United States Government Accountability Office

GAO Testimony before the Subcommittee on 

Homeland Security, Committee on 

Appropriations, House of Representatives

ANTHRAX DETECTION

DHS Cannot Ensure That 

Sampling Activities Will Be 

Validated 

Statement of Keith Rhodes, Chief Technologist, 

Center for Technology and Engineering Applied Research and Methods 

For Release on Delivery

Expected at 10:00 a.m. EDT 

Thursday, March 29, 2007 

 

GAO-07-687T 
What GAO Found

United States Government Accountability Office

Why GAO Did This Study

Highlights

Accountability Integrity Reliability

March 29, 2007

ANTHRAX DETECTION

DHS Cannot Ensure That Sampling 

Highlights of GAO-07-687T, a testimony Activities Will Be Validated 

before the Subcommittee on Homeland 

Security, Committee on Appropriations, 

House of Representatives

Federal agencies conducted several sampling activities, including developing 

a sampling strategy and collecting, transporting, extracting, and analyzing

samples. They primarily collected samples from specific areas, such as mail 

processing areas, using their judgment about where anthrax would most 

likely be found—that is, targeted sampling. The agencies did not use 

probability sampling, which would have allowed agencies to determine, with 

some defined level of confidence, when all results are negative, whether a 

building is contaminated. 

The results of the agencies’ testing in 286 postal facilities were largely 

negative—no anthrax was detected. However, agencies did not use validated 

sample collection and analytical methods. Thus, there can be little 

confidence in negative results. With a validated process, agencies and the 

public could be reasonably confident that any test results generated by that 

process would be reliable. 

The Department of Homeland Security (DHS) is the principal agency 

responsible for coordinating the federal response. Thus, in its 2005 report, 

GAO recommended that the Secretary of Homeland Security develop a 

coordinated approach to improve the overall process for detecting anthrax 

and increase confidence in negative test results generated by that process. 

DHS stated that while it has overall responsibility for coordinating the 

federal response during future biological attacks, other agencies have the

lead responsibility for validation. Therefore, uncertainty over which agency 

would take the lead role—that is, who is in charge—in improving the overall 

process for detecting anthrax, including validation of the methods, 

continued after GAO issued its report. 

On the basis of these uncertainties, GAO recommended in its May 9, 2006, 

testimony that DHS’s approach to validating the overall process start with a 

strategic plan that would include a road map outlining how individual 

agencies’ efforts would lead to the validation of the individual activities as 

well as the overall process, noting that such a plan would assist DHS in 

monitoring progress and measuring agency performance toward improving 

the detection of anthrax and other prioritized threat agents. 

While DHS generally agreed with these recommendations, it stated that it 

cannot ensure validation studies would be done, since “there are legal 

limitations in DHS authority to direct the activities of other agencies.” Also, 

since validation would require a sustained effort over a long period, DHS 

noted that it could not mandate commitment of other agencies’ funds, over 

which it has no control.

Until responsibility is accepted for ensuring that sampling activities will be

validated, the fate of the validation process will remain uncertain. Without 

validation, if another anthrax attack were to occur tomorrow, federal civilian

agencies would not be able to conclude with any given level of statistical 

confidence, in cases of negative results, that a building is free of 

contamination. 

In September and October 2001, 

contaminated letters laced with 

Bacillus anthracis were sent

through the mail to two U.S. 

senators and members of the 

media. Postal facilities in New 

Jersey, Washington, D.C., and 

elsewhere became heavily

contaminated. The anthrax

incidents highlighted major gaps in 

civilian preparedness to detect

anthrax contamination in buildings.

GAO was asked to describe and 

assess federal agencies’ activities

to detect anthrax in postal

facilities, assess the results of 

agencies’ testing, and assess

whether agencies’ detection 

activities were validated. 

What GAO Recommends

GAO is not making any new 

recommendations. 

www.gao.gov/cgi-bin/getrpt?GAO-07-687T.

To view the full product, including the scope 

and methodology, click on the link above. 

For more information, contact Keith Rhodes 

at (202) 512-6412 or rhodesk@gao.gov. 
Mr. Chairman and Members of the Subcommittee: 

We are pleased to be here today to discuss our findings on anthrax 

detection testing. The threat of bioterrorism has been recognized for a 

considerable time. Long before the anthrax attacks of 2001, several hoax 

letters indicating the presence of anthrax had been mailed to federal and 

state agencies, as well as to private sector organizations. These events 

raised the possibility that facilities could become contaminated and would 

therefore have to be evaluated for environmental contamination. However, 

federal agencies were not fully prepared to deal with environmental 

contamination—that is, anthrax released through the mail—including the 

potential for multiple dispersals in indoor environments. 

