|           |                                    |       |            |
| research) |                                    |       |            |
|     what  |                                    |       |            |
|           |                                    |       |            |
|   vehicle |                                    |       |            |
|     would |                                    |       |            |
|     be    |                                    |       |            |
|     ap    |                                    |       |            |
| propriate |                                    |       |            |
|           |                                    |       |            |
|  (Federal |                                    |       |            |
|           |                                    |       |            |
|    agency |                                    |       |            |
|     or    |                                    |       |            |
|     org   |                                    |       |            |
| anization |                                    |       |            |
|     with  |                                    |       |            |
|           |                                    |       |            |
| expertise |                                    |       |            |
|     in    |                                    |       |            |
|     this  |                                    |       |            |
|           |                                    |       |            |
| field)?** |                                    |       |            |
|           |                                    |       |            |
| The       |                                    |       |            |
| Harvard   |                                    |       |            |
| School of |                                    |       |            |
| Public    |                                    |       |            |
| Health    |                                    |       |            |
| has a     |                                    |       |            |
| good      |                                    |       |            |
| working   |                                    |       |            |
| rel       |                                    |       |            |
| ationship |                                    |       |            |
| with      |                                    |       |            |
| trucking  |                                    |       |            |
| companies |                                    |       |            |
| and       |                                    |       |            |
| T         |                                    |       |            |
| eamsters, |                                    |       |            |
| with whom |                                    |       |            |
| they have |                                    |       |            |
| current   |                                    |       |            |
| part      |                                    |       |            |
| nerships. |                                    |       |            |
| A study   |                                    |       |            |
| to        |                                    |       |            |
| address   |                                    |       |            |
| the       |                                    |       |            |
| cognitive |                                    |       |            |
| effects   |                                    |       |            |
| of diesel |                                    |       |            |
| emissions |                                    |       |            |
| exposure  |                                    |       |            |
| could be  |                                    |       |            |
| developed |                                    |       |            |
| in        |                                    |       |            |
| co        |                                    |       |            |
| njunction |                                    |       |            |
| with      |                                    |       |            |
| these     |                                    |       |            |
| organ     |                                    |       |            |
| izations. |                                    |       |            |
|           |                                    |       |            |
| 5         |                                    |       |            |
| .  **What |                                    |       |            |
|           |                                    |       |            |
|   factors |                                    |       |            |
|           |                                    |       |            |
|    should |                                    |       |            |
|     be    |                                    |       |            |
|     c     |                                    |       |            |
| onsidered |                                    |       |            |
|     in    |                                    |       |            |
|     this  |                                    |       |            |
|     re    |                                    |       |            |
| search?** |                                    |       |            |
|           |                                    |       |            |
| -         |                                    |       |            |
|  Symptoms |                                    |       |            |
|     of    |                                    |       |            |
|           |                                    |       |            |
|  exposure |                                    |       |            |
|           |                                    |       |            |
| -         |                                    |       |            |
|   Genetic |                                    |       |            |
|           |                                    |       |            |
|    respon |                                    |       |            |
| ses/blood |                                    |       |            |
|           |                                    |       |            |
|   markers |                                    |       |            |
|           |                                    |       |            |
| -   The   |                                    |       |            |
|     de    |                                    |       |            |
| velopment |                                    |       |            |
|     of    |                                    |       |            |
|     tasks |                                    |       |            |
|     that  |                                    |       |            |
|     are   |                                    |       |            |
|           |                                    |       |            |
| sensitive |                                    |       |            |
|           |                                    |       |            |
|    enough |                                    |       |            |
|     to    |                                    |       |            |
|           |                                    |       |            |
|   measure |                                    |       |            |
|     di    |                                    |       |            |
| fferences |                                    |       |            |
|     in    |                                    |       |            |
|           |                                    |       |            |
| cognitive |                                    |       |            |
|     pe    |                                    |       |            |
| rformance |                                    |       |            |
|           |                                    |       |            |
| 6.  **Can |                                    |       |            |
|     you   |                                    |       |            |
|           |                                    |       |            |
| recommend |                                    |       |            |
|           |                                    |       |            |
|    anyone |                                    |       |            |
|     else  |                                    |       |            |
|     we    |                                    |       |            |
|           |                                    |       |            |
|    should |                                    |       |            |
|           |                                    |       |            |
|   contact |                                    |       |            |
|           |                                    |       |            |
| regarding |                                    |       |            |
|     this  |                                    |       |            |
|     re    |                                    |       |            |
| search?** |                                    |       |            |
|           |                                    |       |            |
| -   Eric  |                                    |       |            |
|           |                                    |       |            |
| Garshick, |                                    |       |            |
|           |                                    |       |            |
|   Harvard |                                    |       |            |
|           |                                    |       |            |
|    School |                                    |       |            |
|     of    |                                    |       |            |
|           |                                    |       |            |
|    Public |                                    |       |            |
|           |                                    |       |            |
|    Health |                                    |       |            |
|           |                                    |       |            |
| -   Mark  |                                    |       |            |
|           |                                    |       |            |
| Weiskopf, |                                    |       |            |
|           |                                    |       |            |
|   Harvard |                                    |       |            |
|           |                                    |       |            |
|    School |                                    |       |            |
|     of    |                                    |       |            |
|           |                                    |       |            |
|    Public |                                    |       |            |
|           |                                    |       |            |
|    Health |                                    |       |            |
|           |                                    |       |            |
| (neurophy |                                    |       |            |
| siologist |                                    |       |            |
|     who   |                                    |       |            |
|     could |                                    |       |            |
|     help  |                                    |       |            |
|           |                                    |       |            |
|  generate |                                    |       |            |
|     tasks |                                    |       |            |
|     for   |                                    |       |            |
|           |                                    |       |            |
| measuring |                                    |       |            |
|           |                                    |       |            |
| cognition |                                    |       |            |
|     at    |                                    |       |            |
|     t     |                                    |       |            |
| erminals) |                                    |       |            |
+-----------+------------------------------------+-------+------------+

+-----------+------------------------------------+-------+------------+
| *         | Eric Garshick and Jaime Hart,      | **Da  | April 6,   |
| *Intervie | Harvard School of Public Health    | te**: | 2007       |
| wee(s)**: |                                    |       |            |
+-----------+------------------------------------+-------+------------+
| 1.  **Are |                                    |       |            |
|     you   |                                    |       |            |
|     aware |                                    |       |            |
|     of    |                                    |       |            |
|     any   |                                    |       |            |
|           |                                    |       |            |
|  research |                                    |       |            |
|     on    |                                    |       |            |
|     the   |                                    |       |            |
|           |                                    |       |            |
|   effects |                                    |       |            |
|     of    |                                    |       |            |
|           |                                    |       |            |
|    diesel |                                    |       |            |
|           |                                    |       |            |
| emissions |                                    |       |            |
|     (p    |                                    |       |            |
| referably |                                    |       |            |
|     at    |                                    |       |            |
|           |                                    |       |            |
|    levels |                                    |       |            |
|     a     |                                    |       |            |
|           |                                    |       |            |
|    driver |                                    |       |            |
|     might |                                    |       |            |
|     be    |                                    |       |            |
|           |                                    |       |            |
|   exposed |                                    |       |            |
|     to)   |                                    |       |            |
|     on    |                                    |       |            |
|     a     |                                    |       |            |
| lertness, |                                    |       |            |
|           |                                    |       |            |
|   decisio |                                    |       |            |
| n-making, |                                    |       |            |
|     or    |                                    |       |            |
|           |                                    |       |            |
| sleeping, |                                    |       |            |
|     or    |                                    |       |            |
|     any   |                                    |       |            |
|     other |                                    |       |            |
|           |                                    |       |            |
|   impacts |                                    |       |            |
|     that  |                                    |       |            |
|     could |                                    |       |            |
|           |                                    |       |            |
|    affect |                                    |       |            |
|     a     |                                    |       |            |
|           |                                    |       |            |
|  driver's |                                    |       |            |
|           |                                    |       |            |
|   ability |                                    |       |            |
|     to    |                                    |       |            |
|     drive |                                    |       |            |
|           |                                    |       |            |
| safely?** |                                    |       |            |
|           |                                    |       |            |
| There are |                                    |       |            |
| organic   |                                    |       |            |
| compounds |                                    |       |            |
| in        |                                    |       |            |
| exhaust   |                                    |       |            |
| that with |                                    |       |            |
| enough    |                                    |       |            |
| exposure  |                                    |       |            |
| could     |                                    |       |            |
| have      |                                    |       |            |
| effects.  |                                    |       |            |
| There is  |                                    |       |            |
| l         |                                    |       |            |
| iterature |                                    |       |            |
| a         |                                    |       |            |
| ddressing |                                    |       |            |
| emissions |                                    |       |            |
| exposure  |                                    |       |            |
| from      |                                    |       |            |
| school    |                                    |       |            |
| buses,    |                                    |       |            |
| and a     |                                    |       |            |
| birth     |                                    |       |            |
| cohort    |                                    |       |            |
| study in  |                                    |       |            |
| the New   |                                    |       |            |
| York area |                                    |       |            |
| that      |                                    |       |            |
| examined  |                                    |       |            |
| the       |                                    |       |            |
| effect of |                                    |       |            |
| PAH       |                                    |       |            |
| (p        |                                    |       |            |
| olycyclic |                                    |       |            |
| aromatic  |                                    |       |            |
| hydr      |                                    |       |            |
| ocarbons) |                                    |       |            |
| exposure  |                                    |       |            |
| on        |                                    |       |            |
| neuro     |                                    |       |            |
| cognitive |                                    |       |            |
| pe        |                                    |       |            |
| rformance |                                    |       |            |
| in        |                                    |       |            |
| schools.  |                                    |       |            |
| No one    |                                    |       |            |
| has yet   |                                    |       |            |
| looked at |                                    |       |            |
| the       |                                    |       |            |
| neuro     |                                    |       |            |
| cognitive |                                    |       |            |
| effects   |                                    |       |            |
| of        |                                    |       |            |
| emissions |                                    |       |            |
| on truck  |                                    |       |            |
| drivers.  |                                    |       |            |
|           |                                    |       |            |
| 2.  **Do  |                                    |       |            |
|     you   |                                    |       |            |
|     think |                                    |       |            |
|     there |                                    |       |            |
|     is    |                                    |       |            |
|     any   |                                    |       |            |
|           |                                    |       |            |
|    chance |                                    |       |            |
|     that  |                                    |       |            |
|     there |                                    |       |            |
|     could |                                    |       |            |
|     be an |                                    |       |            |
|           |                                    |       |            |
|    effect |                                    |       |            |
|     such  |                                    |       |            |
|     as    |                                    |       |            |
|           |                                    |       |            |
|   this?** |                                    |       |            |
|           |                                    |       |            |
| It is     |                                    |       |            |
| hard to   |                                    |       |            |
| tell. The |                                    |       |            |
| cognitive |                                    |       |            |
| issues    |                                    |       |            |
| may be    |                                    |       |            |
| c         |                                    |       |            |
| onfounded |                                    |       |            |
| with      |                                    |       |            |
| other     |                                    |       |            |
| "l        |                                    |       |            |
| ifestyle" |                                    |       |            |
| factors   |                                    |       |            |
| (e.g.,    |                                    |       |            |
| poor      |                                    |       |            |
| sleep,    |                                    |       |            |
| obesity), |                                    |       |            |
| and it    |                                    |       |            |
| will be   |                                    |       |            |
| necessary |                                    |       |            |
| to        |                                    |       |            |
| di        |                                    |       |            |
| sentangle |                                    |       |            |
| the       |                                    |       |            |
| various   |                                    |       |            |
| neuro     |                                    |       |            |
| cognitive |                                    |       |            |
| effects.  |                                    |       |            |
| Add       |                                    |       |            |
| itionally |                                    |       |            |
| there are |                                    |       |            |
| many ways |                                    |       |            |
| to        |                                    |       |            |
| measure   |                                    |       |            |
| c         |                                    |       |            |
| ognition. |                                    |       |            |
|           |                                    |       |            |
| 3         |                                    |       |            |
| .  **Some |                                    |       |            |
|           |                                    |       |            |
|  existing |                                    |       |            |
|           |                                    |       |            |
|  research |                                    |       |            |
|           |                                    |       |            |
|  suggests |                                    |       |            |
|     that  |                                    |       |            |
|     there |                                    |       |            |
|     are   |                                    |       |            |
|           |                                    |       |            |
|  elevated |                                    |       |            |
|           |                                    |       |            |
|    levels |                                    |       |            |
|     of    |                                    |       |            |
|           |                                    |       |            |
| emissions |                                    |       |            |
|     in    |                                    |       |            |
|     truck |                                    |       |            |
|     cabs  |                                    |       |            |
|     that  |                                    |       |            |
|           |                                    |       |            |
|    exceed |                                    |       |            |
|           |                                    |       |            |
|   Federal |                                    |       |            |
|           |                                    |       |            |
|    agency |                                    |       |            |
|     s     |                                    |       |            |
| tandards. |                                    |       |            |
|     Are   |                                    |       |            |
|     you   |                                    |       |            |
|     aware |                                    |       |            |
|     of    |                                    |       |            |
|     any   |                                    |       |            |
|           |                                    |       |            |
|  research |                                    |       |            |
|     that  |                                    |       |            |
|     has   |                                    |       |            |
|           |                                    |       |            |
|  examined |                                    |       |            |
|           |                                    |       |            |
|   ambient |                                    |       |            |
|     air   |                                    |       |            |
|           |                                    |       |            |
|   quality |                                    |       |            |
|     in    |                                    |       |            |
|     \'hot |                                    |       |            |
|           |                                    |       |            |
|   spots\' |                                    |       |            |
|     where |                                    |       |            |
|           |                                    |       |            |
|    trucks |                                    |       |            |
|     might |                                    |       |            |
|     park  |                                    |       |            |
|     or    |                                    |       |            |
|           |                                    |       |            |
|    inside |                                    |       |            |
|     truck |                                    |       |            |
|           |                                    |       |            |
|   cabs?** |                                    |       |            |
|           |                                    |       |            |
| 4.  **If  |                                    |       |            |
|           |                                    |       |            |
|   primary |                                    |       |            |
|           |                                    |       |            |
|  research |                                    |       |            |
|     needs |                                    |       |            |
|     to be |                                    |       |            |
|           |                                    |       |            |
| conducted |                                    |       |            |
|     (in   |                                    |       |            |
|     the   |                                    |       |            |
|           |                                    |       |            |
|   absence |                                    |       |            |
|     of    |                                    |       |            |
|           |                                    |       |            |
|  existing |                                    |       |            |
|           |                                    |       |            |
| research) |                                    |       |            |
|     what  |                                    |       |            |
|           |                                    |       |            |
|   vehicle |                                    |       |            |
|     would |                                    |       |            |
|     be    |                                    |       |            |
|     ap    |                                    |       |            |
| propriate |                                    |       |            |
|           |                                    |       |            |
|  (Federal |                                    |       |            |
|           |                                    |       |            |
|    agency |                                    |       |            |
|     or    |                                    |       |            |
|     org   |                                    |       |            |
| anization |                                    |       |            |
|     with  |                                    |       |            |
|           |                                    |       |            |
| expertise |                                    |       |            |
|     in    |                                    |       |            |
|     this  |                                    |       |            |
|           |                                    |       |            |
| field)?** |                                    |       |            |
|           |                                    |       |            |
| The       |                                    |       |            |
| Harvard   |                                    |       |            |
| School of |                                    |       |            |
| Public    |                                    |       |            |
| Health    |                                    |       |            |
| has       |                                    |       |            |
| es        |                                    |       |            |
| tablished |                                    |       |            |
| rela      |                                    |       |            |
| tionships |                                    |       |            |
| with      |                                    |       |            |
| trucking  |                                    |       |            |
| c         |                                    |       |            |
| ompanies, |                                    |       |            |
| unions,   |                                    |       |            |
| and       |                                    |       |            |
| ma        |                                    |       |            |
| nagement. |                                    |       |            |
| Most      |                                    |       |            |
| truck     |                                    |       |            |
| drivers   |                                    |       |            |
| in their  |                                    |       |            |
| study are |                                    |       |            |
| willing   |                                    |       |            |
| to        |                                    |       |            |
| pa        |                                    |       |            |
| rticipate |                                    |       |            |
| in        |                                    |       |            |
| research  |                                    |       |            |
| studies,  |                                    |       |            |
| par       |                                    |       |            |
| ticularly |                                    |       |            |
| if they   |                                    |       |            |
| are paid  |                                    |       |            |
| to do so. |                                    |       |            |
| Most of   |                                    |       |            |
| their     |                                    |       |            |
| truckers  |                                    |       |            |
| in their  |                                    |       |            |
| study are |                                    |       |            |
| not       |                                    |       |            |
| long-haul |                                    |       |            |
| drivers   |                                    |       |            |
| and do    |                                    |       |            |
| not sleep |                                    |       |            |
| at truck  |                                    |       |            |
| stops.    |                                    |       |            |
| Instead,  |                                    |       |            |
| the       |                                    |       |            |
| drivers'  |                                    |       |            |
| companies |                                    |       |            |
| often pay |                                    |       |            |
| for a     |                                    |       |            |
| hotel on  |                                    |       |            |
| overnight |                                    |       |            |
| trips.    |                                    |       |            |
|           |                                    |       |            |
| 5         |                                    |       |            |
| .  **What |                                    |       |            |
|           |                                    |       |            |
|   factors |                                    |       |            |
|           |                                    |       |            |
|    should |                                    |       |            |
|     be    |                                    |       |            |
|     c     |                                    |       |            |
| onsidered |                                    |       |            |
|     in    |                                    |       |            |
|     this  |                                    |       |            |
|     re    |                                    |       |            |
| search?** |                                    |       |            |
|           |                                    |       |            |
| The       |                                    |       |            |
| question  |                                    |       |            |
| currently |                                    |       |            |
| asked is  |                                    |       |            |
| too broad |                                    |       |            |
| and needs |                                    |       |            |
| to be     |                                    |       |            |
| focused   |                                    |       |            |
| by        |                                    |       |            |
| de        |                                    |       |            |
| termining |                                    |       |            |
| what can  |                                    |       |            |
| be        |                                    |       |            |
| measured  |                                    |       |            |
| emp       |                                    |       |            |
| irically. |                                    |       |            |
| First,    |                                    |       |            |
| exposure  |                                    |       |            |
| can be    |                                    |       |            |
| measured  |                                    |       |            |
| in        |                                    |       |            |
| several   |                                    |       |            |
| ways. A   |                                    |       |            |
| pilot     |                                    |       |            |
| study may |                                    |       |            |
| be needed |                                    |       |            |
| in which  |                                    |       |            |
| several   |                                    |       |            |
| markers   |                                    |       |            |
| are       |                                    |       |            |
| collected |                                    |       |            |
| (e.g.,    |                                    |       |            |
| elemental |                                    |       |            |
| carbons,  |                                    |       |            |
| organic   |                                    |       |            |
| vapors)   |                                    |       |            |
| to        |                                    |       |            |
| determine |                                    |       |            |
| which     |                                    |       |            |
| markers   |                                    |       |            |
| to use    |                                    |       |            |
| and which |                                    |       |            |
| might     |                                    |       |            |
| have the  |                                    |       |            |
| most      |                                    |       |            |
| impact on |                                    |       |            |
| c         |                                    |       |            |
| ognition. |                                    |       |            |
| \$200k is |                                    |       |            |
| a         |                                    |       |            |
| r         |                                    |       |            |
| easonable |                                    |       |            |
| budget    |                                    |       |            |
| for such  |                                    |       |            |
| pilot     |                                    |       |            |
| study.    |                                    |       |            |
| Second, a |                                    |       |            |
| method    |                                    |       |            |
| for       |                                    |       |            |
| measuring |                                    |       |            |
| the       |                                    |       |            |
| neuro     |                                    |       |            |
| cognitive |                                    |       |            |
| impact    |                                    |       |            |
| will need |                                    |       |            |
| to be     |                                    |       |            |
| devised.  |                                    |       |            |
| A pilot   |                                    |       |            |
| study     |                                    |       |            |
| could be  |                                    |       |            |
| conducted |                                    |       |            |
| to test   |                                    |       |            |
| the       |                                    |       |            |
| protocol  |                                    |       |            |
| at local  |                                    |       |            |
| terminals |                                    |       |            |
| before    |                                    |       |            |
| expanding |                                    |       |            |
| it to     |                                    |       |            |
| larger    |                                    |       |            |
| t         |                                    |       |            |
| erminals. |                                    |       |            |
| C         |                                    |       |            |
| ollecting |                                    |       |            |
| blood     |                                    |       |            |
| samples   |                                    |       |            |
| to        |                                    |       |            |
| determine |                                    |       |            |
| the       |                                    |       |            |
| presence  |                                    |       |            |
| of        |                                    |       |            |
| "inf      |                                    |       |            |
| lammatory |                                    |       |            |
| markers"  |                                    |       |            |
| may also  |                                    |       |            |
| be        |                                    |       |            |
| useful,   |                                    |       |            |
| e         |                                    |       |            |
| specially |                                    |       |            |
| if a      |                                    |       |            |
| co        |                                    |       |            |
| rrelation |                                    |       |            |
| can be    |                                    |       |            |
| dem       |                                    |       |            |
| onstrated |                                    |       |            |
| between   |                                    |       |            |
| these     |                                    |       |            |
| markers   |                                    |       |            |
| and       |                                    |       |            |
| impaired  |                                    |       |            |
| cognitive |                                    |       |            |
| response. |                                    |       |            |
|           |                                    |       |            |
| It may    |                                    |       |            |
| also be   |                                    |       |            |
| in        |                                    |       |            |
| teresting |                                    |       |            |
| to        |                                    |       |            |
| examine   |                                    |       |            |
| the       |                                    |       |            |
| effects   |                                    |       |            |
| of        |                                    |       |            |
| exposure  |                                    |       |            |
| versus    |                                    |       |            |
| l         |                                    |       |            |
| ifestyle, |                                    |       |            |
| or to     |                                    |       |            |
| rephrase  |                                    |       |            |
| the       |                                    |       |            |
| question  |                                    |       |            |
| to        |                                    |       |            |
| consider  |                                    |       |            |
| the risk  |                                    |       |            |
| factors   |                                    |       |            |
| of        |                                    |       |            |
| neuro     |                                    |       |            |
| cognitive |                                    |       |            |
| effects.  |                                    |       |            |
|           |                                    |       |            |
| 6.  **Can |                                    |       |            |
|     you   |                                    |       |            |
|           |                                    |       |            |
| recommend |                                    |       |            |
|           |                                    |       |            |
|    anyone |                                    |       |            |
|     else  |                                    |       |            |
|     we    |                                    |       |            |
|           |                                    |       |            |
|    should |                                    |       |            |
|           |                                    |       |            |
|   contact |                                    |       |            |
|           |                                    |       |            |
| regarding |                                    |       |            |
|     this  |                                    |       |            |
|     re    |                                    |       |            |
| search?** |                                    |       |            |
+-----------+------------------------------------+-------+------------+

