Final Report 

Chicago O’Hare Airport 

Air Toxic Monitoring Program 

June – December, 2000 

Illinois Environmental Protection Agency 

Bureau of Air 

May 2002 
i

 Table of Contents

Section Page No.

Executive Summary ii

1.0 Air Monitoring Program Description

 1.1 Background 1

 1.2 Monitoring Objectives 2

 1.3 Monitoring Network 2

 1.4 Laboratory Methods and Quality Assurance 4

2.0 Sampling Results

 2.1 Reporting Units 5

 2.2 Program Data 5

3.0 Findings

 

 3.1 Chicago Area Measurements 6

 

 3.2 Geographic Area Analysis 6

 3.3 Comparison of Results to Other U.S. Cities 10

 

 3.4 O’Hare Airport Impact 11

4.0 Conclusions 16

5.0 References 17

Appendix I. Description of Air Monitoring Sites 21

Appendix II. List of Toxic Air Pollutants 26

Appendix III. Project Sampling Data 27 

Appendix IV. Meteorological Summary of Sampling Days 40

Appendix V. General Information for Selected Target Compounds 44
ii

Executive Summary 

O’Hare International Airport (O’Hare) is one of the world’s busiest airports and the subject of 

much interest regarding the environmental impact airport operations have on the surrounding 

community and the Chicago area in general. As part of its fiscal year 2001 air monitoring 

program, the Illinois EPA measured the airborne levels of various air contaminants in the 

vicinity of O’Hare as well as at other locations in the Chicago area. The purpose of this 

measurement program was to collect information that would help assess the relative impact of 

airport related emissions and levels of airborne contaminants characteristic of large urban areas. 

This monitoring program will supplement a national program designed to assess and minimize 

the impact of toxic air contaminants in urban areas. The national program is referred to as the 

National Integrated Urban Air Toxics Strategy (National Strategy). 

The National Strategy was developed by the United States Environmental Protection Agency 

(USEPA) in response to requirements specified in the federal Clean Air Act. Under these 

requirements, USEPA is charged with assessing the impact of airborne levels of various air toxic 

compounds on human health in urban areas of the United States and taking action to reduce risks 

caused by unacceptable levels of such contaminants. In July 1999, the USEPA released its 

National Strategy describing a framework for addressing air toxic emissions from stationary and 

mobile sources such as O’Hare Airport. As part of the National Strategy, air monitoring 

programs are to be used to identify and measure compounds believed to present the greatest 

concern to public health in urban areas. 

Federal and State funding was provided to allow the initiation of an urban air toxic monitoring 

program in calendar year 2000. The funding was adequate to support a limited air quality 

investigation of targeted compounds through a six month monitoring program with two sites 

located near O’Hare Airport and three other sites in the Chicago metropolitan area. The 

monitoring program began in June 2000 and focused on the urban air toxic compounds identified 

in USEPA’s National Strategy and on mobile source emissions associated with airport 

operations. The compounds sampled included volatile organics, semi-volatile organics, 

carbonyls and trace metals. The monitoring program ended in December 2000. 

The Chicago area toxics monitoring program, as deployed in 2000, was designed to provide data 

to meet four objectives: 

1) Measure the concentrations of specific compounds of concern; 

2) Assess the geographic variability of various compounds in the Chicago area and 

perform a comparison of levels measured at the two O’Hare sites to those recorded 

at the remaining three Chicago area locations; 

3) Compare Chicago area results to data collected for other large U.S. cities; and 

4) Determine if the emissions associated with O’Hare Airport have a measurable 

impact on air quality in areas adjacent to the airport. 
iii

In order to measure the concentrations of the target compounds, comprehensive sampling was 

conducted on sixteen days through the six month period of June through December 2000, using a 

once every twelve days sampling schedule. The sampling results were summarized for each of 

the five monitoring sites and tabulated into two categories, Urban Air Toxic compounds and 

Hazardous Air Pollutants (HAPs). The Urban Air Toxics compounds are those identified by 

USEPA in the National Strategy that present the greatest threat to public health in urban areas, 

including known or suspected cancer risks from compounds such as benzene, formaldehyde, 

chromium and dioxins. The HAPs are compounds required to be regulated by USEPA under the 

Clean Air Amendments of 1990 that are known or suspected to cause cancer or have other 

serious health effects but are not included in the list of Urban Air Toxic compounds covered 

under the National Strategy. The HAPs measured included such compounds as ethyl benzene, 

styrene, toluene, xylenes and various polycyclic aromatics such as naphthalene and 

phenanthrene. The tabulated data included the individual daily sampling results along with the 

overall average concentration found for each target compound. 

The program’s sampling sites were located to provide air toxic measurements at different points 

across the Chicago metropolitan area, thereby allowing for a comparison of the levels found at 

O’Hare Airport to those found in different parts of the metropolitan area. In addition to the two 

sites located near O’Hare in Bensenville and Schiller Park, sites were also located in Northbrook, 

just north of the urban core, at Washington School in highly industrialized Southeast Chicago, 

and in Lemont, just downwind of major refineries and chemical complexes and on the 

southwestern edge of the metropolitan area. 

A review and analysis of the accumulated monitoring results obtained from the five site 

monitoring network provided the following findings: 

1. The average concentrations measured at O’Hare Airport for many of the target 

compounds were found to be comparable with the concentrations found at the other 

Chicago area sites; 

2. The highest concentrations of several target urban air toxic compounds were found 

to be spread between several sites but generally the highest levels for many of the air 

toxics were found to occur in Southeast Chicago; 

3. The lowest concentrations of most target compounds were measured at Lemont. 

A comparison of measured levels of urban air toxics in Chicago to those found in other large 

cities served as a point of reference to what would be considered “typical urban” concentrations. 

USEPA’s Aerometric Storage and Retrieval System (AIRS) was accessed to obtain the air 

quality data collected from monitoring sites nationwide. A review of information submitted to 

AIRS found that data for certain air toxic compounds had been reported for a number of large 

urbanized areas. Based upon a comparison of the results from the Chicago area monitoring 

program to that collected for other large U.S. cities data, it was found that: 

1. Concentrations of several of the principal urban air toxics, such as acetaldehyde, 

benzene, and formaldehyde, compared to the metropolitan areas of Atlanta, Detroit, 

Houston and Milwaukee, were found to be comparable or lower in the Chicago 

metropolitan area. 
iv

2. The acetaldehyde and formaldehyde levels measured near O’Hare Airport were 

comparable or lower than levels measured in Atlanta, Detroit and Houston. 

In order to assess the possible impact of emissions from O’Hare Airport on adjacent areas, two 

monitoring sites were deployed on different sides of the airport. This configuration allowed for 

the collection of sampling data on wind persistent days that would align one site to be upwind, 

unaffected by the airport, and the other to be downwind and subject to airport emissions. The 

difference in concentrations found between the two sites on those wind-persistent days allowed 

for an approximation of the airport’s impact. Of the sixteen sampling days, five days had such 

wind-persistent conditions. An analysis of the results from those five days found the downwind 

site to record levels of some target compounds from 20-85% higher than the upwind site. The 

compounds with measurable differences included acetaldehyde, benzene, formaldehyde, 

polycyclic organics, toluene and lead. All of those compounds have been associated with 

emissions from airport operations. An impact from the airport was not unexpected since airport 

operations are sources of various air contaminants. The concentrations measured downwind of 

O’Hare were at levels considered to be “typical” of an urban area and in some cases lower than 

values measured in other cities. 

Based upon the review of the air toxics monitoring data collected near O’Hare Airport, from 

other Chicago area sites, and from USEPA’s AIRS database, the following conclusions were 

reached: 

1. The levels of air toxic compounds found near O’Hare and other sites in the Chicago 

metropolitan area were comparable or lower than those found in other large U.S. 

cities. 

2. The highest levels of most air toxic compounds measured in the Chicago area were 

found in Southeast Chicago. 

3. An analysis of data collected from the sites at O’Hare found that emissions from the 

Airport have an impact on the air quality in adjacent communities, but that impact 

did not result in levels higher than those found in a typical urban environment. 

The data collected through this study’s air monitoring program indicated that the toxics air 

quality in the vicinity of O’Hare Airport is comparable to the air quality in other parts of Chicago 

and comparable to the air quality in other major urban areas. There are continuing and ongoing 

efforts, such as through USEPA’s National Strategy, to identify, assess and reduce risk from air 

toxics in and around urban areas. 
1

Section 1.0 Air Monitoring Program Description

1.1 Background

Ambient air monitoring for a limited number of air toxic compounds has been conducted 

in Illinois for many years. Measurement of airborne particulate metals, some of which 

are considered haza rdous air pollutants (HAPs), has been done statewide since the early 

1970s. In the early 1990s, the Photochemical (Ozone) Assessment Monitoring (PAMS) 

program began collecting data for volatile organic compounds, which included a number 

of compounds considered to be urban air toxics; e.g., benzene and formaldehyde. The 

PAMS program has been limited to the Chicago metropolitan area. Beyond these two 

programs, air toxic monitoring efforts have been minimal due to a lack of any specific 

regulatory requirements.

In July 1999, as part of its national program to reduce ambient levels of air toxics, the 

United States Environmental Protection Agency (USEPA) released its National 

Integrated Urban Air Toxics Strategy (National Strategy). Reference 1. The National 

Strategy presented a framework for addressing air toxic emissions from stationary 

sources and mobile sources such as Chicago’s O’Hare Airport. An integral part of 

National Strategy called for the establishment of air monitoring programs to begin 

collecting data needed to characterize the ambient concentrations of certain compounds 

known to present the greatest concern for public health in urban areas. 

A preliminary assessment of the air toxic emissions from O’Hare Airport and the 

resulting health effects created by the toxic emissions in surrounding communities was 

sponsored the City of Park Ridge, Illinois, in early 2000. Reference 2. The Park Ridge 

Study concluded that toxic emissions from O’Hare had a widespread impact and 

presented an associated health risk to residents in the communities surrounding O’Hare. 

The Park Ridge Study also identified the need for better assessment of the data used in 

the study and recommended that comprehensive air monitoring be conducted around 

O’Hare and in impacted communities. These data could then be used to conduct a more 

complete and comprehensive air quality analysis.

In the fall of 1999, federal and state funding became available to allow the initiation of an 

urban air toxic monitoring program in Illinois. The funding was adequate to support a 

preliminary air quality investigation of targeted compounds through a six month 

monitoring program with two sites near O’Hare Airport and at three other sites in the 

Chicago metropolitan area. The monitoring program began in June 2000 and focused on 

the urban air toxic compounds identified in USEPA’s National Strategy and on mobile 

source emissions associated with airport operations. The compounds of interest included 

volatile organics, semi-volatile organics, carbonyls and trace metals. The monitoring 

program ended in December 2000.
2

1.2 Monitoring Objectives

The Chicago area air toxics monitoring network deployed in 2000 was designed to 

provide data to meet the following objectives:

1. Determine ambient concentrations of specific compounds of concern;

2. Describe pollutant levels at various locations across the area, assess their 

geographic variability and perform a comparison of the levels of air toxics 

found at O’Hare Airport to other sites in the Chicago area;

3. Provide monitoring results consistent with nationally available air toxics 

information that would allow for a comparison of Chicago area results to data 

collected for other large U.S. cities; and

4. Determine if the target compound emissions from O’Hare Airport have a 

measurable impact on air quality in the surrounding communities.

To meet the above objectives, the focus was on the compounds identified by USEPA as 

Urban Air Toxics and on other compounds known to be emitted by mobile sources (e.g., 

cars, trucks and aircraft). Particular attention was placed on those compounds associated 

with aircraft operations; e.g., takeoff, landing, refueling and idling. 

1.3 Monitoring Network

The monitoring program consisted of five sampling sites located as shown in Figure 1 

that were operated to collect calendar day samples (24-hour integrated samples) on a 

once every 12 day schedule throughout the period of June through December 2000. Air 

monitoring sites were located with two near O’Hare Airport, in Bensenville and Schiller 

Park, one site in Northbrook just downwind (North) of the urban core, at ChicagoWashington in highly industrialized Southeast Chicago, and in Lemont, an area impacted 

by refineries and on the southwestern edge of the metropolitan area.

The site selections were made based upon a review of historical meteorological data from 

the National Weather Service and from air quality data collected as part of the Illinois air 

monitoring network. The sites selected at O’Hare were located to fall into two areas 

where predominant winds would provide the greatest frequency of impact from airport 

operations. The location of other significant emission sources, such as expressways, 

major arterial streets and industrial sources of organic compounds, was also a 

consideration in the final site selections. The sites were also located in areas with 

population exposure; e.g., non-remote areas along the fenceline, to allow the estimation 

of target compound concentrations in public areas adjacent to the airport.

