Homeland Security: First Responders' Ability to Detect and Model 
Hazardous Releases in Urban Areas Is Significantly Limited	 
(27-JUN-08, GAO-08-180).					 
                                                                 
First responders are responsible for responding to		 
terrorist-related and accidental releases of CBRN materials in	 
urban areas. Two primary tools for identifying agents released	 
and their dispersion and effect are equipment to detect and	 
identify CBRN agents in the environment and plume models to track
the dispersion of airborne releases of these agents. GAO reports 
on the limitations of the CBRN detection equipment, its 	 
performance standards and capabilities testing, plume models	 
available for tracking urban dispersion of CBRN materials, and	 
information for determining how exposure to CBRN materials	 
affects urban populations. To assess the limitations of CBRN	 
detection equipment and urban plume modeling for first		 
responders' use, GAO met with and obtained data from agency	 
officials and first responders in three states. 		 
-------------------------Indexing Terms------------------------- 
REPORTNUM:   GAO-08-180 					        
    ACCNO:   A82590						        
  TITLE:     Homeland Security: First Responders' Ability to Detect   
and Model Hazardous Releases in Urban Areas Is Significantly	 
Limited 							 
     DATE:   06/27/2008 
  SUBJECT:   Agency missions					 
	     Biological research				 
	     Biological warfare 				 
	     Chemical agents					 
	     Chemical warfare					 
	     Data collection					 
	     Data integrity					 
	     Emergency preparedness				 
	     Federal/state relations				 
	     First responders					 
	     Hazardous materials emergency response		 
	     Hazardous substances				 
	     Health hazards					 
	     Homeland security					 
	     Laboratories					 
	     Operational testing				 
	     Performance management				 
	     Policy evaluation					 
	     Program management 				 
	     Protective equipment				 
	     Public health					 
	     Radiation exposure hazards 			 
	     Research and development				 
	     Risk assessment					 
	     Risk management					 
	     Security threats					 
	     Standards						 
	     Strategic planning 				 
	     Terrorism						 
	     Terrorists 					 
	     Test equipment					 
	     Policies and procedures				 
	     Program implementation				 
	     DHS BioWatch program				 
	     Interagency Modeling and Atmospheric		 
	     Center (IMACC)					 
                                                                 

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GAO-08-180

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GAO Highlights: 

Highlights of GAO-08-180, a report to congressional requesters. 

Why GAO Did This Study: 

First responders are responsible for responding to terrorist-related 
and accidental releases of CBRN materials in urban areas. Two primary 
tools for identifying agents released and their dispersion and effect 
are equipment to detect and identify CBRN agents in the environment and 
plume models to track the dispersion of airborne releases of these 
agents. GAO reports on the limitations of the CBRN detection equipment, 
its performance standards and capabilities testing, plume models 
available for tracking urban dispersion of CBRN materials, and 
information for determining how exposure to CBRN materials affects 
urban populations. To assess the limitations of CBRN detection 
equipment and urban plume modeling for first respondersï¿½ use, GAO met 
with and obtained data from agency officials and first responders in 
three states. 

What GAO Found: 

While the Department of Homeland Security (DHS) and other agencies have 
taken steps to improve homeland defense, local first responders still 
do not have tools to accurately identify right away what, when, where, 
and how much chemical, biological, radiological, or nuclear (CBRN) 
materials are released in U.S. urban areas, accidentally or by 
terrorists. Equipment local first responders use to detect radiological 
and nuclear material cannot predict the dispersion of these materials 
in the atmosphere. No agency has the mission to develop, certify, and 
test equipment first responders can use for detecting radiological 
materials in the atmosphere. According to DHS, chemical detectors are 
marginally able to detect an immediately dangerous concentration of 
chemical warfare agents. Handheld detection devices for biological 
agents are not reliable or effective. DHSï¿½s BioWatch program monitors 
air samples for biothreat agents in selected U.S. cities but does not 
provide first responders with real-time detection capability. Under the 
BioWatch system, a threat agent is identified within several hours to 
more than 1 day after it is released, and how much material is released 
cannot be determined. 

DHS has adopted few standards for CBRN detection equipment and has no 
independent testing program to validate whether it can detect CBRN 
agents at the specific sensitivities manufacturers claim. DHS has a 
mission to develop, test, and certify first respondersï¿½ CB detection 
equipment, but its testing and certification cover equipment DHS 
develops, not what first responders buy. 

Interagency studies show that federal agenciesï¿½ models to track the 
atmospheric release of CBRN materials have major limitations in urban 
areas. DHSï¿½s national TOPOFF exercises have demonstrated first 
respondersï¿½ confusion over competing plume modelsï¿½ contradictory 
results. The Interagency Modeling and Atmospheric Assessment Center 
(IMAAC), created to coordinate modeling predictions, lacks procedures 
to resolve contradictory predictions. 