+-----------+------------------------------------+-------+------------+
| *         | Haviland Steele, SAIC              | **Da  | April 12,  |
| *Intervie |                                    | te:** | 2007       |
| wee(s):** | Dr. Gail Chapman, Dr. Palur        |       |            |
|           | Gunasekar, Dr. Shawn McInturf,     |       |            |
|           | Wright Patterson Air Force Base    |       |            |
+===========+====================================+=======+============+
| 1.  **Are |                                    |       |            |
|     you   |                                    |       |            |
|     aware |                                    |       |            |
|     of    |                                    |       |            |
|     any   |                                    |       |            |
|           |                                    |       |            |
|  research |                                    |       |            |
|     on    |                                    |       |            |
|     the   |                                    |       |            |
|           |                                    |       |            |
|   effects |                                    |       |            |
|     of    |                                    |       |            |
|           |                                    |       |            |
|    diesel |                                    |       |            |
|           |                                    |       |            |
| emissions |                                    |       |            |
|     (p    |                                    |       |            |
| referably |                                    |       |            |
|     at    |                                    |       |            |
|           |                                    |       |            |
|    levels |                                    |       |            |
|     a     |                                    |       |            |
|           |                                    |       |            |
|    driver |                                    |       |            |
|     might |                                    |       |            |
|     be    |                                    |       |            |
|           |                                    |       |            |
|   exposed |                                    |       |            |
|     to)   |                                    |       |            |
|     on    |                                    |       |            |
|     a     |                                    |       |            |
| lertness, |                                    |       |            |
|           |                                    |       |            |
|   decisio |                                    |       |            |
| n-making, |                                    |       |            |
|     or    |                                    |       |            |
|           |                                    |       |            |
| sleeping, |                                    |       |            |
|     or    |                                    |       |            |
|     any   |                                    |       |            |
|     other |                                    |       |            |
|           |                                    |       |            |
|   impacts |                                    |       |            |
|     that  |                                    |       |            |
|     could |                                    |       |            |
|           |                                    |       |            |
|    affect |                                    |       |            |
|     a     |                                    |       |            |
|           |                                    |       |            |
|  driver's |                                    |       |            |
|           |                                    |       |            |
|   ability |                                    |       |            |
|     to    |                                    |       |            |
|     drive |                                    |       |            |
|           |                                    |       |            |
| safely?** |                                    |       |            |
|           |                                    |       |            |
| The       |                                    |       |            |
| military  |                                    |       |            |
| has       |                                    |       |            |
| ex        |                                    |       |            |
| tensively |                                    |       |            |
| examined  |                                    |       |            |
| the       |                                    |       |            |
| effects   |                                    |       |            |
| of        |                                    |       |            |
| exposure  |                                    |       |            |
| to jet    |                                    |       |            |
| fuel      |                                    |       |            |
| vapors    |                                    |       |            |
| because   |                                    |       |            |
| the       |                                    |       |            |
| potential |                                    |       |            |
| for       |                                    |       |            |
| neurob    |                                    |       |            |
| ehavioral |                                    |       |            |
| effects   |                                    |       |            |
| was       |                                    |       |            |
| noticed.  |                                    |       |            |
| Shawn     |                                    |       |            |
| McInturf  |                                    |       |            |
| assisted  |                                    |       |            |
| in the    |                                    |       |            |
| data      |                                    |       |            |
| c         |                                    |       |            |
| ollection |                                    |       |            |
| of        |                                    |       |            |
| eye-blink |                                    |       |            |
| con       |                                    |       |            |
| ditioning |                                    |       |            |
| data on   |                                    |       |            |
| rats in   |                                    |       |            |
| one study |                                    |       |            |
| that      |                                    |       |            |
| examined  |                                    |       |            |
| whether   |                                    |       |            |
| exposure  |                                    |       |            |
| to jet    |                                    |       |            |
| fuel      |                                    |       |            |
| resulted  |                                    |       |            |
| in any    |                                    |       |            |
| c         |                                    |       |            |
| erebellum |                                    |       |            |
| deficits. |                                    |       |            |
| The       |                                    |       |            |
| results   |                                    |       |            |
| showed    |                                    |       |            |
| di        |                                    |       |            |
| fferences |                                    |       |            |
| in        |                                    |       |            |
| eye-blink |                                    |       |            |
| responses |                                    |       |            |
| among     |                                    |       |            |
| rats with |                                    |       |            |
| high      |                                    |       |            |
| exposure  |                                    |       |            |
| to jet    |                                    |       |            |
| fuel      |                                    |       |            |
| vapors    |                                    |       |            |
| versus    |                                    |       |            |
| those     |                                    |       |            |
| with low  |                                    |       |            |
| exposure. |                                    |       |            |
| A         |                                    |       |            |
| s         |                                    |       |            |
| ubsequent |                                    |       |            |
| study     |                                    |       |            |
| examined  |                                    |       |            |
| the       |                                    |       |            |
| effect of |                                    |       |            |
| jet fuel  |                                    |       |            |
| exposure  |                                    |       |            |
| on the    |                                    |       |            |
| rats'     |                                    |       |            |
| circadian |                                    |       |            |
| rhythms,  |                                    |       |            |
| but the   |                                    |       |            |
| data      |                                    |       |            |
| collected |                                    |       |            |
| showed no |                                    |       |            |
| overall   |                                    |       |            |
| effect.   |                                    |       |            |
| With      |                                    |       |            |
| respect   |                                    |       |            |
| to diesel |                                    |       |            |
| exposure, |                                    |       |            |
| animal    |                                    |       |            |
| models    |                                    |       |            |
| have      |                                    |       |            |
| shown     |                                    |       |            |
| cardi     |                                    |       |            |
| ovascular |                                    |       |            |
| effects.  |                                    |       |            |
|           |                                    |       |            |
| 2.  **Do  |                                    |       |            |
|     you   |                                    |       |            |
|     think |                                    |       |            |
|     there |                                    |       |            |
|     is    |                                    |       |            |
|     any   |                                    |       |            |
|           |                                    |       |            |
|    chance |                                    |       |            |
|     that  |                                    |       |            |
|     there |                                    |       |            |
|     could |                                    |       |            |
|     be an |                                    |       |            |
|           |                                    |       |            |
|    effect |                                    |       |            |
|     such  |                                    |       |            |
|     as    |                                    |       |            |
|           |                                    |       |            |
|   this?** |                                    |       |            |
|           |                                    |       |            |
| It is not |                                    |       |            |
| clear; it |                                    |       |            |
| would be  |                                    |       |            |
| important |                                    |       |            |
| to        |                                    |       |            |
| measure   |                                    |       |            |
| the       |                                    |       |            |
| conc      |                                    |       |            |
| entration |                                    |       |            |
| levels at |                                    |       |            |
| hot spots |                                    |       |            |
| to        |                                    |       |            |
| determine |                                    |       |            |
| what      |                                    |       |            |
| levels    |                                    |       |            |
| are       |                                    |       |            |
| inhaled.  |                                    |       |            |
| If these  |                                    |       |            |
| numbers   |                                    |       |            |
| are       |                                    |       |            |
| sig       |                                    |       |            |
| nificant, |                                    |       |            |
| then      |                                    |       |            |
| a         |                                    |       |            |
| dditional |                                    |       |            |
| research  |                                    |       |            |
| may be    |                                    |       |            |
| needed to |                                    |       |            |
| determine |                                    |       |            |
| the       |                                    |       |            |
| cognitive |                                    |       |            |
| impact.   |                                    |       |            |
|           |                                    |       |            |
| 3         |                                    |       |            |
| .  **Some |                                    |       |            |
|           |                                    |       |            |
|  existing |                                    |       |            |
|           |                                    |       |            |
|  research |                                    |       |            |
|           |                                    |       |            |
|  suggests |                                    |       |            |
|     that  |                                    |       |            |
|     there |                                    |       |            |
|     are   |                                    |       |            |
|           |                                    |       |            |
|  elevated |                                    |       |            |
|           |                                    |       |            |
|    levels |                                    |       |            |
|     of    |                                    |       |            |
|           |                                    |       |            |
| emissions |                                    |       |            |
|     in    |                                    |       |            |
|     truck |                                    |       |            |
|     cabs  |                                    |       |            |
|     that  |                                    |       |            |
|           |                                    |       |            |
|    exceed |                                    |       |            |
|           |                                    |       |            |
|   Federal |                                    |       |            |
|           |                                    |       |            |
|    agency |                                    |       |            |
|     s     |                                    |       |            |
| tandards. |                                    |       |            |
|     Are   |                                    |       |            |
|     you   |                                    |       |            |
|     aware |                                    |       |            |
|     of    |                                    |       |            |
|     any   |                                    |       |            |
|           |                                    |       |            |
|  research |                                    |       |            |
|     that  |                                    |       |            |
|     has   |                                    |       |            |
|           |                                    |       |            |
|  examined |                                    |       |            |
|           |                                    |       |            |
|   ambient |                                    |       |            |
|     air   |                                    |       |            |
|           |                                    |       |            |
|   quality |                                    |       |            |
|     in    |                                    |       |            |
|     \'hot |                                    |       |            |
|           |                                    |       |            |
|   spots\' |                                    |       |            |
|     where |                                    |       |            |
|           |                                    |       |            |
|    trucks |                                    |       |            |
|     might |                                    |       |            |
|     park  |                                    |       |            |
|     or    |                                    |       |            |
|           |                                    |       |            |
|    inside |                                    |       |            |
|     truck |                                    |       |            |
|           |                                    |       |            |
|   cabs?** |                                    |       |            |
|           |                                    |       |            |
| 4.  **If  |                                    |       |            |
|           |                                    |       |            |
|   primary |                                    |       |            |
|           |                                    |       |            |
|  research |                                    |       |            |
|     needs |                                    |       |            |
|     to be |                                    |       |            |
|           |                                    |       |            |
| conducted |                                    |       |            |
|     (in   |                                    |       |            |
|     the   |                                    |       |            |
|           |                                    |       |            |
|   absence |                                    |       |            |
|     of    |                                    |       |            |
|           |                                    |       |            |
|  existing |                                    |       |            |
|           |                                    |       |            |
| research) |                                    |       |            |
|     what  |                                    |       |            |
|           |                                    |       |            |
|   vehicle |                                    |       |            |
|     would |                                    |       |            |
|     be    |                                    |       |            |
|     ap    |                                    |       |            |
| propriate |                                    |       |            |
|           |                                    |       |            |
|  (Federal |                                    |       |            |
|           |                                    |       |            |
|    agency |                                    |       |            |
|     or    |                                    |       |            |
|     org   |                                    |       |            |
| anization |                                    |       |            |
|     with  |                                    |       |            |
|           |                                    |       |            |
| expertise |                                    |       |            |
|     in    |                                    |       |            |
|     this  |                                    |       |            |
|           |                                    |       |            |
| field)?** |                                    |       |            |
|           |                                    |       |            |
| Most of   |                                    |       |            |
| the       |                                    |       |            |
| t         |                                    |       |            |
| oxicology |                                    |       |            |
| research  |                                    |       |            |
| conducted |                                    |       |            |
| at Wright |                                    |       |            |
| Patterson |                                    |       |            |
| Air Force |                                    |       |            |
| Base      |                                    |       |            |
| consists  |                                    |       |            |
| of animal |                                    |       |            |
| studies.  |                                    |       |            |
| These     |                                    |       |            |
| animal    |                                    |       |            |
| studies   |                                    |       |            |
| could be  |                                    |       |            |
| used to   |                                    |       |            |
| develop   |                                    |       |            |
| clear     |                                    |       |            |
| co        |                                    |       |            |
| nclusions |                                    |       |            |
| regarding |                                    |       |            |
| a link    |                                    |       |            |
| between   |                                    |       |            |
| diesel    |                                    |       |            |
| exposure  |                                    |       |            |
| and       |                                    |       |            |
| c         |                                    |       |            |
| ognition. |                                    |       |            |
| Stressors |                                    |       |            |
| could     |                                    |       |            |
| also be   |                                    |       |            |
| i         |                                    |       |            |
| ntroduced |                                    |       |            |
| to        |                                    |       |            |
| examine   |                                    |       |            |
| their     |                                    |       |            |
| effects.  |                                    |       |            |
|           |                                    |       |            |
| Human     |                                    |       |            |
| body      |                                    |       |            |
| exposure  |                                    |       |            |
| studies,  |                                    |       |            |
| if        |                                    |       |            |
| needed,   |                                    |       |            |
| would be  |                                    |       |            |
| better    |                                    |       |            |
| conducted |                                    |       |            |
| by the    |                                    |       |            |
| EPA.      |                                    |       |            |
| Wright    |                                    |       |            |
| Patterson |                                    |       |            |
| AFB has   |                                    |       |            |
| not       |                                    |       |            |
| conducted |                                    |       |            |
| t         |                                    |       |            |
| oxicology |                                    |       |            |
| studies   |                                    |       |            |
| on        |                                    |       |            |
| humans,   |                                    |       |            |
| and if    |                                    |       |            |
| they are  |                                    |       |            |
| needed,   |                                    |       |            |
| IRB       |                                    |       |            |
| approval  |                                    |       |            |
| could     |                                    |       |            |
| take up   |                                    |       |            |
| to a year |                                    |       |            |
| to        |                                    |       |            |
| obtain.   |                                    |       |            |
|           |                                    |       |            |
| 5         |                                    |       |            |
| .  **What |                                    |       |            |
|           |                                    |       |            |
|   factors |                                    |       |            |
|           |                                    |       |            |
|    should |                                    |       |            |
|     be    |                                    |       |            |
|     c     |                                    |       |            |
| onsidered |                                    |       |            |
|     in    |                                    |       |            |
|     this  |                                    |       |            |
|     re    |                                    |       |            |
| search?** |                                    |       |            |
|           |                                    |       |            |
| Driver    |                                    |       |            |
| exposure  |                                    |       |            |
| may occur |                                    |       |            |
| in        |                                    |       |            |
| various   |                                    |       |            |
| ways      |                                    |       |            |
| (e.g.,    |                                    |       |            |
| inhaled   |                                    |       |            |
| from the  |                                    |       |            |
| air,      |                                    |       |            |
| absorbed  |                                    |       |            |
| from the  |                                    |       |            |
| hands).   |                                    |       |            |
| The dose  |                                    |       |            |
| and       |                                    |       |            |
| effects   |                                    |       |            |
| of        |                                    |       |            |
| exposure  |                                    |       |            |
| may vary  |                                    |       |            |
| depending |                                    |       |            |
| on the    |                                    |       |            |
| source    |                                    |       |            |
| and       |                                    |       |            |
| length of |                                    |       |            |
| time of   |                                    |       |            |
| exposure. |                                    |       |            |
| Also,     |                                    |       |            |
| consider  |                                    |       |            |
| whether   |                                    |       |            |
| there are |                                    |       |            |
| any       |                                    |       |            |
| b         |                                    |       |            |
| iomarkers |                                    |       |            |
| (e.g.,    |                                    |       |            |
| blood     |                                    |       |            |
| markers)  |                                    |       |            |
| that      |                                    |       |            |
| could be  |                                    |       |            |
| i         |                                    |       |            |
| ndicative |                                    |       |            |
| of        |                                    |       |            |
| cognitive |                                    |       |            |
| deficits. |                                    |       |            |
|           |                                    |       |            |
| 6.  **Can |                                    |       |            |
|     you   |                                    |       |            |
|           |                                    |       |            |
| recommend |                                    |       |            |
|           |                                    |       |            |
|    anyone |                                    |       |            |
|     else  |                                    |       |            |
|     we    |                                    |       |            |
|           |                                    |       |            |
|    should |                                    |       |            |
|           |                                    |       |            |
|   contact |                                    |       |            |
|           |                                    |       |            |
| regarding |                                    |       |            |
|     this  |                                    |       |            |
|     re    |                                    |       |            |
| search?** |                                    |       |            |
|           |                                    |       |            |
|           |                                    |       |            |
|  -   John |                                    |       |            |
|           |                                    |       |            |
|     Hinz, |                                    |       |            |
|           |                                    |       |            |
|      U.S. |                                    |       |            |
|           |                                    |       |            |
|       Air |                                    |       |            |
|           |                                    |       |            |
|     Force |                                    |       |            |
|           |                                    |       |            |
|     -     |                                    |       |            |
|    Laurie |                                    |       |            |
|           |                                    |       |            |
|  Roszell, |                                    |       |            |
|           |                                    |       |            |
|      U.S. |                                    |       |            |
|           |                                    |       |            |
|      Army |                                    |       |            |
|           |                                    |       |            |
|           |                                    |       |            |
|  -   Dave |                                    |       |            |
|           |                                    |       |            |
|   Mattie, |                                    |       |            |
|           |                                    |       |            |
|      U.S. |                                    |       |            |
|           |                                    |       |            |
|       Air |                                    |       |            |
|           |                                    |       |            |
|     Force |                                    |       |            |
+-----------+------------------------------------+-------+------------+

#  Annotated Bibliography {#annotated-bibliography .Appendix-Heading-1}

The annotated bibliography is organized into five sections. The first
three references the literature addressing the cognitive effects of
exposure to diesel exhaust (B.1), carbon monoxide (B.2), and jet fuel
vapors (B.3) respectively. Each of the studies in these sections is
described in a table that highlights the following:

-   the purpose of the study,

-   the number of participants,

-   the method and level of exposure,

-   the task participants performed,

-   the results of the study, and

-   implications of the research.

Because the literature review identified research that addressed other
aspects of diesel exhaust exposure, two additional sections in the
annotated bibliography are included. Section B.4 lists literature
identified in this search and in the Project Plan Agreement (PPA) that
addresses other health effects of diesel exhaust exposure, e.g., on
cardiovascular and pulmonary functions. The purpose of each study and an
overview of the findings are provided for each article in Section B.4.
Finally, Section B.5 contains literature addressing measurements of air
quality in general traffic and in "hot spots." Because these studies do
not address any health effects, only the purpose is noted.

## Cognitive Effects of Diesel Exposure {#cognitive-effects-of-diesel-exposure .Appendix-Heading-2}

+----------+------------------------------------------------+----+----+
| **       | **Responses to controlled diesel vapor         |    |    |
| Title:** | exposure among chemically sensitive Gulf War   |    |    |
|          | Veterans**                                     |    |    |
+==========+================================================+====+====+
| **Auth   | Fiedler, N., Giardino, N., Natelson, B.,       |    |    |
| or(s):** | Oteenweller, J.E., Weisel, C., Lioy, P.,       |    |    |
|          | Lehrer, P., Ohman-Strickland, P.,              |    |    |
|          | Kelly-McNeil, K., and Kipen, H.                |    |    |
+----------+------------------------------------------------+----+----+
| **Jo     | *Psychosomatic Medicine*, 66, 588-598          | *  | 20 |
| urnal:** |                                                | *Y | 04 |
|          |                                                | ea |    |
|          |                                                | r: |    |
|          |                                                | ** |    |
+----------+------------------------------------------------+----+----+
| **Pu     | To evaluate the health effects of exposure to  |    |    |
| rpose**: | diesel vapors with acetaldehyde on Gulf War    |    |    |
|          | veterans under stressful and non-stressful     |    |    |
|          | conditions                                     |    |    |
+----------+------------------------------------------------+----+----+
| *        | 19 healthy Gulf War veterans and 12 ill Gulf   |    |    |
| *Partici | War veterans (based on criteria for chronic    |    |    |
| pants:** | fatigue syndrome and self-reported chemical    |    |    |
|          | sensitivity, as indicated by sensitivity to 5  |    |    |
|          | or more of 8 chemicals and 1 or more lifestyle |    |    |
|          | change due to chemical sensitivities)          |    |    |
+----------+------------------------------------------------+----+----+
| **Exp    | Participants were seated in a controlled       |    |    |
| osure:** | environment facility (CEF; a 7.3'x 9'x13.6'    |    |    |
|          | stainless steel chamber) and exposed to 5 ppm  |    |    |
|          | diesel vapor, simulating typical exposure      |    |    |
|          | concentrations in garages where diesel and     |    |    |
|          | other fuels are used, with 0.5 ppm             |    |    |
|          | concentration of acetaldehyde added to         |    |    |
|          | simulate the soldiers' environmental           |    |    |
|          | conditions.                                    |    |    |
+----------+------------------------------------------------+----+----+
| *        | The experiment was divided into four phases:   |    |    |
| *Task:** | pre-exposure, exposure, 30-minutes             |    |    |
|          | post-exposure, and 1-hour post exposure.       |    |    |
|          |                                                |    |    |
|          | -   In the pre-exposure phase, participants    |    |    |
|          |     performed tasks to collect baseline data   |    |    |
|          |     in a "clean air" environment. Participants |    |    |
|          |     completed a questionnaire indicating       |    |    |
|          |     whether they experienced specific symptoms |    |    |
|          |     related to eye irritation, anxiety,        |    |    |
|          |     somatic health (e.g., numbness/tingling,   |    |    |
|          |     back pain, muscle aches), respiration, and |    |    |
|          |     cognition (disorientation, dizziness,      |    |    |
|          |     ability to concentrate) and general        |    |    |
|          |     symptoms related to exposure volatile      |    |    |
|          |     organic compounds (e.g., headache,         |    |    |
|          |     fatigue, lightheadedness, drowsiness,      |    |    |
|          |     nausea), and provided ratings on the       |    |    |
|          |     environmental quality, odor intensity, and |    |    |
|          |     odor irritation. Participants also         |    |    |
|          |     performed a dual-task driving simulation   |    |    |
|          |     test, in which they responded to a central |    |    |
|          |     task when a "safe" condition was present   |    |    |
|          |     (e.g., white head lights in the left lane) |    |    |
|          |     and a peripheral task when a critical      |    |    |
|          |     stimulus appeared (e.g., a stop sign).     |    |    |
|          |     These tasks took approximately 50 minutes. |    |    |
|          |                                                |    |    |
|          | -   In the exposure phase, participants were   |    |    |
|          |     exposed to diesel vapors. After 25         |    |    |
|          |     minutes, participants performed a Stroop   |    |    |
|          |     task, which was used as a psychological    |    |    |
|          |     stressor. Participants then completed the  |    |    |
|          |     symptom and environmental questionnaires   |    |    |
|          |     and the dual-task driving simulation test. |    |    |
|          |                                                |    |    |
|          | -   Thirty minutes post-exposure, participants |    |    |
|          |     completed the symptom and environmental    |    |    |
|          |     questionnaires and performed the dual-task |    |    |
|          |     driving simulation test.                   |    |    |
|          |                                                |    |    |
|          | -   One hour post-exposure, participants       |    |    |
|          |     completed the symptom and environmental    |    |    |
|          |     questionnaire.                             |    |    |
+----------+------------------------------------------------+----+----+
| **R      |                                                |    |    |
| esults** |                                                |    |    |
+----------+------------------------------------------------+----+----+
| Ill Gulf |                                                |    |    |
| War      |                                                |    |    |
| veterans |                                                |    |    |
| i        |                                                |    |    |
| ndicated |                                                |    |    |
| more     |                                                |    |    |
| severe   |                                                |    |    |
| s        |                                                |    |    |
| ymptoms, |                                                |    |    |
| e.g.,    |                                                |    |    |
| di       |                                                |    |    |
| fficulty |                                                |    |    |
| concen   |                                                |    |    |
| trating, |                                                |    |    |
| disorie  |                                                |    |    |
| ntation, |                                                |    |    |
| di       |                                                |    |    |
| zziness, |                                                |    |    |
| and      |                                                |    |    |
| he       |                                                |    |    |
| adaches, |                                                |    |    |
| than     |                                                |    |    |
| healthy  |                                                |    |    |
| Gulf War |                                                |    |    |
| v        |                                                |    |    |
| eterans. |                                                |    |    |
| These    |                                                |    |    |
| symptoms |                                                |    |    |
| are      |                                                |    |    |
| co       |                                                |    |    |
| nsistent |                                                |    |    |
| with     |                                                |    |    |
| physi    |                                                |    |    |
| ological |                                                |    |    |
| data     |                                                |    |    |
| showing  |                                                |    |    |
| reduced  |                                                |    |    |
| e        |                                                |    |    |
| nd-tidal |                                                |    |    |
| CO~2~    |                                                |    |    |
| levels   |                                                |    |    |
| and      |                                                |    |    |
| h        |                                                |    |    |
| ypervent |                                                |    |    |
| ilation. |                                                |    |    |
| Other    |                                                |    |    |
| symptoms |                                                |    |    |
| exp      |                                                |    |    |
| erienced |                                                |    |    |
| by ill   |                                                |    |    |
| Gulf War |                                                |    |    |
| veterans |                                                |    |    |
| included |                                                |    |    |
| i        |                                                |    |    |
| ncreased |                                                |    |    |
| dr       |                                                |    |    |
| owsiness |                                                |    |    |
| and      |                                                |    |    |
| i        |                                                |    |    |
| ncreased |                                                |    |    |
| fatigue  |                                                |    |    |
| with     |                                                |    |    |
| p        |                                                |    |    |
| rolonged |                                                |    |    |
| exposure |                                                |    |    |
| relative |                                                |    |    |
| to the   |                                                |    |    |
| healthy  |                                                |    |    |
| v        |                                                |    |    |
| eterans. |                                                |    |    |
| However, |                                                |    |    |
| despite  |                                                |    |    |
| these    |                                                |    |    |
| dif      |                                                |    |    |
| ferences |                                                |    |    |
| in the   |                                                |    |    |
| su       |                                                |    |    |
| bjective |                                                |    |    |
| ratings, |                                                |    |    |
| there    |                                                |    |    |
| was no   |                                                |    |    |
| per      |                                                |    |    |
| formance |                                                |    |    |
| di       |                                                |    |    |
| fference |                                                |    |    |
| on the   |                                                |    |    |
| d        |                                                |    |    |
| ual-task |                                                |    |    |
| driving  |                                                |    |    |
| si       |                                                |    |    |
| mulation |                                                |    |    |
| test     |                                                |    |    |
| between  |                                                |    |    |
| the two  |                                                |    |    |
| groups.  |                                                |    |    |
| It is    |                                                |    |    |
| i        |                                                |    |    |
| mportant |                                                |    |    |
| to note  |                                                |    |    |
| that the |                                                |    |    |
| veterans |                                                |    |    |
| were     |                                                |    |    |
| given    |                                                |    |    |
| only a   |                                                |    |    |
| single   |                                                |    |    |
| exposure |                                                |    |    |
| and that |                                                |    |    |
| there    |                                                |    |    |
| was no   |                                                |    |    |
| control  |                                                |    |    |
| group    |                                                |    |    |
| that did |                                                |    |    |
| not      |                                                |    |    |
| ex       |                                                |    |    |
| perience |                                                |    |    |
| no       |                                                |    |    |
| e        |                                                |    |    |
| xposure, |                                                |    |    |
| apart    |                                                |    |    |
| from the |                                                |    |    |
| baseline |                                                |    |    |
| data     |                                                |    |    |
| c        |                                                |    |    |
| ollected |                                                |    |    |
| before   |                                                |    |    |
| the      |                                                |    |    |
| exposure |                                                |    |    |
| to       |                                                |    |    |
| diesel,  |                                                |    |    |
| so the   |                                                |    |    |
| results  |                                                |    |    |
| could    |                                                |    |    |
| reflect  |                                                |    |    |
| a stress |                                                |    |    |
| r        |                                                |    |    |
| esulting |                                                |    |    |
| from     |                                                |    |    |
| anti     |                                                |    |    |
| cipating |                                                |    |    |
| the      |                                                |    |    |
| odor.    |                                                |    |    |
+----------+------------------------------------------------+----+----+
| **Implic | Persons with chemical intolerances are more    |    |    |
| ations** | likely than those without those same           |    |    |
|          | intolerances to hyperventilate as a result of  |    |    |
|          | exposure to general chemicals. The authors     |    |    |
|          | hypothesize that the ill Gulf War veterans may |    |    |
|          | have exhibited a conditioned response (e.g.,   |    |    |
|          | hyperventilating) to the odor of diesel fumes, |    |    |
|          | possibly the result of associating the odors   |    |    |
|          | with the Gulf War. Thus, veterans' anxiety     |    |    |
|          | about chemical exposures due to previous       |    |    |
|          | illness may lead to chronic anxiety and        |    |    |
|          | contribute to the occurrence of general        |    |    |
|          | somatic symptoms such as fatigue when exposed  |    |    |
|          | to these chemicals.                            |    |    |
+----------+------------------------------------------------+----+----+