In September and October 2001, contaminated letters laced with Bacillus 

anthracis were sent through the mail to two U.S. senators, Thomas 

Daschle and Patrick Leahy, and members of the media.1

 The postal 

facilities in New Jersey and Washington, D.C., that processed the senators’ 

letters became heavily contaminated. Other mail routed through these 

facilities, as well as additional facilities in the postal network, also became 

contaminated. In addition, numerous federal facilities in the Washington,

D.C., area were later found to be contaminated. The letters led to the first 

cases of anthrax disease related to bioterrorism in the United States. In all, 

22 individuals contracted anthrax disease in four states—Connecticut, 

Florida, New Jersey, and New York—as well as in Washington, D.C. Five

of these 22 individuals died. 

The anthrax incidents in September and October 2001 highlighted major 

gaps in civilian preparedness to detect and respond. In today’s testimony, 

I will discuss our findings concerning anthrax sampling activities, 

recommendations we made, and a major issue we identified—the 

Department of Homeland Security (DHS) cannot ensure and guarantee 

that sampling activities will be validated. 

 1

Bacillus anthracis is the microorganism that causes the disease known as anthrax. 

Page 1 GAO-07-687T 
In developing this testimony, we relied on our prior work.2

 We conducted

our review in accordance with generally accepted government auditing 

standards. 

Federal agencies responsible for responding to the 2001 anthrax incidents 

adopted a targeted sampling strategy that they based on their best 

judgment at the time. They primarily collected samples from specific 

areas, such as mail-processing areas, using their judgment about where 

anthrax would most likely be found. Such judgments can be effective in 

some situations—for example, in determining whether a facility is 

contaminated when information on the source of potential contamination 

is definitive. However, in the case of a negative finding, when the source of 

potential contamination is not definitive, the basic question—Is this 

building contaminated?—will remain unanswered. Therefore, in the case 

of a negative result, a different strategy, probability sampling, is needed. 

Probability sampling would have allowed agencies to determine whether 

the building was contaminated with some defined level of confidence. 

Results in Brief 

The federal agencies—CDC, EPA, and USPS—involved in sampling the 

postal facilities in 2001 to detect anthrax undertook several activities. 

These included development of a sampling strategy followed by collection 

of samples using a variety of methods, transporting and extracting, and 

analysis of the samples. Neither these activities nor the overall process 

was validated for anthrax testing. Consequently, the agencies were 

challenged by the limited information available for reliably choosing one 

method over another and the lack of information on the detection limit to 

use when evaluating negative results.

The results of the CDC, EPA, and USPS testing in 286 postal facilities were 

largely negative.3

 Of the 286 facilities, 23 tested positive. For 2 of these 

23 facilities, test results were negative at first but positive on a subsequent 

 2

GAO, Anthrax Detection: Agencies Need to Validate Sampling Activities in Order to 

Increase Confidence in Negative Results, GAO-05-251 (Washington D.C.: Mar 27, 2005);

Anthrax Detection: Agencies Need to Validate Sampling Activities in Order to Increase

Confidence in Negative Results, GAO-05-493T (Washington D.C.: Apr. 5, 2005); and

Anthrax: Federal Agencies Have Taken Some Steps to Validate Sampling Methods and to 

Develop a Next-Generation Anthrax Vaccine, GAO-06-756T (Washington D.C.: May 9,

2006). 

3

While the Federal Bureau of Investigation (FBI) also collected samples, we did not include

the results of its testing due to its ongoing criminal investigation. 

Page 2 GAO-07-687T 
testing. However, in 1 of these facilities—the Wallingford, Connecticut, 

facility—it was not until the fourth testing that positive results were 

obtained. 

The federal agencies’ activities to detect anthrax contamination were not 

validated. Without validation, the sampling activities could have been 

based on false assumptions. 

For example, the lack of validated sample collection methods means that 

it is not known how many spores a particular method will collect from a 

surface and, thus, which method is appropriate for a given situation. Using 

an ineffective method or procedure could result in a finding of no 

contamination when in fact there is contamination—a false negative. 