Table: Top Officials Exercises 1ï¿½4, 2000ï¿½2007: 

Exercise: 1; 
Date: May 20ï¿½24, 2000; 
Place: Portsmouth, N.H;
Type of agent release simulated: Mustard gas. 

Exercise: 1; 
Date: May 20ï¿½24, 2000; 
Place: Denver, Colo;
Type of agent release simulated: Pneumonic plague. 

Exercise: 1; 
Date: May 20ï¿½24, 2000; 
Place: Washington, D.C;
Type of agent release simulated: Radiological dispersion device. 

Exercise: 2; 
Date: May 12ï¿½16, 2003; 
Place: Chicago, Ill;
Type of agent release simulated: Pneumonic plague. 

Exercise: 2; 
Date: May 12ï¿½16, 2003; 
Place: Seattle, Wash;
Type of agent release simulated: Radiological dispersion device. 

Exercise: 3; 
Date: April 4ï¿½8, 2005; 
Place: New London, Conn;
Type of agent release simulated: Mustard gas. 

Exercise: 3; 
Date: April 4ï¿½8, 2005; 
Place: New Jersey;
Type of agent release simulated: Pneumonic plague. 

Exercise: 4; 
Date: October 15ï¿½20, 2007; 
Place: Guam;
Type of agent release simulated: Radiological dispersion device. 

Exercise: 4; 
Date: October 15ï¿½20, 2007; 
Place: Phoenix, Ariz;
Type of agent release simulated: Radiological dispersion device. 

Exercise: 4; 
Date: October 15ï¿½20, 2007; 
Place: Portland, Ore;
Type of agent release simulated: Radiological dispersion device. 

Source: DHS. 

[End of table] 

Evaluations and field testing of plume models developed for urban areas 
show variable predictions in urban environments. They are limited in 
obtaining accurate data on the characteristics and rate of CBRN 
material released. 

Data on population density, land use, and complex terrain are critical 
to first responders, but data on the effects of exposure to CBRN 
materials on urban populations have significant gaps. Scientific 
research is lacking on how low-level exposure to CBRN material affects 
civilian populations, especially elderly persons, children, and people 
whose immune systems are compromised. 

What GAO Recommends: 

The Secretary of Homeland Security should (1) reach agreement with 
agencies on who will have the mission and responsibility to develop, 
certify, and independently test first respondersï¿½ equipment for 
detecting hazardous material releases; (2) ensure testing and 
validation of manufacturersï¿½ claims about CBRN detection equipmentï¿½s 
sensitivity and specificity; (3) refine IMAACï¿½s procedures for 
addressing contradictory modeling predictions in CBRN events; (4) with 
IMAAC, work with the federal plume modeling community to accelerate R&D 
on model deficiencies in urban areas and improve federal modeling and 
assessment capabilities. 

To view the full product, including scope and methodology, click 
[hyperlink, http://www.gao.gov/cgi-bin/getrpt?GAO-08-18]. For more 
information, contact Nancy Kingsbury at 202-512-2700. 

[End of section] 

Report to Congressional Requesters: 

United States Government Accountability Office: 

GAO: 

June 2008: 

Homeland security: 

First Responders' Ability to Detect and Model Hazardous Releases in 
Urban Areas Is Significantly Limited: 

GAO-08-180: 

Contents: 

Letter: 

Results in Brief: 

Background: 

CBRN Detection Equipment Has Significant Limitations for First 
Responders' Use: 

CBRN Detection Equipment Has Few Performance Standards and Is Not 
Independently Tested to Validate Manufacturers' Claims: 

Plume Models for Analyzing Urban Dispersion of CBRN Agents Have Limited 
Capabilities: 

Data Gaps on How CBRN Releases Affect Urban Populations Are 
Significant: 

Conclusions: 

Recommendations for Executive Action: 

Agency Comments and Our Evaluation: 

Appendix I: Scope and Methodology: 

Appendix II: Chemical, Biological, and Radiological Agents: 

Appendix III: Comments from the Department of Homeland Security: 

Appendix IV: Comments from the Department of Commerce: 

Tables: 

Table 1: Fifteen Projected Homeland Security Threats and Their 
Consequences: 

Table 2: DHS's Radiation and Nuclear Detection Equipment Standards: 

Table 3: Agency Missions to Develop, Independently Test, and Certify 
CBR Detection Equipment for First Responders' Use: 

Table 4: Six CBRN Models Federal Agencies and First Responders Use: 

Table 5: Top Officials Exercises 1-4, 2000-2007: 

Table 6: Chemical Warfare Agents: 