A complete description of each of the five sampling sites is provided in Appendix I. The 

descriptions provided include location details (address, building), immediate site locale, 

distance from influencing sources (roadways, airports, industry), landmarks and a 

photograph showing the site exposure. All of the sites were established in USEPA’s 

Aerometric Information Retrieval System (AIRS) complete with the required site 

description information.
#Y

#Y

#Y

#Y

#Y

Lemont

Chicago Washington H.S.

Northbrook

Bensenville Schiller Park

290

294

90

55

294

290

57

80

94 and 90

90 and 94

294 and 80

88

290

90

94

294

88

57

94

355

55

355

290

Cook and DuPage County Boundaries

Interstates

Chicago O'Hare International Airport

#Y Air Monitoring Sites

Chicago Area

Toxic Network

Legend

N

0 2 4 6 8 10 Miles June-December, 2000

Illinois EPA

Bureau of Air

Figure 1
4

Each monitoring site deployed four separate sampling systems to collect a wide-range of 

compounds on each sampling day. The samplers and analytical methods selected were 

consistent with those designated and approved by USEPA. The systems deployed 

included a VOC canister system with sample analysis by method TO-15, DNPH 

cartridge sampler with analysis by method TO-11A for carbonyls, high volume air 

sampler with filter analysis by atomic absorption for metals and PUF sampler with 

analysis by TO-13A method for semi-volatile organics. Appendix II provides a listing of 

specific compounds, considered either as an Urban Toxic or HAP, obtained for each of 

these sampling and analysis methods.

The sampling schedule utilized provided that 24-hour samples were collected on a 

calendar day basis once every 12 days. The schedule overlapped the national one-in-six 

day schedule used for the particulate and PAMS networks. The collected samples 

coincided with samples collected on the same days in other states. Sampling commenced 

on June 17, 2000, and ended on December 26, 2000, providing a total of 16 sampling 

days.

1.4 Laboratory Methods and Quality Assurance

All of the analytical methods used have been recognized and approved by USEPA. The 

four methods used were as follows:

1. volatile organics (53 compounds) - TO-15, gas chromatography with mass

 spectroscopy (confirmation)

2. carbonyls (14 compounds) - TO-11a, high pressure liquid 

 chromatography

3. semi-volatile organics (18 cmpds) - TO-13a gas chromotagraphy and mass

 spectroscopy analysis

4. particulate metals (8 compounds) - atomic absorption 

The above analytical methods provide analyses for additional compounds not shown in 

Appendix II. For example, there are 18 compounds listed under Appendix II, Volatile 

Organics (Category I), but Method TO-15 tests for 53 compounds. This report provides 

the results for all compounds reported by the analytical method.

For the purposes of this report, values are reported according to the Method Detection 

Limit (MDL). The MDL, as defined by USEPA, is the minimum concentration of a 

substance that can be measured and reported with 99% confidence that the target 

compound concentration is greater than zero, and is determined from analysis of a sample 

in a matrix containing the target compound. Analytical results were reported as zero for 

those values below the MDL. 

Quality assurance activities were conducted in a manner consistent with the PAMS and 

particulate sampling programs. This included flow audits, some duplicate sampling for 
5

precision (metals, VOCs), replicate analyses (VOCs) and independent performance audits 

(blind samples) for metals, VOCs and carbonyls. The maintenance and calibration 

procedures used were those provided in the Illinois Quality Assurance Plan for use in the 

Illinois air monitoring network and those that have been approved by USEPA.

2.0 Sampling Results 

2.1 Reporting Units

This report provides both summaries of the accumulated sampling results and data tables 

that present the individual sample values. Because of the nature of the toxic compounds; 

i.e., gases and solid particles, the results are expressed in different units. The volatile 

organic compound and carbonyl data in this report has been reported in parts per billion 

by volume (ppbv). It is important to note that PAMS data are typically reported in parts 

per billion by carbon (ppbc) and that the PAMS data used in this report have been 

converted from ppbc to ppbv. 

Data for the semi-volatile organic compounds and particulate metals have been reported 

in the units of nanograms per cubic meter, with the exception that the dioxins and furans 

data have been reported in picograms per cubic meter due to their extreme low 

concentration. Nanograms are 10-9 grams and picograms are 10-12 grams.

The data available from USEPA’s AIRS database is reported in many different units and 

care should be taken when using AIRS data to note the units reported with each value. 

For example, particulate metals can be reported in micrograms per cubic meter, 

nanograms per cubic meter or picograms per cubic meter.

2.2 Program Data

The Chicago O’Hare air toxics monitoring program began in June 2000, and concluded in 

December 2000. During the seven month period, 24-hour integrated samples were 

collected on 16 calendar days. The results obtained for each individual compound on the 

16 sampling days for each of the five monitoring sites have been summarized and are 

provided in Appendix IIIA through Appendix IIIF. The sampling results for each site 

have been presented in two categories, “Urban Air Toxic Compounds” which include 

compounds designated in USEPA’s National Strategy and “Hazardous Air Pollutants 

(HAPS)” listed by USEPA as air toxic compounds which potentially can have adverse 

public health impacts. For example, Appendix IIIA lists the individual daily sampling

results for Urban Air Toxic compounds measured at Bensenville and Appendix IIIB lists 

the daily HAPS values measured at Bensenville.

The focus of the data analysis included in this report was placed on the compounds 

designated as Urban Air Toxics and on other HAPS known to be emitted by mobile 

sources with emphasis on those associated with airport operations. These “target” 

compounds include those identified in the Park Ridge Study as the chemicals that 

contribute most significantly to risks associated with O’Hare aircraft emissions. 
6

Section 3.0 Findings

3.1 Chicago Area Measurements

 A primary objective of the Chicago urban area air toxics monitoring program was to 

determine ambient concentrations of specific “target” compounds of concern at various 

locations in the metropolitan area. The accumulated sampling data at each site then 

allowed for a determination of the typical concentrations that might be expected in each 

area. The data collected at each site have been summarized in Table 1 that provides the 

average concentration for each target compound at each of the five sampling sites. The 

values reported represent the arithmetic average of the results obtained on each of the 16 

sampling days.

Of the target compounds, only vinyl chloride and 1,1,2,2-tetrachloroethylene were not 

found at a concentration above the sampling methods MDL and have values reported as 

zero. Acrolein was detected only on one day at two sites, Northbrook and ChicagoWashington, in a concentration that would allow a minimal average to be reported. 

Essentially, the average concentration of acrolein was zero at all five sites. While these 

three compounds are considered to be important urban air toxic compounds and may be 

found in significant concentration in some urbanized areas; e.g. Southern California, they 

do not appear to be in measurable levels in the Chicago Metropolitan Area.

All of the other target compounds were found in concentrations above the MDL at all 

five sites. The compounds of most interest, including acetaldehyde, benzene, chromium 

formaldehyde, polycyclic organics and dioxins, were found at concentrations well above 

the MDL. USEPA identified benzene, formaldehyde, chromium and dioxins in their 

National Strategy as those compounds that present the greatest risk to public health in 

urban areas. The Park Ridge Study identified acetaldehyde, formaldehyde, benzene and 

napthalene (a major component of polycyclic organics) as those chemicals that contribute 

most significantly to risks associated with aircraft emissions. The concentrations of these 

compounds found, as shown in Table 1, serve to demonstrate the levels at which they 

might be expected to occur in the Chicago metropolitan area. The following sections 

describe the results of additional data analyses needed to assess the significance of the 

presence of these compounds.

 3.2 Geographic Area Analysis 

In order to better understand the significance of the measured concentrations, a 

comparison of the results found from site to site provided insight into the urban nature of 

the some toxic compounds and identified compounds or areas that showed notable 

differences. The monitoring network design placed the sampling sites in areas with 

differing emission source impacts, thereby allowing an analysis of the results found in 

different areas across the urbanized area. The Bensenville and Schiller Park sites were 

located near O’Hare Airport in areas impacted by airport operations and the traffic in the 

surrounding expressways and major arterial streets. The Northbrook site was located just 

north and downwind of the urban core (Chicago Loop) in a high population density area 
7

impacted by emissions generated throughout the urbanized area. The ChicagoWashington site was located in highly industrialized Southeast Chicago in an area 

impacted by numerous large point source (industrial) emissions. The Lemont site was 

located on the southwestern edge of the metropolitan area in an area impacted by 

refineries and chemical manufacturing facilities.

The review of the monitoring results for each of the target compounds, as recorded at 

each monitoring site, provided the following findings:

1. The average concentrations of target compounds measured at the O’Hare 

Airport sites were found to be comparable to those measured at the other 

metropolitan area sites.

This fact is readily seen from the data presented in Table 1 and from Figures 

2a and 2b which graphically display the five site results for various target 

compounds. As the figures show, the highest concentration of the individual 

target compounds was found to vary between different sampling sites. For 

example, highest levels of benzene were found at Chicago-Washington, while 

highest acetaldehyde levels were at Bensenville and highest formaldehyde 

levels at Schiller Park. Generally, the levels of the target compounds were 

found to be comparable between the five sites. For example, benzene 

averages ranged from 0.33 to 0.69 ppbv, acetaldehyde from 0.60 to 1.07 ppbv, 

formaldehyde from 1.67 to 3.54 ppbv and polycyclic organics (PAHs) levels 

ranged from 140 to 298 nanograms per cubic meter. 

2. Of the five monitoring sites, the highest levels of more target compounds was 

found at the Chicago-Washington site found than any other site.

Using a difference of 20% to indicate a significantly higher value (that is, the 

highest average found was at least 20% higher than the average found at any 

other site), the Chicago-Washington site was found to have the highest levels 

of seven target compounds including benzene, chromium, polycyclic organics 

and dioxins. Table 2 presents a listing by site of target compounds that were 

found to be 20% higher at one site. Four of the five sites recorded the highest 

concentration of at least one compound, with Schiller Park recording the 

highest level of three targets, Bensenville with three targets and Northbrook 

recording the highest levels of one target.

Taken as a group of target compounds, these data indicate that the highest 

concentration of air toxic compounds in the Chicago area was found in 

industrialized Southeast Chicago, not around O’Hare Airport.

3. Two target compounds, acetaldehyde and formaldehyde, were found to be

higher at the O’Hare Airport sites than at any of the other Chicago area sites.
Figure 2a

Comparison of Results by Site

Site Listing

B - Bensenville

S - Schiller Park

C - Chicago Washington

N - Northbrook

L - Lemont

8

Formaldehyde

0.00

0.50

1.00

1.50

2.00

2.50

3.00

3.50

4.00

B S C N L

Average (ppb)

Acetaldehyde

0.00

0.20

0.40

0.60

0.80

1.00

1.20

B S C N L

Average (ppb)

Chromium

0.0

1.0

2.0

3.0

4.0

5.0

6.0

7.0

8.0

9.0

10.0

B S C N L

Average (ng/m3)

Nickel

0.0

1.0

2.0

3.0

4.0

5.0

6.0

7.0

8.0

9.0

10.0

B S C N L

Average (ng/m3)

Benzene

0.00

0.10

0.20

0.30

0.40

0.50

0.60

0.70

0.80

B S C N L

Average (ppb)
Figure 2b

Comparison of Results by Site

Site Listing

B - Bensenville

S - Schiller Park

C - Chicago Washington

N - Northbrook

L - Lemont

NA - Samples not taken for these compounds

9

Perchloroethylene

0.00

0.10

0.20

0.30

0.40

0.50

0.60

0.70

B S C N L

Average (ppb)

Trichloroethylene

0.00

0.20

0.40

0.60

0.80

1.00

1.20

1.40

B S C N L

Average (ppb)

PAHs

0

50

100

150

200

250

300

B S C N L

Average (ng/m3)

NA

Dioxin

0.00

0.50

1.00

1.50

2.00

2.50

3.00

B S C N L

Average (pg/m3)

NA

Toluene

0.00

0.20

0.40

0.60

0.80

1.00

1.20

1.40

1.60

1.80

2.00

B S C N L

Average (ppb)
10

The highest acetaldehyde levels were measured at Bensenville with an 

average of 1.07 ppbv compared to the next highest average of 0.88 ppbv

 recorded at Schiller Park and Lemont. The highest formaldehyde level 

 recorded was at Schiller Park at 3.54 ppbv compared to the next highest value

 of 2.16 ppbv measured at Bensenville. These data indicated that the

 highest levels of aldehydes found during this monitoring study

 occurred around O’Hare Airport.

