TM

NIOSH HEALTH HAZARD EVALUATION REPORT 

HETA #2002-0109-2927 

NIOSH Evaluation of Air Sampling Methodologies for 

Bacillus anthracis in a United States Postal Service 

Processing and Distribution Center 

Trenton, New Jersey 

February 2004 

This Health Hazard Evaluation (HHE) report and any recommendations made herein are for the specific facility evaluated and may not be universally

applicable. Any recommendations made are not to be considered as final statements of NIOSH policy or of any agency or individual involved.

Additional HHE reports are available at http://www.cdc.gov/niosh/hhe/reports

This Health Hazard Evaluation (HHE) report and any recommendations made herein are for the specific facility evaluated and may not be universally

applicable. Any recommendations made are not to be considered as final statements of NIOSH policy or of any agency or individual involved.

Additional HHE reports are available at http://www.cdc.gov/niosh/hhe/reports

applicable. Any recommendations made are not to be considered as final statements of NIOSH policy or of any agency or individual involved.

Additional HHE reports are available at http://www.cdc.gov/niosh/hhe/reports
DEPARTMENT OF HEALTH AND HUMAN SERVICES 

Centers for Disease Control and Prevention 

National Institute for Occupational Safety and Health
ii 

PREFACE

The Hazard Evaluation and Technical Assistance Branch (HETAB) of the National Institute for 

Occupational Safety and Health (NIOSH) conducts field investigations of possible health hazards in the 

workplace. These investigations are conducted under the authority of Section 20(a)(6) of the Occupational 

Safety and Health (OSHA) Act of 1970, 29 U.S.C. 669(a)(6) which authorizes the Secretary of Health and 

Human Services, following a written request from any employers or authorized representative of 

employees, to determine whether any substance normally found in the place of employment has 

potentially toxic effects in such concentrations as used or found. 

HETAB also provides, upon request, technical and consultative assistance to federal, state, and local 

agencies; labor; industry; and other groups or individuals to control occupational health hazards and to 

prevent related trauma and disease. Mention of company names or products does not constitute 

endorsement by NIOSH. 

ACKNOWLEDGMENTS AND AVAILABILITY OF REPORT

This report was prepared by Robert E. McCleery, MSPH; Kenneth F. Martinez, MSEE, CIH; Gregory A. 

Burr, CIH; and Dino A. Mattorano, MS of HETAB, Division of Surveillance, Hazard Evaluations and 

Field Studies (DSHEFS). Field assistance was provided by Donnie Booher, John Cardarelli, Richard 

Hartle, and Bradley King. Analytical support was provided by a Centers for Disease Control and 

Prevention (CDC) contract laboratory. Additional report review was provided by Paul Baron, Beth Reh, 

and Teresa Seitz. Desktop publishing was performed by Robin Smith. Review and preparation for 

printing were performed by Penny Arthur. 

Copies of this report have been sent to employee and management representatives at TPDC and the 

OSHA Regional Office. This report is not copyrighted and may be freely reproduced. The report may be 

viewed and printed from the following internet address: www.cdc.gov/niosh/hhe/hhesearch.html. Single 

copies of this report will be available for a period of three years from the date of this report. To expedite 

your request, include a self-addressed mailing label along with your written request to: 

NIOSH Publications Office 

4676 Columbia Parkway 

Cincinnati, Ohio 45226 

800-356-4674 

After this time, copies may be purchased from the National Technical Information Service (NTIS) at 5825 

Port Royal Road, Springfield, Virginia 22161. Information regarding the NTIS stock number may be 

obtained from the NIOSH Publications Office at the Cincinnati address. 

For the purpose of informing affected employees, copies of this report 

shall be posted by the employer in a prominent place accessible to the 

employees for a period of 30 calendar days.
iii 

Highlights of the NIOSH Health Hazard Evaluation

NIOSH Evaluation of Air Sampling Methodologies for Bacillus anthracis in a United States 

Postal Service Processing and Distribution Center

On January 16, 2002, NIOSH received a request for a health hazard evaluation (HHE) from the United 

States Postal Service (USPS) regarding Bacillus anthracis in the Trenton Processing and Distribution 

Center (TPDC) located in Trenton, New Jersey. The USPS requested assistance in determining the most 

appropriate method(s) of air sampling for B. anthracis spores. In response to this request, NIOSH 

investigators conducted an environmental investigation at the site on February 4-7, 2002. 

What NIOSH Did

# We took surface wipe samples on a Delivery 

Bar Code Sorter (DBCS) before and after 

turning it on. 

# We took air samples using mixed-cellulose, 

polytetrafluoroethylene, and gelatin filters; 

Andersen samplers with sheep blood agar; 

and dry filter units with polyester felt filters. 

# We took air samples around the DBCS 

before, during, and after turning it on. 

# We tested the filter samples two ways. First, 

the samples were tested as normal (not all 

the sample is used). Second, any negative 

results (no B. anthracis) had the remaining 

sample tested to make sure the sample was 

negative. 

What NIOSH Found

# All of the wipe samples were positive, 

indicating the DBCS was heavily 

contaminated with B. anthracis. 

# Some of the Andersen samples collected 

before operating the DBCS were positive, 

while most of the samples collected after 

DBCS operation were positive. 

# The first test of the filter samples collected 

before operating the DBCS resulted in no 

positive samples. 

What NIOSH Found (Cont’d)

# The first test of the filter samples collected 

after operating the DBCS found more positive 

samples. 

# Testing of the remaining sample of the 

negative filters from before and after 

operating the DBCS indicated that all filter 

types had more positive samples. 

# The results suggest that the entire filter 

sample should be used to analyze for B. 

anthracis. 

# The results suggest that the dry filter units 

and their high flow rate could have influenced 

the way the other samplers collected 

B. anthracis. 

# B. anthracis can become airborne by walking 

or lightly working in a contaminated area. 

What NIOSH Recommends

# The Andersen sampler should be one of 

the instruments utilized when screening, 

characterizing, and/or clearing a B. anthracis

contaminated facility for re-occupancy. 

# When taking air samples for B. anthracis

using filter media, the entire sample extract 

must be tested. 

# More information is needed on how well 

these and other methods work when sampling 

for B. anthracis. 

What To Do For More Information:

We encourage you to read the full report. If you 

would like a copy, either ask your health and safety 

representative to make you a copy or call 

1-513-841-4252 and ask for 

 HETA Report #2002-0109-2927
iv 

Health Hazard Evaluation Report 2002-0109-2927 

Trenton Processing and Distribution Center 

Trenton, New Jersey 

February 2004 

Robert E. McCleery, MSPH 

Kenneth F. Martinez, MSEE, CIH 

Gregory A. Burr, CIH 

Dino A. Mattorano, MS 

SUMMARY

On January 16, 2002, NIOSH received a request for a health hazard evaluation (HHE) from the United 

States Postal Service (USPS) regarding Bacillus anthracis (B. anthracis) contamination in the Trenton 

Processing and Distribution Center (TPDC) located in Trenton, New Jersey. The USPS requested 

assistance in determining the most appropriate method(s) of air sampling for B. anthracis spores. 

In response to this request, NIOSH investigators conducted an evaluation of sampling methods at the 

TPDC on February 4-7, 2002. NIOSH investigators collected 106 surface wipe samples on the 

jogger/sorter, feeder, reader, and all final stacker (bin) sections of a Delivery Bar Code Sorter (DBCS), 

130 general area (GA) air samples using Andersen samplers with sheep blood agar, 24 GA air samples 

using mixed-cellulose ester filter media, 24 GA air samples using polytetrafluoroethylene filter media, 

72 GA air samples using gelatin filter media, and 6 GA air samples using a dry filter unit with polyester 

felt filter media. 

Wipe and air samples were collected before and after operating the DBCS. Operating the DBCS provided 

a means of re-aerosolization of spores resulting in enhanced capture potential for air sampling media. All 

of the wipe samples were positive for B. anthracis. The initial analysis of air samples (using 10% of the 

sample extract) collected before DBCS operation resulted in no detectable B. anthracis colonies (negative 

sample), except for some Andersen samples. All of the negative filter samples were re-analyzed using the 

remaining sample, which resulted in each type of filter media having one or more false negative samples. 

All air sample media had detectable B. anthracis colonies subsequent to DBCS operation. 

Based on the surface wipe and air sample data, NIOSH investigators conclude the 

following: (1) walking and light work may be sufficient to re-aerosolize B. anthracis

spores; (2) all air sampling methods used were capable of collecting B. anthracis spores, 

albeit some more efficiently than others; (3) not plating the entire sample during analysis 

may result in false negative sample results; (4) the Andersen sampling method seems to 

be the most sensitive for B. anthracis spore collection; (5) because of its high flow rate 

the dry filter unit may have reduced the number of available spores for collection; (6) the 

dry filter unit may be the least sensitive when considering the volume of air passing 

through the sampler. Further laboratory and field evaluation of these and other methods is 

necessary to understand their practical uses and limitations for collection of B. anthracis

in contaminated facilities. 

Keywords: SIC 4311 (United States Postal Service), Bacillus anthracis, B. anthracis, anthrax, air sample, 

wipe sample, filter cassette, mixed cellulose ester, MCE, polytetrafluoroethylene, PTFE, gelatin, GEL, 

Andersen sampler, dry filter unit, DFU 
Table of Contents 

Preface..........................................................................................................................................................ii

Acknowledgments and Availability of Report..........................................................................................ii

Highlights of the NIOSH Health Hazard Evaluation .............................................................................iii

Summary.....................................................................................................................................................iv

Introduction.................................................................................................................................................1

Background .................................................................................................................................................1

Conduct of Field Study...............................................................................................................................1

Site Selection............................................................................................................................................1

Sample Collection....................................................................................................................................2

Sampling Methods ..................................................................................................................................2

Surface Wipe Sampling ......................................................................................................................2

Air Sampling........................................................................................................................................2

Test Deck Sheets..................................................................................................................................3

Sample Analysis ......................................................................................................................................3

Statistical Strategy ..................................................................................................................................3

Theoretical Decay Curves ......................................................................................................................4

Evaluation Criteria .....................................................................................................................................4

Bacillus anthracis....................................................................................................................................4

Results ..........................................................................................................................................................5

Surface Wipe Samples ............................................................................................................................5

Andersen Sampler...................................................................................................................................6

Filter Media .............................................................................................................................................6

Initial Results.......................................................................................................................................6

Results from the Analysis of the Remaining Sample .......................................................................6

Test Deck Sheets......................................................................................................................................7

Statistical Analysis ..................................................................................................................................7

Discussion ....................................................................................................................................................8

Conclusions................................................................................................................................................10

Recommendations.....................................................................................................................................10

References..................................................................................................................................................10

Tables .........................................................................................................................................................12
Figures........................................................................................................................................................16

Appendices.................................................................................................................................................22

Appendix A. Wipe Sample Results for B. anthracis...........................................................................22

Appendix B. Andersen Sampler Air Sampling Results for B. anthracis..........................................26

Appendix C. Mixed-Cellulose Ester Filter Air Sampling Results for B. anthracis.........................32

Appendix D. Polytetrafluoroethylene Filter Air Sampling Results for B. anthracis.......................34

Appendix E. Gelatin Filter Air Sampling Results for B. anthracis...................................................36

Appendix F. Dry Filter Unit Air Sampling Results for B. anthracis................................................40

Appendix G. Test Kit Sheet Sample Results for B. anthracis ...........................................................41
Health Hazard Evaluation Report No. 2002-0109-2927 Page 1 

INTRODUCTION

On January 16, 2002, the National Institute for 

Occupational Safety and Health (NIOSH) 

received a request for a health hazard 

evaluation (HHE) from the United States Postal 

Service (USPS) regarding Bacillus anthracis 

(B. anthracis) contamination in the Trenton 

Processing and Distribution Center (TPDC) 

located near Trenton, New Jersey. The USPS 

requested assistance in determining the most 

appropriate method(s) for air sampling for 

B. anthracis spores. In response to this request, a 

collaborative research project between NIOSH 

and the USPS was conducted during the week of 

February 4-7, 2002. 