Table 7: Biological Warfare Agents: 

Table 8: Radiological Warfare Agents: 

Figures: 

Figure 1: A BioWatch Aerosol Collector: 

Figure 2: NARAC's TOPOFF 2 Plume Prediction: 

Figure 3: Dose Response for Healthy and General Population Exposures to 
Sarin: 

Abbreviations: 

AEGL: acute exposure guideline level: 

ALOHA: real Locations of Hazardous Atmospheres: 

ASTM: American Society for Testing and Materials: 

CAMEO: Computer-Aided Management of Emergency Operations: 

CB: chemical and biological: 

CBRN: chemical, biological, radiological, nuclear: 

CDC: Centers for Disease Control and Prevention: 

CFD: computational fluid dynamics: 

DHS: Department of Homeland Security: 

DNDO: Domestic Nuclear Detection Office: 

DOC: Department of Commerce: 

DOD: Department of Defense: 

DOE: Department of Energy: 

DTRA: Defense Threat Reduction Agency: 

ECBC: Edgewood Chemical Biological Center: 

EPA: Environmental Protection Agency: 

FBI: Federal Bureau of Investigation: 

FEMA: Federal Emergency Management Agency: 

FRMAC: Federal Radiological Monitoring and Assessment Center: 

hazmat: hazardous materials: 

HHA: handheld immunoassay: 

HPAC: Hazard Prediction and Assessment Capability: 

HSC: Homeland Security Council: 

HYSPLIT: Hybrid Single-Particle Lagrangian Integrated Trajectory: 

IAB: InterAgency Board for Equipment Standardization and 
Interoperability: 

IDA: Institute for Defense Analyses: 

IMAAC: Interagency Modeling and Atmospheric Assessment Center: 

IMS: ion mobility spectrometer: 

LANL: Los Alamos National Laboratory: 

LLNL: Lawrence Livermore National Laboratory: 

LODI: Lagrangian Operational Dispersion Integrator: 

NARAC: National Atmospheric Release Advisory Center: 

NIST: National Institute of Standards and Technology: 

NOAA: National Oceanic and Atmospheric Administration: 

NRC: National Research Council: 

OFCM: Office of the Federal Coordinator for Meteorological Services and 
Supporting Research: 

OLES: Office of Law Enforcement Standards: 

ORNL: Oak Ridge National Laboratory: 

OSTP: Office of Science and Technology Policy: 

QUIC: Quick Urban and Industrial Complex: 

ppb: parts per billion: 

ppm: parts per million: 

RASCAL: Radiological Assessment System for Consequence Analysis: 

RKB: Responder Knowledge Base: 

SAVER: System Assessment and Validation for Emergency: 

Responders: 

SAW: surface acoustic wave: 

SCIPUFF: Second-order Closure Integrated Puff: 

SHSP: State Homeland Security Program: 

S&T: Science and Technology: 

TIC: toxic industrial chemical: 

TIM: toxic industrial material: 

TOPOFF: Top Officials: 

UASI: Urban Areas Security Initiative: 

UDM: Urban Dispersion Model: 

[End of section] 

United States Government Accountability Office: 

Washington, DC 20548: 

June 27, 2008: 

Congressional Requesters: 

A terrorist act involving the use of a chemical, biological, 
radiological, or nuclear (CBRN) agent or weapon presents an array of 
complex issues to state and local responders. The responders, who may 
include firefighters, emergency medical service personnel, and 
hazardous materials technicians, must identify the agent or weapon so 
that they can rapidly decontaminate victims and apply appropriate 
medical treatments. They must also determine whether the agent has 
spread beyond the incident site and what actions should be taken to 
protect other people. 

Since at least 2001, it has been recognized that CBRN materials might 
be released by a terrorist act when letters laced with anthrax were 
sent through the mail to two U.S. senators and members of the 
media.[Footnote 1] The letters led to the first cases of anthrax 
disease related to bioterrorism in the United States. In all, 22 
persons contracted anthrax disease and 5 died in four states and 
Washington, D.C. The anthrax attack highlighted the nation's 
vulnerability. In 2002, the Congress enacted legislation to create the 
Department of Homeland Security (DHS), merging 22 separate agencies, 
with the primary mission of protecting the United States against 
conventional and unconventional attacks. In addition, the Homeland 
Security Council (HSC), in coordination with DHS and other federal 
agencies, identified nine possible scenarios involving the release of 
CBRN materials in urban areas.[Footnote 2] In one scenario, for 
example, terrorists release sarin in three city office buildings. In 
this scenario, it is estimated that 6,000 people are killed and 
economic damages amount to $300 million. 