 The major source of aldehyde emissions in any large metropolitan area has

 been shown to be from mobile sources: cars, trucks and aircraft. The area in

 and around O’Hare Airport has a concentration of cars and trucks on the

 expressways (I-90 and I-294), major arterials (Mannhiem, Irving Park and

 Higgins Roads) and in traffic entering and leaving the airport. Airport 

 operations including aircraft takeoffs, landings, taxiing, refueling and

 support equipment emissions are also sources of aldehydes. With the

 accumulation of these emissions in the area, elevated concentrations of

 aldehydes in the surrounding area would not be unexpected and was likely the

 influencing factor in the levels measured at Bensenville and Schiller Park.

4. The lowest concentrations of most target compounds were measured at the

Lemont site.

While it is near major emission sources such as refineries and chemical plants, 

Lemont is located southwest of the Chicago urban area and lies predominantly 

upwind of it, measuring levels entering the area from downstate and outside 

the area impacted by the Chicago area emissions. As a result, it would be 

expected, as the monitoring data showed, that air toxic levels in Lemont are 

lower than the other monitoring sites located in the urbanized area.

 3.3 Comparison of Results to Other U.S. Cities

A comparison of the measured levels of certain target air toxic compounds found in 

Chicago to those found in other large U.S. cities provided a point of reference to what 

concentrations might be considered as “typical” for an urban area. The comparative 

analyses also identified any unusual or atypical compound measurements for the Chicago 

area.

The other U.S. cities data was extracted from USEPA’s AIRS database that contains air 

quality data collected and reported nationwide. The most recent data reported to AIRS 

was almost exclusively 1999, as no 2000 data had yet been reported, and was used for 

reference in this report. The averages reported from AIRS were based upon sampling 

periods of six to twelve months, consistent with and comparable to the six month average 

data compiled from the June-December 2000 sampling in Chicago. 
11

A review of the information submitted to AIRS found that data for a limited number of 

the target air toxic compounds, obtained primarily from PAMS monitoring networks, had 

been reported for several large urbanized areas, including Atlanta, Detroit, Houston, 

Milwaukee and New York City. The target compound data reported for these cities 

included acetaldehyde, benzene, formaldehyde, toluene and xylenes. The AIRS data 

used in the comparative analysis has been summarized in Table 3. A review and analysis 

of the available information concluded the following:

1. Compared to other major metropolitan areas; e.g., Atlanta, Detroit, Houston

and Milwaukee, concentrations of key “target” air toxic compounds were 

found to be comparable or lower in the Chicago metropolitan area. The

comparative analysis indicated that the levels found at the Chicago area

sites were typical of those found in the other large urban areas.

The data from Table 3 and the corresponding compound data from Table 1 

has been graphically displayed in Figure 3. The highest formaldehyde levels 

were found in Atlanta and Detroit, 5.72 and 5.13 ppbv respectively, compared 

to 3.54 ppbv at Schiller Park, the highest Chicago area site. The highest 

acetaldehyde levels were found in Atlanta and Houston, 2.40 and 1.69 ppbv, 

compared to 1.07 ppbv at Bensenville. The highest benzene levels were found 

in Houston and Detroit, 0.97 and 0.70 ppbv, compared to 0.69 ppbv at 

Chicago-Washington. The highest leve ls of toluene were found in New York 

City at 1.34 ppbv, compared to 1.99 ppbv at Bensenville. The highest levels 

of xylenes were found in Atlanta at 1.22 ppbv compared to 0.90 ppbv at 

Bensenville.

2. The comparative analysis shows that target air toxic compounds measured in 

the Chicago area to be typical of other large urban areas. The concentrations 

of some key target compounds were found to be significantly higher in cities 

like Atlanta and Houston. The acetaldehyde and formaldehyde levels 

measured at O’Hare, while the highest of Chicago area sites, were well below 

those found in Atlanta, Detroit, and Houston.

 3.4 O’Hare Airport Impact

In order to assess the possible impact of O’Hare Airport emissions in areas adjacent to 

the airport, two monitoring sites were deployed on different sides of the airport. This 

allowed for collection of sampling data on days with persistent winds that impacted one 

site but not the other. Essentially, one site was upwind, unaffected by the airport, and the 

other site was downwind of the airport and subjected to its emissions. See the following 

diagram. The difference in the results obtained from the downwind site (impacted by

emissions) and the upwind site (unaffected) provides an indication of the increased levels 

of target compounds associated with the airport’s emissions. For example, the downwind 

site measured a compound concentration at 1.50 ppb and the upwind site reported only 

1.00 ppb, providing a difference of 0.50 ppb (1.50 minus 1.00) or that levels were found 

to be 50% higher at the downwind site (0.50 divided by 1.00).
12

WIND

X

Upwind

Site

X

Downwind

Site

Of the sixteen sampling days, five days did have wind-persistent conditions that allowed 

for a upwind /downwind analysis. The sampling data obtained for each of the five days 

for key target compounds has been presented in Figure 4 along with wind roses (wind 

frequency distribution) that depict the associated wind direction data. Figure 4 also 

provides for each target compound the average value obtained from the five samples for 

the wind positive site and the wind negative site and the calculated percent difference 

(wind positive to wind negative). The Figure 4 wind roses illustrate the site impacts, 

Bensenville located southwest of the airport impacted by winds from the north to east, 

and Schiller Park located east of the airport impacted by winds from the southwest to 

northwest.

The data analysis demonstrated that O’Hare Airport emissions had an impact in the areas 

adjacent to the airport for several key target compounds, including acetaldehyde, 

benzene, formaldehyde, polycyclic organics and lead. All these compounds are Urban

Air Toxics and have been identified as associated with airport operations. The 

downwind concentration of acetaldehyde was found to be 45.6% higher than upwind, 

formaldehyde was 32.8% higher, benzene was 34.1% higher, polycyclics (PAHs) were 

65.9% higher and lead was 87.5% higher. An impact from airport operations was not 

unexpected as airport operations, including aircraft takeoffs, landings, taxiing, refueling 

and use of support equipment, result in significant emissions of volatile organics and 

target air toxic compounds. The resulting airport emissions should have had, as the 

monitoring data shows, some impact in the areas adjacent to the airport. While the 

downwind concentrations were found to be higher, the results showed that the levels 

found at O’Hare Airport are still in the “typical urban” range and lower than levels found 

in other large urban areas.

Appendix IV provides a detailed summary of the meteorological conditions which were 

present on each of the sampling days. The appendix also includes a summary table that 

provides for each sampling day the frequency distribution of hourly wind data, which has 

also been plotted in a wind rose shown in Figure 5. As can be seen from that summary 

table, the most prevalent wind directions on sampling days were winds from the west 

southwest, west and the northeast. These three wind directions provided the opportunity 

for frequent impact of airport emissions on the two O’Hare area monitoring sites. 

EMISSION

SOURCE
Figure 3

Comparison of Results to Other U.S. Cities

Site Listing

A - Atlanta

D - Detroit

H - Houston

M - Milwaukee

NY - New York

B - Bensenville

S - Schiller Park

C - Chicago Washington

13

Formaldehyde

0.00

1.00

2.00

3.00

4.00

5.00

6.00

A D H M NY B S C

Average (ppb)

Acetaldehyde

0.00

0.50

1.00

1.50

2.00

2.50

A D H M NY B S C

Average (ppb)

Benzene

0.00

0.10

0.20

0.30

0.40

0.50

0.60

0.70

0.80

0.90

1.00

A D H M NY B S C

Average (ppb)

Toluene

0.00

0.50

1.00

1.50

2.00

A D H M NY B S C

Average(ppb)

Xylene

0.00

0.20

0.40

0.60

0.80

1.00

1.20

1.40

A D H M NY B S C

Average (ppb)
Figure 4

Wind Persistence Days

Upwind/Downwind Analysis

Downwind Upwind

Percent

Compound 7/23 8/16 9/21 11/20 12/14 Avg 7/23 8/16 9/21 11/20 12/14 Avg Difference

Formaldehyde 2.56 3.32 1.64 0.94 3.09 2.31 1.72 3.04 1.89 0.32 1.73 1.74 32.8%

Acetaldehyde 1.29 1.33 0.56 0.36 1.73 1.05 0.53 0.76 1.00 0.23 1.10 0.72 45.6%

Benzene 0.90 0.24 0.19 1.07 0.60 0.50 0.09 0.13 1.07 0.45 34.1%

PAH(s) 311 175 48 126 440 220 220 10 37 46 350 133 65.9%

Lead 30 60 10 20 30 30 10 10 20 20 20 16 87.5%

Toluene 2.50 0.31 0.16 1.63 1.15 1.00 0.21 0.10 2.52 0.96 20.1%

Chromium 5 6 5 5 5 5 5 7 2 3 3 4 30.0%

Xylenes 1.20 0.25 0.15 1.33 0.73 0.60 0.07 0.02 1.61 0.58 27.4%

axis represents percent of time

14

0.0

5.0

10.0

15.0

20.0

25.0

N

NNE

NE

ENE

E

ESE

SE

SSE

S

SSW

SW

WSW

W

WNW

NW

NNW

Bensenville Downwind

Sampling Days

0.0

5.0

10.0

15.0

20.0

25.0

30.0

35.0

N

NNE

NE

ENE

E

ESE

SE

SSE

S

SSW

SW

WSW

W

WNW

NW

NNW

Calm - 1.4%

Schiller Park Downwind

Sampling Days
15

Figure 5

Wind Rose O'Hare Toxic Project

June - December, 2000

Sampling Days Only

0.0

2.0

4.0

6.0

8.0

10.0

12.0

N

NNE

NE

ENE

E

ESE

SE

SSE

S

SSW

SW

WSW

W

WNW

NW

NNW

Axis represents percent of time Calm = 0.5 %
16

Section 4.0 Conclusions

 Based upon the review of the air toxics monitoring data collected near Chicago O’Hare 

Airport and from other Chicago area monitoring sites and data from USEPA’s AIRS 

database, the following conclusions were reached:

1. The levels of air toxic compounds found near O’Hare Airport and at other

sites in the Chicago metropolitan area are “typical” or lower that those levels 

found in other large U.S. cities.

2. Of the Chicago area sites, the highest levels of acetaldehyde and

formaldehyde were found at the O’Hare Airport sites. However, the

concentrations found were at levels comparable or lower than those found in 

other large U.S. cities.

3. Of the Chicago area sites, the highest levels of most air toxic compounds was

not found near O’Hare Airport, but in industrialized Southeast Chicago.

4. An analysis of data from the sites near O’Hare Airport found that emissions

from the airport have an impact on air quality in the areas adjacent to the 

airport. However, the airport’s impact did not result in levels higher than 

those found in a typical urban environment.

 The data collected through this study’s air monitoring program indicated that the toxics 

air quality in the vicinity of O’Hare Airport is comparable to the air quality in other parts 

of Chicago and comparable to air quality in other major urban areas. 

 

There are continuing efforts to identify, assess and reduce risk from air toxics, especially 

in urban areas. For example, USEPA has completed a nationwide study of potential 

inhalation exposures and health risks associated with 32 HAPs and from diesel particulate 

matter based on 1996 air emissions inventories, known as the National-Scale Air Toxics 

Assessment (NATA). This study has not yet been released to the public, but it will serve 

as a basis for characterizing risk associated with these compounds on a county by county 

level throughout the U.S. As a continuing part of the federal Clean Air Act requirements 

to identify, assess and reduce risk from toxic pollutants, USEPA has also developed the 

National Strategy. Part of the National Strategy is to develop a plan that will attain a 

75% reduction in the incidence of cancer attributable to exposure to HAPs emitted by 

stationary sources, to attain a substantial reduction in public health risks posed by 

exposure to HAP emissions from area sources, and to address disproportionate impacts of 

air toxics across urban areas. USEPA has announced that part of the regulatory actions to 

implement this strategy will include, among others, the development and implementation 

of maximum achievable control technology or MACT standards to reduce emissions of 

HAPs from major source categories beyond those already required under section 112 (d) 

of the Clean Air Act, developing area source standards, and regulating motor vehicle 

emissions and fuels. Moreover, the Chicago Area Cumulative Risk Initiative (CRI) is an 

ongoing community-based effort to assess cumulative air pollution hazards and to then 
17

develop strategies to reduce risks posed by exposure in the Cook County, Illinois and 

Lake County, Indiana. USEPA and the Illinois EPA are cooperating in this effort, and an 

assessment of the risks identified is expected to be released in the Summer of 2002. 