  ----------------------------------------------------------------------------------------
  **Title:**          **Effects of diesel exhaust on neurobehavioral                
                      and pulmonary functions**                                     
  ------------------- ------------------------------------------------- ----------- ------
  **Author(s):**      Kilburn, K.H.                                                 

  **Journal:**        *Archives of Environmental Health*, 55(1), 11-17  **Year:**   2000

  **Purpose**:        To examine whether diesel exhaust exposure causes             
                      impairment in central nervous system functions                

  **Participants:**   16 chemically-exposed workers: 10 railroad                    
                      workers (between 43 -- 60 years old) and 6                    
                      electricians (between 42 -- 56 years old). A                  
                      control group consisted of 159 males with no                  
                      known exposure to chemicals.                                  

  **Exposure:**       Exposure level varied. The 10 railroad workers                
                      had a range of 15-40 years of experience as                   
                      diesel mechanics or train crewmen. The 6                      
                      electricians were working in a contained space                
                      with exhaust from idling diesel engines pouring               
                      into the space                                                

  **Task:**           Participants completed a self-administered                    
                      questionnaire and a set of neurophysiological and             
                      neuropsychological tests measuring reaction time,             
                      balance, visual functioning, memory, dexterity,               
                      coordination, decision making, and peripheral                 
                      sensation and discrimination.                                 

  **Results**                                                                       

  The group of                                                                      
  diesel-exposed                                                                    
  workers showed                                                                    
  impairments on                                                                    
  neurobehavioral                                                                   
  functions relative                                                                
  to the control                                                                    
  group, with                                                                       
  abnormalities                                                                     
  slightly higher in                                                                
  the railroad                                                                      
  workers with                                                                      
  longer-term                                                                       
  exposures.                                                                        
  Specifically, the                                                                 
  tests showed                                                                      
  decrements in                                                                     
  balance, reaction                                                                 
  time, blink reflex                                                                
  latency, problem                                                                  
  solving, perceptual                                                               
  motor functions,                                                                  
  and verbal and                                                                    
  visual memory                                                                     
  recall. Pulmonary                                                                 
  test also showed                                                                  
  that 10 of the                                                                    
  diesel-exposed                                                                    
  participants had                                                                  
  airway                                                                            
  obstructions, and                                                                 
  10 had chronic                                                                    
  bronchitis, chest                                                                 
  pain, tightness,                                                                  
  and hyper reactive                                                                
  airways.                                                                          

  **Implications**    There may be a link between diesel-exhaust                    
                      exposure and impairment to the central nervous                
                      system (including cognitive functioning).                     
                      Specifically, diesel-exhaust exposure led to                  
                      cognitive decrements in memory, problem solving,              
                      reaction time and neurological impairments with               
                      respect to vision and balance. Similar                        
                      impairments were noted regardless of exposure                 
                      time (i.e., exposure for 1 year versus 25 years).             
  ----------------------------------------------------------------------------------------

  ----------------------------------------------------------------------------------------
  **Title:**          **Neurological and cognitive abnormalities                    
                      associated with chronic petrol sniffing**                     
  ------------------- ------------------------------------------------- ----------- ------
  **Author(s):**      Maruff, P., Burns, C.B., Tyler, P., Currie, B.J.,             
                      and Currie, J.                                                

  **Journal:**        *Brain*, 121, 1903-1917                           **Year:**   1998

  **Purpose**:        To examine the effects of chronic petrol sniffing             
                      on neurological and cognitive performance                     

  **Participants:**   34 non-sniffers, 33 current-sniffers, and 30                  
                      ex-sniffers                                                   

  **Exposure:**       Non-sniffers had never sniffed petrol; current                
                      sniffers had sniffed petrol for at least 6 months             
                      and were currently and actively sniffing; and                 
                      ex-sniffers had sniffed petrol for at least 6                 
                      months but had not sniffed petrol in a 6-month                
                      period prior to the study                                     

  **Task:**           Blood tests; neurological examination;                        
                      psychological testing of motor function, simple               
                      and choice reaction time, visual search pattern               
                      recognition, spatial recognition,                             
                      pattern-location paired-associate learning,                   
                      visual attention, drawing and copying                         

  **Results**                                                                       

  Results of the                                                                    
  psychological                                                                     
  testing indicated                                                                 
  that                                                                              
  current-sniffers                                                                  
  performed poorer                                                                  
  than non-sniffers                                                                 
  on tasks of visual                                                                
  search as the                                                                     
  number of                                                                         
  distractors                                                                       
  increased, pattern                                                                
  and spatial                                                                       
  recognition, and                                                                  
  paired association                                                                
  learning and memory                                                               
  tasks (particularly                                                               
  as the number of                                                                  
  patterns                                                                          
  increased).                                                                       
  Ex-sniffers showed                                                                
  poorer performance                                                                
  on pattern and                                                                    
  spatial recognition                                                               
  and paired                                                                        
  associate learning                                                                
  tasks (similar to                                                                 
  current-sniffers,                                                                 
  this deficit was                                                                  
  seen as the number                                                                
  of patterns                                                                       
  increased) relative                                                               
  to non-sniffers.                                                                  
  Performance speed                                                                 
  did not vary among                                                                
  the three groups,                                                                 
  suggesting that the                                                               
  cognitive deficits                                                                
  found were not due                                                                
  to an inability to                                                                
  perform the tasks.                                                                

  **Implications**    Neurological and cognitive function is                        
                      compromised with petrol sniffing but their                    
                      effects may be reduced with abstinence.                       
  ----------------------------------------------------------------------------------------

##  Cognitive Effects of Carbon Monoxide Exposure {#cognitive-effects-of-carbon-monoxide-exposure .Appendix-Heading-2}

  ----------------------------------------------------------------------------------------
  **Title:**          **Neuropsychological impairment from acute                    
                      low-level exposure to carbon monoxide**                       
  ------------------- ------------------------------------------------- ----------- ------
  **Author(s):**      Amitai, Y., Zlotogorski, Z., Golan-Katzav, V.,                
                      Wexler, A., and Gross, D.                                     

  **Journal:**        *Archives of Neurology*, 55, 845-848.             **Year:**   1998

  **Purpose**:        To examine the effect of acute low-level carbon               
                      monoxide exposure on cognitive functioning                    

  **Participants:**   92 students; 45 in the experimental group (6 of               
                      which were smokers) and 47 in the control group               
                      (8 smokers)                                                   

  **Exposure:**       Participants in the experimental group were                   
                      exposed to carbon monoxide from kerosene stoves               
                      in their dormitory rooms for a period of 1.5 to               
                      2.5 hours. The exposure level ranged from 17-100              
                      ppm resulting in COHb levels ranging from 1% to               
                      11%.                                                          

  **Task:**           Participants completed five tests measuring                   
                      short-term and long-term semantic and figural                 
                      memory; visuomotor coordination; visuospatial                 
                      organization and constructional skills; auditory              
                      memory, attention, and concentration; spatial                 
                      planning; and verbal memory and learning                      
                      abilities.                                                    

  **Results**                                                                       

  Low level exposure                                                                
  to carbon monoxide                                                                
  impaired short- and                                                               
  long-term memory,                                                                 
  visuomotor                                                                        
  coordination,                                                                     
  visuospatial                                                                      
  planning and                                                                      
  construction, and                                                                 
  temporospatial                                                                    
  orientation.                                                                      

  **Implications**    Carbon monoxide exposure was linked to cognitive              
                      decrements in memory, learning, attention,                    
                      tracking, abstract thinking, and visuospatial                 
                      planning and processing.                                      
  ----------------------------------------------------------------------------------------

  ---------------- ------------------------------------------------- ----------- ------
  **Title:**       **Carbon monoxide exposure and cerebral                       
                   function**                                                    

  **Author(s):**   Beard, R.R. and Grandstaff, N.                                

  **Journal:**     *Annals of the New York Academy of Sciences*,     **Year:**   1970
                   174(1), 385-395                                               

  **Purpose**:     Summarize the literature regarding the effects of             
                   carbon monoxide on cerebral function                          

  **Results and    Many studies have examined the effects of carbon              
  Implications**   monoxide on cerebral brain function without clear             
                   results. Testing in different environments can                
                   modify behavioral patterns, and the minimal dose              
                   needed to produce a demonstrable effect has                   
                   varied.                                                       
  ---------------- ------------------------------------------------- ----------- ------

  ----------------------------------------------------------------------------------------
  **Title:**          **Behavioral impairment associated with small                 
                      doses of carbon monoxide**                                    
  ------------------- ------------------------------------------------- ----------- ------
  **Author(s):**      Beard, R.R. and Wertheim, G.A.                                

  **Journal:**        *American Journal of Public Health and the        **Year:**   1967
                      Nation's Health*, 57 (11), 2012-2022                          

  **Purpose**:        Examine the effects of carbon monoxide on rats,               
                      monkeys, and humans to determine behavioral                   
                      changes                                                       

  **Experiment 1**                                                                  

  **Participants:**   18 young adult, non-smoking, university students              

  **Exposure:**       Carbon monoxide was administered in                           
                      concentrations of 0, 50, 100, 175, and 200 parts              
                      per million                                                   

  **Task:**           Participants were presented with two tones; the               
                      first was one second long and the second varied               
                      between 0.675 seconds and 1.325 seconds.                      
                      Participants judged whether the length of the                 
                      second tone was the same as, shorter, or longer,              
                      than the first by pressing one of three levers.               

  **Results**                                                                       

  Participants showed                                                               
  no overt changes in                                                               
  motor behavior, but                                                               
  judgments of time                                                                 
  intervals, as                                                                     
  measured by the                                                                   
  ability to                                                                        
  discriminate the                                                                  
  length of two                                                                     
  successively                                                                      
  presented auditory                                                                
  tones, were                                                                       
  impaired as a                                                                     
  result of exposure                                                                
  to all carbon                                                                     
  monoxide                                                                          
  concentrations.                                                                   
  Accuracy decreased                                                                
  as the carbon                                                                     
  monoxide                                                                          
  concentration                                                                     
  exposure increased,                                                               
  and this                                                                          
  performance                                                                       
  decrement in                                                                      
  judgment precision                                                                
  was similar for                                                                   
  small and large                                                                   
  differences in tone                                                               
  duration. Ninety                                                                  
  minutes of exposure                                                               
  was sufficient to                                                                 
  cause significant                                                                 
  decrement with                                                                    
  50ppm, with shorter                                                               
  times needed for                                                                  
  higher                                                                            
  concentrations.                                                                   

  **Experiment 2**                                                                  

  **Participants:**   Rats                                                          

  **Exposure:**       0, 250, 500, 750, 1000 ppm                                    

  **Task:**           Rats were trained to press levers to obtain food              
                      pellets or water (reinforcement) at fixed time                
                      intervals, e.g., the rat was rewarded with a food             
                      pellet three minutes after the previous pellet                
                      was delivered. Rats learn that pressing the level             
                      soon after the reinforcement is delivered is                  
                      useless but increases the rate of lever pressing              
                      as the end of the fixed time interval approaches.             

  **Results**                                                                       

  Ninety minutes of                                                                 
  exposure to carbon                                                                
  monoxide at a                                                                     
  concentration level                                                               
  of 50 ppm led to                                                                  
  decrements in                                                                     
  discriminating the                                                                
  relative length of                                                                
  auditory tones.                                                                   
  Recovery from                                                                     
  carbon monoxide                                                                   
  exposure was quick,                                                               
  however, suggesting                                                               
  that the                                                                          
  performance                                                                       
  decrement was not                                                                 
  related to the                                                                    
  amount of carbon                                                                  
  monoxide hemoglobin                                                               
  in the blood.                                                                     
  Additionally,                                                                     
  carbon monoxide                                                                   
  exposure impacted                                                                 
  the rats' ability                                                                 
  to discriminate                                                                   
  time.                                                                             

  **Implications**    Low levels of carbon monoxide exposure may impact             
                      complex tasks such as time estimation, with                   
                      performance decrements occurring faster for                   
                      higher levels of carbon monoxide. Studies with                
                      rats showed similar effects of carbon monoxide                
                      exposure on time judgments. It is possible that               
                      these decrements in time estimation may lead to               
                      errors in speed estimation. However, this                     
                      hypothesis is based on intuition rather than                  
                      empirical evidence and needs testing.                         
  ----------------------------------------------------------------------------------------

+----------+------------------------------------------------+----+----+
| **       | **Interactive effects of physical work and     |    |    |
| Title:** | carbon monoxide on cognitive task              |    |    |
|          | performance**                                  |    |    |
+==========+================================================+====+====+
| **Auth   | Bunnell, D.E. and Horvath, S.M.                |    |    |
| or(s):** |                                                |    |    |
+----------+------------------------------------------------+----+----+
| **Jo     | *Aviation, Space, and Environmental Medicine*, | *  | 19 |
| urnal:** | December, 1133-1138                            | *Y | 88 |
|          |                                                | ea |    |
|          |                                                | r: |    |
|          |                                                | ** |    |
+----------+------------------------------------------------+----+----+
| **Pu     | To evaluate the effects of carbon monoxide     |    |    |
| rpose**: | exposure and physical work on cognitive        |    |    |
|          | performance                                    |    |    |
+----------+------------------------------------------------+----+----+
| *        | 11 men and 7 women ranging in age from 18-29   |    |    |
| *Partici | years old                                      |    |    |
| pants:** |                                                |    |    |
+----------+------------------------------------------------+----+----+
| **Exp    | \~0.7-1%, 7%, and 10% COHb                     |    |    |
| osure:** |                                                |    |    |
|          | Blood samples were collected prior to the      |    |    |
|          | study to determine the amount of carbon        |    |    |
|          | monoxide required to reach the target COHb     |    |    |
|          | levels. Participants breathed oxygen for 3     |    |    |
|          | min, and then breathed a mixture of carbon     |    |    |
|          | monoxide and oxygen for 5 min. Participants    |    |    |
|          | were then taken to an experimental chamber,    |    |    |
|          | with 45 ppm carbon monoxide in the 7% COHb     |    |    |
|          | condition and 65 ppm in the 10% COHb           |    |    |
|          | condition.                                     |    |    |
+----------+------------------------------------------------+----+----+
| *        | Participants sat or exercised in the           |    |    |
| *Task:** | experimental chamber for 50 minutes. In the    |    |    |
|          | exercise condition, participants walked on a   |    |    |
|          | treadmill at either 35% or 60% of their        |    |    |
|          | maximum aerobic capacity. Participants then    |    |    |
|          | set for 5 min before completing five cognitive |    |    |
|          | tasks measuring spatial processing,            |    |    |
|          | psychomotor tracking, short-term memory,       |    |    |
|          | arithmetic reasoning, visual search, and       |    |    |
|          | response inhibition. Participants then         |    |    |
|          | completed the Environmental Systems            |    |    |
|          | Questionnaire in which they indicated the      |    |    |
|          | extent to which they felt specific somatic     |    |    |
|          | systems during exposure.                       |    |    |
+----------+------------------------------------------------+----+----+
| **R      |                                                |    |    |
| esults** |                                                |    |    |
+----------+------------------------------------------------+----+----+
| Part     |                                                |    |    |
| icipants |                                                |    |    |
| reported |                                                |    |    |
| no       |                                                |    |    |
| increase |                                                |    |    |
| in       |                                                |    |    |
| symptoms |                                                |    |    |
| with     |                                                |    |    |
| in       |                                                |    |    |
| creasing |                                                |    |    |
| levels   |                                                |    |    |
| of COHb, |                                                |    |    |
| su       |                                                |    |    |
| ggesting |                                                |    |    |
| that     |                                                |    |    |
| part     |                                                |    |    |
| icipants |                                                |    |    |
| could    |                                                |    |    |
| not tell |                                                |    |    |
| when     |                                                |    |    |
| they     |                                                |    |    |
| were     |                                                |    |    |
| exposed  |                                                |    |    |
| to       |                                                |    |    |
| carbon   |                                                |    |    |
| m        |                                                |    |    |
| onoxide. |                                                |    |    |
| A        |                                                |    |    |
| c        |                                                |    |    |
| ognitive |                                                |    |    |
| effect   |                                                |    |    |
| of       |                                                |    |    |
| carbon   |                                                |    |    |
| monoxide |                                                |    |    |
| exposure |                                                |    |    |
| was      |                                                |    |    |
| reported |                                                |    |    |
| in       |                                                |    |    |
| parti    |                                                |    |    |
| cipants' |                                                |    |    |
| r        |                                                |    |    |
| esponses |                                                |    |    |
| to the   |                                                |    |    |
| second   |                                                |    |    |
| of two   |                                                |    |    |
| sequ     |                                                |    |    |
| entially |                                                |    |    |
| p        |                                                |    |    |
| resented |                                                |    |    |
| Stroop   |                                                |    |    |
| tasks,   |                                                |    |    |
| such     |                                                |    |    |
| that     |                                                |    |    |
| part     |                                                |    |    |
| icipants |                                                |    |    |
| were     |                                                |    |    |
| hindered |                                                |    |    |
| in their |                                                |    |    |
| ability  |                                                |    |    |
| to learn |                                                |    |    |
| a new    |                                                |    |    |
| response |                                                |    |    |
| set.     |                                                |    |    |
| There    |                                                |    |    |
| was also |                                                |    |    |
| an       |                                                |    |    |
| int      |                                                |    |    |
| eraction |                                                |    |    |
| of COHb  |                                                |    |    |
| level    |                                                |    |    |
| and      |                                                |    |    |
| exercise |                                                |    |    |
| on       |                                                |    |    |
| visual   |                                                |    |    |
| search   |                                                |    |    |
| perf     |                                                |    |    |
| ormance, |                                                |    |    |
| with     |                                                |    |    |
| high     |                                                |    |    |
| levels   |                                                |    |    |
| of work  |                                                |    |    |
| (i.e.,   |                                                |    |    |
| 60%      |                                                |    |    |
| e        |                                                |    |    |
| xertion) |                                                |    |    |
| at       |                                                |    |    |
| elevated |                                                |    |    |
| COHb     |                                                |    |    |
| levels   |                                                |    |    |
| r        |                                                |    |    |
| esulting |                                                |    |    |
| in       |                                                |    |    |
| poorer   |                                                |    |    |
| perf     |                                                |    |    |
| ormance. |                                                |    |    |
+----------+------------------------------------------------+----+----+
| **Implic | COHb levels as high as 10% can be tolerated,   |    |    |
| ations** | even with physical work, with minor            |    |    |
|          | performance decrements in cognitive function   |    |    |
+----------+------------------------------------------------+----+----+

  ----------------------------------------------------------------------------------------
  **Title:**          **Human performance of a psychomotor test as a                
                      function of exposure to carbon monoxide**                     
  ------------------- ------------------------------------------------- ----------- ------
  **Author(s):**      Hanks, T.G.                                                   

  **Journal:**        *Annals of the New York Academy of Sciences*,     **Year:**   1970
                      174(1), 421-424                                               

  **Purpose**:        Determine whether carbon monoxide exposure in                 
                      traffic affects driving judgment and control                  

  **Participants:**   Nonsmoking, healthy young male university                     
                      students (Note: the number of participants was                
                      not specified)                                                

  **Exposure:**       0, 25, 50, 75, and 100ppm carbon monoxide. Breath             
                      samples measured for carbon monoxide content                  
                      before exposure and every 30 minutes during                   
                      exposure, which lasted 4½ hours.                              