Typically, the first to show up in emergency situations like these are 
local first responders.[Footnote 3] Local first responders are 
responsible for identifying the nature of an emergency. In order to 
respond to a CBRN event, first responders need timely and accurate 
information about the type and quantity of agents released, where and 
when they were released, and how far contamination is likely to spread. 
Also critical for first responders is information on the potential 
effects on civilian populations from exposure to concentrations of CBRN 
materials. 

In incidents caused by airborne CBRN releases, first responders' two 
primary tools are (1) detection equipment to identify CBRN materials 
released into the atmosphere and (2) information from plume models that 
track airborne dispersion of CBRN materials and define the area of 
contamination.[Footnote 4] In this report, we focus on the limitations 
of these tools for first responders. Detection devices identify and 
confirm in real time the chemical or particle stimuli by triggering 
signals or alarms when certain sensitivity and specificity parameters 
are detected. With respect to equipment first responders purchase with 
DHS grant funds, DHS is required to establish and implement procedures 
for developing and adopting standards for such equipment to ensure that 
it meets a minimum level of performance, functionality, adequacy, 
durability, sustainability, and interoperability. Information from 
plume models is intended to help inform first responders--from analyses 
of the models' mathematical and computer equations and incorporation of 
field data--on the extent of a contaminated area. A comprehensive model 
takes into account the material released, local topography, and 
meteorological data, such as temperature, humidity, wind velocity, and 
other weather conditions, and continually refines predictions with 
field data. 

In response to your request, we addressed the following questions: (1) 
What are the limitations of detection equipment currently available for 
first responders' use in identifying CBRN materials released in the 
atmosphere? (2) What has DHS done with regard to developing and 
adopting performance standards for CBRN detection equipment and testing 
this equipment to verify its performance? (3) What are the limitations 
of plume models first responders can use to track the dispersion of an 
airborne release of CBRN materials, including toxic industrial 
chemicals (TIC) and toxic industrial materials (TIM), in an urban 
environment? and (4) What information is available to first responders 
for determining the effects of exposure to CBRN materials on 
populations in urban areas? 

To assess the limitations of CBRN detection equipment available for 
first responders' use, we interviewed federal program officials from 
the Science and Technology (S&T) directorate of DHS and its Homeland 
Security Advanced Research Projects Agency, from the Department of 
Defense (DOD) Defense Threat Reduction Agency (DTRA) and Joint Program 
Executive Office for Chemical and Biological Defense, and from the 
Department of Energy's (DOE) Lawrence Livermore National Laboratory 
(LLNL), Los Alamos National Laboratory (LANL), and Oak Ridge National 
Laboratory (ORNL). We reviewed DHS, DOD, and DOE detection programs in 
place and being developed, as well as these agencies' studies on CBRN 
detection systems. We attended conferences and workshops on CBRN 
detection technologies. 

To obtain information on detection equipment standards and the testing 
of CBRN detection equipment for first responders, we met with program 
officials from DHS's Responder Knowledge Base (RKB) and the Department 
of Commerce's (DOC) National Institute of Standards and Technology's 
(NIST) Office of Law Enforcement Standards (OLES). We also interviewed 
local responders in Connecticut, New Jersey, and Washington regarding 
their acquisition of CBRN detection equipment. We chose these states 
because of their participation in DHS-sponsored Top Officials (TOPOFF) 
national counterterrorism exercises. In addition, we interviewed 
members of the InterAgency Board for Equipment Standardization and 
Interoperability (IAB). IAB, made up of local, state, and federal first 
responders, is designed to establish and coordinate local, state, and 
federal standardization, interoperability, compatibility, and responder 
health and safety to prepare for, train and respond to, mitigate, and 
recover from any CBRN incident. 

To assess the limitations of plume models, we interviewed modeling 
experts from DHS, DOD, DOE national laboratories, the National Oceanic 
and Atmospheric Administration (NOAA), and the Office of the Federal 
Coordinator for Meteorological Service and Supporting Research (OFCM) 
in DOC. We interviewed operations staff of the Interagency Modeling and 
Atmospheric Assessment Center (IMAAC) at LLNL. We also interviewed 
local responders in Connecticut, New Jersey, and Washington regarding 
the use of plume models during the TOPOFF 2 and TOPOFF 3 exercises. 

We reviewed documentation on the various plume models and reports and 
studies evaluating models available for tracking CBRN releases in urban 
environments and studies identifying future needs and priorities for 
modeling homeland security threats. We attended several conferences and 
users' workshops sponsored by the American Meteorological Society, DOD, 
OFCM, and George Mason University, where modeling capabilities were 
evaluated. We also reviewed DHS internal reports on lessons learned 
from the use of modeling during TOPOFF national exercises. 