In addition to these efforts, the development and implementation of MACT standards 

required under Section 112 (d) of the Clean Air Act are ongoing. For example, USEPA 

has published over 70 air toxic MACT standards affecting over 113 categories of 

industrial sources, with varying implementation schedules. By May 15, 2002, USEPA 

will have published 106 MACT standards affecting a total of 174 categories of industrial 

sources. After publishing a MACT for a source category, the Clean Air Act also requires 

USEPA to assess and address the remaining risk from these source categories after the 

implementation of the MACT standard and within eight to nine years after the 

development of the initial standard. This effort is now ongoing for the earliest MACT 

standards. In addition to the efforts to address stationary sources, USEPA continues to 

address toxic emissions from motor vehicles and fuels, a major component of toxic 

emissions from O’Hare. USEPA has also promulgated the final rule for “Control of 

Emissions of Hazardous Air Pollutants from Mobile Sources” under Section 202(l) of the 

Clean Air Act. 

Section 5.0 References 

1. USEPA, “National Air Toxics Program: The Integrated Urban Strategy”, Federal 

 Register/Vol. 64, No. 137/ Monday, July 19, 1999. 

2. City of Park Ridge, “Preliminary Study and Analysis of Toxic Air Pollutant 

Emissions from O’Hare International Airport and the Resulting Health Risks Created 

by these Toxic Emissions in Surrounding Residential Communities, Volumes I-IV, 

August, 2000. 

3. USEPA, “Unified Air Toxics Website”, Technology Transfer Network (TTNWeb). 
Lemont

acetaldehyde 0.88

acrolein 0.00

arsenic1

0.70

benzene 0.45

beryllium1

0.10

1,3-butadiene 0.02

cadmium1

2.00

carbon tetrachloride 0.06

chloroform 0.01

chromium1

2.90

ethylene dichloride 0.00

formaldehyde 1.67

lead1

14.4

manganese 25.1

methylene chloride 0.23

nickel1

4.60

1,1,2,2-tetrachloroethane 0.00

perchloroethylene 0.05

trichloroethylene 0.03

toluene 0.77

vinyl chloride 0.00

xylenes (O,M,P) 0.56

polycyclic organics (PAH)1 NA

dioxins (2,3,7,8 total)2 NA

2

values expressed in in picograms per cubic meter (pg/m3)

*values are averages expressed in parts per billion by volume (ppbv) unless otherwise indicated

4.50 7.10 9.20

Table 1

Air Toxic Target Compound Results*

June - December, 2000

Compound Northbrook

1.07 0.88 0.72 0.60

Bensenville Schiller Park Chicago-Washington

0.00 0.00 0.01 0.01

1.10 1.00 1.00 0.70

0.55 0.50 0.69 0.33

0.30 0.50 0.46 0.30

0.08 0.11 0.12 0.02

2.20 2.70 2.60 2.10

0.07 0.07 0.08 0.07

0.18 0.44 0.55 0.14

0.25 0.26 0.15 0.25

2.16 3.54 1.90 1.67

22.7 16.7 31.5 12.0

25.7 31.5 139.9 17.5

0.46 0.07 0.47 0.27

7.00 8.60 6.80 5.30

0.00 0.00 0.00 0.00

0.52 0.34 0.52 0.61

0.00 0.00 0.00

1.37 0.66 0.65 0.59

3.50

172.0 171.0 298.0 140.0

1.99 1.02 0.97 0.80

0.00

0.42

1.399 1.464 2.389 1.956

1

values expressed in nanograms per cubic meter (ng/m3)

0.90 0.61 0.53

18
Lemont

none

*Concentration of the target compound was found to be at least 20% higher than all other sites.

Northbrook

perchloroethylene

Table 2

Urban Air Toxic Compounds

Sites with Highest Concentration*

benzene formaldehyde acetaldehyde

Chicago-Washington Bensenville Schiller Park

chloroform nickel trichloroethylene

chromium toluene xylenes

dioxins

lead

manganese

polycyclic organics

19
Table 3

Air Toxic Data for U.S. Cities

1999 AIRS Data1 

Atlanta Detroit Houston New York Milwaukee Chicago3 

Pollutant (GA) (MI) (TX) City (WI) Study

acetaldehyde 2.40 1.29 1.69 0.96 1.02 1.07

benzene 0.52 0.70 0.97 0.53 0.38 0.69

1-3 butadiene NR 0.10* 0.52 NR 0.13 20.12

formaldehyde 5.72 5.13 4.14 2.96 2.50 3.54

xylenes (m/p) 1.22 0.34 0.47 0.92 0.53 20.90

toluene 0.98 0.84 1.06 1.34 0.84 21.99

1

all values reported in parts per billion volume (ppbv)

*value reported from Midland, MI

 NR - Not Reported

2

values reported in 1998 Wisconsin DNR Report

3

 highest value reported at any of the five Chicago Study sites

20
21

Appendix I

Description of Monitoring sites

Bensenville

This monitoring site is located on the Village of Bensenville sewage treatment plant at 

711 E. Jefferson. Industrial/commercial areas are located east of the site (0.5 – 1.0 km). 

Immediately southwest are residential areas. A large railyard is located 0.5 – 1.0 km 

northeast to east. The closest runway at O’Hare Airport is located 2.5 km to the 

northeast. Irving Park Road is 1.2 km to the north and Mannheim Road is 1.7 km to the 

southeast at its closest point. The Chicago loop is approximately 25 km to the southeast. 

The following picture is from Bensenville looking northeast.
22

Schiller Park

This monitoring site is located on a trailer at 4743 Mannheim Road just south or 

Lawrence Ave. and between Mannheim Road and I-294. The closest runway at O’Hare 

Airport is 0.5 km to the northwest. The immediate vicinity is mostly commercial. 

Residential areas are located east across I-294. Mannheim Road is 30 m to the west and 

I-294 is 100 m to the east. The Chicago loop is located approximately 21 km to the 

southeast. The following picture is from Schiller Park looking northwest.
23

Chicago – Washington High School

This monitoring site is located on Washington High School at 3535 E. 114th Street in the 

Lake Calumet industrial region. Residential areas are located east of the site (from north 

to south). Industrial areas are located west (northwest to southwest) of the site. The 

Indiana border is approximately 1 km to the east. The Chicago loop is approximately 23 

km to the northwest. The following picture is from Washington H.S. looking northwest.
24

Northbrook

The village of Northbrook is located in northeast Cook County. This monitoring site is 

located at the Northbrook Water Filtration Station at 750 Dundee Road. A forest 

preserve is located immediately south with residential areas further south (southeast to 

southwest). Residential areas are also immediately to the west. Commercial areas are 

located along Dundee Road and to the east. A major expressway (I94) is located 1 km to 

the east and north. O’Hare Airport is located 18 km to the southwest and the Chicago 

loop is located 32 km to the southeast. The following picture is from the Northbrook site 

looking northeast.
25

Lemont

The village of Lemont is located in southwest Cook County approximately 38 km from 

the Chicago loop. This monitoring site is located on Lemont High School at 800 Porter 

Street. The building is situated on the edge of the bluffs overlooking the Des Plaines 

River valley. The area surrounding the site is residential to the south (southwest to 

southeast) and to the immediate north (down the bluff). Several industrial and 

commercial facilities are located along the Des Plaines River to the west and southwest in 

the valley. The following picture is from the Lemont site looking north.
26

Appendix II

Toxic Air Pollutants

HAPs

Analytical

Method HAPs

Analytical

Method

Category I Volatile Organics (VOC) Category IV Semi-volatiles

benzene TO-14A/TO-15 acenaphthene TO-13A

carbon tetrachloride TO-14A-TO-15 acenaphthylene TO-13A

chloroform TO-14A/TO-15 anthracene TO-13A

chloroprene TO-14A-TO-15 benzo(ghi)perylne TO-13A

1,4-dichlorobenzene TO-14A-TO-15 fluoranthene TO-13A

ethylene dibromide TO-14A-TO-15 fluorene TO-13A

ethylene dichloride TO-14A-TO-15 naphthalene TO-13A

hexachlorobenzene TO-14A-TO-15 phenanthrene TO-13A

methyl bromide TO-14A-TO-15 pyrene TO-13A

methyl chloride TO-14A-TO-15 benz(a)anthracene TO-13A

styrene TO-14A-TO-15 benzo(a)pyrene TO-13A

tetrachloroethylene TO-14A-TO-15 benzo(b)fluoranthene TO-13A

toluene TO-14A-TO-15 benzo(k)fluoranthene TO-13A

trichloroethylene TO-14A-TO-15 chrysene TO-13A

vinyl chloride TO-14A-TO-15 dibenz(a,h)anthracene TO-13A

xylenes TO-14A-TO-15 indeno(1,2,3-cd)pyrene TO-13A

1,3-butadiene TO-14A-TO-15 2,3,7,8-Tetrachlorodibenzo-p

acrylonitrile TO-14A-TO-15 -dioxin (and congeners and TCDF

 congeners)

TO-13A

----------------------------------------------------------------------------------------------------------------

Category II Carbonyls Category V Metals

acetaldehyde TO-11A antimony & compounds IO-3.5

acrolein TO-11A arsenic & compounds IO-3.5

formaldehyde TO-11A beryllium & compounds IO-3.5

cadimum & compounds IO-3.5

chromium & compounds* IO-3.5

lead & compounds IO-3.5

manganese & compounds IO-3.5

mercury & compounds IO-3.5

nickel & compounds IO-3.5

*Chromium determined from a filter is total chromium, not chromium VI. Chromium VI

oxidizes when sampled on a filter.
Appendix IIIA

Bensenville Air Toxic Data *

6/17 6/29 7/11 7/23 8/4 8/16 8/28 9/9 9/21 10/3 10/18 10/31 11/8 11/20 12/14 12/26 Average

Urban Air Toxic Compounds

acetaldehyde 0.43 1.29 1.82 1.33 1.62 1.02 1 1.53 1.19 1.31 0.45 0.23 1.1 0.63 1.07

acrolein 0 0 0 0 0 0 0 0 0 0.04 0 0 0 0 0.00

acrylonitrile 0 0 0 0 0 0 0 0 0.00

arsenic 1 1 1 1 2 2 0 1 0 4 0 1 0 1 1 1.1

benzene 0.3 0.3 0.9 0.09 0.61 1.51 0.42 0.22 0.13 1.07 0.5 0.55

beryllium (1) 0 3 0 0 0 0 0 0 1 0 0 0 0 0 0 0.3

1,3-butadiene 0 0 0 0 0.11 0.43 0 0 0 0.3 0.08 0.08

cadmium (1) 2 2 2 2 2 2 2 1 2 2 2 3 3 3 3 2.2

carbon tetrachloride 0 0.04 0.09 0.04 0.1 0.1 0.08 0.11 0.07

chloroform 0 2 0 0 0 0 0 0 0 0 0 0.18

chromium (1) 5 5 5 7 6 6 2 2 7 6 6 3 3 3 1 4.5

1,2-dibromoethane 0 0.5 0.6 0 0 0 0 0 0 0 0 0.10

1,2-dichloropropane 0 0 0.4 0 0 0 0 0 0 0 0 0.04

1,2-dichloropropene 0 0 0.7 0 0 0 0 0 0 0 0 0.06

1,2-dichloroethane 0 0 2.7 0 0 0 0 0 0 0 0 0.25

formaldehyde 1.2 2.56 4.17 3.32 4.03 2.31 1.89 3.01 1.72 1.98 0.81 0.32 1.73 1.14 2.16

lead (1) 10 10 30 30 60 20 10 20 30 20 40 10 20 20 10 22.7

manganese (1) 8 14 2 33 43 52 18 12 45 38 67 14 19 17 3 25.7

methylene chloride 0 0 1.6 0 0.38 2.34 0.26 0.16 0 0.26 0.07 0.46

nickel (1) 6 5 7 9 11 8 5 4 10 8 10 6 7 5 4 7.0

polycyclic organics(PAH) (1) 157 311 220 175 95 37 136 85 319 220 46 350 90 172

1,1,2,2-tetrachloroethane 0 0 0 0 0 0 0 0 0 0 0 0.00

perchloroethylene 0.1 1.2 3.2 1.1 0 0.08 0.26 0 0.16 0 0.09 0 0.52

trichloroethylene 1 4.4 4.7 0 0.27 2.81 0 1.47 0 0.4 0.04 1.37

vinyl chloride 0 0 0 0 0 0 0 0 0 0 0 0.00

dioxins(2,3,7,8) (2) 0.156 0.742 0.584 2.09 1.58 2.24 1.53 1.7 0.228 2.59 1.33 2.36 1.06 1.399

furans(2,3,7,8) (2) 0.066 0.165 0.15 0.646 0.25 0.25 0.226 0.143 0.107 0.304 0.475 0.616 0.259 0.281