The site visit began with an opening conference 

on February 4, 2002, with representatives from 

NIOSH, USPS, Environmental Protection 

Agency (EPA), New Jersey Department of 

Health and Senior Services (NJDHSS), The 

Shaw Group IncorporatedTM (formally the IT 

Group), and URS Corporation personnel (USPS 

contractors). Discussion topics included the 

sampling objectives, the sampling protocol for 

composite surface wipe sampling and air 

sampling, the previous decontamination efforts, 

the needs and concerns of the various groups 

involved with on-going efforts in and around the 

site, and the safety requirements of the site. 

Environmental sampling began on the afternoon 

of February 4 and continued until the afternoon 

of February 7. 

BACKGROUND

The roughly 300,000 square foot (ft2

) TPDC is a 

facility that employs approximately 850 people. 

At least four letters containing B. anthracis

were processed through this facility: two on 

September 18, 2001, intended for New York 

City media outlets, and two on October 9, 2001, 

to U.S. Senators in Washington, D.C.1

 The 

facility was closed on October 18, 2001, after 

cutaneous anthrax was confirmed in a TPDC 

postal worker. Seven anthrax cases (three 

confirmed cutaneous, two suspect cutaneous, 

and two confirmed inhalational) were eventually 

identified. Five cases were associated with 

TPDC, one with a downstream post office, and 

one with a private business. On October 25, 

2001, all TPDC employees were offered the 60-

day post-exposure prophylaxis.2,3

After the initial cutaneous anthrax case was 

confirmed, the Federal Bureau of Investigation 

conducted the first directed environmental 

anthrax sampling at TPDC on October 18, 2001. 

Twenty-three wet swab samples were collected, 

which traced the mail paths of the four suspected 

letters; fourteen of these samples were positive 

for B. anthracis. Subsequently, a joint Centers 

for Disease Control and Prevention (CDC)/ 

NJDHSS team collected an additional 95 wet 

swab and surface vacuum samples on 

October 21, 2001, and November 11, 2001, to 

characterize the extent of B. anthracis

contamination throughout the mail processing 

areas. Of these 95 samples, 40 were positive, 

including several from the TPDC air handling 

systems, which suggested that the contamination 

was not limited to specific sorting machines or 

work areas. Since November 2001, hundreds of 

additional wet swabs, wipes, and surface 

vacuum samples have been collected by the 

USPS as part of their clean-up effort. 

CONDUCT OF FIELD 

STUDY

Site Selection 

For this evaluation of various air sampling 

methods, investigators selected Delivery Bar 

Code Sorter #70 (DBCS) for study since it was 

in the direct mail path for several of the 

contaminated letters. A DBCS is divided into the 

following sections: jogger/sorter, feeder, reader, 

and stackers (bins). The unit had been spotcleaned in November 2001 using a four-step 

process: (1) high-efficiency particulate air 

vacuuming; (2) application of a 10% bleach 

solution with a contact time of 10 minutes; (3) 

application of a neutralizing solution (sodium 

thiosulfate); and (4) final rinse with clean water. 

Following cleaning, the machine was loosely 

covered in plastic. For the purpose of our study, 
Page 2 Health Hazard Evaluation Report No. 2002-0109-2927 

in January 2002 a plastic-walled enclosure 

(approximately 70' x 15' x 7') was constructed 

around the machine. Prior to sampling in the 

enclosure, the loose plastic covering over the 

machine was cleaned and removed. The 

enclosure was constructed to improve the 

chances of collecting B. anthracis spores and to 

avoid contaminating surrounding equipment. 

Sample Collection 

CDC/NIOSH investigators collected air and 

surface wipe samples for B. anthracis spores 

before and after operating the DBCS. (Note: 

when referring to air sampling, the phrase “after 

DBCS operation” means during and after DBCS 

operation.) Wipe samples were collected to 

gain insight into whether the DBCS was 

contaminated and the degree of contamination in 

the following areas: the jogger/sorter, feeder, 

reader, and all final stacker (bin) sections of the 

DBCS. In the bin area, most wipe samples were 

collected from a column of four bins (referred 

to as composite wipe samples). There were two 

exceptions where a column consisted of three 

bins and a printer. 

Figure 1 presents the locations where mixedcellulose ester (MCE), polytetrafluoroethylene 

(PTFE), gelatin (GEL), dry filter unit (DFU) 

(developed by the Joint Program Office for 

Biological Defense [JPO-BD]), and Andersen 

air samples were collected. Locations were 

selected to encompass the area around each 

section of the DBCS and maximize the 

possibility of spore collection. The overall 

sample collection period lasted approximately 

8 hours each day, with additional sample 

collection during the first 2 hours of this 8-hour 

period. Investigators conducted this additional 

sampling for the following reasons: (1) to 

address the susceptibility of GEL filters to 

dessication, (2) to balance the air sample 

volumes for comparison of the methods, (3) to 

investigate whether 2- and 8-hour sampling 

periods result in positive samples, and (4) to 

mirror air-sampling periods used in prior 

anthrax investigations. MCE and PTFE filter 

samples were collected for 2- and 8-hour 

sessions. GEL filter samples were collected for 

1-hour each during the initial 2-hour session and 

then over 2-hour intervals each during the 8-

hour session. During the first two hours, 

Andersen samples were collected in succession 

approximately every ten minutes. One 10-

minute sample was then collected every two 

hours over the remaining 6-hour period. DFU 

filter samples were collected for both the 2- and 

8- hour sessions. 

On February 6, a USPS employee entered into 

the building with the CDC/NIOSH team to 

energize and operate the DBCS. At issue was 

whether operation of the DBCS would 

aerosolize B. anthracis spores. The employee 

started the DBCS and its computer program, 

configured it to operational status, and set the 

parameters of the computer program to deposit 

the “test deck” sheets to specific bins. The 

program was then run and the test deck began 

distributing through the system. The employee 

gathered the sheets, set the computer program to 

release the sheets at another set of bins, and ran 

the sheets through again. At times, the DBCS 

jammed which required the employee to re-set 

the computer program and re-initiate the test 

run. In total, the machine was operated for 

45 minutes. The DBCS computer program 

indicated that 6,521 “test deck” sheets had 

passed through the system during that time 

period. 

Sampling Methods 

Surface Wipe Sampling 

Composite wipe samples were collected 

according to CDC guidelines.4

 The procedure 

included the use of 4” x 4” sterile polyester/ 

rayon pads moistened with sterile water, 

placement of samples in sterile conical vials, a 

change of gloves after each sample collection, 

decontamination of sample containers with 

bleach solution, and shipment according to 

established regulations. 

Air Sampling 

Andersen Sampler 

Air samples for B. anthracis were collected 

using trypticase soy agar (TSA) with five 

percent sheep blood (referred to as sheep 
Health Hazard Evaluation Report No. 2002-0109-2927 Page 3 

blood agar [SBA]) in Andersen single-stage 

cascade impactors at a calibrated sampling rate 

of 28.3 liters per minute (lpm). The Andersen 

single-stage cascade impactor has a calculated 

d50 of 0.57 micrometer (μm) (the d50 of an 

impactor is the diameter at which theoretically 

50% of the particles are collected and 50% of 

the particles pass through).5

 Agar plates were 

loaded into the Andersen sampler outside the 

containment area at an approximate height of 

three feet using aseptic techniques (e.g., the 

cleaning and sanitization of working surfaces, 

the wiping of Andersen sampler collection 

surfaces with alcohol between samples, and the 

inversion of sample plates before and after 

sampling). Samplers were then moved inside the 

containment and placed in their predetermined 

location. At that time, the Andersen samplers 

which had operated for their 10-minute sampling 

period were moved outside of containment, their 

agar plates removed and covered, sealed with 

tape around the circumference, and placed into 

individual sealed bags. After sampling was 

complete, the individual sealed bags containing 

the samples went through the decontamination 

process, were packed into containers according 

to existing transportation regulations, and sent to 

the CDC contract laboratory. 

Mixed Cellulose Ester, 

Polytetrafluoroethylene, and Gelatin 

Filters 

Air samples for B. anthracis were collected 

using MCE, PTFE, and GEL filters in a closedfaced cassette at a calibrated sampling rate of 

2.0 lpm. MCE and PTFE filters were 37-

millimeter (mm) diameter, 0.8-μm pore size, 

while GEL filters were 37-mm diameter, 3.0-μm 

pore size. After sampling was complete, each 

filter cassette was capped and placed into 

a plastic cup with a screw-on top. The cups were 

then placed into a large sealed bag for 

decontamination and shipping. 

Dry Filter Unit 

Air samples for B. anthracis were collected 

using a 47-mm diameter, 1.0 μm pore size 

polyester felt filter disk (American Felt and 

Filter Company, New Windsor, New York) at an 

approximate (no specific calibration device 

available) sampling rate of 400 lpm. Samples 

were collected using single filter DFUs, one of 

which was modified to potentially reduce the 

amount of by-pass air-flow around the filter 

(provided by URS personnel). After sampling 

was complete, filters were removed from the 

DFU and placed into a plastic conical vial with a 

screw-on top. These vials were then placed into 

a large sealed bag and were treated the same as 

the above agar plates from the decontamination 

process forward. 

Test Deck Sheets 

Test deck sheets are currently used by the USPS 

to test the operation of a DBCS or other mail 

sorting machinery. These sheets are shaped to 

resemble a typical envelope in dimension and 

are thicker than a normal sheet of paper. Ten 

sheets (not chosen in any particular order) of the 

“test deck” that went through the DBCS during 

the 45-minute operation time were sent to the 

CDC contract laboratory for analysis. 