To identify the information first responders have for determining the 
effects of exposure to CBRN materials on heterogeneous civilian 
populations, we reviewed agency documentation and studies on urban land 
use and population density. We also reviewed documentation on acute 
exposure guideline levels published by the Environmental Protection 
Agency (EPA) and other organizations. In addition, we reviewed studies 
on human toxicity estimates by the U.S. Army and DOE national 
laboratories. (More detail on our scope and methodology is in appendix 
I.) 

We conducted our review from July 2004 to January 2008 in accordance 
with generally accepted government auditing standards. 

Results in Brief: 

More than 6 years after the events of September 11, 2001, local first 
responders do not have tools that can accurately and quickly identify 
the release of CBRN material in an urban environment. While DHS and 
other agencies have undertaken initiatives to improve first responders' 
tools, these tools have many limitations for identifying CBRN materials 
released in urban environments, the extent of their dispersion, and 
their effect on urban populations. While equipment first responders use 
for the detection of radiological and nuclear materials may be able to 
identify the presence of these materials, they cannot predict the 
dispersion of these materials in the atmosphere. No agency now has the 
mission to develop, certify, and test equipment first responders can 
use for detecting radiological materials in the atmosphere. Commercial 
chemical and biological detectors that are available cannot detect all 
agents and have varying sensitivity and specificity. According to DHS, 
current detectors are considered generally inadequate to provide 
information on the presence of chemical warfare agents at less than 
lethal but still potentially quite harmful levels--that is, at higher 
than permissible exposure levels. For suspected exposure to biological 
threat agents, commercially available detection devices, such as 
handheld immunoassays (HHA), are not always reliable, and evaluation 
studies show that the devices have not passed acceptable standards for 
effectiveness. BioWatch--DHS's nationwide environmental monitoring 
system--does not allow first responders to obtain immediate real-time 
information on potential biological pathogens released in the 
atmosphere. Under the current BioWatch system, identification and 
confirmation of biological warfare agents does not occur until several 
hours to more than 1 day after release of the agent, and the quantity 
of the agent released cannot be determined. 

DHS has adopted very few performance standards for CBRN detection 
equipment. As of October 30, 2007, DHS had adopted 39 total standards 
for CBRN equipment but had adopted only 4 standards for radiation 
detection instruments targeted at the interdiction and prevention of 
smuggling radioactive material and none for chemical and biological 
(CB) detection equipment. The remaining standards address personal 
protective equipment such as respirators and protective clothing. 

DHS officials told us that it has the mission to develop, independently 
test, and certify CB detection equipment for first responders' use. 
However, DHS officials stated that their mission to test and certify 
chemical and CB detection equipment is limited to equipment that DHS is 
developing for first responders; it does not extend to detection 
equipment first responders buy from manufacturers. DHS does not have an 
independent testing program to validate manufacturers' claims regarding 
detection equipment for first responders. Consequently, first 
responders are buying detection equipment that may or may not be 
effective. 

A number of nonurban plume models, supported by various agencies such 
as DOD, DOE, EPA, and NOAA, are being used to track the atmospheric 
release of CBRN materials for operational real-time applications. 
However, interagency studies have concluded that these models have 
significant limitations for analyzing the dispersion of CBRN materials 
in urban settings. These models have not been adequately validated and 
are not designed for complex built-up urban environments. DHS's 
national TOPOFF 2 exercise in 2003 demonstrated that using several of 
these models and different model inputs can produce contradictory 
results, causing confusion among first responders. To overcome the 
confusion over the use of multiple models during TOPOFF 2, DHS created 
IMAAC in 2004. IMAAC was expected to serve as a single point for the 
coordination and dissemination of federal dispersion modeling and 
hazard prediction products during actual or potential CBRN incidents 
requiring federal coordination. However, the results from the TOPOFF 3 
exercise conducted in 2005 showed that despite IMAAC, problems with 
coordinating modeling inputs and results continued. Exercise results 
from the TOPOFF 4 exercise, conducted in 2007, showed improvement in 
IMAAC's ability to minimize differences in plume modeling outputs and 
provide one source for consequence predictions. However, decision 
makers had difficulty interpreting the plume and consequence models 
predicting radiation dispersal. 

In addition, federal agencies have developed urban plume models 
specifically for use in urban areas. Evaluation and testing of urban 
plume models DHS, DOD, and DOE conducted in several full-scale field 
experiments has shown an unpredictable range of uncertainty in urban 
plume models' analyses that will not give first responders ground 
truth--that is, the actual hazard area and the level and extent of 
contamination on the ground. Model evaluations and field studies have 
also shown that urban plume models cannot determine with certainty the 
source term from a CBRN release--that is, the characteristics of the 
material that was released and its rate of release--particularly for 
estimating the source term of the release of TICs from accidents or 
terrorist acts. 