27
Appendix IIIA

Bensenville Air Toxic Data *

6/17 6/29 7/11 7/23 8/4 8/16 8/28 9/9 9/21 10/3 10/18 10/31 11/8 11/20 12/14 12/26 Average

Hazardous Air Pollutants

1,4-dichlorobenzene 0 0.2 0.9 0 0 0 0 0 0 0.08 0 0.11

1,2,4-trimethylbenzene 0 0.1 0.4 0 0.57 1 0.18 0.09 0 0.66 0.09 0.28

1,3,5-trimethylbenzene 0.1 0.1 0.2 0 0.2 0.32 0.05 0.02 0 0.23 0.02 0.11

ethyl benzene 0.06 0.1 0.3 0 0.31 0.71 0.18 0.06 0.02 0.35 0.07 0.20

hexachlorobutadiene 0 0.2 0 0 0 0 0 0 0 0 0 0.02

methyl bromide 0 0 0 0 0 0 0 0 0 0 0 0.00

styrene 0.2 0.2 0.06 0 0.06 0.26 0 0.07 0 0.06 0 0.08

toluene 0.6 1.1 2.1 2.5 5.6 0.21 2.87 5.28 1.17 1.19 0.1 2.52 0.68 1.99

xylenes 0.4 0.5 1.2 1.3 0.07 1.35 3.04 0.65 0.28 0.02 1.61 0.34 0.90

propionaldehyde 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0.00

crotonaldehyde 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0.00

butyraldehyde 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0.00

isovaleraldehyde 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0.00

valeraldehyde 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0.00

tolualdehydes 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0.00

hexanaldehyde 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0.00

2,5-dimethylbenzaldehyde 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0.00

acenaphthene (1) 8.7 33.1 19.1 13 6.2 1.7 7.4 2.7 15.8 9.5 1.2 5.8 1.6 9.7

acenaphthylene (1) 0 0 0 0 0 0 0 0 6.4 19.2 0 9.8 0 2.7

anathracene (1) 0 0 0 0 0 0 0 0 0 0 0 0 0 0.0

benzo(ghi)perylene (1) 0 0 0 0 0 0 0 0 0 0 0 0 0 0.0

fluoranthene (1) 9.1 7.5 10.1 8.2 3.6 1.5 3.4 1.4 4.5 6 1.3 3.3 1.5 4.7

fluorene (1) 12.2 31.7 20.9 14 9.2 2.5 8.4 3.6 15.4 14.4 1.9 9.4 3.4 11.3

naphthalene (1) 75.1 144 89.5 88 49.5 20.8 89.7 64 238 127 37.2 294 73.5 106.9

phenanthrene (1) 46.8 90.5 70.2 42.9 25 9.5 25.4 13.3 36 35.9 4.9 22.3 8.7 33.2

pyrene (1) 0.7 3.8 5.9 5 2 1.1 2.1 0 3.3 5.1 0 3.5 1.2 2.6

benza(a)anthracene (1) 0 0 0 0 0 0 0 0 0 0 0 0 0 0.0

benzo(a)pyrene (1) 0 0 0 0 0 0 0 0 0 0 0 0 0 0.0

benzo(b)fluoranthene (1) 0 0 2.6 2.1 0 0 0 0 0 1.6 0 1 0 0.6

benzo(k)fluoranthene (1) 0 0 0 0 0 0 0 0 0 0 0 0 0 0.0

chrysene (1) 0 0.9 1.6 1.5 0 0 0 0 0 1.6 0 1.1 0 0.5

dibenzo(a,h)anthracene (1) 0 0 0 0 0 0 0 0 0 0 0 0 0 0.0

indeno(1,2,3-cd)pyrene (1) 0 0 0 0 0 0 0 0 0 0 0 0 0 0.0

28
Appendix IIIB

Schiller Park Air Toxic Data *

6/17 6/29 7/11 7/23 8/4 8/16 8/28 9/9 9/21 10/3 10/18 10/31 11/8 11/20 12/14 12/26 Average

Urban Air Toxic Compounds

acetaldehyde 0.78 0.85 0.67 0.53 1.02 0.76 1.09 0.17 0.56 1.5 1.46 0.36 1.73 0.8 0.88

acrolein 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0.00

acrylonitrile 0 0 0 0 0 0 0 0 0.00

arsenic (1) 1 1 1 2 4 1 0 1 1 3 0 0 0 0 0 1.0

benzene 0.08 0.6 0.5 0.49 0.24 0.8 0.61 0.66 0.29 0.19 1.07 0.50

beryllium (1) 0 4 1 0 0 0 0 0 1 0 0 0 0 1 1 0.5

1,3-butadiene 0 0.6 0 0 0 0.11 0.14 0 0.08 0 0.28 0.11

cadmium (1) 2 2 2 2 2 2 6 2 2 1 2 4 3 5 4 2.7

carbon tetrachloride 0.09 0.04 0.05 0.04 0.03 0.12 0.1 0.08 0.07

chloroform 1.4 3.4 0 0 0 0 0 0 0 0 0 0.44

chromium (1) 5 7 5 8 7 9 21 5 10 9 1 6 5 5 4 7.1

1,2-dibromoethane 0 0 0.7 0 0 0 0 0 0 0 0 0.06

1,2-dichloropropane 0 0 0 0 0 0 0 0 0 0 0 0.00

1,2-dichloropropene 0 0.3 0.5 0 0 0 0 0 0 0 0 0.07

1,2-dichloroethane 0.3 1.3 1.3 0 0 0 0 0 0 0 0 0.26

formaldehyde 2.29 3.32 2.28 1.72 3.26 3.04 4.04 17.92 1.64 2.19 2.26 0.94 3.09 1.61 3.54

lead (1) 10 0 10 10 10 20 10 10 30 20 50 10 20 30 10 16.7

manganese (1) 30 20 17 24 27 57 22 21 42 47 91 21 18 23 12 31.5

methylene chloride 0 0 0 0.06 0 0.15 0.12 0.16 0.11 0 0.21 0.07

nickel (1) 8 5 7 9 10 8 6 6 11 8 12 8 8 16 7 8.6

polycyclic organics(PAH) (1) 173 220 164 10 150 48 26 252 306 140 126 440 165 171

1,1,2,2-tetrachloroethane 0 0 0 0 0 0 0 0 0 0 0 0.00

perchloroethylene 0.4 1.2 1.8 0 0.08 0 0.04 0 0.08 0 0.1 0.34

trichloroethylene 1.6 2.5 2.1 0 0 0.12 0.06 0.4 0.31 0 0.22 0.66

vinyl chloride 0 0 0 0 0 0 0 0 0 0 0 0.00

dioxins(2,3,7,8) (2) 0.164 0.316 0.51 0.925 1.61 1.08 2.64 1.8 2.62 1.73 1.05 2.66 1.93 1.464

furans(2,3,7,8) (2) 0 0.289 0.07 0.196 0.503 0.108 0.053 0.113 0.834 0.165 0.322 0.795 0.768 0.324

29
Appendix IIIB

Schiller Park Air Toxic Data *

6/17 6/29 7/11 7/23 8/4 8/16 8/28 9/9 9/21 10/3 10/18 10/31 11/8 11/20 12/14 12/26 Average

Hazardous Air Pollutants

1,4-dichlorobenzene 0.3 0.2 0 0 0 0 0 0 0 0 0 0.05

1,2,4-trimethylbenzene 0.2 0.1 0.2 0.15 0.08 0.24 0.28 0.19 0.15 0 0.51 0.19

1,3,5-trimethylbenzene 0 0.1 0.09 0.03 0 0.07 0.1 0.05 0.05 0 0.16 0.06

ethyl benzene 0.09 0.1 0.1 0.15 0.06 0.24 0.2 0.16 0.12 0.05 0.33 0.15

hexachlorobutadiene 0.3 0.2 0.4 0 0 0 0 0 0 0 0 0.08

methyl bromide 0 0 0 0 0 0 0 0 0 0 0 0.00

styrene 0.2 0.2 0.05 0.64 0 0.03 0.12 0.03 0.04 0 0.08 0.13

toluene 1.2 1.1 1 0.65 0.31 1.96 1.21 1.13 0.82 0.16 1.63 1.02

xylenes 0.39 0.5 0.6 0.51 0.25 0.98 0.8 0.66 0.54 0.15 1.33 0.61

propionaldehyde 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0.00

crotonaldehyde 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0.00

butyraldehyde 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0.00

isovaleraldehyde 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0.00

valeraldehyde 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0.00

tolualdehydes 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0.00

hexanaldehyde 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0.00

2,5-dimethylbenzaldehyde 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0.00

acenaphthene (1) 10.7 16.8 13.1 10.5 1.6 1.5 3.4 17.2 4.6 2.6 10.2 3.3 8.0

acenaphthylene (1) 0 0 0 0 0 0 0 7.6 0 0 15.3 0 1.9

anathracene (1) 0 0 0 0 0 0 0 0 0 0 0 0 0.0

benzo(ghi)perylene (1) 0 0 0 0 0 0 0 0 0 0 0 0 0.0

fluoranthene (1) 10.4 9 6.5 4.6 1.3 0.8 1.9 5.9 2.9 2.4 4.5 2.4 4.4

fluorene (1) 15.2 17.6 15 12.9 2.1 0 4.2 15.6 8 4.6 18.1 7.4 10.1

naphthalene (1) 69.6 118 79.4 87.2 35 16.7 224 214 106 103 350 132 127.9

phenanthrene (1) 60.9 53.8 45.5 32.4 7.5 6.6 17.8 38.4 16.8 10.4 34.9 17.1 28.5

pyrene (1) 5.7 4.7 3.3 2.4 1.2 0 1.4 4.6 2.3 2.4 5.6 2.5 3.0

benza(a)anthracene (1) 0 0 0 0 0 0 0 0 0 0 0 0 0.0

benzo(a)pyrene (1) 0 0 0 0 0 0 0 0 0 0 0 0 0.0

benzo(b)fluoranthene (1) 0 0 0 0 0 0 0 1.7 0 0 0 0 0.1

benzo(k)fluoranthene (1) 0 0 0 0 0 0 0 0 0 0 0 0 0.0

chrysene (1) 0 0 0.9 0 0 0 0 1.2 0 0 1.4 0.6 0.3

dibenzo(a,h)anthracene (1) 0 0 0 0 0 0 0 0 0 0 0 0 0.0

indeno(1,2,3-cd)pyrene (1) 0 0 0 0 0 0 0 0 0 0 0 0 0.0

30
Appendix IIIC

Chicago - Washington Air Toxic Data *

6/17 6/29 7/11 7/23 8/4 8/16 8/28 9/9 9/21 10/3 10/18 10/31 11/8 11/20 12/14 12/26 Average

Urban Air Toxic Compounds

acetaldehyde 0.52 0.78 0.6 0.52 1.04 0.41 0.86 0.65 0.61 0.42 1.12 0.86 0.57 0.35 1.48 0.66 0.72

acrolein 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0.14 0 0.01

acrylonitrile 0 0 0 0 0 0 0 0 0.00

arsenic (1) 1 1 1 2 2 1 1 1 1 0 0 2 0 1.0

benzene 0.6 1 0.3 0.6 0.7 1.22 0.19 0.49 0.39 0.51 0.66 1.87 0.5 0.69

beryllium (1) 0 2 2 0 0 0 0 0 1 0 0 1 0 0.46

1,3-butadiene 0 0 0 0 1.1 0.1 0 0 0 0.04 0 0.2 0.06 0.12

cadmium (1) 2 1 2 1 2 1 1 2 2 3 5 7 5 2.6

carbon tetrachloride 0.08 0.04 0.09 0.05 0.04 0.1 0.1 0.1 0.08

chloroform 0 3 0 0 3.9 0.2 0 0 0 0 0 0 0 0.55

chromium (1) 14 6 1 8 5 7 6 9 8 9 38 4 4 9.2

1,2-dibromoethane 0 0 0 0.9 0.6 0 0 0 0 0 0 0 0 0.12

1,2-dichloropropane 0 0 0 0.9 0 0 0 0 0 0 0 0 0 0.07

1,2-dichloropropene 0 0 0 0 0.5 0 0 0 0 0 0 0 0 0.04

1,2-dichloroethane 0 0.6 0 0.9 0.5 0 0 0 0 0 0 0 0 0.15

formaldehyde 1.69 2.07 1.98 1.5 2.61 1.36 3.07 1.8 1.5 1.36 3.86 1.75 1.48 0.57 2.57 1.25 1.90

lead (1) 40 10 10 20 10 20 20 40 40 30 110 30 30 31.5

manganese (1) 106 84 50 114 60 98 103 143 198 93 628 53 89 139.9

methylene chloride 0 0 0 0 0.6 0.32 0 4.5 0.1 0.33 0 0.22 0.07 0.47

nickel (1) 7 5 6 8 6 7 5 5 6 8 15 6 5 6.8

polycyclic organics(PAH) (1) 128 163 111 129 192 328 521 220 115 193 750 500 530 298