Sample Analysis 

A CDC contract laboratory (provisionally 

approved Level B in the Laboratory Response 

Network) analyzed the samples by using a 

wet extraction for wipes and wet extraction with 

modifications for other sample collection 

matrices,6

 and it presumptively identified B. 

anthracis (Level A screening) according to CDC 

protocol.7

 The confirmation of presumptive 

positive samples was accomplished by Gamma 

Phage Lysis (GPL) and Direct Fluorescence 

Antibody (DFA) analyses. 

Statistical Strategy 

A statistical analysis of the Andersen sampling 

results was done to assess the effects of time and 

sampling location on B. anthracis concentration. 

Individual air sample concentrations from 

Andersen samplers were compiled into a 

STATGRAPHICS Plus® database. Histograms 

and the Shapiro-Wilks test for normality of 

the log-transformed data indicated that the data 

were approximately lognormally distributed. 

Thus, B. anthracis concentrations were logtransformed for statistical analyses using 

multiple linear regression. Factors including 
Page 4 Health Hazard Evaluation Report No. 2002-0109-2927 

time, location, and their interaction term, were 

added to the model and eliminated using a 

backwards elimination process. Only factors 

with P-values less than 0.05 were kept in the 

final model. 

Theoretical Decay Curves 

Theoretical B. anthracis concentration decay 

curves were established for each type of sampler 

inside containment (i.e., DFU, Andersen, and 

other pumps). This information was used to 

investigate the operating sampler contribution to 

the decrease of airborne B. anthracis inside the 

containment. Specific interest was placed on 

the theoretical curve of the DFU due to its 

high flow rate (≈400 lpm). The sampler decay 

curves were combined to form one overall 

theoretical B. anthracis decay curve, which is 

presented with the actual Andersen sampler 

decay curve to investigate the consistency 

between theoretical and actual data. The 

cureves were also subjectively evaluated to 

determine the extent to which the samplers 

potentially “filtered” the air of B. anthracis as 

well as affected the sampling collection potential 

of the other samplers. 

EVALUATION CRITERIA

As a guide to the evaluation of the hazards posed 

by workplace exposures, NIOSH field staff 

employ environmental evaluation criteria for 

the assessment of a number of chemical and 

physical agents. These criteria are intended to 

suggest levels of exposure to which most 

workers may be exposed up to 10 hours per day, 

40 hours per week for a working lifetime 

without experiencing adverse health effects. It 

is, however, important to note that not all 

workers will be protected from adverse 

health effects even though their exposures are 

maintained below these levels. A small 

percentage may experience adverse health 

effects because of individual susceptibility, a 

pre-existing medical condition, and/or a 

hypersensitivity (allergy). In addition, some 

hazardous substances may act in combination 

with other workplace exposures, the general 

environment, or with medications or personal 

habits of the worker to produce health effects 

even if the occupational exposures are controlled 

at the level set by the criterion. These combined 

effects are often not considered in the evaluation 

criteria. Also, some substances are absorbed by 

direct contact with the skin and mucous 

membranes, and thus potentially increases the 

overall exposure. Finally, evaluation criteria 

may change over the years as new information 

on the toxic effects of an agent become 

available. 

The primary sources of environmental 

evaluation criteria for the workplace are: (1) 

NIOSH Recommended Exposure Limits 

(RELs),8

 (2) the American Conference of 

Governmental Industrial Hygienists’ (ACGIH®) 

Threshold Limit Values (TLVs®),9

 and (3) the 

U.S. Department of Labor, OSHA Permissible 

Exposure Limits (PELs).10 Employers are 

encouraged to follow the OSHA limits, the 

NIOSH RELs, the ACGIH TLVs, or whichever 

are the more protective criterion. 

OSHA requires an employer to furnish 

employees a place of employment that is free 

from recognized hazards that are causing or 

are likely to cause death or serious physical 

harm [Occupational Safety and Health Act of 

1970, Public Law 91-596, sec. 5(a)(1)]. Thus, 

employers should understand that not all 

hazardous chemicals have specific OSHA 

exposure limits such as PELs and short-term 

exposure limits (STELs). An employer is still 

required by OSHA to protect their employees 

from hazards, even in the absence of a specific 

OSHA PEL. 

A time-weighted average (TWA) exposure 

refers to the average airborne concentration of 

a substance during a normal 8- to 10-hour 

workday. Some substances have recommended 

STEL or ceiling values which are intended to 

supplement the TWA where there are 

recognized toxic effects from higher exposures 

over the short-term. 

Bacillus anthracis 

B. anthracis is a rod-shaped, gram-positive, nonmotile, spore-forming bacterium which is 
Health Hazard Evaluation Report No. 2002-0109-2927 Page 5 

present globally. The sporulated form of 

B. anthracis is typically found in the soil and is 

known to inhabit environments for decades. The 

bacteria are known to produce a variety of 

toxins. Anthrax, also referred to as Woolsorter’s 

disease and Ragpicker’s disease, is the clinical 

term for the disease caused by B. anthracis. The 

word originates from the Greek word for coal, 

which probably refers to the skin appearance of 

the cutaneous form of the disease. Anthrax has 

an extensive human history and is referred to in 

the following: (1) Homer’s Iliad,

11,12 (2) biblical 

passages describing the fifth Egyptian plague 

affecting livestock and the sixth plague called 

the “plague of boils”12,13 (although a study 

conducted by John Marr and Curtis Malloy 

presents a different explanation for the fifth and 

sixth biblical plagues14) and (3) Virgil’s The 

Georgics.

12,15,16 Robert Koch showed that 

B. anthracis spores caused anthrax disease in 

mice17 and Lewis Pasteur developed an effective 

immunization against anthrax in animals.18 

Several countries have experimented with 

anthrax as a biological warfare agent. A large 

outbreak in Sverdlovsk, Russia, killed at least 

60 people and is thought to be the result of 

spores from a Soviet Army biological research 

facility upwind of the town.19

Humans can naturally contract anthrax disease 

through exposure to infected livestock or wild 

animals, or contaminated animal products such 

as hides or hair. There are three clinical forms 

of anthrax: cutaneous (the most common), 

gastrointestinal, and inhalational. The cutaneous 

form begins when B. anthracis enters the skin 

through a cut or abrasion forming a black lesion. 

Once the bacterium enter the blood stream it 

can cause septicemia (blood poisoning) and 

ultimately death. The gastrointestinal form of 

anthrax is caused by the consumption of 

contaminated animal meat. Symptoms usually 

begin with nausea, vomiting, and fever which 

can progress to septicemia. Inhalational anthrax 

is the most deadly form. The number of spores 

needed to cause disease and the incubation 

period are both unknown. Symptoms may begin 

with a flu-like feeling and mild fever and 

progress to respiratory failure. Anthrax-related 

information, publications, and guidance for postexposure prophylaxis and treatment are available 

on the CDC website, http://www.cdc.gov/. 

There are currently no numeric criteria against 

which to compare environmental measurements 

for anthrax. 

RESULTS

The following information provides summary 

results for the composite wipe samples and each 

type of air sampling media used in this study. 

Results are described as positive (detectable 

colonies) or negative (no detectable colonies). 

Appendices A-G present the individual sample 

results before and after DBCS operation (in 

tabular form) for the composite wipe samples, 

each type of air sampling media (Andersen 

sampler, MCE, PTFE, GEL, DFU), and test kit 

sheet samples, respectively. 

In Appendices B-F, the air samples “after DBCS 

operation” were started at the same time the 

machine was started and ran for their allotted 

time periods. Table 1 presents the “test deck” 

information from the DBCS machine operation 

period. Table 2 presents the sample results from 

the initial sample analysis by individual sample 

location. Table 3 provides a summary of all the 

sample results before and after DBCS operation 

including initial analysis and analysis of the 

remaining sample results. 

The sample B. anthracis concentration of each 

initially positive filter, assuming a homogeneous 

mixture, was calculated by extrapolating from 

the plated portion of the sample concentrate. 

Filter media that were initially positive did not 

have the remaining sample analyzed to establish 

an overall B. anthracis colony concentration. 

Surface Wipe Samples 

Wipe sample results before and after DBCS 

operation are presented in Appendix A. A total 

of 106 wipe samples were collected on the 

DBCS machine (53 samples were collected 

before and 53 after the machine was in 

operation). All stackers (bins) were included in 

the wipe sampling. All of the wipe samples 

were positive. B. anthracis concentrations before 
Page 6 Health Hazard Evaluation Report No. 2002-0109-2927 

the machine was operated ranged from 50 to 

100 colony forming units per wipe (CFUs/wipe) 

in the feeder, jogger, and reader sections of 

the DBCS, with a mean of 80 CFUs/wipe. 

B. anthracis concentrations in the bin section of 

the DBCS ranged from 4 to 8 x 108

 CFUs/wipe, 

with a mean of 1.7 x 107

 CFUs/wipe. The 

highest concentration (8 x 108

 CFUs/wipe) was 

found on the wipe sample collected from 

bins 167-170. 

B. anthracis concentrations after the machine 

was operated ranged from 12 to 3500 CFUs/ 

wipe in the feeder, jogger, and reader sections of 

the DBCS, with a mean of 724 CFUs/wipe. 

B. anthracis concentrations in the bin section 

of the DBCS ranged from 1 to 2.5 x 104

 CFUs/ 

wipe, with a mean of 5052 CFUs/wipe. The 

highest concentration (2.5 x 104

 CFUs/wipe) 

was found on the wipe samples collected on bins 

155-158 and 167-170. 

Andersen Sampler 

Andersen sampler results before and after DBCS 

operation are presented in Appendix B. Sixtyfive Andersen samples were collected before 

DBCS operation. During the first 2-hour session, 

sample locations 1, 2, 4, and 5 each had positive 

samples. During the 6-hour period, sample 

locations 1 and 5 had a positive sample. Sixtyfour Andersen air samples were collected after 

DBCS operation. During the first 2-hour session, 

all samples collected were positive. During the 

6-hour period, all sampling locations had some 

positive samples. 

B. anthracis concentrations before DBCS 

operation ranged from no detectable colonies 

to 7 colony forming units per cubic meter 

(CFUs/m3

). The highest concentration 

(7 CFUs/m3

) was at location 3 during the 6-hour 

period and location 5 during the first 2-hour 

period. B. anthracis concentrations after the 

DBCS was operated ranged from no detectable 

colonies to 360 CFUs/m3

. The highest 

concentration (360 CFUs/m3

) was at location 2 

during the 2-hour session. 

Filter Media 

Initial Results 

MCE filter sample results before and after 

DBCS operation are presented in Appendix C. 