  **Task:**           Critical tracking task                                        

  **Results**                                                                       

  There was no effect                                                               
  of carbon monoxide                                                                
  exposure on                                                                       
  tracking                                                                          
  performance.                                                                      

  **Implications**    Exposure to carbon monoxide at levels up to 100               
                      ppm (14.6% CoHB) did not result in decrements in              
                      tracking performance                                          
  ----------------------------------------------------------------------------------------

+----------+------------------------------------------------+----+----+
| **       | **Neurorimaging, cognitive, and                |    |    |
| Title:** | neurobehavioral outcomes following carbon      |    |    |
|          | monoxide poisoning**                           |    |    |
+==========+================================================+====+====+
| **Auth   | Hopkins, R.O. and Moon. F.L.M.                 |    |    |
| or(s):** |                                                |    |    |
+----------+------------------------------------------------+----+----+
| **Jo     | *Behavioral and Cognitive Neuroscience         | *  | 20 |
| urnal:** | Reviews*, 5, 141-155                           | *Y | 06 |
|          |                                                | ea |    |
|          |                                                | r: |    |
|          |                                                | ** |    |
+----------+------------------------------------------------+----+----+
| **Pu     | To report on neurological and cognitive        |    |    |
| rpose**: | impairments resulting from carbon monoxide     |    |    |
|          | poisoning                                      |    |    |
+----------+------------------------------------------------+----+----+
| *        | The focus of this review was on the effects of |    |    |
| *Results | carbon monoxide-poisoning. The literature      |    |    |
| and      | shows that carbon monoxide-poisoning leads to  |    |    |
| Implic   | impairments in memory, executive function,     |    |    |
| ations** | mental processing speed, intellectual          |    |    |
|          | function, and attention, but the onset and     |    |    |
|          | severity of the impairments vary from          |    |    |
|          | individual to individual. Thus, a consistent   |    |    |
|          | pattern of cognitive deficits due to carbon    |    |    |
|          | monoxide-poisoning has not been found.         |    |    |
|          |                                                |    |    |
|          | There is no consistent criterion for           |    |    |
|          | characterizing less severe carbon monoxide     |    |    |
|          | poisoning, e.g., carbon monoxide exposure.     |    |    |
|          | COHb levels range from 1% to 15%, with few     |    |    |
|          | studies assessing the cognitive effects.       |    |    |
+----------+------------------------------------------------+----+----+

  ----------------------------------------------------------------------------------------
  **Title:**          **Carbon monoxide and human vigilance**                       
  ------------------- ------------------------------------------------- ----------- ------
  **Author(s):**      Horvath, S.M., Dahms, T.E., and O'Hanlon, J.F.                

  **Journal:**        *Archives of Environmental Health*, 23, 343-347   **Year:**   1971

  **Purpose**:        To determine whether the levels of carbon                     
                      monoxide found in the urban atmosphere affect                 
                      visual vigilance                                              

  **Participants:**   10 healthy males between 21 and 34 years old                  

  **Exposure:**       The experiment consisted of three test sessions,              
                      one week apart. Participants inhaled a different              
                      gas mixture in each session, containing 0, 26, or             
                      111 ppm carbon monoxide. During exposure,                     
                      participants breathed the gas mixture for one                 
                      hour before performing a monitoring task.                     
                      Participants were also exposed to the gas while               
                      performing the task. COHb levels approached 0.8%              
                      in the control condition, 2.3% with 26 ppm                    
                      exposure, and 6.6% in the 111 ppm condition.                  

  **Task:**           Participants were asked to perform a monitoring               
                      task that required them to judge and discriminate             
                      between visual light signals and nonsignals. In               
                      the first part, participants were shown 10                    
                      signals interspersed among 50 nonsignals. In the              
                      second part, they were shown 10 signals within                
                      290 nonsignals for four 15-minute periods.                    

  **Results**                                                                       

  There was no effect                                                               
  of carbon monoxide                                                                
  exposure in                                                                       
  monitoring task                                                                   
  performance at when                                                               
  the exposure level                                                                
  was 26 ppm relative                                                               
  to the control                                                                    
  condition (0 ppm).                                                                
  Carbon monoxide                                                                   
  exposure at 111 ppm                                                               
  (COHb levels of                                                                   
  6.6%) increased the                                                               
  effects of monotony                                                               
  and led to accuracy                                                               
  decrements in                                                                     
  detecting signals                                                                 
  over the two-hour                                                                 
  period. Heart rates                                                               
  and respiratory                                                                   
  functioning was not                                                               
  affected.                                                                         

  **Implications**    Carbon monoxide exposure combined with monotony               
                      during driving could lead to less efficient                   
                      performance of routine tasks and inability to                 
                      cope with unexpected events.                                  
  ----------------------------------------------------------------------------------------

+----------+------------------------------------------------+----+----+
| **       | **Carbon monoxide: A danger to the driver?**   |    |    |
| Title:** |                                                |    |    |
+==========+================================================+====+====+
| **Auth   | Mayron, L.W. and Winterhalter, J.J.            |    |    |
| or(s):** |                                                |    |    |
+----------+------------------------------------------------+----+----+
| **Jo     | *Journal of the Air Pollution Control          | *  | 19 |
| urnal:** | Association*, 26(11), 1085-1088                | *Y | 76 |
|          |                                                | ea |    |
|          |                                                | r: |    |
|          |                                                | ** |    |
+----------+------------------------------------------------+----+----+
| **Pu     | To determine carbon monoxide levels at         |    |    |
| rpose**: | intersections, busy streets and expressways,   |    |    |
|          | and in cars                                    |    |    |
+----------+------------------------------------------------+----+----+
| **M      | Measured carbon monoxide levels in the inside  |    |    |
| ethod:** | of an idling car from the driver's seat, in    |    |    |
|          | ventilating air entering the car, and in the   |    |    |
|          | ambient air at busy traffic locations and      |    |    |
|          | intersections                                  |    |    |
+----------+------------------------------------------------+----+----+
| **R      |                                                |    |    |
| esults** |                                                |    |    |
+----------+------------------------------------------------+----+----+
| Meas     |                                                |    |    |
| urements |                                                |    |    |
| of       |                                                |    |    |
| carbon   |                                                |    |    |
| m        |                                                |    |    |
| onoxide, |                                                |    |    |
| c        |                                                |    |    |
| ollected |                                                |    |    |
| in       |                                                |    |    |
| Southern |                                                |    |    |
| Ca       |                                                |    |    |
| lifornia |                                                |    |    |
| under    |                                                |    |    |
| standard |                                                |    |    |
| driving  |                                                |    |    |
| co       |                                                |    |    |
| nditions |                                                |    |    |
| g        |                                                |    |    |
| enerally |                                                |    |    |
| show     |                                                |    |    |
| levels   |                                                |    |    |
| less     |                                                |    |    |
| than     |                                                |    |    |
| 25ppm    |                                                |    |    |
| carbon   |                                                |    |    |
| m        |                                                |    |    |
| onoxide. |                                                |    |    |
| The      |                                                |    |    |
| highest  |                                                |    |    |
| conce    |                                                |    |    |
| ntration |                                                |    |    |
| of       |                                                |    |    |
| carbon   |                                                |    |    |
| monoxide |                                                |    |    |
| measured |                                                |    |    |
| was      |                                                |    |    |
| 45ppm    |                                                |    |    |
| for a    |                                                |    |    |
| 3-minute |                                                |    |    |
| period.  |                                                |    |    |
| High     |                                                |    |    |
| concen   |                                                |    |    |
| trations |                                                |    |    |
| (3-5%)   |                                                |    |    |
| of       |                                                |    |    |
| c        |                                                |    |    |
| arboxyhe |                                                |    |    |
| moglobin |                                                |    |    |
| (r       |                                                |    |    |
| esulting |                                                |    |    |
| from     |                                                |    |    |
| exposure |                                                |    |    |
| to 18-32 |                                                |    |    |
| ppm      |                                                |    |    |
| carbon   |                                                |    |    |
| m        |                                                |    |    |
| onoxide) |                                                |    |    |
| may have |                                                |    |    |
| adverse  |                                                |    |    |
| effects  |                                                |    |    |
| on the   |                                                |    |    |
| d        |                                                |    |    |
| etection |                                                |    |    |
| of small |                                                |    |    |
| envir    |                                                |    |    |
| onmental |                                                |    |    |
| changes. |                                                |    |    |
| However, |                                                |    |    |
| the      |                                                |    |    |
| impact   |                                                |    |    |
| on       |                                                |    |    |
| driving  |                                                |    |    |
| per      |                                                |    |    |
| formance |                                                |    |    |
| is not   |                                                |    |    |
| clear.   |                                                |    |    |
|          |                                                |    |    |
| The      |                                                |    |    |
| effect   |                                                |    |    |
| of       |                                                |    |    |
| carbon   |                                                |    |    |
| monoxide |                                                |    |    |
| levels   |                                                |    |    |
| found in |                                                |    |    |
| cars is  |                                                |    |    |
| d        |                                                |    |    |
| ependent |                                                |    |    |
| on how   |                                                |    |    |
| much     |                                                |    |    |
| time the |                                                |    |    |
| driver   |                                                |    |    |
| spends   |                                                |    |    |
| in       |                                                |    |    |
| his/her  |                                                |    |    |
| car at   |                                                |    |    |
| one time |                                                |    |    |
| and      |                                                |    |    |
| cumul    |                                                |    |    |
| atively. |                                                |    |    |
| Carbon   |                                                |    |    |
| monoxide |                                                |    |    |
| levels   |                                                |    |    |
| were     |                                                |    |    |
| measured |                                                |    |    |
| in 51    |                                                |    |    |
| cars;    |                                                |    |    |
| two were |                                                |    |    |
| e        |                                                |    |    |
| xtremely |                                                |    |    |
| high     |                                                |    |    |
| (70ppm   |                                                |    |    |
| and over |                                                |    |    |
| 100ppm), |                                                |    |    |
| and 9    |                                                |    |    |
| had      |                                                |    |    |
| levels   |                                                |    |    |
| higher   |                                                |    |    |
| than the |                                                |    |    |
| 8-hour   |                                                |    |    |
| standard |                                                |    |    |
| of 9ppm. |                                                |    |    |
| This     |                                                |    |    |
| ambient  |                                                |    |    |
| air      |                                                |    |    |
| standard |                                                |    |    |
| may be   |                                                |    |    |
| exceeded |                                                |    |    |
| re       |                                                |    |    |
| gularly, |                                                |    |    |
| d        |                                                |    |    |
| epending |                                                |    |    |
| upon     |                                                |    |    |
| wind     |                                                |    |    |
| di       |                                                |    |    |
| rection, |                                                |    |    |
| wind     |                                                |    |    |
| s        |                                                |    |    |
| trength, |                                                |    |    |
| and      |                                                |    |    |
| traffic  |                                                |    |    |
| density. |                                                |    |    |
| Readings |                                                |    |    |
| of       |                                                |    |    |
| carbon   |                                                |    |    |
| monoxide |                                                |    |    |
| levels   |                                                |    |    |
| in       |                                                |    |    |
| ven      |                                                |    |    |
| tilating |                                                |    |    |
| air      |                                                |    |    |
| ranged   |                                                |    |    |
| from 2   |                                                |    |    |
| to 36    |                                                |    |    |
| ppm. In  |                                                |    |    |
| traffic, |                                                |    |    |
| the      |                                                |    |    |
| carbon   |                                                |    |    |
| monoxide |                                                |    |    |
| level    |                                                |    |    |
| varied   |                                                |    |    |
| from     |                                                |    |    |
| 25ppm to |                                                |    |    |
| a high   |                                                |    |    |
| enough   |                                                |    |    |
| level to |                                                |    |    |
| produce  |                                                |    |    |
| nausea   |                                                |    |    |
| and      |                                                |    |    |
| d        |                                                |    |    |
| izziness |                                                |    |    |
| when     |                                                |    |    |
| traffic  |                                                |    |    |
| was      |                                                |    |    |
| stop     |                                                |    |    |
| -and-go. |                                                |    |    |
| At busy  |                                                |    |    |
| inters   |                                                |    |    |
| ections, |                                                |    |    |
| the      |                                                |    |    |
| values   |                                                |    |    |
| of       |                                                |    |    |
| carbon   |                                                |    |    |
| monoxide |                                                |    |    |
| ranged   |                                                |    |    |
| from     |                                                |    |    |
| 3-60     |                                                |    |    |
| ppm.     |                                                |    |    |
|          |                                                |    |    |
| The main |                                                |    |    |
| p        |                                                |    |    |
| redictor |                                                |    |    |
| of       |                                                |    |    |
| carbon   |                                                |    |    |
| monoxide |                                                |    |    |
| levels   |                                                |    |    |
| is       |                                                |    |    |
| traffic  |                                                |    |    |
| delay.   |                                                |    |    |
| The      |                                                |    |    |
| actual   |                                                |    |    |
| amount   |                                                |    |    |
| of       |                                                |    |    |
| exposure |                                                |    |    |
| to the   |                                                |    |    |
| driver   |                                                |    |    |
| is       |                                                |    |    |
| unknown. |                                                |    |    |
+----------+------------------------------------------------+----+----+
| **Implic | It is not clear whether carbon monoxide        |    |    |
| ations** | exposure leads to car accidents, but           |    |    |
|          | measurements of carbon monoxide levels in cars |    |    |
|          | suggest that it may be a contributing factor.  |    |    |
+----------+------------------------------------------------+----+----+

+----------+------------------------------------------------+----+----+
| **       | **Low level exposure to carbon monoxide and    |    |    |
| Title:** | driving performance**                          |    |    |
+==========+================================================+====+====+
| **Auth   | McFarland, R.A.                                |    |    |
| or(s):** |                                                |    |    |
+----------+------------------------------------------------+----+----+
| **Jo     | *Archives of Environmental Health*, 27,        | *  | 19 |
| urnal:** | 355-359                                        | *Y | 73 |
|          |                                                | ea |    |
|          |                                                | r: |    |
|          |                                                | ** |    |
+----------+------------------------------------------------+----+----+
| **Pu     | Examine the effects of low levels of carbon    |    |    |
| rpose**: | monoxide on human performance and on driving   |    |    |
+----------+------------------------------------------------+----+----+
| *        | 27 participants ranging in age from 20-50      |    |    |
| *Partici | years old                                      |    |    |
| pants:** |                                                |    |    |
+----------+------------------------------------------------+----+----+
| **Exp    | 17% COHb, 11% COHb, and no carbon monoxide     |    |    |
| osure:** | exposure                                       |    |    |
|          |                                                |    |    |
|          | A blood sample and alveolar sample were        |    |    |
|          | collected at the start of the experiment to    |    |    |
|          | determine initial COHb levels. Participants    |    |    |
|          | were then given normal room air or a mixture   |    |    |
|          | of 700 ppm carbon monoxide using a 500-liter   |    |    |
|          | gasometer; participants exhaled into a second  |    |    |
|          | gasometer to measure the amount retained. Each |    |    |
|          | participant was exposed to carbon monoxide     |    |    |
|          | until one of the three levels was reached.     |    |    |
+----------+------------------------------------------------+----+----+
| *        | In the first phase of the study, participants  |    |    |
| *Task:** | completed laboratory tests measuring           |    |    |
|          | psychomotor reactions in dual-task             |    |    |
|          | performance, dark adaptation and glare         |    |    |
|          | recovery, peripheral vision, and depth         |    |    |
|          | perception. In the second phase, participants  |    |    |
|          | drove an automobile on an unopened, divided    |    |    |
|          | highway.                                       |    |    |
+----------+------------------------------------------------+----+----+
| **R      |                                                |    |    |
| esults** |                                                |    |    |
+----------+------------------------------------------------+----+----+
| The      |                                                |    |    |
| psy      |                                                |    |    |
| chomotor |                                                |    |    |
| task     |                                                |    |    |
| required |                                                |    |    |
| part     |                                                |    |    |
| icipants |                                                |    |    |
| to       |                                                |    |    |
| respond  |                                                |    |    |
| to       |                                                |    |    |
| co       |                                                |    |    |
| ncurrent |                                                |    |    |
| tasks    |                                                |    |    |
| a        |                                                |    |    |
| ppearing |                                                |    |    |
| in the   |                                                |    |    |
| central  |                                                |    |    |
| field of |                                                |    |    |
| vision   |                                                |    |    |
| and in   |                                                |    |    |
| the      |                                                |    |    |
| pe       |                                                |    |    |
| riphery. |                                                |    |    |
| Per      |                                                |    |    |
| formance |                                                |    |    |
| on the   |                                                |    |    |
| central  |                                                |    |    |
| task     |                                                |    |    |
| showed   |                                                |    |    |
| no       |                                                |    |    |
| effect   |                                                |    |    |
| of       |                                                |    |    |
| carbon   |                                                |    |    |
| monoxide |                                                |    |    |
| e        |                                                |    |    |
| xposure, |                                                |    |    |
| but      |                                                |    |    |
| per      |                                                |    |    |
| formance |                                                |    |    |
| on the   |                                                |    |    |
| pe       |                                                |    |    |
| ripheral |                                                |    |    |
| task     |                                                |    |    |
| showed   |                                                |    |    |
| evidence |                                                |    |    |
| of       |                                                |    |    |
| att      |                                                |    |    |
| entional |                                                |    |    |
| lapses;  |                                                |    |    |
| part     |                                                |    |    |
| icipants |                                                |    |    |
| failed   |                                                |    |    |
| to       |                                                |    |    |
| respond  |                                                |    |    |
| to the   |                                                |    |    |
| pe       |                                                |    |    |
| ripheral |                                                |    |    |
| task if  |                                                |    |    |
| it       |                                                |    |    |
| appeared |                                                |    |    |
| close in |                                                |    |    |
| time to  |                                                |    |    |
| the      |                                                |    |    |
| central  |                                                |    |    |
| task     |                                                |    |    |
| more     |                                                |    |    |
| fr       |                                                |    |    |
| equently |                                                |    |    |
| at COHb  |                                                |    |    |
| levels   |                                                |    |    |
| of 17%   |                                                |    |    |
| and less |                                                |    |    |
| so at    |                                                |    |    |
| 11%.     |                                                |    |    |
| There    |                                                |    |    |
| was no   |                                                |    |    |
| clear    |                                                |    |    |
| effect   |                                                |    |    |
| of       |                                                |    |    |
| carbon   |                                                |    |    |
| monoxide |                                                |    |    |
| exposure |                                                |    |    |
| on dark  |                                                |    |    |
| ad       |                                                |    |    |
| aptation |                                                |    |    |
| or glare |                                                |    |    |
| r        |                                                |    |    |
| ecovery. |                                                |    |    |
| The      |                                                |    |    |
| pe       |                                                |    |    |
| ripheral |                                                |    |    |
| vision   |                                                |    |    |
| task     |                                                |    |    |
| required |                                                |    |    |
| part     |                                                |    |    |
| icipants |                                                |    |    |
| to look  |                                                |    |    |
| directly |                                                |    |    |
| at a     |                                                |    |    |
| point    |                                                |    |    |
| while    |                                                |    |    |
| re       |                                                |    |    |
| sponding |                                                |    |    |
| to       |                                                |    |    |
| lights   |                                                |    |    |
| in       |                                                |    |    |
| d        |                                                |    |    |
| ifferent |                                                |    |    |
| patterns |                                                |    |    |
| p        |                                                |    |    |
| resented |                                                |    |    |
| at 10º,  |                                                |    |    |
| 20º, and |                                                |    |    |
| 30º from |                                                |    |    |
| the      |                                                |    |    |
| center   |                                                |    |    |
| field of |                                                |    |    |
| view.    |                                                |    |    |
| The      |                                                |    |    |
| results  |                                                |    |    |
| showed   |                                                |    |    |
| that     |                                                |    |    |
| part     |                                                |    |    |
| icipants |                                                |    |    |
| missed   |                                                |    |    |
| more     |                                                |    |    |
| lights   |                                                |    |    |
| that     |                                                |    |    |
| appeared |                                                |    |    |
| at a 20º |                                                |    |    |
| point    |                                                |    |    |
| from the |                                                |    |    |
| line of  |                                                |    |    |
| sight at |                                                |    |    |
| a 17%    |                                                |    |    |
| COHb     |                                                |    |    |
| level    |                                                |    |    |
| than     |                                                |    |    |
| under    |                                                |    |    |
| control  |                                                |    |    |
| con      |                                                |    |    |
| ditions. |                                                |    |    |
| There    |                                                |    |    |
| was no   |                                                |    |    |
| di       |                                                |    |    |
| fference |                                                |    |    |
| at other |                                                |    |    |
| levels   |                                                |    |    |
| or at    |                                                |    |    |
| other    |                                                |    |    |
| points.  |                                                |    |    |
| There    |                                                |    |    |
| was no   |                                                |    |    |
| di       |                                                |    |    |
| fference |                                                |    |    |
| in depth |                                                |    |    |
| pe       |                                                |    |    |
| rception |                                                |    |    |
| as a     |                                                |    |    |
| function |                                                |    |    |
| of COHb  |                                                |    |    |
| levels.  |                                                |    |    |
|          |                                                |    |    |
| Parti    |                                                |    |    |
| cipants' |                                                |    |    |
| visual   |                                                |    |    |
| inf      |                                                |    |    |
| ormation |                                                |    |    |
| pr       |                                                |    |    |
| ocessing |                                                |    |    |
| while    |                                                |    |    |
| driving  |                                                |    |    |
| was      |                                                |    |    |
| measured |                                                |    |    |
| using a  |                                                |    |    |
| visual   |                                                |    |    |
| inte     |                                                |    |    |
| rruption |                                                |    |    |
| a        |                                                |    |    |
| pparatus |                                                |    |    |
| that     |                                                |    |    |
| c        |                                                |    |    |
| onsisted |                                                |    |    |
| of a     |                                                |    |    |
| helmet   |                                                |    |    |
| with a   |                                                |    |    |
| tra      |                                                |    |    |
| nslucent |                                                |    |    |
| face     |                                                |    |    |
| shield   |                                                |    |    |
| which    |                                                |    |    |
| moved up |                                                |    |    |
| and      |                                                |    |    |
| down.    |                                                |    |    |
| While    |                                                |    |    |
| part     |                                                |    |    |
| icipants |                                                |    |    |
| g        |                                                |    |    |
| enerally |                                                |    |    |
| required |                                                |    |    |
| more     |                                                |    |    |
| visual   |                                                |    |    |
| inf      |                                                |    |    |
| ormation |                                                |    |    |
| at       |                                                |    |    |
| higher   |                                                |    |    |
| speeds   |                                                |    |    |
| (i.e.,   |                                                |    |    |
| 50 mph)  |                                                |    |    |
| than     |                                                |    |    |
| lower    |                                                |    |    |
| speeds   |                                                |    |    |
| (i.e.,   |                                                |    |    |
| 30 mph), |                                                |    |    |
| under    |                                                |    |    |
| co       |                                                |    |    |
| nditions |                                                |    |    |
| of       |                                                |    |    |
| carbon   |                                                |    |    |
| monoxide |                                                |    |    |
| e        |                                                |    |    |
| xposure, |                                                |    |    |
| part     |                                                |    |    |
| icipants |                                                |    |    |
| required |                                                |    |    |
| more     |                                                |    |    |
| roadway  |                                                |    |    |
| viewing  |                                                |    |    |
| at       |                                                |    |    |
| higher   |                                                |    |    |
| speeds   |                                                |    |    |
| than     |                                                |    |    |
| without  |                                                |    |    |
| carbon   |                                                |    |    |
| m        |                                                |    |    |
| onoxide. |                                                |    |    |
+----------+------------------------------------------------+----+----+
| **Implic | COHb levels of 11% and 17% have slight effects |    |    |
| ations** | on visual information processing, leading      |    |    |
|          | drivers to focus more attention on information |    |    |
|          | in the forward field of view and consequently, |    |    |
|          | miss information in peripheral vision.         |    |    |
+----------+------------------------------------------------+----+----+