1,1,2,2-tetrachloroethane 0 0 0 0 0 0 0 0 0 0 0 0 0 0.00

perchloroethylene 0.4 0.7 1.2 2.8 1.3 0.04 0 0.2 0 0 0 0.12 0 0.52

trichloroethylene 0.9 1.9 0 2 2.9 0.05 0 0.12 0 0 0.13 0.3 0.18 0.65

vinyl chloride 0 0 0 0 0 0 0 0 0 0 0 0 0 0.00

dioxins(2,3,7,8) (2) 0.187 0.325 0.511 1.24 2.63 2.5 8.34 1.91 2.21 1.37 2.84 2.19 4.8 2.389

furans(2,3,7,8) (2) 0.025 0.058 0.049 0.577 0.207 0.15 2.05 0.267 0.398 0.422 3.62 0.386 5.35 1.043

 31
Appendix IIIC

Chicago - Washington Air Toxic Data *

6/17 6/29 7/11 7/23 8/4 8/16 8/28 9/9 9/21 10/3 10/18 10/31 11/8 11/20 12/14 12/26 Average

Hazardous Air Pollutants

1,4-dichlorobenzene 0 0.1 0.2 0 0.3 0.1 0 0.07 0.09 0.07 0 0 0 0.07

1,2,4-trimethylbenzene 0.08 0.2 0.09 0.2 0.5 0.57 0.08 0.19 0.17 0.16 0 0.41 0.11 0.21

1,3,5-trimethylbenzene 0.3 0.3 0 0.2 0.3 0.18 0 0.06 0.05 0.05 0 0.12 0.03 0.12

ethyl benzene 0 0.1 0 0.1 0.3 0.3 0.05 0.23 0.15 0.15 0.05 0.31 0.11 0.14

hexachlorobutadiene 0 0.2 0 4.1 0.9 0 0 0 0 0 0 0 0 0.40

methyl bromide 0 0 0 0 0 0 0 0 0 0 0 0 0 0.00

styrene 0.3 0.3 0 0 0.2 0.11 0 0.11 0 0.09 0 0.19 0.03 0.10

toluene 0.4 1 0.6 1.3 1.8 47.18# 0.45 1.42 0.85 0.93 0.35 1.82 0.66 0.97

xylenes 0.29 0.5 0.26 0.2 0.5 1.06 0.14 0.79 0.55 0.55 0.21 1.44 0.42 0.53

propionaldehyde 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0.00

crotonaldehyde 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0.00

butyraldehyde 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0.00

isovaleraldehyde 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0.00

valeraldehyde 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0.00

tolualdehydes 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0.00

hexanaldehyde 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0.00

2,5-dimethylbenzaldehyde 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0.00

acenaphthene (1) 13.1 18.8 14.7 13 18.2 6.4 34.6 7.5 6.4 7.9 7.7 9.8 7.7 12.8

acenaphthylene (1) 0 0 0 0 0 0 0 0 0 0 15.9 16.4 14.9 3.6

anathracene (1) 0 0 0 0 0 2 0 0 0 0 7.5 3.2 6.4 1.5

benzo(ghi)perylene (1) 0 0 0 0 0 0 0 0 0 0 0 0 0 0.0

fluoranthene (1) 8.8 5.7 3.7 4.3 6.1 9.1 20.9 0 2.7 4.6 20.8 7.2 18.4 8.6

fluorene (1) 13 19.5 11.3 14.6 18.6 10.3 30 6.7 7.1 10 16.9 17 15.9 14.7

naphthalene (1) 42.2 50.8 49.5 55.2 92.6 256 299 181 80.1 144 597 400 390 202.9

phenanthrene (1) 47.1 66.5 30.7 40.3 53.8 36.8 126 24.9 16.8 24 50.2 38.1 53.6 46.8

pyrene (1) 4.2 2.3 1.5 1.9 2.9 5.4 10 0 2.1 2.8 13.1 6.4 10.9 4.9

benza(a)anthracene (1) 0 0 0 0 0 1.9 0 0 0 0 5.8 0 4.7 1.0

benzo(a)pyrene (1) 0 0 0 0 0 0 0 0 0 0 0 0 1.7 0.1

benzo(b)fluoranthene (1) 0 0 0 0 0 0 0 0 0 0 7.5 0 0 0.6

benzo(k)fluoranthene (1) 0 0 0 0 0 0 0 0 0 0 0 0 0 0.0

chrysene (1) 0 0 0 0 0 0 0 0 0 0 7.3 2.2 6.5 1.2

dibenzo(a,h)anthracene (1) 0 0 0 0 0 0 0 0 0 0 0 0 0 0.0

indeno(1,2,3-cd)pyrene (1) 0 0 0 0 0 0 0 0 0 0 0 0 0 0.0

# - toluene value on 9/21/00 has been excluded from the average as it is a suspected anomaly and needs further investigation.

 32
Appendix IIID

Northbrook Air Toxic Data *

6/17 6/29 7/11 7/23 8/4 8/16 8/28 9/9 9/21 10/3 10/18 10/31* 11/8 11/20 12/14 12/26 Average

Urban Air Toxic Compounds

acetaldehyde 0.50 0.42 0.41 0.34 0.59 0.44 0.63 0.69 0.37 0.69 1.13 1.06 0.40 0.27 1.01 0.70 0.60

acrolein 0 0 0.2 0 0 0 0 0 0 0 0 0 0 0 0 0 0.01

acrylonitrile 0 0 0 0 0 0 0 0 0.00

arsenic (1) 1 0 1 2 1 1 1 0 0 3 0 0 0 1 0 0.7

benzene 0.3 0.3 0.3 0.5 0.17 0.4 0.49 0.09 0.28 0.14 0.47 0.49 0.33

beryllium (1) 0 3 1 0 0 0 0 0 0 0 0 0 0 0 0 0.3

1,3-butadiene 0 0 0 0 0 0 0.04 0.03 0 0 0.05 0.13 0.02

cadmium (1) 2 1 1 1 2 2 1 2 2 2 3 2 3 4 4 2.1

carbon tetrachloride 0.04 0.04 0.04 0.04 0.08 0.09 0.11 0.09 0.07

chloroform 0 1.5 0 0 0.06 0 0 0 0 0.05 0.06 0.02 0.14

chromium (1) 5 4 1 5 3 5 3 2 3 5 8 2 2 2 2 3.5

1,2-dibromoethane 0 0 0 0.5 0 0 0 0 0 0 0 0 0.04

1,2-dichloropropane 0 0 0 0 0 0 0 0 0 0 0 0 0.00

1,2-dichloropropene 0 0 0 0.4 0 0 0 0 0 0 0 0 0.03

1,2-dichloroethane 0 0.5 0 2.5 0 0 0 0 0 0 0 0 0.25

formaldehyde 1.53 1.47 1.32 0.94 1.58 1.42 2.17 1.92 1.04 1.46 2.33 1.59 1.26 1.99 3.12 1.6 1.67

lead (1) 10 0 10 10 10 20 10 10 10 20 30 10 10 10 10 12.0

manganese (1) 8 6 5 13 8 42 12 11 15 21 90 8 8 8 8 17.5

methylene chloride 0 0 0 1.4 0.04 0.2 0.17 0.32 0.91 0 0.16 0 0.27

nickel (1) 6 5 8 7 6 4 4 2 3 5 9 5 6 5 5 5.3

polycyclic organics(PAH) (1) 102 326 119 94 135 44 71 217 227 80 50 293 67 140

1,1,2,2-tetrachloroethane 0 0 0 0 0 0 0 0 0 0 0 0 0.00

perchloroethylene 0 0.7 1.1 5.3 0 0.04 0.06 0.08 0.03 0 0.03 0 0.61

trichloroethylene 0 0.9 0.4 5.4 0 0.21 0.14 0 0 0 0.03 0 0.59

vinyl chloride 0 0 0 0 0 0 0 0 0 0 0 0 0.00

dioxins(2,3,7,8) (2) 0.321 0.752 0.086 1.44 1.54 0.179 1.76 1.05 1.38 2.01 2.98 2.61 9.32 1.956

furans(2,3,7,8) (2) 0.065 0.57 0 0.397 0.378 0.18 0.128 0.071 0.334 0.22 1.49 1.13 5.27 0.787

* VOC sampling date 10/27 33
Appendix IIID

Northbrook Air Toxic Data *

6/17 6/29 7/11 7/23 8/4 8/16 8/28 9/9 9/21 10/3 10/18 10/31* 11/8 11/20 12/14 12/26 Average

Hazardous Air Pollutants

1,4-dichlorobenzene 0 0.9 0 0.1 0 0 0 0 0 0 0 0 0.08

1,2,4-trimethylbenzene 0.09 0.12 0.09 0.3 0.06 0.17 0.41 0.19 0.07 0 0.17 0.12 0.15

1,3,5-trimethylbenzene 0 0.02 0 0.1 0 0.05 0.14 0.06 0.02 0 0.05 0.04 0.04

ethyl benzene 0.06 0.08 0 0.2 0.07 0.15 0.23 0.17 0.09 0 0.12 0.09 0.11

hexachlorobutadiene 0 0.3 0.2 0 0 0 0 0 0 0 0 0 0.04

methyl bromide 0 0 0 0 0 0 0 0 0 0 0 0 0.00

styrene 0.06 0.08 0 0.1 0 0 0.1 0 0 0 0 0.03 0.03

toluene 0.3 0.6 0.2 1.4 1.9 0.34 1.06 1.77 0.92 0.55 0.1 0.79 0.5 0.80

xylenes 0.16 0.39 0.2 0.9 0.22 0.61 0.63 0.62 0.31 0.09 0.55 0.35 0.42

propionaldehyde 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0.00

crotonaldehyde 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0.00

butyraldehyde 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0.00

isovaleraldehyde 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0.00

valeraldehyde 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0.00

tolualdehydes 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0.00

hexanaldehyde 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0.00

2,5-dimethylbenzaldehyde 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0.00

acenaphthene (1) 8 22.2 11.4 8.1 9.1 2.2 5 6.2 5.3 3.3 0.8 4.7 1.3 6.7

acenaphthylene (1) 0 0 0 0 0 0 0 0 0 0 0 8.2 0 0.6

anathracene (1) 0 0 1.5 0 0 0 0 0 7.4 0 0 0 0 0.7

benzo(ghi)perylene (1) 0 0 0 0 0 0 0 0 0 0 0 0 0 0.0

fluoranthene (1) 8.8 10.7 7 4.6 6.9 1.6 2.8 2.3 4.2 2.4 1.1 2.4 11.5 5.1

fluorene (1) 10.3 21.3 12 8.8 13.4 2.3 4.3 6.8 7.1 4.7 1.6 6.6 39.3 10.7

naphthalene (1) 19.3 165 43 41.7 62.8 28.6 41.2 174 187 57.3 41.4 254 51.6 89.8

phenanthrene (1) 52 104 41.7 28.4 40.5 9.2 17.1 18.1 20.2 12 4.2 14 8.2 28.4

pyrene (1) 3.9 3.7 2.8 2.1 2.6 0 1.1 0 2.8 0 0.8 2.2 0.8 1.8

benza(a)anthracene (1) 0 0 0 0 0 0 0 0 0 0 0 0 0 0.0

benzo(a)pyrene (1) 0 0 0 0 0 0 0 0 0 0 0 0 0 0.0

benzo(b)fluoranthene (1) 0 0 0 0 0 0 0 0 0 0 0 0 0 0.0

benzo(k)fluoranthene (1) 0 0 0 0 0 0 0 0 0 0 0 0 0 0.0

chrysene (1) 0 0 0 0 0 0 0 0 0 0 0 0 0 0.0

dibenzo(a,h)anthracene (1) 0 0 0 0 0 0 0 0 0 0 0 0 0 0.0

indeno(1,2,3-cd)pyrene (1) 0 0 0 0 0 0 0 0 0 0 0 0 0 0.0

* VOC sampling date 10/27 34
Appendix IIIE

Lemont Air Toxic Data *

6/17 6/29 7/11 7/23 8/4 8/16 8/28 9/9 9/21 10/3 10/18 10/31 11/8 11/20 12/14 12/26 Average