Validating the overall process, as well as the individual activities, is 

important because operational and health-related decisions are made on

the basis of testing results generated by that process. In addition, 

validation would offer assurance that the results of using a particular 

method, which is part of that process, are robust enough to be reproduced, 

regardless of which agency, contractor, or laboratory is involved. Thus, 

agencies and the public could be reasonably confident that any test results 

generated by a process that includes that method would be reliable and, in 

particular, that any negative results would mean that a sample was free 

from contamination (within the method’s limits of detection). 

Given the lack of validated methods for detecting anthrax contamination 

in facilities, we recommended that the Secretary of Homeland Security 

develop a coordinated approach to (1) improve the overall process for 

detecting anthrax and (2) increase confidence in negative test results 

generated by that process. This approach would include working with 

agencies to ensure that appropriate validation studies of the overall 

process of sampling activities, including the methods, are conducted. 

Specifically, we recommended that the Secretary

1. take a lead role in promoting and coordinating the activities of the 

various agencies that have the technical expertise related to

environmental testing; 

2. ensure that a definition of validation is developed and agreed on; 

3. guarantee that the overall process of sampling activities, including 

methods, is validated so that performance characteristics, including 

Page 3 GAO-07-687T 
limitations, are clearly understood and results can be correctly

interpreted; 

4. see that appropriate investments are made in empirical studies to 

develop probability-based sampling strategies that take into account 

the complexities of indoor environments; 

5. ensure that appropriate, prioritized investments are made for all 

biothreat agents; and 

6. make sure that agency policies, procedures, and guidelines reflect the

results of such efforts.4

When we issued our report, CDC, DHS, and USPS agreed with our 

conclusion—that methods for detecting anthrax contamination in facilities 

were not validated—and with the thrust of our recommendations—calling 

for a coordinated, systematic effort to validate the methods to be used for 

such testing. But they (1) disagreed with or expressed concern about our 

conclusions or the recommendation dealing with targeted versus 

probability sampling, (2) emphasized that validated testing methods for 

anthrax were not available in 2001 and that federal and state organizations 

did the best they could under the circumstances, and (3) identified factors

or issues that need to be considered in validating testing methods. 

In addition, uncertainty over which agency would take the lead role—that 

is, who is in charge—in improving the overall process for detecting 

anthrax, and how studies were to be funded, continued after we issued our 

report. DHS stated that while it has overall responsibility for coordinating 

the federal response during future biological attacks, EPA had the 

“primary responsibility for establishing the strategies, guidelines, and 

plans for the recovery from a biological attack,” while the Department of 

Health and Human Services (HHS) had the lead role for any related public

health response and guidelines. DHS also stated that it coordinated 

regularly with EPA’s National Homeland Research Center to exchange

information on research needs and to discuss priorities and gaps for a 

wide range of security-related research areas. DHS stated that it would 

coordinate with EPA to ensure that appropriate investments were made to 

explore improved sampling. However, it is unclear to us how DHS would 

ensure that appropriate prioritized investments are made for all biothreat

agents and how such priorities and gaps would be addressed.

 4

GAO-05-251, pp. 82–83. 

Page 4 GAO-07-687T 
On the basis of these uncertainties, we recommended in our May 9, 2006, 

testimony that DHS’s approach to validating the overall process start with 

a strategic plan that includes a road map outlining how individual 

agencies’ efforts would lead to the validation of the individual activities as

well as the overall process, noting that such a plan would assist DHS in 

monitoring progress and measuring agency performance toward 

improving the detection of anthrax and other prioritized threat agents. 5

On May 19, 2006, DHS officials stated that DHS cannot ensure and 

guarantee that validation studies would be done, since this is a shared 

responsibility among different agencies. DHS stated that “there are legal 

limitations in DHS authority to direct the activities of other agencies.” 

Also, since validation would require a sustained effort over a long period, 

these officials noted that they could not mandate commitment of other 

agencies’ funds, because of legal and budgetary limitations. 

DHS officials told us in July 2006 that they recognize that DHS is the 

principal agency responsible for coordinating the federal response and 

they would work with a good faith effort toward developing a strategy for 

validation studies and a road map by the end of calendar year 2006, 

outlining how individual agencies’ efforts would lead to the validation of 

the overall sampling process. On March 27, 2007, DHS told us that it had 

developed a working draft of the strategic plan and the road map by 

December 2006 but it could not share these with us because they were not 

final.6

Until responsibility is accepted for ensuring that sampling activities will be 

validated, the fate of the validation process will remain uncertain. Without

validation, if another anthrax attack were to occur tomorrow, federal 

civilian agencies would not be able to conclude with any given level of 

statistical confidence, in cases of negative results, that a building is free of 

contamination. 