+----------+------------------------------------------------+----+----+
| **       | **Carbon monoxide exposure and information     |    |    |
| Title:** | processing during perceptual-motor             |    |    |
|          | performance**                                  |    |    |
+==========+================================================+====+====+
| **Auth   | Mihevic, P.M., Gliner, J.A., and Horvath, S.M. |    |    |
| or(s):** |                                                |    |    |
+----------+------------------------------------------------+----+----+
| **Jo     | *International Archives of Occupational and    | *  | 19 |
| urnal:** | Environmental Health*, 51, 353-363             | *Y | 83 |
|          |                                                | ea |    |
|          |                                                | r: |    |
|          |                                                | ** |    |
+----------+------------------------------------------------+----+----+
| **Pu     | Examine the effects of carbon monoxide         |    |    |
| rpose**: | exposure on dual-task motor performance        |    |    |
+----------+------------------------------------------------+----+----+
| *        | 16 participants between 20 to 36 years old     |    |    |
| *Partici |                                                |    |    |
| pants:** |                                                |    |    |
+----------+------------------------------------------------+----+----+
| **Exp    | Participants were seated in an 1.85 m x 1.85 m |    |    |
| osure:** | x 2.46 m chamber with clear walls. Carbon      |    |    |
|          | monoxide was mixed into the air stream from a  |    |    |
|          | tank containing 10% carbon monoxide in         |    |    |
|          | nitrogen (approximately 100 ppm).              |    |    |
+----------+------------------------------------------------+----+----+
| *        | Participants were seated in the environmental  |    |    |
| *Task:** | chamber for 2 ½ hours. In the first 1½-hour,   |    |    |
|          | participants sat in the chamber. In the last   |    |    |
|          | hour, participants completed a reciprocal      |    |    |
|          | tapping task, the reciprocal tapping task in   |    |    |
|          | conjunction with a digit identification task,  |    |    |
|          | and the reciprocal tapping task in conjunction |    |    |
|          | with a digit subtraction task. In the          |    |    |
|          | reciprocal tapping task, participants tapped a |    |    |
|          | stylus alternatively between two metal targets |    |    |
|          | on a board. The task difficulty was            |    |    |
|          | manipulated by varying the width of the target |    |    |
|          | (0.35 or 0.75cm) and the distance between the  |    |    |
|          | targets (5.2, 10.2, 20.5, or 41.0 cm). In the  |    |    |
|          | digit identification task, participants were   |    |    |
|          | asked to verbally identify the digit (from 0   |    |    |
|          | -- 9) that appeared on a circular display,     |    |    |
|          | mounted on the board used for the tapping      |    |    |
|          | task, showed digits from 0 -- 9. In the digit  |    |    |
|          | subtraction task, participants subtracted the  |    |    |
|          | digit that appeared from 100.                  |    |    |
|          |                                                |    |    |
|          | Participants completed the tasks in room air   |    |    |
|          | and carbon monoxide conditions, the order of   |    |    |
|          | which was counterbalanced).                    |    |    |
+----------+------------------------------------------------+----+----+
| **R      |                                                |    |    |
| esults** |                                                |    |    |
+----------+------------------------------------------------+----+----+
| Per      |                                                |    |    |
| formance |                                                |    |    |
| on the   |                                                |    |    |
| primary  |                                                |    |    |
| tapping  |                                                |    |    |
| task did |                                                |    |    |
| not vary |                                                |    |    |
| as a     |                                                |    |    |
| function |                                                |    |    |
| of       |                                                |    |    |
| whether  |                                                |    |    |
| it was   |                                                |    |    |
| p        |                                                |    |    |
| erformed |                                                |    |    |
| alone or |                                                |    |    |
| in       |                                                |    |    |
| con      |                                                |    |    |
| junction |                                                |    |    |
| with the |                                                |    |    |
| s        |                                                |    |    |
| econdary |                                                |    |    |
| digit    |                                                |    |    |
| mani     |                                                |    |    |
| pulation |                                                |    |    |
| task     |                                                |    |    |
| (digit   |                                                |    |    |
| identi   |                                                |    |    |
| fication |                                                |    |    |
| or digit |                                                |    |    |
| subtr    |                                                |    |    |
| action). |                                                |    |    |
| However, |                                                |    |    |
| per      |                                                |    |    |
| formance |                                                |    |    |
| on the   |                                                |    |    |
| s        |                                                |    |    |
| econdary |                                                |    |    |
| digit    |                                                |    |    |
| mani     |                                                |    |    |
| pulation |                                                |    |    |
| task was |                                                |    |    |
| higher   |                                                |    |    |
| when it  |                                                |    |    |
| was      |                                                |    |    |
| p        |                                                |    |    |
| erformed |                                                |    |    |
| alone    |                                                |    |    |
| than     |                                                |    |    |
| p        |                                                |    |    |
| erformed |                                                |    |    |
| in       |                                                |    |    |
| con      |                                                |    |    |
| junction |                                                |    |    |
| with the |                                                |    |    |
| primary  |                                                |    |    |
| task.    |                                                |    |    |
| Carbon   |                                                |    |    |
| monoxide |                                                |    |    |
| exposure |                                                |    |    |
| served   |                                                |    |    |
| as a     |                                                |    |    |
| stressor |                                                |    |    |
| which    |                                                |    |    |
| led to   |                                                |    |    |
| per      |                                                |    |    |
| formance |                                                |    |    |
| de       |                                                |    |    |
| crements |                                                |    |    |
| on the   |                                                |    |    |
| digit    |                                                |    |    |
| mani     |                                                |    |    |
| pulation |                                                |    |    |
| task at  |                                                |    |    |
| moderate |                                                |    |    |
| levels   |                                                |    |    |
| of       |                                                |    |    |
| di       |                                                |    |    |
| fficulty |                                                |    |    |
| on the   |                                                |    |    |
| primary  |                                                |    |    |
| tapping  |                                                |    |    |
| task     |                                                |    |    |
| relative |                                                |    |    |
| to       |                                                |    |    |
| regular  |                                                |    |    |
| room air |                                                |    |    |
| e        |                                                |    |    |
| xposure. |                                                |    |    |
| There    |                                                |    |    |
| was no   |                                                |    |    |
| di       |                                                |    |    |
| fference |                                                |    |    |
| in       |                                                |    |    |
| primary  |                                                |    |    |
| task     |                                                |    |    |
| per      |                                                |    |    |
| formance |                                                |    |    |
| as a     |                                                |    |    |
| function |                                                |    |    |
| of       |                                                |    |    |
| carbon   |                                                |    |    |
| monoxide |                                                |    |    |
| exposure |                                                |    |    |
| during   |                                                |    |    |
| the      |                                                |    |    |
| digit    |                                                |    |    |
| identi   |                                                |    |    |
| fication |                                                |    |    |
| task.    |                                                |    |    |
+----------+------------------------------------------------+----+----+
| **Implic | Carbon monoxide exposure had minimal effects   |    |    |
| ations** | on motor performance. However, there is some   |    |    |
|          | evidence to suggest that as task difficulty    |    |    |
|          | increases -- hence increasing the attentional  |    |    |
|          | demands, carbon monoxide exposure may          |    |    |
|          | contribute to deficits if other tasks are      |    |    |
|          | performed concurrently.                        |    |    |
+----------+------------------------------------------------+----+----+

+----------+------------------------------------------------+----+----+
| **       | **The effect of carbon monoxide on human       |    |    |
| Title:** | performance**                                  |    |    |
+==========+================================================+====+====+
| **Auth   | Mikulka, P., O'Donnell, R., Heinig, P., and    |    |    |
| or(s):** | Theodore, J.                                   |    |    |
+----------+------------------------------------------------+----+----+
| **Jo     | *Annals of the New York Academy of Sciences*,  | *  | 19 |
| urnal:** | 174(1), 409--420                               | *Y | 70 |
|          |                                                | ea |    |
|          |                                                | r: |    |
|          |                                                | ** |    |
+----------+------------------------------------------------+----+----+
| **       | **Low level carbon monoxide exposure and human |    |    |
| Title:** | psychomotor performance**                      |    |    |
+----------+------------------------------------------------+----+----+
| **Auth   | O'Donnell, R.D., Mikulka, P., Heinig, P., and  |    |    |
| or(s):** | Theodore, J.                                   |    |    |
+----------+------------------------------------------------+----+----+
| **Jo     | *Toxicology and Applied Pharmacology*, 18,     | *  | 19 |
| urnal:** | 593-602                                        | *Y | 71 |
|          |                                                | ea |    |
|          |                                                | r: |    |
|          |                                                | ** |    |
+----------+------------------------------------------------+----+----+
| **Pu     | Determine the effects of carbon monoxide       |    |    |
| rpose**: | exposure on time estimation, tracking, and     |    |    |
|          | ataxia                                         |    |    |
+----------+------------------------------------------------+----+----+
| *        | 9 male students between 19 and 22 years old    |    |    |
| *Partici |                                                |    |    |
| pants:** |                                                |    |    |
+----------+------------------------------------------------+----+----+
| **Exp    | Experiments were conducted in the Thomas Domes |    |    |
| osure:** | at Wright-Patterson Air Force Base. The domes  |    |    |
|          | are enclosed environments, in which air flow   |    |    |
|          | at a rate of 40 ft^3^/min allows the           |    |    |
|          | atmosphere to change completely in a 20-minute |    |    |
|          | time period.                                   |    |    |
|          |                                                |    |    |
|          | There were five exposure levels -- 0, 50, 125, |    |    |
|          | 200, and 250 ppm carbon monoxide, resulting in |    |    |
|          | mean COHb levels of 0.96% at no exposure,      |    |    |
|          | 2.98% at 50 ppm, 6.64% at 125 ppm, 10.35% at   |    |    |
|          | 200 ppm, and 12.37% at 250 ppm.                |    |    |
+----------+------------------------------------------------+----+----+
| *        | Participants completed 3 3-hour sessions at    |    |    |
| *Task:** | carbon monoxide-levels of 0, 50, and 125 ppm.  |    |    |
|          | Participants were given a 15-minute rest       |    |    |
|          | period and then asked to complete a series of  |    |    |
|          | tracking and time estimation tasks. In the     |    |    |
|          | tracking task, participants manipulated a      |    |    |
|          | control stick to keep a needle on a display    |    |    |
|          | dial from going off scale. In the time         |    |    |
|          | estimation task, participants estimated 10     |    |    |
|          | second time-intervals for a 3-minute time      |    |    |
|          | period by tapping on an electric switch.       |    |    |
|          |                                                |    |    |
|          | At the end of the exposure period, blood       |    |    |
|          | samples were collected, and participants       |    |    |
|          | completed the Pensacola Ataxia battery, which  |    |    |
|          | comprises of a set of balancing tasks.         |    |    |
+----------+------------------------------------------------+----+----+
| **R      |                                                |    |    |
| esults** |                                                |    |    |
+----------+------------------------------------------------+----+----+
| The      |                                                |    |    |
| results  |                                                |    |    |
| showed   |                                                |    |    |
| no       |                                                |    |    |
| effect   |                                                |    |    |
| of       |                                                |    |    |
| carbon   |                                                |    |    |
| monoxide |                                                |    |    |
| exposure |                                                |    |    |
| on       |                                                |    |    |
| tracking |                                                |    |    |
| per      |                                                |    |    |
| formance |                                                |    |    |
| or time  |                                                |    |    |
| es       |                                                |    |    |
| timation |                                                |    |    |
| ability; |                                                |    |    |
| rather   |                                                |    |    |
| per      |                                                |    |    |
| formance |                                                |    |    |
| on the   |                                                |    |    |
| tasks    |                                                |    |    |
| improved |                                                |    |    |
| over     |                                                |    |    |
| time.    |                                                |    |    |
| Addit    |                                                |    |    |
| ionally, |                                                |    |    |
| carbon   |                                                |    |    |
| monoxide |                                                |    |    |
| exposure |                                                |    |    |
| did not  |                                                |    |    |
| affect   |                                                |    |    |
| parti    |                                                |    |    |
| cipants' |                                                |    |    |
| balance. |                                                |    |    |
+----------+------------------------------------------------+----+----+
| **Implic | Low levels of carbon monoxide exposure do not  |    |    |
| ations** | lead to a performance decrement                |    |    |
+----------+------------------------------------------------+----+----+

  ------------------- ------------------------------------------------- ----------- ------
  **Title:**          **Effect of carbon monoxide exposure on human                 
                      sleep and psychomotor performance**                           

  **Author(s):**      O'Donnell, R.D., Chikos, P., and Theodore, J.                 

  **Journal:**        *Journal of Applied Physiology*, 31(4), 513-518   **Year:**   1971

  **Purpose**:        To analyze the effects of carbon monoxide                     
                      exposure on sleep patterns and subsequent                     
                      performance                                                   

  **Participants:**   4 non-smoking, male Air Force personnel with                  
                      altitude training                                             

  **Exposure:**       Exposure was conducted in the Thomas Domes at                 
                      Wright-Patterson Air Force Base. Participants                 
                      slept for nine nights in the Thomas dome. The                 
                      first four nights were used to adapt the                      
                      participant to the dome. Over the next five                   
                      nights, participants were presented with two                  
                      exposures, either to 75 of 150 ppm carbon                     
                      monoxide. Each "exposure" night was followed by               
                      one night of "clean air", and the final night                 
                      served as a control condition where no carbon                 
                      monoxide was given. Carboxyhemoglobin levels                  
                      reflected a relationship with the level of carbon             
                      monoxide exposure; 0.6% in the control condition,             
                      5.9% in the 75-ppm condition, and 12.7% at 150                
                      ppm.                                                          

  **Task:**           Electrophysiological measures were collected each             
                      night. In the mornings, participants performed a              
                      series of performance tasks to measure visual                 
                      function (e.g., critical flicker fusion), mental              
                      arithmetic, tracking performance, and time                    
                      estimation.                                                   

  **Results**                                                                       

  There was no effect                                                               
  on sleep. In fact,                                                                
  participants                                                                      
  experience more                                                                   
  periods of "deep                                                                  
  sleep" and less                                                                   
  light sleep under                                                                 
  carbon monoxide                                                                   
  exposure than in                                                                  
  the control                                                                       
  condition.                                                                        
  Performance                                                                       
  measurements also                                                                 
  showed no effect of                                                               
  carbon monoxide                                                                   
  exposure.                                                                         

  **Implications**    Carbon monoxide did affect sleep, increasing the              
                      amount of deep sleep, but these changes did not               
                      affect subsequent cognitive functioning.                      
  ------------------- ------------------------------------------------- ----------- ------

  ----------------------------------------------------------------------------------------
  **Title:**          **Memory disturbances following chronic,                      
                      low-level carbon monoxide exposure**                          
  ------------------- ------------------------------------------------- ----------- ------
  **Author(s):**      Ryan, C.M.                                                    

  **Journal:**        *Archives of Clinical Neuropscyhology*, 5, 59-67  **Year:**   1990

  **Purpose**:        Demonstrate transient decrements in cognitive                 
                      function may occur with carbon monoxide exposure              

  **Participants:**   48-year old right-handed married female with a                
                      3-year history of headaches, lethargy, and memory             
                      problems                                                      

  **Exposure:**       Approximately 180 ppm carbon monoxide, possibly               
                      due to exposure from her furnace                              

  **Task:**           Pittsburgh Occupational Exposures Test Battery,               
                      which consisted of a set of cognitive tests                   
                      including incidental memory (requiring recall of              
                      digit-symbol pairs), recognition of recurring                 
                      words, verbal learning (requiring learning pairs              
                      of unrelated words), word association, symbol                 
                      digit learning, short- and long-term memory (copy             
                      a design and recall it 30 minutes later)                      

  **Results**                                                                       

  Prior to exposure,                                                                
  the subject held a                                                                
  job that required                                                                 
  heavy concentration                                                               
  and memory skills,                                                                
  but following                                                                     
  exposure, the                                                                     
  subject was not                                                                   
  able to track                                                                     
  verbal information                                                                
  and visual                                                                        
  information                                                                       
  presented within 30                                                               
  minutes. While it                                                                 
  cannot be ruled out                                                               
  that the subject is                                                               
  suffering from a                                                                  
  medical disease                                                                   
  that disrupts                                                                     
  memory, it is more                                                                
  likely that this                                                                  
  memory deficit is                                                                 
  due to a three-year                                                               
  low-level carbon                                                                  
  monoxide exposure.                                                                

  **Implications**    Long duration exposure to low-levels of carbon                
                      monoxide could lead to decrements in                          
                      concentration and memory.                                     
  ----------------------------------------------------------------------------------------

  ----------------------------------------------------------------------------------------
  **Title:**          **Experimental human exposure to high                         
                      concentrations of carbon monoxide**                           
  ------------------- ------------------------------------------------- ----------- ------
  **Author(s):**      Stewart, R.D., Fisher, T.N., Baretta, E.D., and               
                      Herrmann, A.A.                                                

  **Journal:**        *Archives of Environmental Health*, 26, 1-7       **Year:**   1973

  **Participants:**   6 healthy male volunteers                                     

  **Exposure:**       13 carbon monoxide exposure levels ranging from               
                      1,000 ppm for 10 min to 30,400 ppm for 1 min.                 
                      COHb levels ranged from 3.2% to 15.2%.                        

  **Task:**           A physical examination was performed to collect               
                      baseline information including cardiovascular                 
                      data (ECG) at rest and after 3-minutes of                     
                      exercise on a stationary bicycle and blood                    
                      samples. During exposure, participants sat in a               
                      slightly reclined position, and their heart rate,             
                      respiratory rate, brain activity (EEG), and                   
                      visual evoked response (VER) were monitored.                  
                      Following exposure, participants were given 100%              
                      oxygen for 20 minutes. A physical examination was             
                      performed again 16 hours after exposure and one               
                      week following exposure.                                      

  **Results**                                                                       

  Two participants                                                                  
  reported headaches                                                                
  following high                                                                    
  levels of exposure                                                                
  (15,000 ppm for 2                                                                 
  min and 30,000 ppm                                                                
  for 1 min resulting                                                               
  in COHb levels of                                                                 
  11.6% and 9.1%) and                                                               
  one noted a                                                                       
  pounding sensation                                                                
  (35,600 ppm for 45                                                                
  seconds). There was                                                               
  no change in                                                                      
  participants'                                                                     
  cardiovascular                                                                    
  function (ECGs),                                                                  
  blood pressure,                                                                   
  heart rate, or                                                                    
  brain activity                                                                    
  (EEG) following                                                                   
  exposure.                                                                         

  **Implications**    Carbon monoxide was rapidly absorbed during                   
                      exposure, and this abrupt increase (as measured               
                      by the COHb concentration) led to headaches in                
                      three participants. There was no change in                    
                      cardiovascular, respiratory, or brain activity.               
  ----------------------------------------------------------------------------------------

  ----------------------------------------------------------------------------------------
  **Title:**          **Experimental human exposure to carbon                       
                      monoxide**                                                    
  ------------------- ------------------------------------------------- ----------- ------
  **Author(s):**      Stewart, R.D., Peterson, J.E., Baretta, E.D.,                 
                      Bachand, R.T., Hosco, M.J., and Herrmann, A.A.                

  **Journal:**        *Archives of Environmental Health*, 21, 154-164   **Year:**   1970

  **Participants:**   18 healthy males ranging from 24 -- 42 years old              

  **Exposure:**       \< 1, 25, 50, 100, 200, 500, and 1,000 ppm for 30             
                      minutes to 24 hours                                           

  **Task:**           Blood samples were collected, and participants                
                      completed tasks to measure time estimation,                   
                      reaction time, hand steadiness, manual dexterity,             
                      brain activity, visual activity, and                          
                      cardiovascular activity.                                      

  **Results**                                                                       

  The data showed no                                                                
  subjective symptoms                                                               
  or objective                                                                      
  evidence of                                                                       
  decrements in task                                                                
  performance during                                                                
  exposure levels                                                                   
  less than 100 ppm                                                                 
  of carbon monoxide                                                                
  over an 8-hour                                                                    
  period (a COHb                                                                    
  saturation of 11%                                                                 
  to 13%). Carbon                                                                   
  monoxide exposure                                                                 
  at a level of 200                                                                 
  ppm for four hours                                                                
  (leading to a COHb                                                                
  level of 15% to                                                                   
  20%) led to reports                                                               
  of headaches in the                                                               
  final hour, but                                                                   
  there was no change                                                               
  in task                                                                           
  performance.                                                                      
  Exposure to higher                                                                
  carbon                                                                            
  monoxide-levels                                                                   
  (500 and 1,000 ppm,                                                               
  COHb saturation                                                                   
  close to 30%) also                                                                
  led to subjective                                                                 
  reports of                                                                        
  headaches, the                                                                    
  onset of which                                                                    
  typically occurred                                                                
  within 1-2 hours of                                                               
  exposure, with                                                                    
  minimal levels of                                                                 
  exertion increasing                                                               
  the pain. At these                                                                
  higher levels of                                                                  
  carbon monoxide                                                                   
  exposure, changes                                                                 
  in participants'                                                                  
  visual evoked                                                                     
  response (VER) and                                                                
  poorer manual                                                                     
  dexterity were                                                                    
  noted.                                                                            

  **Implications**    Poorer dexterity at high levels of carbon                     
                      monoxide exposure (i.e., 1,000 ppm) could                     
                      potentially lead to mechanical driving errors                 
                      (e.g., shifting gears).                                       
  ----------------------------------------------------------------------------------------

+----------+------------------------------------------------+----+----+
| **       | **Carbon monoxide and driving skills**         |    |    |
| Title:** |                                                |    |    |
+==========+================================================+====+====+
| **Auth   | Wright, G., Randell, P., and Shephard, R.J.    |    |    |
| or(s):** |                                                |    |    |
+----------+------------------------------------------------+----+----+
| **Jo     | *Archives of Environmental Health*, 27,        | *  | 19 |
| urnal:** | 349-354                                        | *Y | 73 |
|          |                                                | ea |    |
|          |                                                | r: |    |
|          |                                                | ** |    |
+----------+------------------------------------------------+----+----+
| **Pu     | To examine the effect of carbon monoxide       |    |    |
| rpose**: | exposure on tasks of driving skill             |    |    |
+----------+------------------------------------------------+----+----+
| *        | 50 adult volunteers                            |    |    |
| *Partici |                                                |    |    |
| pants:** |                                                |    |    |
+----------+------------------------------------------------+----+----+
| **Exp    | Half the participants breathed in 80 ml of     |    |    |
| osure:** | carbon monoxide, added to a rebreathing system |    |    |
|          | at a 2% concentration level, and the other     |    |    |
|          | half received no exposure (control group)      |    |    |
+----------+------------------------------------------------+----+----+
| *        | Before exposure, the level of                  |    |    |
| *Task:** | carboxyhemoglobin in the blood was measured    |    |    |
|          | using a rebreathing method. Participants then  |    |    |
|          | completed a set of driving tests evaluating    |    |    |
|          | brake reaction time, night vision, glare       |    |    |
|          | vision, glare vision recovery, hand            |    |    |
|          | steadiness, and depth perception followed by a |    |    |
|          | period on the driving simulator.               |    |    |
|          |                                                |    |    |
|          | Participants were then randomly distributed    |    |    |
|          | into two groups, with some receiving carbon    |    |    |
|          | monoxide (experimental condition) and some     |    |    |
|          | clean air (control condition). Participants    |    |    |
|          | then repeated the driving tests and simulation |    |    |
|          | task.                                          |    |    |
+----------+------------------------------------------------+----+----+
| **R      |                                                |    |    |
| esults** |                                                |    |    |
+----------+------------------------------------------------+----+----+
| Carbon   |                                                |    |    |
| monoxide |                                                |    |    |
| exposure |                                                |    |    |
| i        |                                                |    |    |
| ncreased |                                                |    |    |
| COHb     |                                                |    |    |
| levels   |                                                |    |    |
| by 3.4%  |                                                |    |    |
| relative |                                                |    |    |
| to       |                                                |    |    |
| initial  |                                                |    |    |
| values.  |                                                |    |    |
| This     |                                                |    |    |
| di       |                                                |    |    |
| fference |                                                |    |    |
| led to   |                                                |    |    |
| sig      |                                                |    |    |
| nificant |                                                |    |    |
| per      |                                                |    |    |
| formance |                                                |    |    |
| de       |                                                |    |    |
| crements |                                                |    |    |
| in the   |                                                |    |    |
| driving  |                                                |    |    |
| s        |                                                |    |    |
| imulator |                                                |    |    |
| for      |                                                |    |    |
| part     |                                                |    |    |
| icipants |                                                |    |    |
| in the   |                                                |    |    |
| expe     |                                                |    |    |
| rimental |                                                |    |    |
| c        |                                                |    |    |
| ondition |                                                |    |    |
| post-e   |                                                |    |    |
| xposure. |                                                |    |    |
| When     |                                                |    |    |
| c        |                                                |    |    |
| omparing |                                                |    |    |
| per      |                                                |    |    |
| formance |                                                |    |    |
| pre-and  |                                                |    |    |
| post-e   |                                                |    |    |
| xposure, |                                                |    |    |
| the      |                                                |    |    |
| control  |                                                |    |    |
| group    |                                                |    |    |
| (no      |                                                |    |    |
| e        |                                                |    |    |
| xposure) |                                                |    |    |
| e        |                                                |    |    |
| xhibited |                                                |    |    |
| more     |                                                |    |    |
| careful  |                                                |    |    |
| driving  |                                                |    |    |
| habits   |                                                |    |    |
| (e.g.,   |                                                |    |    |
| r        |                                                |    |    |
| eleasing |                                                |    |    |
| the      |                                                |    |    |
| parking  |                                                |    |    |
| break,   |                                                |    |    |
| using    |                                                |    |    |
| the turn |                                                |    |    |
| s        |                                                |    |    |
| ignals). |                                                |    |    |
| The      |                                                |    |    |
| exposure |                                                |    |    |
| group,   |                                                |    |    |
| however, |                                                |    |    |
| showed   |                                                |    |    |
| less     |                                                |    |    |
| impr     |                                                |    |    |
| ovements |                                                |    |    |
| with     |                                                |    |    |
| respect  |                                                |    |    |
| to their |                                                |    |    |
| previous |                                                |    |    |
| per      |                                                |    |    |
| formance |                                                |    |    |
| and when |                                                |    |    |
| compared |                                                |    |    |
| to the   |                                                |    |    |
| per      |                                                |    |    |
| formance |                                                |    |    |
| of the   |                                                |    |    |
| control  |                                                |    |    |
| group.   |                                                |    |    |
| These    |                                                |    |    |
| per      |                                                |    |    |
| formance |                                                |    |    |
| de       |                                                |    |    |
| crements |                                                |    |    |
| are      |                                                |    |    |
| at       |                                                |    |    |
| tributed |                                                |    |    |
| to       |                                                |    |    |
| impaired |                                                |    |    |
| judgment |                                                |    |    |
| due to a |                                                |    |    |
| lack of  |                                                |    |    |
| cerebral |                                                |    |    |
| oxygen.  |                                                |    |    |
| There    |                                                |    |    |
| was no   |                                                |    |    |
| effect   |                                                |    |    |
| on       |                                                |    |    |
| per      |                                                |    |    |
| formance |                                                |    |    |
| on the   |                                                |    |    |
| driving  |                                                |    |    |
| tests    |                                                |    |    |
| due to   |                                                |    |    |
| carbon   |                                                |    |    |
| monoxide |                                                |    |    |
| e        |                                                |    |    |
| xposure. |                                                |    |    |
+----------+------------------------------------------------+----+----+
| **Implic | A 3.4% increase in carboxyhemoglobin levels    |    |    |
| ations** | may be expected through carbon monoxide        |    |    |
|          | exposure to 100 ppm for two hours or 50 ppm    |    |    |
|          | for five hours. Truck drivers, regularly       |    |    |
|          | exposed to exhaust fumes, may experience these |    |    |
|          | high carbon monoxide concentrations, which may |    |    |
|          | impair safe driving habits.                    |    |    |
+----------+------------------------------------------------+----+----+