All 12 MCE air samples collected before 

DBCS operation were initially negative. Of 

the 12 MCE air samples collected after DBCS 

operation, four were initially positive (locations 

4, 5, and 6 during the 2-hour period and 

location 5 during the 8-hour period). 

PTFE filter sample results before and after 

DBCS operation are presented in Appendix D. 

All 12 PTFE air samples collected before 

DBCS operation were initially negative. Of the 

12 PTFE air samples collected after DBCS 

operation, six were initially positive (locations 3, 

4, and 5 during the 2-hour period and 

locations 2, 3, and 4 during the 8-hour period). 

GEL filter sample results before and after DBCS 

operation are presented in Appendix E. All 

36 GEL air samples collected before DBCS 

operation were initially negative. Of the 36 GEL 

air samples collected after DBCS operation, 

13 were initially positive (locations 2-6 with 

location 3 having two positive samples during 

the 2-hour period and locations 1-4 and 6 with 

locations 3 and 4 each having two positive 

samples during the 8-hour period). 

DFU filter sample results before and after 

DBCS operation are presented in Appendix F. 

All three DFU air samples collected before 

DBCS operation were initially negative. All 

three of the DFU air samples collected after 

DBCS operation were initially positive. 

Results from the Analysis of the 

Remaining Sample 

Mixed Cellulose Ester Filter 

All 12 MCE air samples collected before DBCS 

operation were initially negative. Analysis of 

the remaining portion of these samples indicated 

1 of 12 was positive (at location 5 during the 2-

hour session). Of the eight initially negative 

MCE air samples collected after DBCS 
Health Hazard Evaluation Report No. 2002-0109-2927 Page 7 

operation, analysis of the remaining sample 

indicated all eight were positive. 

Figure 2 presents the 2- and 8-hour MCE filter 

data by location for both days of sampling. 

B. anthracis concentrations before DBCS 

operation ranged from no detectable colonies 

to 4 CFUs/m3

. The highest concentration (4 

CFUs/m3

) was at location 5 during the 2-hour 

session. B. anthracis concentrations after DBCS 

operation ranged from 7 to 400 CFUs/m3

. 

The highest concentration (400 CFUs/m3

) was at 

location 6 during the 2-hour session. 

Polytetrafluoroethylene Filter 

All 12 PTFE air samples collected before DBCS 

operation were initially negative. Analysis of the 

remaining portion of these samples indicated 1 

of 12 was positive (at location 4 during the 8-

hour session). Of the six initially negative 

PTFE air samples collected after DBCS 

operation, analysis of the remaining sample 

indicated all six were positive. 

Figure 3 presents the 2- and 8-hour PTFE filter 

data by location for both days of sampling. 

B. anthracis concentrations before DBCS 

operation ranged from no detectable colonies 

to 1 CFU/m3

. The highest concentration 

(1 CFU/m3

) was at location 4 during the 8-hour 

session. B. anthracis concentrations after 

DBCS operation ranged from 10 to 

120 CFUs/m3

. The highest concentration 

(120 CFUs/m3

) was at location 6 during the 

8-hour session. 

Gelatin Filter 

All 36 GEL air samples collected before DBCS 

operation were initially negative. Analysis of 

the remaining portion of these samples indicated 

1 of 36 was positive (at location 3 during one 

of the two 1-hour sessions). Of the 23 initially 

negative GEL air samples collected after DBCS 

operation, analysis of the remaining sample 

indicated 14 were positive (locations 1-2 and 

4-6 with location 1 having two positive samples 

during the 2-hour session and locations 1-6 with 

location 5 having three positive samples during 

the 8-hour period). 

Figure 4 presents the 2- and 8-hour GEL filter 

data by location for both days of sampling 

(samples averaged). B. anthracis concentrations 

before DBCS operation ranged from no 

detectable colonies to 5 CFU/m3

. The highest 

concentration (5 CFU/m3) was at location 3 

during the 2-hour session. B. anthracis

concentrations after DBCS operation ranged 

from 11 to 84 CFUs/m3

. The highest 

concentration (84 CFUs/m3

) was at location 5 

during the 2-hour session. 

Dry Filter Unit Filter 

All three initially negative DFU air samples 

collected before DBCS operation were positive 

after analysis of the remaining portion of the 

sample. 

Figure 5 presents the 2- and 8-hour DFU filter 

data by location for both days of sampling. 

B. anthracis concentrations before DBCS 

operation were all less than 1 CFU/m3

. B. 

anthracis concentrations after DBCS operation 

ranged from 5 to 15 CFUs/m3

. The highest 

concentration (15 CFUs/m3

) was from the filter 

in the modified DFU, which operated for a 

2-hour session. 

Test Deck Sheets 

“Test deck” information is presented in Table 1 

and results are provided in Appendix G. One of 

the ten sheets was positive (1 CFU) from the 

initial analysis. Of the nine initially negative 

sheets, analysis of the remaining portion of these 

samples indicated all six were positive (range of 

1 to 5 CFUs). 

Statistical Analysis 

The airborne B. anthracis concentrations 

collected with Andersen samplers were logtransformed to perform statistical analyses. A 

multiple regression analysis was performed on 

the data to describe the relationship between logtransformed concentration, time of sample 

collection, and location of sample collection. 

Results indicate that the only statistically 

significant covariate was time (P-value 

< 0.0001). The final mathematical model is 

presented graphically in Figure 7. Since the 
Page 8 Health Hazard Evaluation Report No. 2002-0109-2927 

factors (“location” and the interaction term 

[location x time]) were not statistically 

significant, regression lines grouped by location 

were not statistically different from each other 

and the parameter estimates (slope and intercept) 

from individual regression lines were not 

statistically different from each other. Therefore, 

grouping data from all locations into one 

regression model was appropriate and the final 

model can be used to describe B. anthracis

concentrations. 

Figures 6 and 7 show the decay curves, 

including the regression curve, of the Andersen 

sampler results before and after DBCS 

operation (raw data and log-transformed 

data, respectively). The regression model 

(subsequently referred to as the Andersen decay 

curve) above was used to calculate 2- and 

8-hour TWA concentrations based upon 

Andersen sampler data from five different 

locations in containment. The 2- and 8-hour 

predicted concentrations based on this model 

were 122 CFU/m3

 and 15 CFU/m3 TWAs, 

respectively. 

DISCUSSION

The wipe sampling data should be viewed as 

semi-quantitative since there was not a 

quantitatively defined area of collection. 

However, persons collecting wipe samples were 

instructed to wipe the bin and its surrounding 

surfaces in a manner which created a relatively 

consistent collection area. The initial round of 

wipe samples (before DBCS operation) may 

have reduced the surface loading of B. anthracis

spores resulting in the observed reduction in 

concentrations. While it is unknown how 

this reduction may have impacted the air 

concentrations, NIOSH investigators believe it 

was minimal since spore dissemination was 

probably due to mechanical action of the belts 

and pinch rollers as opposed to test envelopes 

collecting in receiving bins. 

The positive air samples before DBCS operation 

suggest that walking and light work may be 

sufficient to re-aerosolize B. anthracis spores. 

Additionally, there does not appear to be a 

single event that re-aerosolized spores since the 

positive air samples were found at various 

locations in the beginning, middle, and end of 

the 8-hour sampling period. 

Analysis of the remaining portion of the initially 

negative filter samples resulted in additional 

positive samples. Therefore, if the entire sample 

is not analyzed, there is a potential for false 

negative results (recalling that the initial analysis 

of filter media samples used only 10% of 

the sample). This can play a significant role in 

the selection of air sampling methodologies 

when considering the intent of sampling, e.g., 

screening, characterization, or clearance. 

The positive air samples collected before and 

after DBCS operation demonstrate that all 

evaluated sample methods are capable of 

collecting B. anthracis spores and that reaerosolization of B. anthracis spores by 

mechanical disruption is possible. Additionally, 

the positive results of the initial air sampling 

suggest that all evaluated methods are capable 

of collecting B. anthracis spores at low 

concentrations. Of the samples collected before 

DBCS operation, the Andersen appeared to be 

more sensitive than other air sampling methods. 

Additional advantages of the Andersen sampler 

include lower risk processing for the laboratory, 

quicker turn-around time, and less laboratory 

bias due to reduced sample processing. A 

disadvantage of the Andersen sampler is that the 

maximum sample collection time is limited to 

20 minutes, depending upon the concentration. 

Operating this instrument is a labor-intensive, 

time-consuming process when compared to 

sampling with filters where one sample can be 

collected over long time periods, (hours). 

The objective of the statistical analysis of 

Andersen sampler results was to assess the effect 

of sample location and time on B. anthracis

concentration. The decline in B. anthracis

concentration over time can be attributed to the 

influence of the pumps in effectively filtering 

the air inside the containment and the 

contribution of spore settling. 

As part of the investigation into the pump 

influence in filtering containment air, theoretical 
Health Hazard Evaluation Report No. 2002-0109-2927 Page 9 

B. anthracis concentration curves were 

developed for the Andersen sampler, DFU, and 

the other filter media (combination of MCE, 

PTFE, and GEL) based on a purging equation 

for dilution ventilation, factoring in time, 

containment volume, and ventilation rate (in this 

case a collection rate).20 B. anthracis

concentrations and a decay curve were also 

established for the particle loss (spore settling) 

contribution.21 For this calculation, it was 

assumed that there was uniform stirring of 

spores in the containment, spores inside the 

containment were 1 μm in diameter,22,23 and the 

spore density was 1.1 g/cm3

.

24

The 8-hour decay curve (Figure 6) reflects two 

distinct periods: (1) the first 2-hrs inside the 

containment when five Andersen samplers, three 

DFUs, and 36 pumps for MCE, PTFE, and GEL 

filter media were operating, totaling 1414 lpm 

and (2) the next 6-hour period when one DFU, 

18 pumps for MCE, PTFE, and GEL filter 

media, and five Andersen samplers (one tenminute session every two hours) were operating, 

totaling 578 lpm and 436 lpm when the 

Andersen samplers were in use and not in use, 

respectively. Additionally, it is assumed that 

the Andersen data (Figure 6) reflects the 

B. anthracis concentration inside the 

containment at the start of sampling (1st event) 

and at the 2-hour point (start of 2nd event). 

Specifically, the initial B. anthracis

concentrations used for the first and second 

event were 245 CFU/m3

 and 60 CFU/m3, 

respectively. 

Figures 8 and 9 present the theoretical curves for 

each set of air sampling media (Andersen, DFU, 

other media), the settling curve, as well as a 

curve which combines all the sampling media 

representing the overall removal rate (the 

reduction or capture of B. anthracis in 

containment). The decay curves in both figures 

indicate that based on removal rate, the DFU 

would be expected to have more of an impact 

on the reduction of B. anthracis inside the 

containment than the other sampling media and 

may have influenced the capture potential of the 

other sampling media inside the containment. 