In October 2001, an American Media Incorporated employee died from 

inhalation anthrax disease. In the same month, contaminated letters laced Background 

 5

GAO-06-756T 

6

Also on March 27, 2007, DHS officials gave us a short status report on the Anthrax

Sampling Working Group. However, we could not evaluate the significance of the activities 

it summarized without the strategic plan. 

Page 5 GAO-07-687T 
with Bacillus anthracis, or anthrax spores, were sent through the mail to 

Senators Thomas Daschle and Patrick Leahy. The response to the incident 

in the American Media Incorporated building in Florida in September 2001 

led to the identification of mail as the potential source of contamination; 

eventually, it led to the sampling of the postal facilities. The agencies 

began sampling on October 12, 2001, in Florida and stopped on April 21, 

2002, when the Wallingford, Connecticut, facility was sampled for the last

time. The letters led to the first cases of anthrax disease related to 

bioterrorism in the United States. In all, 22 individuals contracted anthrax

disease in Connecticut, Florida, New Jersey, and New York, as well as in 

Washington, D.C., and 5 died. 

The federal agencies involved in the response in the postal facilities have 

different responsibilities. CDC and state and local health departments 

primarily provided public health advice and assistance to USPS. CDC has 

primary responsibility for national surveillance of specific diseases, 

including anthrax; it also conducts epidemiologic investigations to 

determine, among other things, the source of the disease, and it 

participates in environmental sample collection and analysis activities. 

The FBI is responsible for criminal investigations involving interstate 

commerce and the mail and crimes committed on federal property. EPA is 

the nation’s lead agency for responding to a release of hazardous 

substances into the environment and subsequent decontamination. 

On October 8, 2001, the President created the Office of Homeland Security 

to develop and coordinate a comprehensive national strategy for dealing

with domestic terrorist threats or attacks. The office, which had limited 

involvement in the 2001 response, was superseded by the Homeland 

Security Act of 2002, which transferred many of its functions to DHS, 

which became operational in 2003. DHS was created by combining many 

previously separate agencies and is assigned a lead role in coordinating 

the efforts of federal agencies that respond to acts of terrorism in the 

United States. 

Major Findings

Sampling Strategy The federal agencies primarily used a targeted strategy—they collected 

samples from specific areas considered more likely to be contaminated, 

based on judgments. Such judgments can be effective in some situations—

for example, in determining whether a facility is contaminated when 

information on the source of potential contamination is definitive. 

Page 6 GAO-07-687T 
However, in the case of a negative finding, when the source of potential 

contamination is not definitive, the basic question—Is this building 

contaminated?—will remain unanswered. 

CDC and USPS officials said that they used a targeted strategy for several

reasons, including limitations on how many samples could be collected 

and analyzed. They also said that in 2001, they lacked the data from 

empirical research to develop an initial sampling strategy that

incorporated probability sampling. We disagree with this interpretation. 

Probability sampling is statistically based and does not depend solely on 

empirical criteria regarding the details of possible contamination. 

The situation in 2001 was unique, and the agencies were not fully prepared 

to deal with environmental contamination. In the future, if the agencies 

decide to use a targeted rather than a probability sampling strategy, they 

must recognize that they could lose a number of days if their targeted 

sampling produces negative test results. In this case, additional samples 

would have to be collected and analyzed, resulting in the loss of critical 

time for public health interventions. This was so at the Wallingford postal 

facility in the fall of 2001, when about 3 weeks elapsed between the time 

the first sampling took place and the results of the fourth testing, which 

revealed positive results. Furthermore, about 5 months elapsed between 

the time of the first sampling event and the time anthrax was found in the 

Wallingford facility’s high-bay area. 

Therefore, strategies that include probability sampling need to be 

developed in order to provide statistical confidence in negative results. 

Further, even if information on all the performance characteristics of 

methods is not yet available, a probability sampling strategy could be 

developed from assumptions about the efficiency of some of the methods. 

And even if precise data are not available, a conservative, approximate 

number could be used for developing a sampling strategy. This would give

agencies and the public greater confidence in negative test results than 

was associated with the sampling strategy used in 2001. 