##  Cognitive Effects of Exposure to Jet Fuel Vapors {#cognitive-effects-of-exposure-to-jet-fuel-vapors .Appendix-Heading-2}

  ----------------------------------------------------------------------------------------
  **Title:**          **Jet Fuel Intoxication**                                     
  ------------------- ------------------------------------------------- ----------- ------
  **Author(s):**      Davies, N.E.                                                  

  **Journal:**        *Aerospace Medicine*, May, 481-482                **Year:**   1964

  **Purpose**:        To report a case of in-flight intoxication due to             
                      jet fuel                                                      

  **Participants:**   32-year old male Air Force pilot                              

  **Exposure:**       Pilot flying a T-33A (two seated jet trainer) was             
                      exposed to what was estimated to be 3000 to 7000              
                      ppm JP-4 fuel vapors for approximately 7 minutes              

  **Task:**           Flight from Craig Air Force Base, Alabama, to                 
                      Dover Air Force Base, Delaware, with an emergency             
                      landing at Dobbins Air Force Base, Georgia                    

  **Results**                                                                       

  At 15,000 feet,                                                                   
  pilot began to feel                                                               
  groggy and switched                                                               
  regulator to 100%                                                                 
  oxygen. At 20,000                                                                 
  feet, he felt weak                                                                
  and decided to land                                                               
  as quickly as                                                                     
  possible. Symptoms                                                                
  showed a slight                                                                   
  stagger in his                                                                    
  gait, mild                                                                        
  headache, slurred                                                                 
  speech, and mild                                                                  
  muscle weakness.                                                                  

  **Implications**    There are large individual differences with                   
                      respect to hydrocarbon intoxication. Mild                     
                      symptoms include giddiness, slurred speech, poor              
                      coordination, nausea, and mild euphoria. These                
                      may be followed by a headache, mild depression,               
                      throat irritation, or staggering. Severe cases                
                      lead to dyspnea, cyanosis, and coma.                          
  ----------------------------------------------------------------------------------------

+----------+------------------------------------------------+----+----+
| **       | **Long-term exposure to jet fuel**             |    |    |
| Title:** |                                                |    |    |
|          | **An investigation on occupationally exposed   |    |    |
|          | workers with special reference to the nervous  |    |    |
|          | system.**                                      |    |    |
+==========+================================================+====+====+
| **Auth   | Knave, B., Persson, H.E., Goldberg, J.M., and  |    |    |
| or(s):** | Westerholm, P.                                 |    |    |
+----------+------------------------------------------------+----+----+
| **Jo     | *Scandinavian Journal of Work Environment and  | *  | 19 |
| urnal:** | Health*, 3, 152-164                            | *Y | 76 |
|          |                                                | ea |    |
|          |                                                | r: |    |
|          |                                                | ** |    |
+----------+------------------------------------------------+----+----+
| **Pu     | To examine the effects of long-term exposure   |    |    |
| rpose**: | to jet fuel on the nervous system              |    |    |
+----------+------------------------------------------------+----+----+
| *        | 29 aircraft factory workers, of which 13 were  |    |    |
| *Partici | considered "heavily exposed" and 16 were       |    |    |
| pants:** | considered "less heavily exposed"              |    |    |
+----------+------------------------------------------------+----+----+
| **Exp    | All had been exposed for at least 5 years of   |    |    |
| osure:** | employment. The \"heavily exposed" group       |    |    |
|          | experienced continuous exposure to high        |    |    |
|          | concentrations of jet fuel fumes for several   |    |    |
|          | hours every day, for at least 20-30 minutes    |    |    |
|          | each time. The "less heavily exposed" group    |    |    |
|          | reported a more intermittent pattern of        |    |    |
|          | exposure than the heavily exposed group, with  |    |    |
|          | several days of heavy exposure followed by     |    |    |
|          | weeks or months without exposure.              |    |    |
+----------+------------------------------------------------+----+----+
| *        | Participants provided a personal history       |    |    |
| *Task:** | (heredity, previous health, occupational       |    |    |
|          | history, smoking, symptoms, etc.) and          |    |    |
|          | completed a neurological examination.          |    |    |
+----------+------------------------------------------------+----+----+
| **R      |                                                |    |    |
| esults** |                                                |    |    |
+----------+------------------------------------------------+----+----+
| All      |                                                |    |    |
| part     |                                                |    |    |
| icipants |                                                |    |    |
| in the   |                                                |    |    |
| heavily  |                                                |    |    |
| exposed  |                                                |    |    |
| group    |                                                |    |    |
| reported |                                                |    |    |
| symptoms |                                                |    |    |
| of       |                                                |    |    |
| exposure |                                                |    |    |
| co       |                                                |    |    |
| nsisting |                                                |    |    |
| of       |                                                |    |    |
| d        |                                                |    |    |
| izziness |                                                |    |    |
| (77%),   |                                                |    |    |
| headache |                                                |    |    |
| (23%),   |                                                |    |    |
| nausea   |                                                |    |    |
| (31%),   |                                                |    |    |
| res      |                                                |    |    |
| piratory |                                                |    |    |
| tract    |                                                |    |    |
| ir       |                                                |    |    |
| ritation |                                                |    |    |
| (46%),   |                                                |    |    |
| and      |                                                |    |    |
| palp     |                                                |    |    |
| itations |                                                |    |    |
| and      |                                                |    |    |
| pressure |                                                |    |    |
| on the   |                                                |    |    |
| chest    |                                                |    |    |
| (23%).   |                                                |    |    |
| In the   |                                                |    |    |
| less     |                                                |    |    |
| heavily  |                                                |    |    |
| exposed  |                                                |    |    |
| group,   |                                                |    |    |
| 44% of   |                                                |    |    |
| the      |                                                |    |    |
| part     |                                                |    |    |
| icipants |                                                |    |    |
| reported |                                                |    |    |
| s        |                                                |    |    |
| ymptoms, |                                                |    |    |
| ranging  |                                                |    |    |
| from     |                                                |    |    |
| d        |                                                |    |    |
| izziness |                                                |    |    |
| (31%),   |                                                |    |    |
| headache |                                                |    |    |
| (31%),   |                                                |    |    |
| nausea   |                                                |    |    |
| (13%),   |                                                |    |    |
| res      |                                                |    |    |
| piratory |                                                |    |    |
| tract    |                                                |    |    |
| ir       |                                                |    |    |
| ritation |                                                |    |    |
| (19%),   |                                                |    |    |
| and      |                                                |    |    |
| palp     |                                                |    |    |
| itations |                                                |    |    |
| and      |                                                |    |    |
| pressure |                                                |    |    |
| on the   |                                                |    |    |
| chest    |                                                |    |    |
| (13%).   |                                                |    |    |
| There    |                                                |    |    |
| were no  |                                                |    |    |
| sig      |                                                |    |    |
| nificant |                                                |    |    |
| dif      |                                                |    |    |
| ferences |                                                |    |    |
| found    |                                                |    |    |
| between  |                                                |    |    |
| the two  |                                                |    |    |
| groups   |                                                |    |    |
| from the |                                                |    |    |
| neur     |                                                |    |    |
| ological |                                                |    |    |
| tests,   |                                                |    |    |
| but it   |                                                |    |    |
| is       |                                                |    |    |
| likely   |                                                |    |    |
| that     |                                                |    |    |
| there    |                                                |    |    |
| current  |                                                |    |    |
| sample   |                                                |    |    |
| was too  |                                                |    |    |
| small to |                                                |    |    |
| show     |                                                |    |    |
| such an  |                                                |    |    |
| effect.  |                                                |    |    |
| A        |                                                |    |    |
| co       |                                                |    |    |
| mparison |                                                |    |    |
| of the   |                                                |    |    |
| jet fuel |                                                |    |    |
| exposed  |                                                |    |    |
| workers  |                                                |    |    |
| to       |                                                |    |    |
| several  |                                                |    |    |
| other    |                                                |    |    |
| occu     |                                                |    |    |
| pational |                                                |    |    |
| groups   |                                                |    |    |
| (workers |                                                |    |    |
| in a     |                                                |    |    |
| storage  |                                                |    |    |
| battery  |                                                |    |    |
| factory, |                                                |    |    |
| workers  |                                                |    |    |
| in heavy |                                                |    |    |
| metals   |                                                |    |    |
| i        |                                                |    |    |
| ndustry) |                                                |    |    |
| showed   |                                                |    |    |
| an       |                                                |    |    |
| increase |                                                |    |    |
| in       |                                                |    |    |
| symptoms |                                                |    |    |
| of       |                                                |    |    |
| neur     |                                                |    |    |
| asthenia |                                                |    |    |
| (a lack  |                                                |    |    |
| of the   |                                                |    |    |
| central  |                                                |    |    |
| nervous  |                                                |    |    |
| system's |                                                |    |    |
| energy   |                                                |    |    |
| r        |                                                |    |    |
| eserves) |                                                |    |    |
| and      |                                                |    |    |
| polyne   |                                                |    |    |
| uropathy |                                                |    |    |
| (a       |                                                |    |    |
| neur     |                                                |    |    |
| ological |                                                |    |    |
| disorder |                                                |    |    |
| in which |                                                |    |    |
| the      |                                                |    |    |
| pe       |                                                |    |    |
| ripheral |                                                |    |    |
| nerves   |                                                |    |    |
| th       |                                                |    |    |
| roughout |                                                |    |    |
| the body |                                                |    |    |
| malfu    |                                                |    |    |
| nction). |                                                |    |    |
+----------+------------------------------------------------+----+----+
| **Implic | Heavily exposed workers were more likely to    |    |    |
| ations** | report symptoms of exposure than less heavily  |    |    |
|          | exposed workers. Additionally, jet fuel        |    |    |
|          | exposed workers were more likely to report     |    |    |
|          | symptoms of potential neurological disorders   |    |    |
|          | than a reference group of non-jet fuel exposed |    |    |
|          | workers. However, information regarding the    |    |    |
|          | fuel concentrations in the air when the        |    |    |
|          | symptoms occurred was not available.           |    |    |
+----------+------------------------------------------------+----+----+

+----------+------------------------------------------------+----+----+
| **       | **Neurasthenic symptoms in workers             |    |    |
| Title:** | occupationally exposed to jet fuel**           |    |    |
+==========+================================================+====+====+
| **Auth   | Knave, B., Mindus, P., and Struwe, G.          |    |    |
| or(s):** |                                                |    |    |
+----------+------------------------------------------------+----+----+
| **Jo     | *Acta Psychiatry Scandinavia*, 60, 39-49       | *  | 19 |
| urnal:** |                                                | *Y | 79 |
|          |                                                | ea |    |
|          |                                                | r: |    |
|          |                                                | ** |    |
+----------+------------------------------------------------+----+----+
| **       | **Long-term exposure to jet fuel**             |    |    |
| Title:** |                                                |    |    |
|          | **II. A cross-sectional epidemiologic          |    |    |
|          | investigation on occupationally exposed        |    |    |
|          | industrial workers with special reference to   |    |    |
|          | the nervous system.**                          |    |    |
+----------+------------------------------------------------+----+----+
| **Auth   | Knave, B., Olson, B.A., Elofsson, S.,          |    |    |
| or(s):** | Gamberale, F., Isaksson, A., Mindus, P.,       |    |    |
|          | Persson, H.E., Struwe, G., Wennberg, A., and   |    |    |
|          | Westerholm, P.                                 |    |    |
+----------+------------------------------------------------+----+----+
| **Jo     | *Scandinavian Journal of Work Environment and  | *  | 19 |
| urnal:** | Health*, 4, 19-45                              | *Y | 78 |
|          |                                                | ea |    |
|          |                                                | r: |    |
|          |                                                | ** |    |
+----------+------------------------------------------------+----+----+
| **Pu     | To examine the effects of long-term exposure   |    |    |
| rpose**: | to jet fuel on the nervous system              |    |    |
+----------+------------------------------------------------+----+----+
| *        | 30 jet fuel exposed workers and 30 nonexposed  |    |    |
| *Partici | workers (control)                              |    |    |
| pants:** |                                                |    |    |
+----------+------------------------------------------------+----+----+
| **Exp    | Mean exposure time for experimental group was  |    |    |
| osure:** | 17.7 years and control group was 19.8 years.   |    |    |
|          | Measured by time of employment, analysis of    |    |    |
|          | work practices, and measurements of airborne   |    |    |
|          | fuel contents during exposure                  |    |    |
+----------+------------------------------------------------+----+----+
| *        | Interviews; psychological tests of reaction    |    |    |
| *Task:** | time addition, simple reaction time, memory,   |    |    |
|          | manual dexterity, and perceptual speed; and    |    |    |
|          | neurophysiological measurements (EEGs)         |    |    |
+----------+------------------------------------------------+----+----+
| **R      |                                                |    |    |
| esults** |                                                |    |    |
+----------+------------------------------------------------+----+----+
| Only     |                                                |    |    |
| four     |                                                |    |    |
| part     |                                                |    |    |
| icipants |                                                |    |    |
| in the   |                                                |    |    |
| exposure |                                                |    |    |
| group    |                                                |    |    |
| did not  |                                                |    |    |
| indicate |                                                |    |    |
| any      |                                                |    |    |
| symptoms |                                                |    |    |
| on       |                                                |    |    |
| e        |                                                |    |    |
| xposure. |                                                |    |    |
| Tw       |                                                |    |    |
| enty-one |                                                |    |    |
| of the   |                                                |    |    |
| 30       |                                                |    |    |
| part     |                                                |    |    |
| icipants |                                                |    |    |
| in the   |                                                |    |    |
| exposure |                                                |    |    |
| group    |                                                |    |    |
| i        |                                                |    |    |
| ndicated |                                                |    |    |
| they had |                                                |    |    |
| exp      |                                                |    |    |
| erienced |                                                |    |    |
| symptoms |                                                |    |    |
| such as  |                                                |    |    |
| di       |                                                |    |    |
| zziness, |                                                |    |    |
| h        |                                                |    |    |
| eadache, |                                                |    |    |
| nausea,  |                                                |    |    |
| res      |                                                |    |    |
| piratory |                                                |    |    |
| tract    |                                                |    |    |
| s        |                                                |    |    |
| ymptoms, |                                                |    |    |
| palpi    |                                                |    |    |
| tations, |                                                |    |    |
| and      |                                                |    |    |
| thoracic |                                                |    |    |
| opp      |                                                |    |    |
| ression. |                                                |    |    |
| Thirteen |                                                |    |    |
| of the   |                                                |    |    |
| part     |                                                |    |    |
| icipants |                                                |    |    |
| i        |                                                |    |    |
| ndicated |                                                |    |    |
| feeling  |                                                |    |    |
| fatigued |                                                |    |    |
| while    |                                                |    |    |
| working  |                                                |    |    |
| with jet |                                                |    |    |
| fuel and |                                                |    |    |
| in the   |                                                |    |    |
| e        |                                                |    |    |
| venings. |                                                |    |    |
| A        |                                                |    |    |
| co       |                                                |    |    |
| mparison |                                                |    |    |
| of       |                                                |    |    |
| symptoms |                                                |    |    |
| reported |                                                |    |    |
| between  |                                                |    |    |
| the two  |                                                |    |    |
| groups   |                                                |    |    |
| also     |                                                |    |    |
| showed   |                                                |    |    |
| that     |                                                |    |    |
| those in |                                                |    |    |
| the      |                                                |    |    |
| exposed  |                                                |    |    |
| group    |                                                |    |    |
| reported |                                                |    |    |
| more     |                                                |    |    |
| dep      |                                                |    |    |
| ression, |                                                |    |    |
| lack of  |                                                |    |    |
| ini      |                                                |    |    |
| tiative, |                                                |    |    |
| palpi    |                                                |    |    |
| tations, |                                                |    |    |
| and      |                                                |    |    |
| sleep    |                                                |    |    |
| distu    |                                                |    |    |
| rbances. |                                                |    |    |
| The      |                                                |    |    |
| psych    |                                                |    |    |
| ological |                                                |    |    |
| test     |                                                |    |    |
| results  |                                                |    |    |
| showed   |                                                |    |    |
| part     |                                                |    |    |
| icipants |                                                |    |    |
| in the   |                                                |    |    |
| exposure |                                                |    |    |
| group    |                                                |    |    |
| had      |                                                |    |    |
| poorer   |                                                |    |    |
| per      |                                                |    |    |
| formance |                                                |    |    |
| on       |                                                |    |    |
| reaction |                                                |    |    |
| time and |                                                |    |    |
| pe       |                                                |    |    |
| rceptual |                                                |    |    |
| speed    |                                                |    |    |
| tasks    |                                                |    |    |
| (i.e.,   |                                                |    |    |
| those    |                                                |    |    |
| tasks    |                                                |    |    |
| with     |                                                |    |    |
| high     |                                                |    |    |
| att      |                                                |    |    |
| entional |                                                |    |    |
| demand)  |                                                |    |    |
| but no   |                                                |    |    |
| di       |                                                |    |    |
| fference |                                                |    |    |
| attr     |                                                |    |    |
| ibutable |                                                |    |    |
| to       |                                                |    |    |
| exposure |                                                |    |    |
| on       |                                                |    |    |
| memory   |                                                |    |    |
| or       |                                                |    |    |
| manual   |                                                |    |    |
| de       |                                                |    |    |
| xterity. |                                                |    |    |
+----------+------------------------------------------------+----+----+
| **Implic | Exposure in the work context studied here was  |    |    |
| ations** | relatively stable. 87% of the participants in  |    |    |
|          | the experimental group reported recurrent      |    |    |
|          | symptoms due to exposure (depression, fatigue, |    |    |
|          | lack of initiative, dizziness were most        |    |    |
|          | common). Additionally, psychological testing   |    |    |
|          | showed greater variability in performance for  |    |    |
|          | participants in the experimental group         |    |    |
|          | relative to the control group for complex      |    |    |
|          | reaction time, greater decrement in            |    |    |
|          | performance over time on tasks of simple       |    |    |
|          | reaction time, and poorer perceptual speed     |    |    |
|          | performance.                                   |    |    |
+----------+------------------------------------------------+----+----+

  ----------------------------------------------------------------------------------------
  **Title:**          **Developmental neurobehavioral effects on JP-8               
                      jet fuel on pups from female Sprague-Dawley rats              
                      exposed by oral gavage**                                      
  ------------------- ------------------------------------------------- ----------- ------
  **Author(s):**      Mattie, D.R., Cooper, J.R., Sterner, T.R.,                    
                      Schimmel, B.D., Bekkedal, M.Y.V., Bausman, T.A.,              
                      and Young, S.M.                                               

  **Journal:**        United States Air Force Research Laboratory       **Year:**   2001

  **Purpose**:        To examine the effects of prenatal JP-8 exposure              
                      on central nervous system development                         

  **Participants:**   140+ female rats                                              

  **Exposure:**       0, 325, 750, 1500 mg/kg JP-8 daily by gavage                  
                      (minimum of 35 female rats in each condition)                 

  **Task:**           Tests of neurobehavioral development were                     
                      conducted on the 68 litters consisting of 4 male              
                      and 4 female pups. Pups performed tasks requiring             
                      them to turn over, raise their head, swim, and                
                      complete a water maze.                                        

  **Results**                                                                       

  The results showed                                                                
  no difference in                                                                  
  neurobehavioral                                                                   
  development on                                                                    
  simple tasks (e.g.,                                                               
  turning over and                                                                  
  raising one's head)                                                               
  or in completing                                                                  
  the water maze.                                                                   
  However,                                                                          
  dose-related                                                                      
  effects were found                                                                
  for swimming                                                                      
  ability, such that                                                                
  pups exposed to jet                                                               
  fuel showed poorer                                                                
  performance                                                                       
  initially than                                                                    
  non-exposed pups                                                                  
  although                                                                          
  performance between                                                               
  the two groups                                                                    
  equalized over                                                                    
  time. This result                                                                 
  suggests that                                                                     
  exposure to jet                                                                   
  fuel may delay                                                                    
  brain development                                                                 
  in areas of motor                                                                 
  coordination, but                                                                 
  that these effects                                                                
  disappear at later                                                                
  ages.                                                                             

  **Implications**    Exposure to JP-8 jet fuel may delay cerebellum                
                      development in pups but this effect is not                    
                      lasting.                                                      
  ----------------------------------------------------------------------------------------

  ----------------------------------------------------------------------------------------
  **Title:**          **Cognitive neurobehavioral toxicity assessment               
                      of three hydrocarbon fuels**                                  
  ------------------- ------------------------------------------------- ----------- ------
  **Author(s):**      Nordholm, A.F.                                                

  **Journal:**        U.S. Army Medical Research and Materiel Command:  **Year:**   1998
                      Fort Detrick, Maryland                                        

  **Purpose**:        Examine the effects of jet fuel exposure (JP-8,               
                      JP-4, and JP-5) on rats to determine                          
                      neurobehavioral changes                                       

  **Participants:**   32 Sprague-Dawley rats                                        

  **Exposure:**       Whole-body inhalation of JP-8 (1.0 mg/L±10%) or               
                      JP-5 (1.2 mg/L±10%) vapor for 6 hours/day, 5                  
                      days/week for 6 weeks; to JP-4 (2.0 mg/L±10%)                 
                      vapor for 6 hours/day for 14 days; or to a                    
                      control condition. Concentrations were                        
                      representative of real world vapor exposures                  
                      experienced by operational military. Rats were                
                      rested 14-65 days after exposure to minimize the              
                      neurobehavioral effects resulting from                        
                      physiological irritance or stress during exposure             
                      and to examine the presence of neurobehavioral                
                      deficits resulting several weeks post-exposure.               