Using the decay curves (Figures 8 and 9) and the 

data generated from the calculations above, an 

additional decay curve was generated for the two 

events and is presented in Figures 10 and 11. 

This curve is the combined effect that each set 

of air sampling media and spore settling 

provide to the overall decrease in B. anthracis

concentration inside containment. The Andersen 

decay curve and the theoretical DFU decay 

curve are also provided to offer a visual 

reference for comparison. Assuming that the 

Andersen decay curve provides a time indication 

of the B. anthracis concentration in containment, 

the combined decay curve reflects the general 

trend shown by the Andersen sampler. 

In the investigation of the Andersen sampler 

decay curve, the assumption was made that 

the B. anthracis spores were 1 μm in diameter. 

However, there is the possibility of 

agglomeration of spores into a particle greater 

than 1 μm in diameter. The larger particle size 

would result in a settling curve showing a 

sharper decrease in overall B. anthracis

concentration inside containment over time. 

Subsequently, the combined decay curve would 

also indicate this decrease in concentration. 

Previous study into B. anthracis reaerosolization 

in the Hart Senate Office Building, Washington, 

D.C. suggests that 80% of B. anthracis spores 

ranged from 0.95 μm to 3.5 μm.25 It is 

reasonable to suspect that B. anthracis spores in 

the TPDC also fall into this size range. 

However, size discrimination inside the TPDC is 

unknown. 

Figures 8-11 suggest that the removal rate of the 

DFU (which is presumed high based on the large 

volume of air that is run through these samplers) 

would have a “cleansing” effect (removal of 

material) inside the containment. However, the 

B. anthracis concentrations were considerably 

lower than any of the other sampling methods. 

This may be indicative of spores passing through 

the filter due to the flow rate, spores passing 

around the filter due to a poor seal, and/or spores 

becoming imbedded in the filter to a degree 

where typical laboratory sample preparation was 

unable to extract them. This raises a concern 

with the reliability of quantitative data from the 

polyester felt filter. A second concern stems 
Page 10 Health Hazard Evaluation Report No. 2002-0109-2927 

from the extraction efficiency associated with 

each type of filter media. In general, as the 

extraction efficiency decreases so does the 

precision of the data, which can significantly 

impact the limit of detection for that analytical 

method. For example, a low airborne 

concentration may not provide enough spores 

for collection to overcome the limit of detection, 

resulting in the possibility of false negative 

results. 

Further laboratory and field evaluation of these 

and other methods is necessary to understand their practical uses and limitations for 

the collection of B. anthracis in facilities 

contaminated from bioterrorist events. 

Analytical methods must be validated, including 

studies of the extraction efficiencies of sample 

collection matrices, to ensure consistent and 

reliable results from response laboratories. 

Greater confidence in environmental 

measurements can result in better informed 

public health decisions. 

CONCLUSIONS

1. Although all types of air sampling media 

were capable of collecting B. anthracis spores 

before and after DBCS operation, the Andersen 

sampler appeared to be the most sensitive. 

2. The DFUs were capable of sampling a 

substantial volume of air over extended time 

periods. However, compared to the B. anthracis 

concentrations found by the other sampling 

media, the low DFU concentrations suggest that 

spores may have passed through the instrument 

uncollected and/or spores were imbedded in the 

filter too deeply to be extracted. 

3. Re-aerosolization of B. anthracis spores is 

possible and may occur from merely walking or 

conducting light work in a contaminated area. 

4. The positive results for the ten “test deck” 

sheets suggests that it is possible for 

B. anthracis spores to adhere to sheets moving 

through an operating DBCS. 

5. Further investigation into air sampling and 

analytical methods, specifically sample 

collection and extraction efficiencies, is 

necessary to have confidence in their reliability 

when used in potential future bioterrorism 

events. 

RECOMMENDATIONS

NIOSH investigators provide the following 

recommendations based on findings from this 

investigation. 

1. When air sampling is to be utilized for 

screening, characterizing, and/or clearing a 

B. anthracis-contaminated facility for reoccupancy, the Andersen sampler should be one

of the instruments used. 

2. When collecting B. anthracis using filter 

media, the entire filter should be analyzed to 

obtain the greatest sensitivity. 

3. Laboratory and field evaluation of the 

methods used in this investigation and other 

methods available, as well as research into 

future air sampling methodologies, must be 

continued to provide bioterrorism responders the 

best available instruments to detect not only 

B. anthracis but also other bioterrorism agents. 

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Page 12 Health Hazard Evaluation Report No. 2002-0109-2927 

TABLES

Abbreviations and Symbols Used in the Following Tables, Figures, and Appendices 

DBCS = delivery bar code sorter 

MCE = mixed-cellulose ester filter 

PTFE = polytetrafluorethylene filter 

GEL = gelatin filter 

DFU = dry filter unit 

pos = positive sample (detectable colonies) 

neg = negative sample (no detectable colonies) 

tot = total number of samples 

min = minutes 

hr = hour 

n/a = not applicable 

CFUs = colony forming units 

CFU/m3

 = colony forming units per cubic meter of air 

* = two sequential samples @ 60 min each 

** = four sequential samples @ 120 min each 

$ = 10% of the sample extract was analyzed 

 = sample(s) were initially positive; therefore, no further analysis 

† = ten sequential samples @ 10 min each @ five locations 

†† = one ten minute sample every 2 hours @ five locations 

n/a = not applicable (100% of the sample was initially analyzed) 

theo = theoretical curve (see Discussion Section) 

calc = calculated curve (see Discussion Section) 
Health Hazard Evaluation Report No. 2002-0109-2927 Page 13 

Table 1. DBCS Operation and Test Kit Information (bins sheets sent to)

Start Time Bins Start Time Bins

0927 Machine Start - 1, 2, 3 0956 32, 33, 34, 35 

0934 Machine Jam 0958 64, 65, 66, 67, 190 

0938 32, 33, 34 1000 96, 97, 98, 99 

0940 32, 33, 34, 35 1004 1, 2, 3 

0941 64, 65, 66, 67 1006 32, 33, 34, 35 

0943 96, 97, 98, 99 1008 64, 65, 66, 67 

0944 Machine Jam 1010 96, 97, 98, 99 

0945 1, 2, 3 1012 1, 2, 3 

0947 32, 33, 34, 35 1013 32, 33, 34, 35, 187, 188, 

190 

0948 64, 65, 66, 67 1017 64, 65, 66, 67 

0949 96, 97, 98, 99 1019 96 

0954 1, 2, 3 1020 Machine Stop 

Total Sheets Run Through Machine = 6521 
Page 14 Health Hazard Evaluation Report No. 2002-0109-2927 

Table 2. Initial Sampling Results for B. anthracis Presented By Location Before and After DBCS Op

Test Description: Air Sampling Before DBCS Operation (Test Duration: 60, 120, and 480 minutes)

Gel Filters MCE Filter PTFE Filter Andersen D

60 min 120 min 120 min 120 min 120 min 120 min 480 min 120 min 480 min †120 min ††360 min 120 

Sample Location

Pos Tot Pos Tot Pos Tot Pos Tot Pos Tot Pos Tot Pos Tot Pos Tot Pos Tot Pos Tot Pos Tot Pos 

1 0 2 0 1 0 1 0 1 0 1 0 1 0 1 0 1 0 1 2 10 1 3 –– 2 0 2 0 1 0 1 0 1 0 1 0 1 0 1 0 1 0 1 2 10 0 3 –– 3 0 2 0 1 0 1 0 1 0 1 0 1 0 1 0 1 0 1 0 10 2 3 –– 4 0 2 0 1 0 1 0 1 0 1 0 1 0 1 0 1 0 1 1 10 0 3 0 5 0 2 0 1 0 1 0 1 0 1 0 1 0 1 0 1 0 1 3 10 1 3 0 6 0 2 0 1 0 1 0 1 0 1 0 1 0 1 0 1 0 1 –– –– –– –– –– 

Totals per Test 0 12 0 6 0 6 0 6 0 6 0 6 0 6 0 6 0 6 8 50 4 15 0 

Test Description: Air Sampling After DBCS Operation (Test Duration: 60, 120 and 480 minutes)

Gel Filters MCE Filter PTFE Filter Andersen D

60 min 120 min 120 min 120 min 120 min 120 min 480 min 120 min 480 min †120 min ††360 min 120 

Sample Location

Pos Tot Pos Tot Pos Tot Pos Tot Pos Tot Pos Tot Pos Tot Pos Tot Pos Tot Pos Tot Pos Tot Pos 

1 0 2 1 1 0 1 0 1 0 1 0 1 0 1 0 1 0 1 9 9 1 3 –– 2 1 2 0 1 1 1 0 1 0 1 0 1 0 1 0 1 1 1 10 10 3 3 –– 3 2 2 1 1 1 1 0 1 0 1 0 1 0 1 1 1 1 1 10 10 2 3 –– 4 1 2 1 1 1 1 0 1 0 1 1 1 0 1 1 1 1 1 10 10 2 3 1 5 1 2 0 1 0 1 0 1 0 1 1 1 1 1 1 1 0 1 10 10 2 3 1 6 1 2 1 1 0 1 0 1 0 1 1 1 0 1 0 1 0 1 –– –– –– –– –– 

Totals per Test 6 12 4 6 3 6 0 6 0 6 3 6 1 6 3 6 3 6 49 49 10 15 2 

†Sample media changed every 10 min for the 120 min sampling period ††360 min sampling period, samples were collected every t
Health Hazard Evaluation Report No. 2002-0109-2927 Page 15 

Table 3. Sample Results for B. anthracis Before and After DBCS Operation Per Sample 

Before 

DBCS 

Operation 

(10% of sample 

analyzed)

Before 

DBCS 

Operation 

(remaining 

sample 

analyzed)

After 

DBCS 

Operation 

(10% of sample 

analyzed)

After 

DBCS 

Operation 

(remaining 

sample 

analyzed)

Sample 

Media

Time 

Period

% Positive % Positive % Positive % Positive

MCE 120 min 0% (0 of 6) 17% (1 of 6) 50% (3 of 6) 100% (3 of 3) 

480 min 0% (0 of 6) 0% (0 of 6) 17% (1 of 6) 100% (5 of 5) 

PTFE 120 min 0% (0 of 6) 0% (0 of 6) 50% (3 of 6) 100% (3 of 3) 

480 min 0% (0 of 6) 17% (1 of 6) 50% (3 of 6) 100% (3 of 3) 

Gel 120 min* 0% (0 of 12) 8% (1 of 12) 50% (6 of 12) 100% (6 of 6) 

480 min** 0% (0 of 24) 0% (0 of 24) 29% (7 of 24) 47% (8 of 17) 

DFU 120 min 0% (0 of 2) 100% (2 of 2) 100% (2 of 2) 

480 min 0% (0 of 1) 100% (1 of 1) 100% (1 of 1) 

Andersen 120 min† 16% (8 of 50) n/a 100% (49 of 49) n/a 

360 min†† 27% (4 of 15) n/a 67% (10 of 15) n/a 

* = two sequential samples @ 60 min each 

** = four sequential samples @ 120 min each 

 = all samples were initially positive; therefore, no further analysis 

† = ten sequential samples @ 10 min each @ five locations 

†† = one sample every 2 hours @ five locations 

n/a = not applicable (100% of the sample was initially analyzed) 
Page 16 Health Hazard Evaluation Report No. 2002-0109-2927 

FIGURES

Figure 1. Diagram of the Air Sampling Locations Surrounding the DBCS

1 2 

3 4 5 

6

Bins F 

e 

e 

d 

e 

r 

Reader 

Enclosure 

Enclosure 

Jogger 

= Dry Filter Unit (DFU)

≈70’

≈15’

Sample locations 1 through 6 contained MCE, PTFE, and GEL filters; while 

Andersen samples were located at 1-5. 