Sampling Methods CDC, EPA, and USPS, the federal agencies involved in sampling the postal 

facilities in 2001 to detect anthrax, undertook several activities. These 

included development of a sampling strategy followed by collecting 

samples, using a variety of methods, and transporting, extracting, and 

analyzing the samples. Neither these activities nor the overall process was 

validated for anthrax testing. Consequently, the agencies were challenged

by limited information for reliably choosing one method over another and

Page 7 GAO-07-687T 
by lack of information on the detection limit to use when evaluating 

negative results. 

Federal agencies used different methods for collecting samples. While 

USPS generally used dry swabs to collect samples (the least effective 

method), CDC and EPA used multiple methods—dry swabs, premoistened 

swabs, wet wipes, and a high-efficiency particulate air (HEPA) vacuum—

in various combinations or alone. 

However, none of the agencies’ collection methods were evaluated for 

anthrax detection in environmental samples. In the absence of empirical 

research, agencies had no information available for reliably choosing one 

method over another and no information on the limits of detection to use 

when evaluating negative results. 

Results of Testing The majority of the samples collected from the postal facilities tested 

negative. In all, federal agencies collected about 10,000 samples during 

initial testing. It is interesting that of the 9,807 samples that the agencies 

collected, more than 98 percent, or 9,648, were negative; a little more than

1 percent, or 159, were positive. In all, 286 facilities were tested for 

anthrax contamination. Of these, Brentwood, Trenton, and Morgan were 

primary facilities; that is, these 3 facilities processed the original letters 

containing the anthrax. 

The results of the CDC, EPA, and USPS testing in 286 postal facilities were 

largely negative. Of 286 facilities, 23 tested positive. For 2 of these 

23 facilities, test results were negative at first but positive on a subsequent 

testing. However, in 1 of these facilities—the Wallingford, Connecticut, 

facility—it was not until the fourth testing that positive results were 

obtained. 

Testing results differed between the primary facilities and Wallingford. In

the 3 primary facilities, results were positive each time a facility was 

tested, with the important exception of the two quick tests in Brentwood. 

In Wallingford, considered less likely to be contaminated, results were 

positive only on the fourth sampling. These results underscore the 

importance of retesting and cast doubt on the efficiency of the judgmental 

sampling strategy. 

Of the 263 facilities that tested negative, only 9 were sampled more than 

once. A facility in West Trenton tested negative, even though an employee 

had contracted cutaneous anthrax. The facility in West Trenton was tested 

Page 8 GAO-07-687T 
twice by the FBI and once by CDC, during which a total of 57 samples 

were collected, with negative results.

Final, or confirmed, results will be negative if contamination is not present 

in a facility. However, a result can be erroneously negative for several 

other reasons, such as (1) the sampling method was not efficient enough, 

(2) samples were not collected from places where contamination was 

present, (3) not enough samples were collected, (4) not enough spores 

were recovered from the sample material, or (5) analysis of the sample 

extract was not sensitive enough to detect anthrax spores that were 

present. 

Conclusions The agencies that sampled postal facilities in 2001—USPS, CDC, and 

EPA—did not use validated sample collection and analysis methods to 

perform their tests. According to these agencies, validated methods were 

not available at that time. They conducted several interdependent 

activities, including sample strategy development, followed by sample 

collection, transportation, and analysis of the samples to detect anthrax. 

Neither these activities nor the overall process had been validated for 

anthrax testing. 

Validation is a formal, empirical process in which an authority determines

and certifies the performance characteristics of a given method. 

Therefore, investments are also needed to validate these methods, as well 

as the overall anthrax detection process. Validating the overall process, as 

well as the individual activities, is important because operational and 

health-related decisions are made on the basis of testing results that the 

process generates. 

CDC and USPS officials said that they used targeted sampling; that is, they

collected samples from specific areas considered—based on agencies’ 

technical judgments—more likely to be contaminated. Such judgments can 

be effective in some situations, for example, in determining the source of

contamination in a disease outbreak investigation, provided results are 

positive. However, if the results are negative, the basic question—Is this 

building contaminated?—cannot be answered with statistical confidence.