Significant gaps exist in information first responders have for 
determining the effects of exposure to CBRN materials on heterogeneous 
urban populations. Scientific research on the effects of low-level 
exposure to CBRN material on civilian populations is severely lacking, 
especially for vulnerable populations such as elderly people, children, 
and individuals with compromised immune systems. A dose that may not be 
lethal for a healthy young adult might be lethal for them. For example, 
in the 2001 anthrax attack, many postal workers exposed to high 
concentrations over a prolonged period did not develop the anthrax 
disease, while an elderly woman in Connecticut with a compromised 
immune system died, presumably from inhaling very few spores. Dose 
response parameters for the general population also do not exist for 
most chemical warfare agents believed to pose a threat to civilians. 
Data are needed on exposure and dose assessments to identify vulnerable 
populations and how to adjust individual and population post-event 
activities and behavior to reduce casualties. Information on population 
density, land use, and nearby complex terrain is especially critical. 

We are making recommendations in this report to the Secretary of 
Homeland Security for executive action to address shortcomings in 
detection and modeling capabilities. Specifically, we recommend that 
the Secretary of Homeland Security (1) reach agreement with other 
agencies on which agency should have the mission and responsibility to 
develop, test, and certify detection equipment that first responders 
use to detect hazardous material releases in the atmosphere; (2) ensure 
that manufacturers' claims are independently tested and validated 
regarding whether their commercial off-the-shelf CBRN detection 
equipment can detect given hazardous material at specific 
sensitivities; (3) refine IMAAC's procedures by working with other 
federal, state, and local agencies to (a) develop common/joint IMAAC 
emergency response practices, including procedures for dealing with 
contradictory plume modeling information, (b) refine the concept of 
operations for chemical, biological, and radiological releases, and (c) 
delineate the type and scale of major CBRN incidents that would qualify 
for IMAAC assistance; and (4) in conjunction with IMAAC, work with the 
federal plume modeling community to accelerate research and development 
to address plume model deficiencies in urban areas and improve federal 
modeling and assessment capabilities. Such efforts should include 
improvements to meteorological information, plume models, and data sets 
to evaluate plume models. 

We obtained general comments on a draft of this report from DHS and DOC 
(see apps. III and IV). DHS concurred with our recommendations but 
stated that GAO should consider other scenarios as alternative ways of 
looking at the present national capabilities for CBRN response and the 
current status of testing and certification of detection equipment. DHS 
stated that in one alternative scenario, first responders, in the event 
of a terrorist attack, will use a variety of prescreening tools, and 
they will be assisted immediately by state and federal agencies that 
will bring the best available state-of-the-art CBRN detection 
equipment. 

In our report, we have considered scenarios in which first responders 
are on the scene before federal assets arrive, not knowing what 
hazardous materials (including CBRN agents) have been released, either 
accidentally or by terrorist acts. In these situations, it is the first 
responder who has to first determine what was released and what tools 
to use to make that determination before receiving assistance from 
state and federal agencies. As discussed in our report, by DHS's own 
assessments, these state-of-the-art tools have significant limitations. 

In its general comments on our draft report, DOC stated it believed 
that even with the implementation of GAO recommendations aimed at 
improving IMAAC operations, the plume models would still have several 
limitations as a primary tool for tracking the release of CBRN 
materials in urban areas. To improve information available for 
emergency managers, DOC suggested offering a recommendation that DHS 
work with the federal plume modeling community to accelerate research 
and development to address plume model deficiencies in urban areas. 
Such efforts should include improvements to meteorological information, 
plume models, and data sets to evaluate plume models. We believe that 
DOC's recommendation has merit and have included it in our final report 
for DHS's consideration. 

We received technical comments from DHS, DOD, DOE (LLNL), and NIST and 
we made changes to the report where appropriate. Technical comments we 
received from LLNL, in particular, proposed broadening the 
recommendation related to revising IMAAC standard operating procedures 
to deal with contradictory modeling inputs. IMAAC operations staff at 
LLNL believed that integrated procedures with other emergency response 
agencies are the key to clarifying plume modeling information. We 
agreed and have revised our recommendation accordingly. 

Background: 

The National Strategy for Homeland Security characterizes terrorism as 
"any premeditated, unlawful act dangerous to human life or public 
welfare that is intended to intimidate or coerce civilian populations 
or governments."[Footnote 5] This definition includes attacks involving 
CBRN materials. The National Strategy recognizes that the consequences 
of such an attack could be far more devastating than those the United 
States suffered on September 11: "a chemical, biological, radiological, 
or nuclear terrorist attack in the United States could cause large 
numbers of casualties, mass psychological disruption, contamination and 
significant economic damage, and could overwhelm local medical 
capabilities."[Footnote 6] 

Government Responsibilities for Responding to CBRN Events: 

State and Local Responsibilities: 

State and local responders share in the responsibility for responding 
to CBRN events, but local first responders play the key role because 
they are the first to respond. The first line of defense in any 
terrorist attack on the United States is its first responder community-
-police officers, firefighters, emergency medical providers, public 
works personnel, and emergency management officials. Their role is to 
protect against, respond to, and assist in recovery from emergency 
events. Traditionally, first responders have been trained and equipped 
to arrive at the scene of a natural or accidental emergency and take 
immediate action. 