Modified DFU
Health Hazard Evaluation Report No. 2002-0109-2927 Page 17 

Figures 2 and 3. 2-hour and 8-hour Filter Sample B. anthracis Concentrations 

MCE Filters

February 5 and 6, 2002

0

10

20

30

40

50

60

70

80

90

100

110

120

130

123456123456

Stations 1- 6

Concentration

(CFU/m3

)

2-hr

8-hr

DBCS Off DBCS On

400 CFU/m3

PTFE Filters

February 5 and 6, 2002

0

10

20

30

40

50

60

70

80

90

100

110

120

130

123456123456

Stations 1- 6

Concentration

(CFU/m3

)

2-hr

8-hr

DBCS Off DBCS On
Page 18 Health Hazard Evaluation Report No. 2002-0109-2927 

Figures 4 and 5. 2-hour and 8-hour Filter Sample B. anthracis Concentrations 

GEL Filters

February 5 and 6, 2002

0

10

20

30

40

50

60

70

80

90

100

110

120

130

123456123456

Stations 1- 6

Concentration

(CFU/m3

)

2-hr

8-hr

DBCS Off DBCS On

DFU Filters

February 5 and 6, 2002

0

10

20

30

40

50

60

70

80

90

100

110

120

130

123123

Stations 1- 3

Concentration

(CFU/m3

)

2-hr

8-hr

DBCS Off DBCS On
Health Hazard Evaluation Report No. 2002-0109-2927 Page 19 

Figures 6 and 7. Andersen Sampler Decay Curves. 

Andersen Sampler Decay Curve

February 6, 2002

0

50

100

150

200

250

300

350

400

9:00 AM

9:45 AM

10:30 AM

11:15 AM

12:00 PM

12:45 PM

1:30 PM

2:15 PM

3:00 PM

3:45 PM

4:30 PM

5:15 PM

Time (hr:min)

Concentration

(CFU/m3

)

Location 1 Location 2 Location 3 Location 4 Location 5 Regression

Andersen Sampler Decay Curve (log scale)

February 6, 2002

1

10

100

1000

0

50

100

150

200

250

300

350

400

450

Time (min)

Concentration

(CFU/m3

)

Location 1 Location 2 Location 3 Location 4 Location 5 Regression
Page 20 Health Hazard Evaluation Report No. 2002-0109-2927 

Figures 8 and 9. Rate of Purging and Settling Equations. 

Theoretical Concentration Decay Curves

 Rate of Purging & Settling Equations Over Initial 120 min.

0

20

40

60

80

100

120

140

160

180

200

220

240

260

0

10

20

30

40

50

60

70

80

90

100

110

120

Time

(minutes)

Concentration

(CFU/m3

)

Andersen (theo) DFU (theo) Other pumps (theo) Settling (calc) Total pumps (theo)

Theoretical Concentration Decay Curves

Rate of Purging & Settling Equations Over Remaining 360 min.

0

10

20

30

40

50

60

70

120

150

180

210

240

270

300

330

360

390

420

450

480

Time

(minutes)

Concentration

(CFU/m3

)

Andersen (theo) DFU (theo) Other pumps (theo) Settling (calc) Total pumps (theo)
Health Hazard Evaluation Report No. 2002-0109-2927 Page 21 

Figures 10 and 11. Combined Theoretical Decay Curve and Reference Curves. 

Concentration Decay Curves

Theoretical and Calculated Decay Curves Over Initial 120 min.

0

20

40

60

80

100

120

140

160

180

200

220

240

260

010

203040

50

60

7080

90

100

110120

Time

(minutes)

Concentration

(CFU/m3

)

All pumps (theo) & Settling (calc) Andersen Model DFU (theo)

Decay Curves

Theoretical and Calculated Decay Curves Over Remaining 360 min.

0

10

20

30

40

50

60

70

120

150

180

210

240

270

300

330

360

390

420

450

480

Time

(minutes)

Concentration

(CFU/m3

)

All Pumps (theo) & Settling (calc) Andersen Model DFU (theo)
Page 22 Health Hazard Evaluation Report No. 2002-0109-2927 

APPENDICES

Appendix A. Wipe Sample Results for B. anthracis

Before DBCS Machine in Operation

Sample Location Sample # Concentration (CFUs)

Jogger - table and frame Wipe - 001 100 

Feeder - transport and frame (front) Wipe - 002 100 

Feeder - transport (interior, back) Wipe - 003 52 

Reader (interior) - front section Wipe - 004 100 

Reader (interior) - back section Wipe - 005 50 

Column 1, bins 1-3 and printer Wipe - 006 11 

Column 2, bins 4-7 Wipe - 007 33 

Column 3, bins 8-11 Wipe - 008 50 

Column 4, bins 12-15 Wipe - 009 4 

Column 5, bins 16-19 Wipe - 010 10 

Column 6, bins 20-23 Wipe - 011 14 

Column 7, bins 24-27 Wipe - 012 22 

Column 8, bins 28-31 Wipe - 013 13 

Column 9, bins 32-35 Wipe - 014 19 

Column 10, bins 36-39 Wipe - 015 23 

Column 11, bins 40-43 Wipe - 016 28 

Column 12, bins 44-47 Wipe - 017 104 

Column 13, bins 48-51 Wipe - 018 68 

Column 14, bins 52-55 Wipe - 019 63 

Column 15, bins 56-59 Wipe - 020 37 

Column 16, bins 60-63 Wipe - 021 40 

Column 17, bins 64-67 Wipe - 022 68 

Column 18, bins 68-71 Wipe - 023 67 

Column 19, bins 72-75 Wipe - 024 124 

Column 20, bins 76-79 Wipe - 057 17 

Column 21, bins 80-83 Wipe - 058 10 
Health Hazard Evaluation Report No. 2002-0109-2927 Page 23 

Appendix A. Wipe Sample Results for B. anthracis

Before DBCS Machine in Operation

Sample Location Sample # Concentration (CFUs)

Column 22, bins 84-87 Wipe - 059 19 

Column 23, bins 88-91 Wipe - 060 69 

Column 24, bins 92-95 Wipe - 056 51 

Column 25, bins 96-99 Wipe - 025 180 

Column 26, bins 100-103 Wipe - 026 110 

Column 27, bins 104-107 Wipe - 027 540 

Column 28, bins 108-111 Wipe - 028 320 

Column 29, bins 112-114 Wipe - 029 700 

Column 30, bins 115-118 Wipe - 030 1,600 

Column 31, bins 119-122 Wipe - 031 28,000 

Column 32, bins 123-126 Wipe - 032 48,000 

Column 33, bins 127-130 Wipe - 033 28,000 

Column 34, bins 131-134 Wipe - 034 68,000 

Column 35, bins 135-138 Wipe - 035 110,000 

Column 36, bins 139-142 Wipe - 036 750,000 

Column 37, bins 143-146 Wipe - 037 600,000 

Column 38, bins 147-150 Wipe - 038 690,000 

Column 39, bins 151-154 Wipe - 039 1,500,000 

Column 40, bins 155-158 Wipe - 040 2,000,000 

Column 41, bins 159-162 Wipe - 041 6,300,000 

Column 42, bins 163-166 Wipe - 042 690,000 

Column 43, bins 167-170 Wipe - 043 800,000,000 

Column 44, bins 171-174 Wipe - 044 130,000 

Column 45, bins 175-178 Wipe - 045 60,000 

Column 46, bins 179-182 Wipe - 046 110,000 

Column 47, bins 183-186 Wipe - 047 21,000 

Column 48, bins 187-190 Wipe - 048 70,000 
Page 24 Health Hazard Evaluation Report No. 2002-0109-2927 

Appendix A. Wipe Sample Results for B. anthracis

After DBCS Machine in Operation

Sample Location Sample # Concentration (CFUs)

Jogger - table and frame Wipe - 116 26 

Feeder table (open end) Wipe - 117 12 

Feeder assembly (interior) Wipe - 118 27 

Reader (interior) - front section Wipe - 119 57 

Reader (interior) - back section Wipe - 120 3,500 

Column 1, bins 1-3 Wipe - 061 3 

Column 2, bins 4-7 Wipe - 062 32 

Column 3, bins 8-11 Wipe - 063 45 

Column 4, bins 12-15 Wipe - 064 7 

Column 5, bins 16-19 Wipe - 065 18 

Column 6, bins 20-23 Wipe - 066 68 

Column 7, bins 24-27 Wipe - 067 17 

Column 8, bins 28-31 Wipe - 068 6 

Column 9, bins 32-35 Wipe - 069 22 

Column 10, bins 36-39 Wipe - 070 6 

Column 11, bins 40-43 Wipe - 071 15 

Column 12, bins 44-47 Wipe - 072 1 

Column 13, bins 48-51 Wipe - 073 15 

Column 14, bins 52-55 Wipe - 074 5 

Column 15, bins 56-59 Wipe - 075 22 

Column 16, bins 60-63 Wipe - 076 70 

Column 17, bins 64-67 Wipe - 077 100 

Column 18, bins 68-71 Wipe - 078 49 

Column 19, bins 72-75 Wipe - 079 32 

Column 20, bins 76-79 Wipe - 080 56 

Column 21, bins 80-83 Wipe - 081 17 
Health Hazard Evaluation Report No. 2002-0109-2927 Page 25 

Appendix A. Wipe Sample Results for B. anthracis

After DBCS Machine in Operation

Sample Location Sample # Concentration (CFUs)