When the level of contamination is extremely high and dispersed in a 

facility, the method of sampling (for example, wipes versus swabs) is not 

as critical if the purpose is to find some contaminant. However, at lower 

levels, a way of interpreting the significance of negative results is needed, 

and this requirement emphasizes the importance of validation of the 

Page 9 GAO-07-687T 
methods and the need for statistically based sampling strategies. This 

emphasizes the need for methods that have been validated, and sampling 

strategies that are likely to find contamination at low levels. Probabilitybased sampling does allow conclusions, at specific levels of confidence,

about testing results. 

Using a probability-based sampling strategy, together with validated 

methods for detecting contamination, would provide a known level of 

confidence with which to interpret any negative results. This would allow 

agencies to be more definitive in determining necessary actions. Figure 1 

shows how lack of validation could affect individual activities—including 

the sampling strategy—as well as the results generated by the overall

process. 

Figure 1: Lack of Validation Can Affect Individual Activities and the Overall Process 

1

Includes sample size,

locations to collect 

samples from, method 

of collection 

2

From surfaces or air

or both, using specified 

methods

3

From facility to

laboratory, under 

appropriate conditions

5

Of living organisms in

4

At laboratory in

preparation for 

analysis ·

·

preliminary tests

and

confirmatory tests

Sampling

strategy 

development

Sample

collection

Sample

transportation

Sample

extraction

Sample

analysis

. . . techniques for 

sampling, transporting, 

extracting, and analysis 

will not be known, and 

thus the strategy may 

be based on false 

assumptions . . .

. . . performance 

characteristics of the 

methods for sampling 

surfaces will not be 

known . . .

. . . an adequate 

balance between 

safety and sample 

integrity cannot be 

ensured . . .

. . . the basic 

capabilities and skills 

staff need may not be 

understood or

required . . .

. . . tests may not be 

reproducible and 

therefore results 

cannot be trusted

Sampling activities: The overall process

Without validation

Sampling activities

Activities without validation

Source: GAO analysis of CDC, EPA, and USPS data.

Page 10 GAO-07-687T 
The lack of validated methods for assessing contamination in postal 

facilities impeded the agencies in responding to the incidents. The 

significance of the lack of validated methods was exemplified in the case 

of the one postal facility where negative preliminary results were obtained 

by field-based methods of analysis, with limitations that appear not to have 

been well understood by some agencies. Negative results do not 

necessarily mean a facility is free from contamination. As we reported, 

results can be negative if (1) samples were not collected from places 

where anthrax was present, (2) the detection limit of the method was 

greater than the actual contamination level, (3) not enough samples were 

recovered from the sample material, (4) analysis of the sample extract did

not detect spores, or (5) anthrax was not present in the facility. 

In addition, while the 2001 events involved anthrax, many other biothreat 

agents exist. Differences in their characteristics mean different solutions. 

Accordingly, efforts to develop sampling strategies and to validate 

methods should address requirements specific to those threat agents as 

well. However, since addressing other agents would consume resources 

and time, all these efforts should be prioritized in a long-term strategy. 

The several agencies that dealt with the anthrax attacks generally worked 

well together, but we have identified areas that would have benefited from 

one agency’s taking the lead in coordinating the response. Given the 

mission of DHS and its responsibilities, it appears that DHS is now well 

positioned to take a lead role in promoting and coordinating the activities 

of the various agencies that have technical expertise related to

environmental testing. In addition, it is important that all participating 

agencies recognize and support DHS in that role and that they have an 

effective structure for participating in identifying and addressing the 

appropriate issues. 

Given the lack of validated methods for detecting anthrax contamination 

in facilities, we recommended in our 2005 report that the Secretary of 

Homeland Security develop a coordinated approach to (1) improve the 

overall process for detecting anthrax and (2) increase confidence in 

negative test results generated by that process. This approach would 

include working with agencies to ensure that appropriate validation 

studies of the overall process of sampling activities, including the 

methods, are conducted. Specifically, we recommended that the Secretary 

Recommendations for 

Executive Action 

Page 11 GAO-07-687T 
1. take a lead role in promoting and coordinating the activities of the 

various agencies that have the technical expertise related to

environmental testing; 

2. ensure that a definition of validation is developed and agreed on; 

3. guarantee that the overall process of sampling activities, including 

methods, is validated so that performance characteristics, including 

limitations, are clearly understood and results can be correctly

interpreted; 

4. see that appropriate investments are made in empirical studies to 

develop probability-based sampling strategies that take into account 

the complexities of indoor environments; 

5. ensure that appropriate, prioritized investments are made for all 

biothreat agents; and 

6. make sure that agency policies, procedures, and guidelines reflect the

results of such efforts. 