  **Task:**           Neurobehavioral Toxicity Assessment Battery                   
                      (NTAB), which consisted of 10 tests that                      
                      evaluated muscle strength, locomotion, physical               
                      fatigue, nociception (i.e., pain perception),                 
                      auditory brainstem function, short-term memory,               
                      emotional depression, spatial localization,                   
                      short-term memory, central nervous system                     
                      sensitization, and social behavior.                           

  **Results**                                                                       

  In the "long-term"                                                                
  (i.e., 60 days),                                                                  
  exposure to the                                                                   
  vapors led to no                                                                  
  changes in                                                                        
  neurology or                                                                      
  behavior. However,                                                                
  14-days                                                                           
  post-exposure to                                                                  
  JP-4 vapor for 6                                                                  
  hours/day led to a                                                                
  significant                                                                       
  decrease in the                                                                   
  rats' response to                                                                 
  pain, their                                                                       
  acoustic startle                                                                  
  response, and                                                                     
  locomotion, and a                                                                 
  significant                                                                       
  increase in                                                                       
  approaching "novel"                                                               
  food stimulus; this                                                               
  finding is                                                                        
  consistent with an                                                                
  increase in                                                                       
  dopamine and/or                                                                   
  serotonin levels in                                                               
  the brain. Exposure                                                               
  to JP-8 also                                                                      
  resulted in a                                                                     
  significant                                                                       
  increase in                                                                       
  approaching "novel"                                                               
  food stimulus and                                                                 
  significant                                                                       
  increase in muscle                                                                
  strength,                                                                         
  consistent with                                                                   
  changes in the                                                                    
  dopamine and DOPAC                                                                
  levels in several                                                                 
  brain regions. JP-5                                                               
  exposure led to no                                                                
  significant                                                                       
  deficits on the                                                                   
  NTAB tests.                                                                       
  Exposure to the                                                                   
  vapors reduced                                                                    
  weight gains                                                                      
  relative to rats in                                                               
  the control group;                                                                
  during exposure,                                                                  
  rats in the                                                                       
  experimental                                                                      
  conditions weighed                                                                
  less than the                                                                     
  control groups, but                                                               
  recovered their                                                                   
  weight rapidly once                                                               
  the exposure period                                                               
  ended.                                                                            

  **Implications**    Exposure (of rats) to JP-4, JP-6, or JP-8 vapors              
                      from 14-30 days may cause neurological and                    
                      behavioral changes. Increased dopamine and/or                 
                      serotonin levels due to JP-4 and JP-8 exposure                
                      have cognitive implications although it is not                
                      clear what that effect is. The results suggest                
                      that JP-4 has the greatest risk on neurological               
                      functioning and behavior, with the effect of JP-8             
                      being greater than or equal to that of JP-5.                  
                      Additional research is needed to determine if                 
                      these humans will experience these same effects.              
  ----------------------------------------------------------------------------------------

+----------+------------------------------------------------+----+----+
| **       | **Audiological and vestibulo-oculomotor        |    |    |
| Title:** | findings in workers exposed to solvents and    |    |    |
|          | jet fuel**                                     |    |    |
+==========+================================================+====+====+
| **Auth   | Ödkvist, L.M., Arlinger, S.D., Edling, C.,     |    |    |
| or(s):** | Larsby, B., and Bergoltz., L.M.                |    |    |
+----------+------------------------------------------------+----+----+
| **Jo     | *Scandinavian Audiology*, 16, 75-91            | *  | 19 |
| urnal:** |                                                | *Y | 87 |
|          |                                                | ea |    |
|          |                                                | r: |    |
|          |                                                | ** |    |
+----------+------------------------------------------------+----+----+
| **       | **Audiological findings in solvent-exposed     |    |    |
| Title:** | workers**                                      |    |    |
+----------+------------------------------------------------+----+----+
| **Auth   | Bergoltz., L.M. and Ödkvist, L.M.              |    |    |
| or(s):** |                                                |    |    |
+----------+------------------------------------------------+----+----+
| **Jo     | *Acta Otolaryngologica Supplementum*, 412,     | *  | 19 |
| urnal:** | 109-110                                        | *Y | 84 |
|          |                                                | ea |    |
|          |                                                | r: |    |
|          |                                                | ** |    |
+----------+------------------------------------------------+----+----+
| **Pu     | Examine the effects of occupational exposure   |    |    |
| rpose**: | to solvents/jet fuel on the central and        |    |    |
|          | peripheral nervous systems                     |    |    |
+----------+------------------------------------------------+----+----+
| *        | 3 participant groups:                          |    |    |
| *Partici |                                                |    |    |
| pants:** | (A) 16 participants with diagnosis of          |    |    |
|          |     solvent-induced psychoorganic syndrome     |    |    |
|          |     based on neurophysiological and            |    |    |
|          |     psychological testing                      |    |    |
|          |                                                |    |    |
|          | (B) 7 participants with suspected              |    |    |
|          |     psychoorganic syndrome (neurasthenic       |    |    |
|          |     symptoms) but normal findings on           |    |    |
|          |     psychological tests                        |    |    |
|          |                                                |    |    |
|          | (C) 8 participants with significant exposure   |    |    |
|          |     to jet fuel but free from psychoorganic    |    |    |
|          |     syndrome                                   |    |    |
+----------+------------------------------------------------+----+----+
| **Exp    | (A) Participants were paint mixers,            |    |    |
| osure:** |     construction painters, spray painters,     |    |    |
|          |     printers, and truck drivers with a range   |    |    |
|          |     of exposure from 9 -- 40 years. All        |    |    |
|          |     participants had been free from exposure   |    |    |
|          |     for at least 2 years                       |    |    |
|          |                                                |    |    |
|          | (B) House painters, spray painters, and tanker |    |    |
|          |     drivers with a range of exposure time from |    |    |
|          |     5 -- 30 years                              |    |    |
|          |                                                |    |    |
|          | (C) Aircraft mechanics with a range of         |    |    |
|          |     exposure from 15 -- 41 years               |    |    |
+----------+------------------------------------------------+----+----+
| *        | Audiological and vestibular tests              |    |    |
| *Task:** |                                                |    |    |
+----------+------------------------------------------------+----+----+
| **R      |                                                |    |    |
| esults** |                                                |    |    |
+----------+------------------------------------------------+----+----+
| The test |                                                |    |    |
| results  |                                                |    |    |
| suggest  |                                                |    |    |
| p        |                                                |    |    |
| otential |                                                |    |    |
| dist     |                                                |    |    |
| urbances |                                                |    |    |
| in the   |                                                |    |    |
| central  |                                                |    |    |
| nervous  |                                                |    |    |
| system   |                                                |    |    |
| as a     |                                                |    |    |
| con      |                                                |    |    |
| sequence |                                                |    |    |
| of       |                                                |    |    |
| exposure |                                                |    |    |
| to       |                                                |    |    |
| s        |                                                |    |    |
| olvents. |                                                |    |    |
| In       |                                                |    |    |
| par      |                                                |    |    |
| ticular, |                                                |    |    |
| parti    |                                                |    |    |
| cipants' |                                                |    |    |
| per      |                                                |    |    |
| formance |                                                |    |    |
| on the   |                                                |    |    |
| test     |                                                |    |    |
| suggest  |                                                |    |    |
| that     |                                                |    |    |
| greater  |                                                |    |    |
| exposure |                                                |    |    |
| i        |                                                |    |    |
| ncreases |                                                |    |    |
| the      |                                                |    |    |
| li       |                                                |    |    |
| kelihood |                                                |    |    |
| of       |                                                |    |    |
| lesions  |                                                |    |    |
| in the   |                                                |    |    |
| auditory |                                                |    |    |
| cortex   |                                                |    |    |
| and      |                                                |    |    |
| br       |                                                |    |    |
| ainstem. |                                                |    |    |
| De       |                                                |    |    |
| crements |                                                |    |    |
| in       |                                                |    |    |
| per      |                                                |    |    |
| formance |                                                |    |    |
| were     |                                                |    |    |
| found on |                                                |    |    |
| those    |                                                |    |    |
| tests    |                                                |    |    |
| ev       |                                                |    |    |
| aluating |                                                |    |    |
| the      |                                                |    |    |
| fu       |                                                |    |    |
| nctional |                                                |    |    |
| state of |                                                |    |    |
| the      |                                                |    |    |
| ce       |                                                |    |    |
| rebellum |                                                |    |    |
| rather   |                                                |    |    |
| than     |                                                |    |    |
| tests of |                                                |    |    |
| simple   |                                                |    |    |
| r        |                                                |    |    |
| eflexes. |                                                |    |    |
+----------+------------------------------------------------+----+----+
| **Implic | The results suggests a dose-effect             |    |    |
| ations** | relationship with greater levels of exposure   |    |    |
|          | resulting in an increased likelihood of        |    |    |
|          | psychoorganic syndrome and neurasthenic        |    |    |
|          | symptoms.                                      |    |    |
+----------+------------------------------------------------+----+----+

  ----------------------------------------------------------------------------------------
  **Title:**          **Aviators intoxicated by inhalation of JP-5 fuel             
                      vapors**                                                      
  ------------------- ------------------------------------------------- ----------- ------
  **Author(s):**      Porter, H.O.                                                  

  **Journal:**        *Aviation, Space, and Environmental Medicine*,    **Year:**   1990
                      July, 654 -- 656                                              

  **Purpose**:        To report two cases of inhalation of JP-5 fuel                
                      vapors                                                        

  **Participants:**   Two pilots (instructor and student)                           

  **Exposure:**       Two pilots were exposed to jet fuel vapors in a               
                      T-34C, unpressurized aircraft                                 

  **Task:**           Radio instrument night-training flight                        

  **Results**                                                                       

  Pilots reported                                                                   
  irritation to the                                                                 
  eyes and euphoria                                                                 
  (even after the                                                                   
  instructor pilot                                                                  
  notified the                                                                      
  student pilot of                                                                  
  the emergency), and                                                               
  experienced                                                                       
  difficulty walking                                                                
  after exiting the                                                                 
  aircraft and                                                                      
  filling out                                                                       
  familiar forms.                                                                   
  Both appeared                                                                     
  fatigued but a                                                                    
  physical                                                                          
  examination                                                                       
  indicated that they                                                               
  were normal.                                                                      

  **Implications**    Pilots have reported JP-5 exposure-related                    
                      symptoms such as transient memory loss (e.g.,                 
                      difficulty remembering emergency procedures),                 
                      lightheadedness, and "slow thinking". Jet fuel                
                      exposure has led to errors by experienced pilots              
                      in navigation and communication.                              
  ----------------------------------------------------------------------------------------

  ---------------------------------------------------------------------------------------
  **Title:**         ***Biological and Health Effects of JP-8                      
                     Exposure***                                                   
  ------------------ ------------------------------------------------- ----------- ------
  **Author(s):**     Ritchie, G.D., Bekkedal, M.Y.V., Bobb, A.J., and              
                     Still, K.R.                                                   

  **Journal:**       Naval Health Research Center Detachment           **Year:**   2001
                     Toxicology: Wright Patterson Air Force Base, OH               

  **Purpose**:       To summarize the human, animal, and in vitro                  
                     studies examining the biological and neurological             
                     health effects due to acute or long-term exposure             
                     to JP-8 and its chemical constituents                         

  **Implications**   Long-term occupational exposure to JP-8 jet fuel              
                     vapors could lead to deficits in cerebellar                   
                     functioning (e.g., eye-blink responses, balance).             
  ---------------------------------------------------------------------------------------

  ----------------------------------------------------------------------------------------
  **Title:**          **Effect of chronic low-level exposure to jet                 
                      fuel on postural balance of U.S. Air Force                    
                      Personnel**                                                   
  ------------------- ------------------------------------------------- ----------- ------
  **Author(s):**      Smith, L.B., Bhattacharya, A., Lemasters, G.,                 
                      Succop, P., Puhala II, E., Medvedovic, M., and                
                      Joyce, J.                                                     

  **Journal:**        *Journal of Occupational and Environmental        **Year:**   1997
                      Medicine*, 39(7), 623-632                                     

  **Purpose**:        To examine the effect of low-level exposure to                
                      JP-8 jet fuel vapors on postural stability                    

  **Participants:**   27 United States Air Force aircraft maintenance               
                      personnel (20 male, 7 female) served in the                   
                      experimental group; 25 unexposed participants (14             
                      male, 11 female) from the military, university,               
                      and other sources served as the control group                 

  **Exposure:**       8-hour breathing zone samples were collected from             
                      each participant in the occupational group                    

  **Task:**           Postural sway, measured on a force platform, to               
                      determine the effects of the proprioceptive,                  
                      visual, and vestibular systems on balance.                    
                      Participants stood on the platform with their                 
                      eyes open and closed and then stood on a 4-inch               
                      foam over the platform with their eyes open and               
                      closed.                                                       

  **Results**                                                                       

  Participants                                                                      
  balance decreased                                                                 
  (i.e., sway                                                                       
  increased) as                                                                     
  exposure level                                                                    
  increased. The                                                                    
  neurotoxic effect                                                                 
  of jet fuel vapor                                                                 
  exposure could be                                                                 
  seen at low-levels                                                                
  of exposure (e.g.,                                                                
  the level received                                                                
  when opening a                                                                    
  storage tank).                                                                    

  **Implications**    The effect of jet fuel vapor inhalation on                    
                      proprioception has safety consequences, e.g., for             
                      workers in dark areas and slippery surfaces.                  
                      Long-term exposure could lead to degraded                     
                      neurological functions.                                       
  ----------------------------------------------------------------------------------------

## Other Health Effects of Diesel Exposure {#other-health-effects-of-diesel-exposure .Appendix-Heading-2}

  ---------------- ------------------------------------------------- ----------- ------
  **Title:**       **Environmental and clinical investigation of                 
                   workmen exposed to diesel exhaust in railroad                 
                   engine houses**                                               

  **Author(s):**   Battigelli, M.C., Mannella, R.J., and Hatch, T.F.             

  **Journal:**     *Industrial Medicine and Surgery*, March, 121-124 **Year:**   1964

  **Purpose**:     To investigate the clinical and physiological                 
                   effects of diesel exhaust exposure on railroad                
                   workers                                                       

  **Notes:**       Physical examination, chest x-rays, ECGs,                     
                   spirometry, and medical histories were collected              
                   for 364 railroad workers (210 exposed engine                  
                   repairmen, 154 railroad workers). The results                 
                   showed no differences in pulmonary functions or               
                   chest abnormalities due to exposure.                          
  ---------------- ------------------------------------------------- ----------- ------

  ---------------- ------------------------------------------------- ----------- ------
  **Title:**       **Health problems resulting from prolonged                    
                   exposure to air pollution in diesel bus garages**             

  **Author(s):**   El Batawi, M.A. and Noweir, M.H.                              

  **Journal:**     *Industrial Health*, 4, 1-10                      **Year:**   1966

  **Purpose**:     To evaluate environmental conditions in two bus               
                   garages and to examine the effect on workers'                 
                   health                                                        

  **Notes:**       Measurements of gases and vapors in the garages               
                   were below the known threshold levels. 161                    
                   workers were examined to determine the health                 
                   effects. Workers complained of irritation of the              
                   eyes (42%) and throat (19%) from gases and fumes,             
                   dyspepsia (25.5%), and cough and sputum (10.6%).              
                   Clinical examination indicated that 13.7% of the              
                   workers showed signs of upper respiratory tract               
                   disease, 8.7% had chronic bronchitis, and 4.3%                
                   had asthma. These levels are higher than those                
                   found in similar working groups without diesel                
                   exposure (8.9% for URT, 5.6% chronic bronchitis,              
                   and 1.1% asthma). The number of cases of                      
                   gastritis and peptic ulcer was also higher than               
                   expected (14.3%). Finally, 29.8% of workers had               
                   high blood pressure (over 150 mmHG systolic and               
                   80mmHG diastolic); for those working night                    
                   shifts, the rate was 39.6%.                                   
  ---------------- ------------------------------------------------- ----------- ------

  ---------------- ------------------------------------------------- ----------- ------
  **Title:**       **Acute changes in pulmonary function in salt                 
                   miners**                                                      

  **Author(s):**   Gamble, J., Jones, W., Hudak, J., and Merchant,               
                   J.                                                            

  **Journal:**     *Industrial Hygiene for Mining and Tunneling --   **Year:**   1978
                   Proceedings of an ACGIH Topical Symposium*                    
                   (11/6-7/78), 119-128                                          

  **Purpose**:     To examine dose-response relationship of                      
                   particulate and/or NO~2~ exposure over work                   
                   shifts                                                        

  **Notes:**       There was no relationship found between pulmonary             
                   function due to particulate and/or NO~2~ exposure             
  ---------------- ------------------------------------------------- ----------- ------

  ---------------- ------------------------------------------------- ----------- ------
  **Title:**       **Epidemiological-environmental study of diesel               
                   bus garage workers: Chronic effects of diesel                 
                   exhaust on the respiratory system**                           

  **Author(s):**   Gamble, J., Jones, W., and Minshall, S.                       

  **Journal:**     *Environmental Research*, 44, 6-17                **Year:**   1987

  **Purpose**:     To determine the relationship between diesel                  
                   exposure and respiratory symptoms, cardiac                    
                   function, and pulmonary function in diesel bus                
                   garage workers                                                

  **Notes:**       Diesel-exposed workers had a higher prevalence of             
                   coughing, phlegm, and wheezing than a comparison              
                   group, but there was no association with length               
                   of time in the occupation. Pulmonary function                 
                   decreased as tenure increased. There was no                   
                   effect found on cardiac function.                             
  ---------------- ------------------------------------------------- ----------- ------

  ---------------- ------------------------------------------------- ----------- ------
  **Title:**       **Diesel Exhaust: A Critical Analysis of                      
                   Emissions, Exposure, and Health Effects**                     

  **Author(s):**   Health Effects Institute                          **Year:**   1995

  **Purpose**:     To evaluate the evidence examining the potential              
                   that diesel emissions cause cancer and to                     
                   identify information gaps in the literature                   

  **Notes:**       Epidemiologic data suggests a weak association                
                   between diesel exposure and lung cancer, but it               
                   is not clear what the relative risk of diesel                 
                   exposure is with respect to other lifestyle                   
                   factors (e.g., smoking, asbestos, diet).                      
                   Additionally, no studies provide exposure                     
                   information, i.e., a measurement of exposure for              
                   the time period most relevant to the development              
                   of lung cancer. Developing markers to measure                 
                   diesel emissions exposure would help establish a              
                   risk assessment for lung cancer.                              
  ---------------- ------------------------------------------------- ----------- ------

  ---------------- ------------------------------------------------- ----------- ------
  **Title:**       **Acute overexposure to diesel exhaust: Report of             
                   13 cases**                                                    

  **Author(s):**   Kahn, G., Orris, P., and Weeks, J.                            

  **Journal:**     *American Journal of Industrial Medicine*, 13,    **Year:**   1988
                   405-406                                                       

  **Purpose**:     To determine the risk of overexposure and its                 
                   health effects                                                

  **Notes:**       13 incidents of overexposure at five underground              
                   coal mines were identified. Twelve miners                     
                   reported mucous membrane irritation, headaches,               
                   and feeling light-headed. Eight miners indicated              
                   feelings of nausea; 4 reported feeling "high" and             
                   experiencing heartburn; 3 reported weakness,                  
                   numbness and tingling in extremities; 2 reported              
                   chest tightness; and 2 reported wheezing. These               
                   symptoms were resolved within 1-2 days.                       
  ---------------- ------------------------------------------------- ----------- ------

  ---------------- ------------------------------------------------- ----------- ------
  **Title:**       **Historical estimation of diesel exhaust                     
                   exposure in a cohort study of U.S. railroad                   
                   workers and lung cancer**                                     

  **Author(s):**   Laden, F., Hart, J.E., Eschenroeder, A., Smith,               
                   T.J., and Garshick, E.                                        

  **Journal:**     *Cancer Causes Control*, 17(7), 911-919           **Year:**   2006

  **Purpose**:     To develop a profile of exposure in the railroad              
                   industry and to estimate lung cancer risk                     
                   associated with the exposures                                 

  **Notes:**       After adjusting for time and differences in the               
                   probability and intensity of exposure, the data               
                   showed an increased risk of lung cancer deaths                
                   for diesel-exposed railroad workers than                      
                   non-exposed workers                                           
  ---------------- ------------------------------------------------- ----------- ------

  ---------------- ------------------------------------------------- ----------- ------
  **Title:**       **Diesel exhaust inhalation causes vascular                   
                   dysfunction and impaired endogenous                           
                   fibrinolysis**                                                

  **Author(s):**   Mills, N.L., Törnqvist, H., Robinson, S.D.,                   
                   Gonzalez, M., Darnley, K., MacNee, W., Boon,                  
                   N.A., Donaldson, K., Blomberg, A., Sandstrom, T.,             
                   and Newby, D.E.                                               

  **Journal:**     *Circulation,* December 20/27, 3930-3936.         **Year:**   2005

  **Purpose**:     Examine the effects of diesel exhaust inhalation              
                   on cardiovascular function (endothelial vasomotor             
                   and fibrinolytic function)                                    

  **Notes:**       30 healthy, male nonsmokers, aged 20-38 years                 
                   old, were exposed to diesel exhaust generated by              
                   an idling Volvo diesel engine. Inhalation of                  
                   diluted diesel exhaust led to impairments in                  
                   human vascular functioning, with as little as 1               
                   hour of exposure.                                             
  ---------------- ------------------------------------------------- ----------- ------

  -------------------------------------------------------------------------------------
  **Title:**       **Airway inflammation following exposure to                   
                   diesel exhaust: a study of time kinetics using                
                   induced sputum**                                              
  ---------------- ------------------------------------------------- ----------- ------
  **Author(s):**   Nordenhäll, C., Pourazar, J., Blomberg, A.,                   
                   Levin, J-O., Sandström, T., and Ädelroth, E.                  

  **Journal:**     *European Respiratory Journal*, 15, 1046-1051     **Year:**   2000

  **Purpose**:     Examine the time kinetics of airway inflammation              
                   following exposure to diesel fuel                             

  **Notes:**       15 healthy nonsmoking volunteers were exposed to              
                   diesel exhaust generated by an idling Volvo                   
                   diesel engine. Participants alternated between                
                   moderate levels of exercise and rest periods for              
                   15-minute intervals. Sputum induction, performed              
                   6 hours and 24 hours after each exposure, showed              
                   that diesel exposure led to a time-dependent                  
                   inflammatory response in the airways.                         
  -------------------------------------------------------------------------------------

  -------------------------------------------------------------------------------------
  **Title:**       **Urbanization and traffic related exposures as               
                   risk factors for schizophrenia**                              
  ---------------- ------------------------------------------------- ----------- ------
  **Author(s):**   Pedersen, C.B. and Mortensen, P.B.                            