Column 22, bins 84-87 Wipe - 082 26 

Column 23, bins 88-91 Wipe - 083 111 

Column 24, bins 92-95 Wipe - 084 123 

Column 25, bins 96-99 Wipe - 085 97 

Column 26, bins 100-103 Wipe - 086 150 

Column 27, bins 104-107 Wipe - 087 3,200 

Column 28, bins 108-111 Wipe - 089 1,800 

Column 29, bins 112-114 Wipe - 088 5,200 

Column 30, bins 115-118 Wipe - 090 5,700 

Column 31, bins 119-122 Wipe - 091 15,000 

Column 32, bins 123-126 Wipe - 092 6,500 

Column 33, bins 127-130 Wipe - 093 12,000 

Column 34, bins 131-134 Wipe - 094 9,800 

Column 35, bins 135-138 Wipe - 095 12,000 

Column 36, bins 139-142 Wipe - 096 20,000 

Column 37, bins 143-146 Wipe - 097 11,000 

Column 38, bins 147-150 Wipe - 098 12,000 

Column 39, bins 151-154 Wipe - 099 11,000 

Column 40, bins 155-158 Wipe - 100 25,000 

Column 41, bins 159-162 Wipe - 101 13,000 

Column 42, bins 163-166 Wipe - 102 20,000 

Column 43, bins 167-170 Wipe - 103 25,000 

Column 44, bins 171-174 Wipe - 104 8,000 

Column 45, bins 175-178 Wipe - 105 3,500 

Column 46, bins 179-182 Wipe - 106 8,700 

Column 47, bins 183-186 Wipe - 107 6,200 

Column 48, bins 187-190 Wipe - 108 6,800 
Page 26 Health Hazard Evaluation Report No. 2002-0109-2927 

Appendix B. Andersen Sampler Air Sampling Results for 

B. anthracis

Before DBCS Machine in Operation

Sample # Sample Location Sample Time 

(military)

Volume 

(liters)

Concentration 

(CFU/m3)

SBA - 054 1 0948 - 0958 280 4 

SBA - 053 1 1006 - 1016 280 0 

SBA - 060 1 1020 - 1030 280 0 

SBA - 044 1 1049 - 1102 364 3 

SBA - 025 1 1102 - 1112 280 0 

SBA - 018 1 1120 - 1130 280 0 

SBA - 005 1 1135 - 1145 280 0 

SBA - 032 1 1153 - 1203 280 0 

SBA - 034 1 1211 - 1221 280 0 

SBA - 029 1 1229 - 1239 280 0 

SBA - 013 1 1350 - 1400 280 0 

SBA - 017 1 1554 - 1604 280 0 

SBA - 071 1 1710 - 1720 280 4 

SBA - 055 2 0947 - 0958 308 0 

SBA - 052 2 1006 - 1016 280 0 

SBA - 059 2 1033 - 1043 280 0 

SBA - 042 2 1049 - 1102 364 0 

SBA - 024 2 1102 - 1112 280 0 

SBA - 022 2 1120 - 1130 280 0 

SBA - 019 2 1135 - 1145 280 4 

SBA - 020 2 1153 - 1203 280 4 

SBA - 010 2 1211 - 1221 280 0 

SBA - 049 2 1229 - 1239 280 0 

SBA - 003 2 1350 - 1400 280 0 

SBA - 016 2 1554 - 1604 280 0 

SBA - 070 2 1710 - 1720 280 0 
Health Hazard Evaluation Report No. 2002-0109-2927 Page 27 

Appendix B. Andersen Sampler Air Sampling Results for B. anthracis

Before DBCS Machine in Operation

Sample # Sample Location Sample Time 

(military)

Volume 

(liters)

Concentration 

(CFU/m3)

SBA - 056 3 0947 - 0958 308 0 

SBA - 051 3 1006 - 1016 280 0 

SBA - 041 3 1020 - 1030 280 0 

SBA - 043 3 1049 - 1102 364 0 

SBA - 038 3 1102 - 1112 280 0 

SBA - 004 3 1120 - 1130 280 0 

SBA - 006 3 1135 - 1145 280 0 

SBA - 033 3 1153 - 1203 280 0 

SBA - 011 3 1211 - 1221 280 0 

SBA - 001 3 1229 - 1239 280 0 

SBA - 002 3 1350 - 1400 280 4 

SBA - 050 3 1554 - 1604 280 0 

SBA - 073 3 1710 - 1720 280 7 

SBA - 057 4 0947 - 0958 308 0 

SBA - 048 4 1006 - 1016 280 0 

SBA - 046 4 1033 - 1043 280 0 

SBA - 036 4 1049 - 1102 364 0 

SBA - 037 4 1102 - 1112 280 4 

SBA - 021 4 1120 - 1130 280 0 

SBA - 031 4 1135 - 1145 280 0 

SBA - 039 4 1153 - 1203 280 0 

SBA - 009 4 1211 - 1221 280 0 

SBA - 014 4 1229 - 1239 280 0 

SBA - 015 4 1350 - 1400 280 0 

SBA - 079 4 1554 - 1604 280 0 

SBA - 072 4 1710 - 1720 280 0 
Page 28 Health Hazard Evaluation Report No. 2002-0109-2927 

Appendix B. Andersen Sampler Air Sampling Results for B. anthracis

Before DBCS Machine in Operation

Sample # Sample Location Sample Time 

(military)

Volume 

(liters)

Concentration 

(CFU/m3)

SBA - 058 5 0947 - 1058 308 3 

SBA - 047 5 1006 - 1016 280 4 

SBA - 045 5 1033 - 1043 280 0 

SBA - 035 5 1049 - 1102 364 0 

SBA - 023 5 1102 - 1112 280 0 

SBA - 027 5 1120 - 1130 280 0 

SBA - 007 5 1135 - 1145 280 0 

SBA - 008 5 1153 - 1203 280 0 

SBA - 028 5 1211 - 1221 280 7 

SBA - 030 5 1229 - 1239 280 0 

SBA - 012 5 1350 - 1400 280 0 

SBA - 077 5 1554 - 1604 280 0 

SBA - 080 5 1710 - 1720 280 4 
Health Hazard Evaluation Report No. 2002-0109-2927 Page 29 

Appendix B. Andersen Sampler Air Sampling Results for B. anthracis

After DBCS Machine in Operation

Sample # Sample Location Sample Time 

(military)

Volume 

(liters)

Concentration 

(CFU/m3)

SBA - 103 1 0931 - 0941 280 159 

SBA - 131 1 0947 - 0957 280 297 

SBA - 125 1 0958 - 1008 280 244 

SBA - 154 1 1011 - 1021 280 no impact holes 

(blank) 

SBA - 152 1 1023 - 1033 280 141 

SBA - 118 1 1036 - 1046 280 127 

SBA - 123 1 1049 - 1059 280 14 

SBA - 107 1 1102 - 1112 280 85 

SBA - 093 1 1114 - 1125 308 45 

SBA - 082 1 1133 - 1143 280 32 

SBA - 134 1 1330 - 1340 280 21 

SBA - 150 1 1532 - 1542 280 0 

SBA - 146 1 1703 - 1713 280 0 

SBA - 109 2 0931 - 0941 280 360 

SBA - 129 2 0947 - 0957 280 300 

SBA - 127 2 0958 - 1008 280 226 

SBA - 159 2 1011 - 1021 280 223 

SBA - 115 2 1023 - 1033 280 191 

SBA - 114 2 1036 - 1046 280 141 

SBA - 111 2 1049 - 1059 280 99 

SBA - 143 2 1102 - 1112 280 92 

SBA - 158 2 1114 - 1125 308 67 

SBA - 089 2 1133 - 1143 280 49 

SBA - 094 2 1330 - 1340 280 4 

SBA - 148 2 1532 - 1542 280 4 

SBA - 145 2 1703 - 1713 280 7 
Page 30 Health Hazard Evaluation Report No. 2002-0109-2927 

Appendix B. Andersen Sampler Air Sampling Results for B. anthracis

After DBCS Machine in Operation

Sample # Sample Location Sample Time 

(military)

Volume 

(liters)

Concentration 

(CFU/m3)

SBA - 104 3 0931 - 0941 280 219 

SBA - 130 3 0947 - 0957 280 251 

SBA - 138 3 0958 - 1008 280 230 

SBA - 153 3 1011 - 1021 280 170 

SBA - 140 3 1023 - 1033 280 159 

SBA - 105 3 1036 - 1046 280 95 

SBA - 155 3 1049 - 1059 280 78 

SBA - 157 3 1102 - 1112 280 74 

SBA - 144 3 1114 - 1125 308 58 

SBA - 084 3 1133 - 1143 280 25 

SBA - 122 3 1330 - 1340 280 14 

SBA - 126 3 1532 - 1542 280 0 

SBA - 135 3 1703 - 1713 280 7 

SBA - 110 4 0931 - 0941 280 300 

SBA - 116 4 0947 - 0957 280 233 

SBA - 117 4 0958 - 1008 280 223 

SBA - 100 4 1011 - 1021 280 205 

SBA - 120 4 1023 - 1033 280 194 

SBA - 097 4 1036 - 1046 280 194 

SBA - 151 4 1049 - 1059 280 95 

SBA - 147 4 1102 - 1112 280 46 

SBA - 142 4 1114 - 1125 308 77 

SBA - 112 4 1133 - 1143 280 21 

SBA - 096 4 1330 - 1340 280 14 

SBA - 133 4 1532 - 1542 280 0 

SBA - 136 4 1703 - 1713 280 4 
Health Hazard Evaluation Report No. 2002-0109-2927 Page 31 

Appendix B. Andersen Sampler Air Sampling Results for B. anthracis

After DBCS Machine in Operation

Sample # Sample Location Sample Time 

(military)

Volume 

(liters)

Concentration 

(CFU/m3)

SBA - 102 5 0931 - 0941 280 353 

SBA - 128 5 0947 - 0957 280 346 

SBA - 139 5 0958 - 1008 280 247 

SBA - 101 5 1011 - 1021 280 240 

SBA - 119 5 1023 - 1033 280 205 

SBA - 121 5 1036 - 1046 280 134 

SBA - 160 5 1049 - 1059 308 71 

SBA - 091 5 1102 - 1112 280 102 

SBA - 141 5 1114 - 1125 308 64 

SBA - 113 5 1133 - 1143 280 49 

SBA - 124 5 1330 - 1340 280 11 

SBA - 108 5 1532 - 1542 280 4 

SBA - 137 5 1703 - 1713 280 0 
Page 32 Health Hazard Evaluation Report No. 2002-0109-2927 

Appendix C. Mixed-Cellulose Ester Filter Air Sampling 

Results for B. anthracis

Before DBCS Machine in Operation

Sample # Sample 

Location

Sample Time 

(military)

Volume 

(liters)

10%$

(CFU/m3)

Remainder 

(CFU/m3)