Urban Air Toxic Compounds

acetaldehyde 1.13 0.96 1.32 1.16 0.96 0.47 0.3 0.64 1.02 0.88

acrolein 0 0 0 0 0 0 0 0 0 0.00

acrylonitrile 0 0 0 0 0 0 0 0 0.00

arsenic (1) 1 0 0 0 3 0 0 1 1 0.7

benzene 0.24 0.46 0.75 0.34 0.37 0.28 0.7 0.44 0.45

beryllium (1) 0 0 0 0 0 0 0 0 1 0.1

1,3-butadiene 0 0.04 0.04 0 0 0 0.1 0 0.02

cadmium (1) 1 2 1 1 1 3 3 3 3 2.0

carbon tetrachloride 0.05 0.04 0.09 0.04 0 0.08 0.1 0.1 0.06

chloroform 0 0 0 0 0 0 0.05 0 0.01

chromium (1) 3 2 4 3 4 3 4 2 1 2.9

1,2-dibromoethane 0 0 0 0 0 0 0 0 0.00

1,2-dichloropropane 0 0 0 0 0 0 0 0 0.00

1,2-dichloropropene 0 0 0 0 0 0 0 0 0.00

1,2-dichloroethane 0 0 0 0 0 0 0 0 0.00

formaldehyde 2.34 1.8 2.42 2.04 1.91 0.91 0.64 1.04 1.96 1.67

lead (1) 20 10 20 10 20 20 10 10 10 14.4

manganese (1) 26 9 52 14 36 18 49 16 6 25.1

methylene chloride 0.04 0.26 0.19 0.07 0.04 0.91 0.25 0.05 0.23

nickel (1) 3 3 5 3 6 5 6 5 5 4.6

polycyclic organics(PAH) (1)

1,1,2,2-tetrachloroethane 0 0 0 0 0 0 0 0 0.00

perchloroethylene 0 0.07 0.18 0 0 0.03 0.1 0 0.05

trichloroethylene 0 0.11 0.12 0 0 0 0.04 0 0.03

vinyl chloride 0 0 0 0 0 0 0 0 0.00

dioxins(2,3,7,8) (2)

furans(2,3,7,8) (2)

35
Appendix IIIE

Lemont Air Toxic Data *

6/17 6/29 7/11 7/23 8/4 8/16 8/28 9/9 9/21 10/3 10/18 10/31 11/8 11/20 12/14 12/26 Average

Hazardous Air Pollutants

1,4-dichlorobenzene 0 0 0 0 0 0 0 0 0.00

1,2,4-trimethylbenzene 0.09 0.17 0.27 0.09 0.09 0.07 0.23 0.1 0.14

1,3,5-trimethylbenzene 0 0.05 0.09 0.02 0 0.02 0.08 0.02 0.04

ethyl benzene 0.08 0.18 0.21 0.17 0.09 0.09 0.18 0.07 0.13

hexachlorobutadiene 0 0 0 0 0 0 0 0 0.00

methyl bromide 0 0 0 0 0 0 0 0 0.00

styrene 0.03 0.02 0.27 0 0.06 0 0.15 0.05 0.07

toluene 0.56 1.26 1.21 0.57 0.46 0.55 1.12 0.39 0.77

xylenes 0.33 0.71 0.83 0.93 0.33 0.31 0.74 0.27 0.56

propionaldehyde 0 0 0 0 0 0 0 0 0 0.00

crotonaldehyde 0 0 0 0 0 0 0 0 0 0.00

butyraldehyde 0 0 0 0 0 0 0 0 0 0.00

isovaleraldehyde 0 0 0 0 0 0 0 0 0 0.00

valeraldehyde 0 0 0 0 0 0 0 0 0 0.00

tolualdehydes 0 0 0 0 0 0 0 0 0 0.00

hexanaldehyde 0 0 0 0 0 0 0 0 0 0.00

2,5-dimethylbenzaldehyde 0 0 0 0 0 0 0 0 0 0.00

acenaphthene (1)

acenaphthylene (1)

anathracene (1)

benzo(ghi)perylene (1)

fluoranthene (1)

fluorene (1)

naphthalene (1)

phenanthrene (1)

pyrene (1)

benza(a)anthracene (1)

benzo(a)pyrene (1)

benzo(b)fluoranthene (1)

benzo(k)fluoranthene (1)

chrysene (1)

dibenzo(a,h)anthracene (1)

indeno(1,2,3-cd)pyrene (1)

36
Footnotes for Appendices IIIA-E

* - values expressed in parts per billion volume (ppbv) unless otherwise noted

(1) - values expressed in nanograms per cubic meter (ng/m3)

(2) - values expressed in picograms per cubic meter (pg/m3)

37
Collection Air volume 2378-PCDFs 2378-PCDDs Total PCDD/F PAH N-PAH Other

Field ID MRI ID Date (m3 )

a

pg/m3pg/m3pg/m3μg/m3μg/m3μg/m3

Bensenville 00001134 7/11/00 299.5 0.0661 0.156 0.778 0.157 ND 0.0588

North Brook 00001135 7/11/00 143.8 0.0647 0.321 0.532 0.102 ND 0.0570

Schiller Park 00001136 7/11/00 238.2 ND 0.164 0.473 0.173 ND 0.0443

Washington HS 00001137 7/11/00 314.8 0.0250 0.187 0.549 0.128 ND 0.0434

Bensenville 00001156 7/23/00 335.0 0.165 0.742 1.18 0.311 ND 0.00873

North Brook 00001154 7/23/00 385.8 0.570 0.752 1.55 0.326 ND 0.00827

Schiller Park 00001153 7/23/00 365.3 0.289 0.316 0.605 0.220 ND 0.0100

Washington HS 00001155 7/23/00 299.7 0.0579 0.325 0.641 0.163 ND 0.0137

Bensenville 00001251 8/4/00 333.4 0.150 0.584 1.00 0.220 ND 0.0231

North Brook 00001249 8/4/00 343.6 ND 0.0856 0.117 0.119 ND 0.0763

Schiller Park 00001248 8/4/00 345.6 0.0700 0.510 0.804 0.164 ND 0.0220

Washington HS 00001247 8/4/00 153.2 0.0492 0.511 0.711 0.111 ND 0.0240

Bensenville 00001326 8/16/00 236.7 0.646 2.09 4.64 0.175 ND 0.309

North Brook 00001329 8/16/00 227.6 0.397 1.44 2.75 0.0938 ND 0.0351

Schiller Park 00001328 8/16/00 307.4 0.196 0.925 1.65 0.00972 ND 0.0634

Washington HS 00001330 8/16/00 299.6 0.577 1.24 4.67 0.129 ND 0.241

Bensenville 00001486 8/28/00 238.2 0.250 1.58 2.48 0.0953 ND 0.144

North Brook 00001485 8/28/00 229.0 0.378 1.54 2.44 0.135 ND 0.0435

Schiller Park 00001487 8/28/00 275.7 0.503 1.61 3.14 0.150 ND 0.0317

Washington HS 00001489 8/28/00 149.9 0.207 2.63 4.00 0.192 ND 0.0640

Bensenville 00001650 9/20/00 258.5 0.250 2.24 2.71 0.0371 ND 0.0274

North Brook 00001653 9/20/00 204.0 0.180 0.179 0.613 0.0440 ND 0.0451

Schiller Park 00001651 9/20/00 268.6 0.108 1.08 1.19 0.0485 ND 0.0183

Washington HS 00001654 9/20/00 150.9 0.150 2.50 3.57 0.328 ND 0.0424

Bensenville 00001722 10/3/00 230.0 0.226 1.53 2.01 0.136 ND 0.111

North Brook 00001720 10/3/00 225.8 0.128 1.76 1.91 0.0714 ND 0.0807

Schiller Park 00001723 10/3/00 299.6 0.0527 2.64 2.82 0.0256 ND 0.0593

Washington HS 00001721 10/3/00 38.7 2.05 8.34 11.4 0.521 ND 0.355

Appendix IIIF

 Summary of PCDDs, PCDFs, PAHs, Nitro-PAHs, and

Semivolatile Vapor Plus Particulate Results

38
Collection Air volume 2378-PCDFs 2378-PCDDs Total PCDD/F PAH N-PAH Other

Field ID MRI ID Date (m3 )

a

pg/m3pg/m3pg/m3μg/m3μg/m3μg/m3

Bensenville 00001808 10/18/00 240.9 0.143 1.70 2.40 0.0850 ND 2.76

North Brook 00001807 10/18/00 226.4 0.0710 1.05 1.47 0.207 ND 0.255

Schiller Park 00001809 10/18/00 324.0 0.113 1.80 2.66 0.252 ND 0.0618

Washington HS 00001810 10/18/00 155.9 0.266 1.91 3.53 0.220 ND 6.41

Bensenville 00001901 11/1/00 317.8 0.107 0.228 1.83 0.319 ND 0.00906

North Brook 00001899 11/1/00 281.8 0.334 1.38 3.38 0.227 ND 0.00565

Schiller Park 00001900 11/1/00 326.1 0.834 2.62 7.19 0.306 ND 0.0327

Washington HS 00001903 11/1/00 224.5 0.398 2.21 4.07 0.115 ND 0.225

Bensenville 00001920 11/9/00 304.2 0.304 2.59 3.26 0.220 ND 0.0287

North Brook 00001922 11/9/00 273.4 0.220 2.01 2.79 0.0797 ND 0.0210

Schiller Park 00001921 11/9/00 326.7 0.165 1.73 2.24 0.140 ND 0.0411

Washington HS 00001925 11/9/00 234.3 0.422 1.37 2.80 0.193 ND 0.0352

Bensenville 00002076 11/21/00 319.0 0.475 1.33 2.27 0.0465 ND 0.0302

North Brook 00002077 11/21/00 274.4 1.49 2.98 5.57 0.0500 ND 0.0438

Schiller Park 00002075 11/21/00 334.5 0.322 1.05 1.69 0.126 ND 0.0300

Washington HS 00002079 11/21/00 234.9 3.62 2.84 16.4 0.750 ND 0.0579

Bensenville 00002205 12/15/00 315.1 0.616 2.36 4.21 0.350 ND 0.0638

North Brook 00002207 12/15/00 292.4 1.13 2.61 4.57 0.293 ND 0.0329

Schiller Park 00002206 12/15/00 341.6 0.795 2.66 4.90 0.440 ND 0.0510

Washington HS 00002208 12/15/00 231.6 0.386 2.19 4.15 0.500 ND 0.0573

Bensenville 01000060 12/27/00 321.0 0.259 1.06 1.92 0.0899 ND 0.0277

North Brook 01000059 12/27/00 384.8 5.27 9.32 18.1 0.0668 ND 0.0162

Schiller Park 01000061 12/27/00 346.0 0.768 1.93 3.46 0.165 ND 0.0333

Washington HS 01000063 12/27/00 230.3 5.35 4.80 26.1 0.530 ND 0.125

a

 Concentration data calculated from air volume sampled corrected to 25 oC and 760mm pressure based on 24-hr average temperature and

 pressure recorded at O'Hare International, Chicago IL.

Appendix IIIF (continued)

Semivolatile Vapor Plus Particulate Results

Summary of PCDDs, PCDFs, PAHs, Nitro-PAHs, and

39
40

Appendix IV

Meteorological Summary on Sampling Days

A meteorological summary of each sampling day is provided below. The large-scale 

weather pattern is discussed and the local weather conditions in the Chicago area are 

listed. A wind rose/frequency distribution (Figure 5) is also provided which is a 

composite of the wind conditions on the sampling days only as provided in the following 

table.

June 17

A cold front had passed through the area on June 16 and was located along the Ohio 

River. High pressure over northern Iowa was the dominate feature. There were clouds 

and a few showers throughout the Chicago area, bur precipitation amounts were light, 

less than 0.1 in. At O’Hare the maximum temperature was 64 deg F, winds were 

generally from the northeast with an average speed of 8.4 mph.

June 29

High pressure over Kansas was dominating the weather throughout the region. Some 

light rainfall had occurred over the Chicago area during the past day. At O’Hare the 

maximum temperature was 76 deg F with a low of 55 deg F. Winds were from the west 

to northwest at an average speed of 7.7 mph.

July 11

High pressure over southern Ontario was providing a flow of Canadian air into the 

region. A stationary front was located over central Illinois. Moderate rainfall, over 1 in., 

had occurred in the Chicago area the previous day. At O’Hare the maximum temperature 

was 75 deg F with a minimum of 65 deg F. Winds were from the northeast at an average 

speed of 7.1 mph.