When we issued our report, CDC, DHS, and USPS agreed with our 

conclusion—that methods for detecting anthrax contamination in facilities 

were not validated—and with the thrust of our recommendations—calling 

for a coordinated, systematic effort to validate the methods to be used for 

such testing. But they (1) disagreed with or expressed concern about our 

conclusions or the recommendation dealing with targeted versus 

probability sampling, (2) emphasized that validated testing methods for 

anthrax were not available in 2001 and that federal and state organizations 

did the best they could under the circumstances, and (3) identified factors

or issues that need to be considered in validating testing methods. 

After we issued our 2005 report, it became evident that there was 

uncertainty over which agency would take the lead role in improving the 

overall process for detecting anthrax and how studies were to be funded.

For example, DHS stated that while it has overall responsibility for 

coordinating the federal response during future biological attacks, EPA 

had the “primary responsibility for establishing the strategies, guidelines, 

and plans for the recovery from a biological attack” and HHS had the lead

role for any related public health response and guidelines. DHS also stated 

that it coordinated regularly with EPA’s National Homeland Research 

Center to exchange information on research needs and to discuss 

priorities and gaps for a wide range of security-related research areas. 

Who Is Responsible 

for Ensuring and 

Guaranteeing That 

Anthrax Detection 

Methods Will Be 

Validated? 

Page 12 GAO-07-687T 
DHS stated that it would coordinate with EPA to ensure that appropriate 

investments were made to explore improved sampling. However, it is 

unclear to us how DHS would ensure that appropriate prioritized 

investments are made for all biothreat agents and how such priorities and 

gaps would be addressed. 

On the basis of these uncertainties, we recommended in our May 9, 2006, 

testimony that DHS’s approach to validating the overall process should 

start with a strategic plan that includes a road map outlining how 

individual agencies efforts would lead to the validation of the individual 

activities as well as the overall process, noting that such a plan would 

assist DHS in monitoring progress and measuring agency performance 

toward improving the detection of anthrax and other prioritized threat 

agents. 

On May 19, 2006, DHS officials stated that while they concurred with the 

recommendations from our report and accepted the overall responsibility 

to ensure the methods will be validated, they stated that “there are legal 

limitations in DHS authority to direct the activities of other agencies.” 

They said that while they take a lead role in coordinating the meetings and 

in bringing people from different agencies together, they cannot guarantee

that the overall process of sampling will be validated because different 

agencies have responsibility for different aspects of validation, and DHS’s 

control over other agencies actions and budgets is ultimately limited. They 

stated that DHS cannot ensure and guarantee that validation studies would 

be done, since this is a shared responsibility among different agencies. 

Also, since validation would require a sustained effort over a long period, 

DHS noted that it could not mandate commitment of other agencies’ funds, 

over which it has no control. 

DHS officials told us in July 2006 that they recognize that DHS is the 

principal agency responsible for coordinating the federal response and 

they would work with a good faith effort toward developing a strategy for 

validation studies and a road map by the end of calendar year 2006 

outlining how individual agencies’ efforts would lead to the validation of 

the overall sampling process. On March 27, 2007, DHS told us that it had 

developed a working draft of the strategic plan and the road map by 

December 2006 but it could not share these with us because they were not 

final. 

Until responsibility is accepted for ensuring that sampling activities will be 

validated, the fate of the validation process will remain uncertain. Without

validation, if another anthrax attack were to occur tomorrow, federal 

Page 13 GAO-07-687T 
civilian agencies would not be able to conclude with any given level of 

statistical confidence, in cases of negative results, that a building is free of 

contamination. 

Mr. Chairman, this concludes my prepared remarks. I would be happy to 

respond to any questions that you or other members of the subcommittee 

may have at this time. 

For further information regarding this statement, please contact Keith 

Rhodes at (202) 512-6412, or rhodesk@gao.gov, or Sushil K. Sharma, Ph.D., 

Dr.PH, at (202) 512-3460, or sharmas@gao.gov. Contact points for our 

Offices of Congressional Relations and Public Affairs may be found on the 

last page of this statement. William Carrigg, Barbara Chapman, Crystal 

Jones, Penny Pickett, and Elaine Vaurio made key contributions to this 

statement. 

Contacts and 

Acknowledgments 

(460584) Page 14 GAO-07-687T 
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