MCE - 004 1 0949 - 1145 232 0 0 

MCE - 001 1 0949 - 1724 910 0 0 

MCE - 007 2 0949 - 1145 232 0 0 

MCE - 003 2 0949 - 1724 910 0 0 

MCE - 005 3 0949 - 1145 232 0 0 

MCE - 011 3 0949 - 1724 910 0 0 

MCE - 019 4 0949 - 1145 232 0 0 

MCE - 006 4 0949 - 1724 910 0 0 

MCE - 009 5 0949 - 1145 232 0 4 

MCE - 018 5 0949 - 1724 910 0 0 

MCE - 013 6 0949 - 1145 232 0 0 

MCE - 016 6 0949 - 1724 910 0 0 
Health Hazard Evaluation Report No. 2002-0109-2927 Page 33 

Appendix C. Mixed-Cellulose Ester Filter Air Sampling Results for B. anthracis

After DBCS Machine in Operation

Sample # Sample 

Location

Sample Time 

(military)

Volume 

(liters)

10%$

(CFU/m3)

Remainder 

(CFU/m3)

MCE - 038 1 0927 - 1130 246 0 49 

MCE - 025 1 0927 - 1734 974 0 28 

MCE - 030 2 0927 - 1140 266 0 64 

MCE - 036 2 0927 - 1730 966 0 7 

MCE - 035 3 0927 - 1134 254 0 31 

MCE - 029 3 0927 - 1731 968 0 7 

MCE - 032 4 0927 - 1135 256 4 

MCE - 031 4 0927 - 1732 970 0 11 

MCE - 021 5 0927 - 1138 262 4 

MCE - 022 5 0927 - 1728 962 1 

MCE - 023 6 0927 - 1132 250 40 

MCE - 026 6 0927 - 1734 974 0 38 
Page 34 Health Hazard Evaluation Report No. 2002-0109-2927 

Appendix D. Polytetrafluoroethylene Filter Air Sampling 

Results for B. anthracis

Before DBCS Machine in Operation

Sample # Sample 

Location

Sample Time 

(military)

Volume 

(liters)

10%$

(CFU/m3)

Remainder 

(CFU/m3)

PTFE - 004 1 0949 - 1145 232 0 0 

PTFE - 001 1 0949 - 1724 910 0 0 

PTFE - 007 2 0949 - 1145 232 0 0 

PTFE - 006 2 0949 - 1724 910 0 0 

PTFE - 015 3 0949 - 1145 232 0 0 

PTFE - 013 3 0949 - 1724 910 0 0 

PTFE - 017 4 0949 - 1145 232 0 0 

PTFE - 009 4 0949 - 1724 910 0 1 

PTFE - 003 5 0949 - 1145 232 0 0 

PTFE - 008 5 0949 - 1724 910 0 0 

PTFE - 002 6 0949 - 1145 232 0 0 

PTFE - 014 6 0949 - 1724 910 0 0 
Health Hazard Evaluation Report No. 2002-0109-2927 Page 35 

Appendix D. Polytetrafluoroethylene Filter Air Sampling Results for B. anthracis

After DBCS Machine in Operation

Sample # Sample 

Location

Sample Time 

(military)

Volume 

(liters)

10%$

(CFU/m3)

Remainder 

(CFU/m3)

PTFE - 038 1 0927 - 1131 248 0 56 

PTFE - 022 1 0927 - 1734 974 0 26 

PTFE - 030 2 0927 - 1134 254 0 98 

PTFE - 031 2 0927 - 1730 966 3 

PTFE - 029 3 0927 - 1134 254 4 

PTFE - 039 3 0927 - 1731 968 1 

PTFE - 025 4 0927 - 1135 256 4 

PTFE - 040 4 0927 - 1732 970 3 

PTFE - 027 5 0927 - 1138 262 4 

PTFE - 026 5 0927 - 1728 962 0 16 

PTFE - 036 6 0927 - 1132 250 0 120 

PTFE - 037 6 0927 - 1734 974 0 39 
Page 36 Health Hazard Evaluation Report No. 2002-0109-2927 

Appendix E. Gelatin Filter Air Sampling Results for 

B. anthracis

Before DBCS Machine in Operation

Sample # Sample 

Location

Sample Time 

(military)

Volume 

(liters)

10%$

(CFU/m3)

Remainder 

(CFU/m3)

GEL - 027 1 0949 - 1050 122 0 0 

GEL - 001 1 1050 - 1145 110 0 0 

GEL - 019 1 0949 - 1145 232 0 0 

GEL - 031 1 1145 - 1351 252 0 0 

GEL - 025 1 1351 - 1548 234 0 0 

GEL - 026 1 1548 - 1724 192 0 0 

GEL - 020 2 0949 - 1051 124 0 0 

GEL - 009 2 1051 - 1145 108 0 0 

GEL - 008 2 0949 - 1148 238 0 0 

GEL - 013 2 1148 - 1355 254 0 0 

GEL - 036 2 1356 - 1549 226 0 0 

GEL - 022 2 1549 - 1724 190 0 0 

GEL - 018 3 0949 - 1052 126 0 0 

GEL - 002 3 1052 - 1145 106 0 9 

GEL - 004 3 0949 - 1149 240 0 0 

GEL - 023 3 1149 - 1358 258 0 0 

GEL - 030 3 1358 - 1550 224 0 0 

GEL - 038 3 1550 - 1724 188 0 0 

GEL - 006 4 0949 - 1053 128 0 0 

GEL - 010 4 1053 - 1145 104 0 0 

GEL - 011 4 0949 - 1130 202 0 0 

GEL - 015 4 1150 - 1358 256 0 0 

GEL - 021 4 1358 - 1551 226 0 0 

GEL - 028 4 1551 - 1724 186 0 0 
Health Hazard Evaluation Report No. 2002-0109-2927 Page 37 

Appendix E. Gelatin Filter Air Sampling Results for B. anthracis

Before DBCS Machine in Operation

Sample # Sample 

Location

Sample Time 

(military)

Volume 

(liters)

10%$

(CFU/m3)

Remainder 

(CFU/m3)

GEL - 007 5 0949 - 1054 130 0 0 

GEL - 005 5 1054 - 1145 102 0 0 

GEL - 016 5 0949 - 1151 244 0 0 

GEL - 012 5 1151 - 1402 262 0 0 

GEL - 037 5 1404 - 1551 214 0 0 

GEL - 029 5 1552 - 1724 184 0 0 

GEL - 003 6 0949 - 1055 132 0 0 

GEL - 014 6 1056 - 1145 98 0 0 

GEL - 017 6 0949 - 1152 246 0 0 

GEL - 032 6 1152 - 1404 264 0 0 

GEL - 035 6 1404 - 1553 218 0 0 

GEL - 024 6 1554 - 1724 180 0 0 
Page 38 Health Hazard Evaluation Report No. 2002-0109-2927 

Appendix E. Gelatin Filter Air Sampling Results for B. anthracis

After DBCS Machine in Operation

Sample # Sample 

Location

Sample Time 

(military)

Volume 

(liters)

10%$

(CFU/m3)

Remainder 

(CFU/m3)

GEL - 098 1 0927 - 1027 120 0 75 

GEL - 079 1 1027 - 1130 126 0 40 

GEL - 096 1 0927 - 1128 242 4 

GEL - 067 1 1128 - 1321 226 0 4 

GEL - 064 1 1322 - 1521 238 0 0 

GEL - 063 1 1521 - 1734 266 0 0 

GEL - 089 2 0927 - 1029 124 8 

GEL - 094 2 1029 - 1140 142 0 56 

GEL - 090 2 0927 - 1140 272 0 120 

GEL - 075 2 1140 - 1322 204 5 

GEL - 070 2 1323 - 1522 238 0 0 

GEL - 074 2 1522 - 1730 256 0 0 

GEL - 100 3 0927 - 1027 120 8 

GEL - 076 3 1027 - 1134 134 7 

GEL - 085 3 0927 - 1135 256 8 

GEL - 077 3 1135 - 1323 216 5 

GEL - 095 3 1324 - 1522 236 0 4 

GEL - 065 3 1523 - 1731 256 0 0 

GEL - 062 4 0927 - 1027 120 8 

GEL - 081 4 1027 - 1135 136 0 37 

GEL - 080 4 0927 - 1135 256 4 

GEL - 071 4 1136 - 1324 216 5 

GEL - 088 4 1324 - 1523 238 0 4 

GEL - 099 4 1524 - 1732 256 0 0 
Health Hazard Evaluation Report No. 2002-0109-2927 Page 39 

Appendix E. Gelatin Filter Air Sampling Results for B. anthracis

After DBCS Machine in Operation

Sample # Sample 

Location

Sample Time 

(military)

Volume 

(liters)

10%$

(CFU/m3)

Remainder 

(CFU/m3)

GEL - 072 5 0927 - 1028 122 8 

GEL - 092 5 1028 - 1137 138 0 87 

GEL - 073 5 0927 - 1139 264 0 80 

GEL - 066 5 1140 - 1325 210 0 10 

GEL - 068 5 1325 - 1524 238 0 4 

GEL - 084 5 1525 - 1728 246 0 0 

GEL - 086 6 0927 - 1028 122 8 

GEL - 083 6 1028 - 1132 128 0 8 

GEL - 061 6 0927 - 1133 252 4 

GEL - 091 6 1133 - 1326 226 0 18 

GEL - 069 6 1326 - 1526 240 0 0 

GEL - 082 6 1526 - 1734 256 0 0 
Page 40 Health Hazard Evaluation Report No. 2002-0109-2927 

Appendix F. Dry Filter Unit Air Sampling Results for 

B. anthracis

Before DBCS Machine in Operation

Sample # Sample 

Location

Sample Time 

(military)

Volume 

(liters)

10%$

(CFU/m3)

Remainder 

(CFU/m3)

DFU - 001 4 0949 - 1153 49,600 0 < 1 

DFU - 015 5 0949 - 1153 49,600 0 < 1 

DFU - 005 6 0949 - 1729 184,000 0 < 1 

After DBCS Machine in Operation

Sample # Sample 

Location

Sample Time 

(military)

Volume 

(liters)

10%$

(CFU/m3)

Remainder 

(CFU/m3)

DFU - 008 4 0927 - 1134 50,800 6 

DFU - 010 5 0927 - 1134 50,800 15 

DFU - 011 6 0927 - 1727 192,000 5 
Health Hazard Evaluation Report No. 2002-0109-2927 Page 41 

Appendix G. Test Kit Sheet Sample Results for B. anthracis

Test Kit Sheet 10%$

(CFUs)

Remainder 

(CFUs)

1 0 1 

2 0 3 

3 0 4 

4 0 3 

5 0 3 

6 0 3 

7 0 4 

8 0 2 

9 1 # 

10 0 5 
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