July 23

High pressure over northern Lake Michigan dominated the weather in the region 

providing a flow of Canadian air. Skies were mostly clear and there had been no rainfall 

in the Chicago area for the last three days. At O’Hare the maximum temperature was 73 

deg F and the minimum was 52 deg F, the lowest in July. Winds were northwest early in 

the day, shifting to northeast by 8 a.m., at an average speed of 5.8 mph.

August 4

High pressure located over central Lake Michigan provided a light flow of Canadian air 

into the region. The high pressure moved southeast during the day. There was no rain on 

August 4 but some scattered showers in the Chicago area the previous day. At O’Hare 

the maximum temperature was 80 deg F and the minimum was 54 deg F, the lowest in 
41

August. Winds were from the north early in the day and shifted around the south by late 

in the day. Wind speeds were light, averaging 4.7 mph.

August 16

A cold front had moved through the region late on the previous day and was located in 

southern Illinois. High pressure was moving south out of southwest Ontario. The 

maximum temperature the previous day was 92 deg F, the warmest day in August. The 

cold front brought much cooler temperatures on August 16. There was no rainfall that 

day or the previous day. At O’Hare the maximum temperature was 77 deg F and the 

minimum was 77 deg F. Winds were north in the morning shifting to east by evening at 

an average speed of 9.5 mph

August 28

A high pressure system located over Quebec was providing southeast flow into the 

region. A stationary front was located to the southwest over Missouri and another 

stationary front was starting to move east as a cold front out of the plains. There was no 

rainfall that day or the previous day. At O’Hare the maximum temperature was 85 deg F 

and the minimum was 64 deg F. Winds were southeast at an average speed of 8.7 mph.

September 9

High pressure was located east over the Virginia/North Carolina border providing 

southerly flow into the region. A warm front was located over Wisconsin and a cold 

front was moving in from the west. There was no rainfall on this day but some scattered 

precipitation occurred the previous morning. At O’Hare the maximum temperature was 

85 deg F and the minimum was 67 deg F. Winds were from the south all day at an 

average speed of 9.4 mph.

September 21

High pressure was located over Missouri providing westerly flow into the region. A cold 

front had moved through the area the previous day with rainfall amounts around 0.25 in. 

There was no precipitation on this day. Winds were west to northwest most of the day 

shifting to east by evening. Winds speeds averaged 8.5 mph but were stronger prior to 

the wind shift.

October 3

A cold front had moved through the area the previous day and was located in southern 

Illinois. A second cold front was moving southeast into northern Wisconsin. Scattered 

showers occurred throughout the Chicago area with rainfall amounts above 0.5 in. At 

O’Hare the maximum temperature was 73 deg F and the minimum was 44 deg F. Winds 

were light and variable until afternoon when a shift to the northeast occurred. The 

average speed was 6.0 mph but was higher after the wind shift.
42

October 18

A high pressure system located over the southern plains (from southern Colorado to 

southern Missouri) dominated the weather in the region. A cold front was moving into 

southern Wisconsin in the morning but no precipitation occurred in the area. At O’Hare 

the maximum temperature was 70 deg F and the minimum was 38 deg F. Winds were 

from the southwest at an average speed of 6.1 mph.

October 31

High pressure located over eastern Canada dominated the weather in the region. A weak 

stationary front was located southwest over the Mississippi Valley. There had been no 

precipitation in the Chicago area for several days. At O’Hare the maximum temperature 

was 70 deg F and the minimum was 47 deg F. Winds were southeast at an average speed 

of 7.7 mph.

November 8

A cold front had moved through the area the previous day with light precipitation and a 

weak surface trough was moving into northwest Illinois. Rainfall this day was less than 

0.1 in. At O’Hare the maximum temperature was 48 deg F and the minimum was 32 deg 

F. Winds were southwest early shifting to west by afternoon and north by evening. The 

average speed was 5.8 mph.

November 20

A strong cold front had moved through the area the previous day. Low pressure located 

north of Lake Huron dominated the weather. Traces of snow fell this day and on the 

previous day. At O’Hare the maximum temperature was 29 deg F and the minimum was 

18 deg F. Winds were strong out of the west all day. The average speed was 16.2 mph.

December 14

A low pressure system was located east over western New York State and high pressure 

was located over eastern Kansas. A trace of snow fell in the morning; however there had 

been 6 in. of snow the previous day and a total of 15 in. were on the ground. At O’Hare 

the maximum temperature was 27 deg F and the minimum was 7 deg F. Winds were 

northwest early, shifting to west be early afternoon and to south by evening. This 

average speed was 6.5 mph.

December 26

Low pressure over Lake Superior was pulling a cold front into northwest Wisconsin. A 

high pressure system located from Illinois east to North Carolina dominated the weather. 

Light snow totaling 0.5 in. fell throughout the day. At O’Hare the maximum temperature 

was 19 deg F and the minimum was 3 deg F. Winds were southwest early shifting to 

west by evening. The average speed was 8.3 mph.
Appendix IV (continued)

Frequency of Wind Direction on Sampling Days

Sampling Day N NNE NE ENE E ESE SE SSE S SSW SW WSW W WNW NW NNW CALM

June 17, 2000 7 5 4 6 1 1

June 29, 2000 1 1 1 1 5 3 11 1

July 11, 2000 3 3 14 4

July 23, 2000 3 4 7 4 1 5

August 4, 2000 4 1 2 3 5 1 1 1 2 4

August 16, 2000 8 4 4 6 1 1

August 28, 2000 1 2 5 7 7 2

September 9, 2000 17 7

September 21, 2000 4 1 1 4 6 7 1

October 3, 2000 1 3 2 4 1 1 1 2 3 1 1 4

October 18, 2000 7 9 7 1

October 31, 2000 3 2 8 9 2

November 8, 2000 2 1 9 6 3 1 2

November 20, 2000 5 14 5

December 14, 2000 1 1 1 1 6 3 1 10

December 26, 2001 1 10 9 4

Total Hours 29 19 32 27 16 15 18 19 25 22 28 39 35 17 23 18 2

Percent of Time 7.6 4.9 8.3 7.0 4.2 3.9 4.7 4.9 6.5 5.7 7.3 10.2 9.1 4.4 6.0 4.7 0.5

43
44

Appendix V

General Information for Selected Target Compounds

The following is a general discussion of the nature and sources for each of selected target 

compounds (Reference 3).

Acetaldehyde and Formaldehyde

These compounds are both from a large family of chemical compounds called volatile 

organic compounds (VOCs) and fall within a chemical group called aldehydes and 

ketones which are structured to include a carbonyl group, double-bonded carbon and 

oxygen atoms. 

Formaldehyde is released into the air by burning wood, kerosene or natural gas, by 

automobiles, trucks and aircraft through the burning of motor fuels and by cigarettes. 

Formaldehyde can off-gas from materials made with it, e.g., from glue or adhesive in 

press wood products, from preservatives in some paints and cosmetics, the coating that 

provides permanent press quality to fabrics and draperies. Formaldehyde is also a 

naturally occurring substance. 

Acetaldehyde is ubiquitous in the ambient environment. It is an intermediate product of

higher plant respiration and is formed from the burning of wood, tobacco and roasting 

coffee. It is also released from automobiles, trucks and aircraft burning motor fuels, 

from industrial processes which synthesize other chemicals, e.g., production of 

perfumes, polyester resins and basic dyes, and from its use as a solvent in the rubber, 

tanning and paper industries. 

Benzene

Benzene is also a volatile organic compound and is from a chemical family called 

aromatics or cyclic compounds. Aromatic compounds are formed in a ring with a series 

of single and doubled bonded carbon atoms, e.g., benzene, which has six carbon atoms 

with one hydrogen atom attached to each carbon in the ring.

Benzene is a constituent in motor fuels, is used as a solvent for fats, waxes, resins, oils 

inks, paint, plastics and rubber, in the extraction of oils from nuts and seeds and is used in 

photogravure printing. Benzene is also used in the manufacture of detergents, explosives, 

pharmaceuticals, and dyestuffs. Benzene is released in the air from the combustion of 

motor fuels, fugitive emissions from vehicle fueling and fuel storage, burning of coal and 

oil, industrial process and fugitive emissions and from tobacco smoking.

1,3-butadiene

This compound is also a volatile organic compound and is from a chemical family of 

straight chain compounds called alkenes that, when formed, contain carbon-carbon 
45

double bonds are called dienes. 1,3-butadiene is the most common and is used in the 

production of rubber and plastics. It is also used in copolymers including acrylics. 

1,3-butadiene is released from the burning motor fuels by automobiles, trucks and 

aircraft, from refineries and chemical manufacturing facilities (especially the plastic and 

rubber industries). It is also released by incineration of products in which it is contained, 

e.g. rubber, plastics and resins.

Chromium

Chromium is a naturally occurring element found in rocks, animals, plants, soil and in 

volcanic dust and gases. It occurs in the environment in two major valence states, 

trivalent chromium (Cr III) and hexavalent chromium Cr (VI). Chromium (III) is 

essential to normal glucose, protein and fat metabolism and is thus an essential dietary 

element. Chromium (VI) is much more toxic than Chromium (III) and is know human 

carcinogen.

The metal chromium is used mainly for making steel and other alloys. Chromium 

compounds, in either Chromium (III) or (VI) forms, are used for chrome plating, the 

manufacture of dyes and pigments, leather and wood preservation, and treatment of 

cooling tower water. Smaller amounts are used in drilling muds, textiles, and toner for 

coping machines.

Dioxins

A dioxin is any compound that contains the dibenzo-p-dioxin nucleus and remains one of 

the most toxic compounds known to man. Dioxins have no known technical use and are 

not intentionally produced. They are formed as unwanted byproducts of certain chemical 

processes during the manufacture of chlorinated intermediates and in the combustion of 

chlorinated materials.

Dioxins are emitted into the atmosphere from a wide variety of processes such as waste 

incineration, combustion of solid and liquid fuels in stationary sources for heat and power 

generation, crematories, iron and steel foundries/scrap metal melting, combustion-aided

metal recovery, kraft pulp and paper production/black liquor combustion, internal 

combustion engines, carbon regeneration, forest fires, organic chemical manufacture and 

use and Portland cement manufacture.

Polycyclic Organic Compounds (PAHs)

The term polycyclic organic compounds defines not one compound, but a broad class of 

compounds which generally includes all organic compounds with more than one benzene 

ring, and which have a boiling point above 212 degrees (F). Sixteen polycyclic aromatic 

hydocarbons (PAHs), a subset of the class of polycyclic compounds, were designated by 

USEPA as the compounds of interest as Urban Air Toxics. Notable such compounds are 

napthalene, anthracene, phenanthrene and chrysene.
46

The principal formation mechanism for PAHs occurs as part of the fuel combustion 

process in many different types of source categories. The combustion processes which 

are much more significant in terms of air emissions include stationary external 

combustion for heat and electricity generation, internal combustion engines and turbines, 

motor vehicles ( cars, trucks, and aircraft), and a variety of industrial fuel combustion 

sources.

Tetrachloroethylene (perchloroethylene)

Perchloroethylene is an organic chemical used in many industrial processes and is 

considered as a probable and possible human carcinogen. Perchloroethylene is used for 

dry cleaning and textile processing, as a chemical intermediate and as a degreasing agent. 

It is also used for rubber coatings, solvent soaps, printing inks, adhesives and glues, 

sealants, polishes, lubricants and silicones.

Nickel

Nickel is a silvery-white metal that is usually found in nature as a component of silicate, 

sulfide or arsenic ores. The most predominant forms of nickel in the atmosphere are 

nickel sulfate, sulfide and complex oxides of nickel. Various forms of nickel are 

considered to be human carcinogens.

Nickel is used for nickel alloys, electroplating baths, batteries, textile dyes, coins, spark 

plugs, machinery parts, stainless-steel, nickel-chrome wires and catalysts.

Toluene

Toluene is a man-made aromatic hydrocarbon produced mostly from petroleum. The 

chemical intermediate is the predominant feedstock in benzene production and a key 

octane-boosting component for gasoline blending. Toluene is also used as a raw material 

in the production of other chemicals and as a solvent in paints and coatings, inks, 

adhesives, cosmetics and pharmaceuticals.

Toluene is released into the air from several man-made sources including emissions from 

motor vehicles and aircraft exhaust, gasoline marketing, chemical and paint 

manufacturing and cigarette smoke. Air emissions also result from the production of 

polymers (nylon), plastic soda bottles and polyurethanes.