  **Journal:**     *BMC Psychiatry*, 6(2)                            **Year:**   2006

  **Purpose**:     To explore the urban-rural difference in                      
                   schizophrenia by examining whether                            
                   traffic-related exposure increases the risk of                
                   the disease                                                   

  **Notes:**       Initial examination of the data suggested that                
                   geographical proximity to the nearest major road              
                   and degree of urbanization had significant                    
                   effects on the risk of developing schizophrenia.              
                   With respect to the former, higher risk levels                
                   were found in children living 500-1000 meters                 
                   from the nearest major road; with respect to the              
                   latter, children living in the capital city at                
                   the time of their 15^th^ birthday had a greater               
                   risk of schizophrenia compared to children living             
                   in rural areas. However, further analysis                     
                   indicated that the degree of urbanization                     
                   accounted for the effect of geographical                      
                   distance. That is, traffic-related exposure                   
                   (e.g., to carbon monoxide, benzene) does not                  
                   explain urban-rural differences in schizophrenia              
                   risk                                                          
  -------------------------------------------------------------------------------------

  ---------------- ------------------------------------------------- ----------- ------
  **Title:**       **Effect of prenatal exposure to airborne                     
                   polycyclic aromatic hydrocarbons on                           
                   neurodevelopment in the first three years of life             
                   among inner-city children**                                   

  **Author(s):**   Perera, F.P., Rauh, V., Whyatt, R.M., Tsai, W.Y.,             
                   Tang, D., Diaz, D., Hopener, L., Barr, D., Tu,                
                   Y.H., Camann, D., and Kinney, P.                              

  **Journal:**     *Environmental Health Perspectives*               **Year:**   2006

  **Purpose**:     To evaluate the effects of prenatal exposure to               
                   urban air pollutants on child mental and                      
                   psychomotor development                                       

  **Notes:**       Three-year olds with high levels of prenatal                  
                   exposure to polycyclic aromatic hydrocarbons                  
                   (PAHs) received lower scores on tests of their                
                   mental development than those with lower levels               
                   of exposure. This exposure could lead to                      
                   performance deficits in language, reading, and                
                   math in early school years. There was no effect               
                   of PAH-exposure on cognitive development observed             
                   for children under 3 years of age, nor were there             
                   any effects seen with respect to psychomotor                  
                   development and behavioral issues.                            
  ---------------- ------------------------------------------------- ----------- ------

  ---------------- ------------------------------------------------- ----------- ------
  **Title:**       **An experimental investigation in animals of the             
                   functional and morphologic effects of single and              
                   repeated exposures to high and low concentrations             
                   of carbon monoxide**                                          

  **Author(s):**   Preziosi, T.J., Lindenberg, R., Levy, D., and                 
                   Christenson, M.                                               

  **Journal:**     *Annals of the New York Academy of Sciences*,     **Year:**   1970
                   174(1), 369-384                                               

  **Purpose**:     To examine the pathological effects of carbon                 
                   monoxide and to determine what levels of carbon               
                   monoxide in the atmosphere are safe if                        
                   continuously exposed using animals (dogs)                     
  ---------------- ------------------------------------------------- ----------- ------

  ---------------- ------------------------------------------------- ----------- ------
  **Title:**       **Coal miners exposed to diesel exhaust                       
                   emissions**                                                   

  **Author(s):**   Reger, R., Hancock, J., Hankinson, J., Hearl, F.,             
                   and Merchant, J.                                              

  **Journal:**     *American Occupational Hygiene*, 26 (1-4),        **Year:**   1982
                   799-815                                                       

  **Purpose**:     To examine differences in respiratory symptoms                
                   and pulmonary function between diesel-exposed and             
                   non-diesel exposed coal miners.                               

  **Notes:**       Underground miners and surface workers at                     
                   diesel-use mines reported more coughing and                   
                   phlegm than the control group of non-diesel                   
                   exposed workers and showed patterns consistent                
                   with small airways disease. However, because                  
                   miners' exposure time and exposure level to                   
                   diesel emissions is low, no clear link between                
                   the health effects and diesel emissions could be              
                   made.                                                         
  ---------------- ------------------------------------------------- ----------- ------

  ---------------- ------------------------------------------------- ----------- ------
  **Title:**       **Particulate matter exposure in cars is                      
                   associated with cardiovascular effects in healthy             
                   young men**                                                   

  **Author(s):**   Riediker, M., Cascio, W.E., Griggs, T.R., Herbst,             
                   M.C., Bromberg, P.A., Neas, L., Williams, R.W.,               
                   and Devlin, R.B.                                              

  **Journal:**     *American Journal of Respiratory Critical Care    **Year:**   2004
                   Medicine*, 169, 934-940                                       

  **Purpose**:     To understand the cardiovascular effects of                   
                   occupational exposure to particulates (PM~2.5~)               

  **Notes:**       Nine young (23 to 30 years old), nonsmoking,                  
                   North Carolina State Highway Patrol troopers were             
                   monitored over 4 days, while working a 3pm to                 
                   12am shift. Blood samples were collected before               
                   the first shift and 10 to 14 hours after each                 
                   shift, and the troopers wore electrocardiogram                
                   monitors throughout their shift. Air-quality                  
                   monitors were installed in their vehicles to                  
                   measure PM~2.5~ levels. The results showed that               
                   PM~2.5~ exposure was associated with changes in               
                   heart rate variability and inflammatory and                   
                   coagulatory responses in blood markers.                       
  ---------------- ------------------------------------------------- ----------- ------

  ---------------- ------------------------------------------------- ----------- ------
  **Title:**       **Diesel Asthma: Reactive airways disease                     
                   following overexposure to locomotive exhaust**                

  **Author(s):**   Wade III, J.F. and Newman, L.S.                               

  **Journal:**     *Journal of Occupational Medicine*, 35(2),        **Year:**   1993
                   149-154                                                       

  **Purpose**:     Report of three cases of railroad workers who                 
                   developed asthma from diesel exhaust inhalation               
  ---------------- ------------------------------------------------- ----------- ------

## Measuring Air Quality {#measuring-air-quality .Appendix-Heading-2}

  ---------------- ------------------------------------------------- ----------- ------
  **Title:**       **Heavy-Duty Vehicle Idle Activity and Emissions              
                   Characterization Study**                                      

  **Author(s):**   Baker, R., Ahanotou, D., and Allen, J.D.                      

  **Journal:**     N/A                                               **Year:**   2004

  **Purpose**:     To refine the Texas Commission on Environmental               
                   Quality's statewide On-Road Heavy-Duty Vehicle                
                   (HDV) Extended Idling Activity Database and                   
                   Emissions Inventory for different source                      
                   generators. Truck idling was characterized at                 
                   different time scales and annual emissions                    
                   projected through 2030                                        
  ---------------- ------------------------------------------------- ----------- ------

  ---------------- ------------------------------------------------- ----------- ------
  **Title:**       **Methodology for evaluating mobile source air                
                   toxic emissions: Transportation project                       
                   alternatives**                                                

  **Author(s):**   Claggett, M. and Miller, T.L.                                 

  **Journal:**     *Transportation Research Record: Journal of the   **Year:**   2006
                   Transportation Research Board,* 1987, 32-41.                  

  **Purpose**:     To present a method for computing and evaluating              
                   mobile source air toxics (MSATs) emissions among              
                   a group of transportation project alternatives                
  ---------------- ------------------------------------------------- ----------- ------

  ---------------- ------------------------------------------------- ----------- ------
  **Title:**       **Variability of mobile air toxic emissions                   
                   factors with MOBILE6.2**                                      

  **Author(s):**   Claggett, M. and Miller. T.L.                                 

  **Journal:**     *Transportation Research Record: Journal of the   **Year:**   2006
                   Transportation Research Board,* 1987, 103-109                 

  **Purpose**:     To discuss the range of mobile source air toxic               
                   (MSAT) emissions factors produced by the                      
                   MOBILE6.2 model as a function of calendar year,               
                   ambient temperature, fuel (gasoline), Reid vapor              
                   pressure, and vehicle speed                                   
  ---------------- ------------------------------------------------- ----------- ------

  ---------------- ------------------------------------------------- ----------- ------
  **Title:**       **Air quality measurements inside diesel truck                
                   cabs during long term idling**                                

  **Author(s):**   Doraiswamy, P., Davis, W.T., Miller, T.L., Lam,               
                   N., and Bubbosh, P.                                           

  **Journal:**     *Transportation Research Record: Journal of the   **Year:**   2006
                   Transportation Research Board*, 1987, 82-91                   

  **Purpose**:     To measure air quality inside and outside diesel              
                   truck cabs for different truck types in extended              
                   idling conditions                                             
  ---------------- ------------------------------------------------- ----------- ------

  ---------------- ------------------------------------------------- ----------- ------
  **Title:**       **Integrating geographic information systems for              
                   transportation and air quality models for                     
                   microscale analysis**                                         

  **Author(s):**   Hallmark, S. and O'Neill, W.                                  

  **Journal:**     *Transportation Research Record: Journal of the   **Year:**   1996
                   Transportation Research Board,* 1551, 133-140                 

  **Purpose**:     To apply geographic information system (GIS)                  
                   tools to microscale air quality analysis                      
  ---------------- ------------------------------------------------- ----------- ------

  ---------------- ------------------------------------------------- ----------- ------
  **Title:**       **Patterns of Drivers' Exposure to Particulate                
                   Matter**                                                      

  **Author(s):**   Krausse, B. and Mardaljevic, J.                               

  **Journal:**     *Spatial Planning, Urban Form, and Sustainable    **Year:**   2005
                   Transport*. In K. Williams, Ed., (pp. 151-167).               
                   Ashgate: Burlington, VT.                                      

  **Purpose**:     To evaluate drivers' exposure to particle                     
                   emissions in urban traffic conditions                         
  ---------------- ------------------------------------------------- ----------- ------

  ---------------- ------------------------------------------------- ----------- ------
  **Title:**       **Exposure of trucking company workers to                     
                   particulate matter during the winter**                        

  **Author(s):**   Lee, N.K., Smith, T.J., Garshick, E., Natkin, J.,             
                   Reaser, P., Lane, K., Lee, H.K.                               

  **Journal:**     *Chemosphere*, 61, 1677-1690                      **Year:**   2005

  **Purpose**:     To analyze air pollutant concentrations in the                
                   workplaces of various trucking companies during               
                   the winter                                                    
  ---------------- ------------------------------------------------- ----------- ------

  ---------------- ------------------------------------------------- ----------- ------
  **Title:**       **Study of exhaust emissions from idling                      
                   heavy-duty diesel trucks and commercially                     
                   available idle-reducing devices**                             

  **Author(s):**   Lim, H.                                                       

  **Journal:**     *United States Environmental Protection Agency*   **Year:**   2002
                   (EPA420-R-02-025)                                             

  **Purpose**:     To understand exhaust emissions and fuel                      
                   consumption due to long-duration idling in                    
                   different weather conditions and accessory loads              
  ---------------- ------------------------------------------------- ----------- ------

  ---------------- ------------------------------------------------- ----------- ------
  **Title:**       **Project level carbon monoxide hot-spot analysis             
                   for level of service D intersections**                        

  **Author(s):**   Meng, Y. and Niemeier, D.                                     

  **Journal:**     *Transportation Research Record: Journal of the   **Year:**   1998
                   Transportation Research Board,* 1641, 73-80.                  

  **Purpose**:     To present a screening methodology for modeling               
                   carbon monoxide concentrations at level of                    
                   service D intersections using meteorological                  
                   situation-orientated reference charts                         
  ---------------- ------------------------------------------------- ----------- ------

  ---------------- ------------------------------------------------------------------------------------------------------ ----------- ------
  **Title:**       [**Characteristics and emissions of heavy-duty vehicles in Tennessee under the MOBILES                             
                   model**](http://trb.metapress.com/content/9281l5u302810722/?p=71f7b524980b4db2979912b5a71d6d7e&pi=1)               

  **Author(s):**   Miller, T.L., Davis, W.T., Reed, G.D., Doraiswamy, P., and Fu, J.S.                                                

  **Journal:**     *Transportation Research Record: Journal of the Transportation Research Board,* 1842/2003, 99-108      **Year:**   2003

  **Purpose**:     To compare characteristics of heavy-duty vehicles in the state of Tennessee with that described by                 
                   national data in the MOBILE6 model and to propose a new method for classifying vehicles                            
  ---------------- ------------------------------------------------------------------------------------------------------ ----------- ------

  ---------------- ------------------------------------------------- ----------- ------
  **Title:**       **Corrections to mileage accumulation rates for               
                   older vehicles and the effect on air pollution                
                   emissions**                                                   

  **Author(s):**   Miller, T.L., Davis, W.T., Reed, G.D.,                        
                   Doraiswamy, P., Tang, A., and Sanhueza, P.                    

  **Journal:**     *Transportation Research Record: Journal of the   **Year:**   2001
                   Transportation Research Board,* 1750, 49-55                   

  **Purpose**:     To present a model for predicting average                     
                   cumulative mileage for older vehicles to be used              
                   in estimating emissions levels                                
  ---------------- ------------------------------------------------- ----------- ------

  ---------------- ------------------------------------------------- ----------- ------
  **Title:**       **Effect of county-level income on vehicle age                
                   distribution and emissions**                                  

  **Author(s):**   Miller, T.L., Davis, W.T., Reed, G.D.,                        
                   Doraiswamy, P., and Tang, A.                                  

  **Journal:**     *Transportation Research Record: Journal of the   **Year:**   2002
                   Transportation Research Board,* 1815, 47-53.                  

  **Purpose**:     To analyze trends in the types and ages of                    
                   vehicles driven in Tennessee relative to national             
                   data and to average personal income                           
  ---------------- ------------------------------------------------- ----------- ------

  ---------------- ------------------------------------------------- ----------- ------
  **Title:**       **Diesel truck idling emissions -- measurements               
                   at a PM~2.5~ hot spot**                                       

  **Author(s):**   Miller, T.L., Fu, J.S., Hromis, B., Storey,                   
                   J.M.E., and Parks, J.E.                                       

  **Journal:**     *Proceedings of the Transportation Research Board **Year:**   2007
                   86^th^ Annual Meeting*                                        

  **Purpose**:     To measure ambient concentrations of PM**~1.0~**,             
                   PM**~2.5~**, and PM**~10~** at the Watt Road                  
                   interchange on I-40 in Knoxville, TN. There are               
                   three large truck stops at this interchange, with             
                   up to 400 trucks idling at night and 20,000                   
                   trucks traveling by day.                                      
  ---------------- ------------------------------------------------- ----------- ------

  ---------------- ------------------------------------------------- ----------- ------
  **Title:**       **Diesel truck idling emissions -- mobile source              
                   air toxics measured at a hot spot**                           

  **Author(s):**   Parks, J.E., Storey, J.M.E., Miller, T.L., Fu,                
                   J.S., and Hromis, B.                                          

  **Journal:**     *Proceedings of the Transportation Research Board **Year:**   2007
                   86^th^ Annual Meeting*                                        

  **Purpose**:     To measure mobile source air toxics (MSATs)                   
                   emissions (e.g., formaldehyde, acetaldehyde,                  
                   acrolein, and other species collected on                      
                   di-nitrophenyl hydrazine (DNPH) filters) at the               
                   Watt Road interchange on I-40 in Knoxville, TN.               
  ---------------- ------------------------------------------------- ----------- ------

  ---------------- ------------------------------------------------- ----------- ------
  **Title:**       **Travel characteristics of urban freight                     
                   vehicles and their effects on emission factors**              

  **Author(s):**   Protopapas, A., Chatterjee, A., Miller, T.L., and             
                   Everett, J.                                                   

  **Journal:**     *Transportation Research Record: Journal of the   **Year:**   2005
                   Transportation Research Board,* 1941, 89-98                   

  **Purpose**:     To analyze and compare data for different                     
                   commercial vehicle usage classes to develop input             
                   parameters for the MOBILE6 model                              
  ---------------- ------------------------------------------------- ----------- ------

  ---------------- ------------------------------------------------- ----------- ------
  **Title:**       **Mass, surface area and number metrics in diesel             
                   occupational exposure assessment**                            

  **Author(s):**   Ramachandran, G., Paulsen, D., Watts, W., and                 
                   Kittelson, D.                                                 

  **Journal:**     *Journal of Environmental Monitoring*, 7, 728-735 **Year:**   2005

  **Purpose**:     To evaluate diesel exposure using three different             
                   metrics (aerosol mass, surface area, and number               
                   concentration) using three different occupational             
                   groups (bus drivers, parking garage attendants,               
                   and mechanics)                                                
  ---------------- ------------------------------------------------- ----------- ------

  ---------------- ------------------------------------------------- ----------- ------
  **Title:**       **Exposure to particulate matter, volatile                    
                   organic compounds, and other air pollutants                   
                   inside patrol cars**                                          

  **Author(s):**   Riediker, M., Williams, R., Devlin, R., Griggs,               
                   T., and Bromberg, P.                                          

  **Journal:**     *Environmental Science and Technology*, 37(1),    **Year:**   2003
                   2084-2093                                                     

  **Purpose**:     To understand the potential occupational exposure             
                   of North Carolina Highway State troopers to air               
                   pollutants by measuring the average pollutant                 
                   levels inside patrol cars                                     
  ---------------- ------------------------------------------------- ----------- ------

  ---------------- ------------------------------------------------- ----------- ------
  **Title:**       **The mobile source effect on curbside                        
                   1,3-butadiene, benzene, and particle-bound                    
                   polycyclic aromatic hydrocarbons assessed at a                
                   tollbooth**                                                   

  **Author(s):**   Sapkota, A. and Buckley, T.J.                                 

  **Journal:**     *Journal of the Air and Waste Management          **Year:**   2003
                   Association*, 53, 740-748                                     

  **Purpose**:     To measure human exposure (to benzene and                     
                   1,3-butadiene) with respect to vehicle volume and             
                   class                                                         

  **Notes:**       Vehicles with more 2 axles produced higher levels             
                   of air pollutants than 2-axle vehicles (9 times               
                   more benzene, 32 times more 1,3-butadiene, and 60             
                   times more particle-bound PAH)                                
  ---------------- ------------------------------------------------- ----------- ------

  ---------------- ------------------------------------------------- ----------- ------
  **Title:**       **Exposure to Diesel Exhaust Emissions on Board               
                   Locomotives**                                                 

  **Author(s):**   Seshagiri, B.                                                 

  **Journal:**     *American Industrial Hygiene Association          **Year:**   2003
                   Journal*, 64, 678-683                                         

  **Purpose**:     To measure elemental carbon concentrations of                 
                   diesel exhaust emissions in train cabs                        
  ---------------- ------------------------------------------------- ----------- ------

  ---------------- ------------------------------------------------- ----------- ------
  **Title:**       **Overview of particulate exposure in the U.S.                
                   trucking industry**                                           

  **Author(s):**   Smith, T.J., Davis, M.E., Reaser, P., Natkin, J.,             
                   Hart, J.E., Laden, F., Heff, A., and Garshick, E.             

  **Journal:**     *Journal of Environmental Monitoring*, 8, 711-720 **Year:**   2006

  **Purpose**:     To measure occupational exposure to diesel                    
                   exhaust and other common environmental pollutants             
                   at various work sites (e.g., terminal sites,                  
                   office, dock area, shop areas)                                
  ---------------- ------------------------------------------------- ----------- ------

  ---------------- ------------------------------------------------- ----------- ------
  **Title:**       **Mobile source air toxics from idling trucks --              
                   A report from the Mexican Border**                            

  **Author(s):**   Storey, J.M.E., Lewis Sr., S.A., Zietsman, J.,                
                   Villa, J.C., and Forrest, T.L.                                

  **Journal:**     *Proceedings of the Transportation Research Board **Year:**   2007
                   86^th^ Annual Meeting*                                        

  **Purpose**:     To estimate idling emissions (in particular MSATs             
                   and diesel PM) from trucks crossing at the El                 
                   Paso -- Ciudad Juarez border                                  
  ---------------- ------------------------------------------------- ----------- ------

  ---------------- ------------------------------------------------- ----------- ------
  **Title:**       **Particulate matter and aldehyde emissions from              
                   idling heavy-duty diesel trucks**                             

  **Author(s):**   Storey, J.M.E., Thomas, J.F., Lewis Sr., S.A.,                
                   Dam, T.Q., Edwards, K.D., DeVault, G.L., and                  
                   Retrossa, D.J.                                                

  **Journal:**     2003 SAE World Congress (SAE Technical Paper      **Year:**   2003
                   Series 2003-01-0289), Detroit, MI, March 3-6,                 
                   2003                                                          

  **Purpose**:     To measure diesel emissions from in-use idling                
                   trucks at the Aberdeen Test Center and to examine             
                   the impact of idle reduction technologies on                  
                   emission levels                                               
  ---------------- ------------------------------------------------- ----------- ------

  ---------------- ------------------------------------------------- ----------- ------
  **Title:**       **A simultaneous job- and task-based exposure                 
                   evaluation of petroleum tanker drivers to benzene             
                   and total hydrocarbons**                                      

  **Author(s):**   Verma, D.K., Cheng, W.K., Shaw, D.S., Shaw, M.L.,             
                   Verma, P., Julian, J.A., Dumschat, R.E., and                  
                   Mulligan, S.J.P.                                              

  **Journal:**     *Applied Occupational and Environmental Hygiene*, **Year:**   2004
                   1, 725-737                                                    

  **Purpose**:     To evaluate petroleum tanker drivers' exposure to             
                   benzene per task (e.g., loading, unloading, and               
                   travel) and on a full-shift basis                             
  ---------------- ------------------------------------------------- ----------- ------

  ---------------- ------------------------------------------------- ----------- ------
  **Title:**       **Diesel exhaust exposure in the Canadian                     
                   railroad work environment**                                   

  **Author(s):**   Verma, D.K., Finkelstein, M.M., Kurtz, L.,                    
                   Smolynec, K., and Eyre, S.                                    

  **Journal:**     *Applied Occupational and Environmental Hygiene*, **Year:**   2003
                   18(1), 25-34                                                  

  **Purpose**:     To investigate occupational exposure to diesel                
                   exhaust in the railroad industry. Specifically,               
                   to collect and measure elemental carbon levels in             
                   diesel exhaust and compare it to other industries             
  ---------------- ------------------------------------------------- ----------- ------

  ---------------- ------------------------------------------------- ----------- ------
  **Title:**       **A comparison of sampling and analytical methods             
                   for assessing occupational exposure to diesel                 
                   exhaust in a railroad work environment**                      

  **Author(s):**   Verma, D.K., Shaw, L., Julian, J., Smolynek, K.,              
                   Wood, C., and Shaw, D.                                        

  **Journal:**     *Applied Occupational and Environmental Hygiene*, **Year:**   1999
                   14(10), 701-714                                               

  **Purpose**:     To evaluate sampling methods for measuring diesel             
                   exhaust in the railroad environment                           
  ---------------- ------------------------------------------------- ----------- ------

  ---------------- ------------------------------------------------- ----------- ------
  **Title:**       **Comparison of daytime and nighttime                         
                   concentration profiles and size distribution of               
                   ultrafine particles near a major highway**                    

  **Author(s):**   Zhu, Y., Kuhn, T., Mayo, P., and Hinds, W.C.                  

  **Journal:**     *Environmental Science and Technology*, 40(8),    **Year:**   2006
                   2531-2536                                                     

  **Purpose**:     To measure the concentration and size                         
                   distribution of ultrafine particles near major                
                   highways during the day and at night                          
  ---------------- ------------------------------------------------- ----------- ------

  ---------------- ------------------------------------------------- ----------- ------
  **Title:**       **Toxic Gases In Heavy Duty Diesel Truck Cabs**               

  **Author(s):**   Ziskind, R., Carlin, T., Axelrod, M., Allen,                  
                   R.W., and Schwartz, S.H.                                      

  **Journal:**     FHWA-RD-77-139                                    **Year:**   1977

  **Purpose**:     To measure in-cab concentrations of carbon                    
                   monoxide, nitric oxide, and nitrogen dioxide.                 
  ---------------- ------------------------------------------------- ----------- ------