Federal Responsibilities: 

If state and local resources and capabilities are overwhelmed, 
governors may request federal assistance. In his February 28, 2003, 
Homeland Security Presidential Directive/HSPD-5, the President 
designated the Secretary of Homeland Security the principal federal 
official responsible for domestic incident management. The directive 
empowered the Secretary to coordinate federal resources used to respond 
to or recover from terrorist attacks, major disasters, or other 
emergencies in specific cases.[Footnote 7] The Secretary, in 
coordination with other federal departments and agencies, is to 
initiate actions to prepare for, respond to, and recover from such 
incidents. The directive also called for the Secretary to develop a 
National Response Plan to provide the framework for federal interaction 
with nonfederal entities.[Footnote 8] 

In addition, HSPD-8, issued on December 17, 2003, established policies 
to strengthen first responder preparedness for preventing and 
responding to threatened or actual domestic terrorist attacks.[Footnote 
9] Among other things, it required DHS to provide assistance to state 
and local efforts, including planning, training, exercises, 
interoperability, and equipment acquisition for terrorist events. HSPD- 
8 also required DHS to coordinate with other federal agencies and state 
and local officials in establishing and implementing (1) procedures for 
developing and adopting first responder equipment standards and (2) 
plans to identify and address national first responder equipment 
research and development needs. 

First Responders' Challenges in CBRN Events: 

First responders face difficult challenges when they arrive at the 
scene of an accidental or terrorist release of CBRN agents in an urban 
environment. Local police, fire, and emergency medical units would be 
the first on the scene, attempting to control the situation while 
requesting technical assistance, specialized units, and backup. County 
and local hazardous materials (hazmat) teams and bomb squads would be 
among the first units called to augment the first responders. A major 
terrorist act involving CBRN materials might cause significant 
casualties among the first responders. It is therefore critical that 
they be able to quickly identify, locate, characterize, and assess the 
potential effect of CBRN, explosive, or incendiary threats and 
communicate this information rapidly and effectively. 

The primary challenge facing first responders is knowing how to 
identify and distinguish between CBRN releases. The first responders 
need to be able to communicate what was released, the quantity of the 
material released (and its purity, in the case of chemical agents), 
where it is going, who is at risk, and how to respond. Of ultimate 
interest are the human health and environmental effects, since exposure 
to CBRN materials can kill or seriously injure people through their 
physiological effects. A chemical agent attacks the organs of the human 
body so as to prevent them from functioning normally. The results are 
usually disabling and can even be fatal. However, DHS S&T officials 
said that for biological agents, there "will be no first responders" in 
the traditional sense of being present while the aerosol cloud is 
present, and so they are not preferentially exposed in the initial 
exposure. Follow-up investigation does pose additional risk to the 
first responders from contamination and reaerosolization, but they can 
be suitably protected by both personal protective equipment and 
antimicrobials.[Footnote 10] 

The danger that TICs and TIMs will be released in urban areas from 
industrial and transportation accidents is also of concern. 
Approximately 800,000 shipments of hazardous materials such as liquid 
chlorine and ammonia travel daily throughout the United States by 
ground, rail, air, water, and pipeline. Many are explosive, flammable, 
toxic, and corrosive and can be extremely dangerous when improperly 
released. They are often transported over, through, and under densely 
populated areas, where a release could cause injury or death and 
significant environmental damage. 

Both international and domestic accidents illustrate the potentially 
catastrophic effects of the release of TICs and TIMs. An accidental, 
large-scale hazardous release in Bhopal, India, in 1984, killed 
approximately 3,800 people and left thousands of people with permanent 
or partial disabilities.[Footnote 11] More recently, on January 6, 
2005, in Graniteville, South Carolina, a freight train pulling three 
chlorine tanker cars and a sodium hydroxide tanker car collided with a 
train parked on an industrial rail spur. Almost immediately, 11,500 
gallons of chlorine gas released from the tankers caused 9 people to 
die, 8 from inhaling chlorine gas, and at least 529 to seek medical 
care for possible chlorine exposure. A visible cloud that spread 
initially in all directions led local emergency officials to issue a 
shelter-in-place order. South Carolina officials later declared a state 
of emergency, under which local authorities evacuated 5,453 residents 
within a mile's radius of the collision. 

In contrast to chemical agents, biological agents can multiply in the 
human body, significantly increasing their effects. Many biological 
agents are highly virulent and toxic; they may have an incubation 
period so that their effects are not seen for hours to days. According 
to DHS, biological attacks that have the greatest potential for 
widespread catastrophic damage include, but are not limited to, 
aerosolized anthrax and smallpox. 

When radioactive materials are incorporated and retained in the body, 
the tissues in which the materials are concentrated, or in some 
instances the whole body, can suffer significant radiation injury. 
Radiation from deposited radiological material is a significant cause 
of radiation exposures and potential casualties once the airborne plume 
has passed. (Appendix II lists chemical, biological, and radiological 
agents and their effects on human health.) 

Planning scenarios DHS developed for use in federal, state, and local 
security preparedness illustrate the difficult challenges first 
responders face in CBRN events and the extent of potential injuries and 
fatalities. Nine of the 15 possible scenarios in table 1 involve the 
release of CBRN agents or toxic industrial materials in metropolitan 
areas. 

Table 1: Fifteen Projected Homeland Security Threats and Their 
Consequences: 

[See PDF for image] 

Source: Congressional Research Service, The National Preparedness 
System: Issues in the 109th Congress (Washington, D.C.: 2005). 

[A] Includes injuries. 

[End of table] 

Tools Used to Identify and Track CBRN Materials: 

First responders have two primary tools in CBRN events: (1) equipment 
to identify CBRN materials in the atmosphere and (2) information from 
plume models and field measurements that track the atmospheric 
dispersion of CBRN materials. Detection devices identify and confirm 
CBRN material stimuli by triggering signals or alarms when certain 
sensitivity and specificity parameters are detected. 

The sensitivity, specificity, and selectivity of CB detection equipment 
are key performance characteristics. Biological detection equipment has 
to be sensitive enough to detect very small amounts of biological 
agents and also has to have a high degree of specificity in order to 
distinguish biological agents from harmless biological and 
nonbiological material in the environment. For chemical detectors, 
sensitivity is the lowest concentration at which a chemical agent can 
be detected. As with biological agents, the most challenging aspect of 
identifying chemical agents with a detector is its selectivity in 
extracting the agent of interest from other chemicals in the 
environment. The sensitivity, specificity, and selectivity of CB 
detection equipment also determine false positive or negative alarm 
rates. Detectors should have minimal false positive and false negative 
alarm rates. 

Information from plume models is intended to help tell first 
responders--from analyses of the models' mathematical or computer 
equations or both--the extent of the contaminated area. In emergency 
response, plume models are used to provide early estimates of 
potentially contaminated areas and should be used in combination with 
data gathered from the field. Model results are used to guide field 
sampling, data from which, in turn, are used to update plume 
predictions in a cyclical process until the effects have been 
accurately characterized. 

A comprehensive model takes into account the material released, local 
topography, and meteorological data, such as temperature, humidity, 
wind velocity, and other weather conditions. Plume modeling requires 
several accurate components: 

* meteorological data (for example, temperature, humidity, barometric 
pressure, dew point, wind velocity and direction at varying altitudes, 
and other related measures of weather conditions); 

* data from global weather models to simulate large-scale weather 
patterns and from regional and local weather models to simulate the 
weather in the area of the chemical agent release and throughout the 
area of dispersion; 

* the source term, or the characteristics or properties of the material 
that was released and its rate of release (for example, its quantity 
and purity, vapor pressure, the temperature at which the material 
burns, particle size distribution, its persistence and toxicity, and 
height of release); 

* temporal and geographical information (for example, transport and 
dispersion processes such as whether the agent was initially released 
during daylight hours, when it might rapidly disperse into the surface 
air, or at night, when a different set of breakdown and dispersion 
characteristics would pertain, depending on terrain, and plume height, 
complex terrain, urban effects, and agent processes such as 
environmental degradation and decay and growth rates for radiological 
agents); and: 

* information on the potentially exposed populations, such as dose 
response (conversion of exposures into health effects), animals, crops, 
and other assets that may be affected by the agent's release. 

CBRN Detection Equipment Has Significant Limitations for First 
Responders' Use: 

Current CBRN detection equipment has significant limitations for first 
responders' use in an event involving the release of CBRN materials in 
an urban environment. First, the detection equipment first responders 
now use for radiological and nuclear incidents cannot detect the 
dispersal of radiological contamination in the atmosphere. Second, 
according to DHS, chemical detection equipment is generally inadequate 
to provide information on the presence of chemical warfare agents at 
less than lethal but still potentially harmful levels. Third, for 
biological detection equipment, the handheld assays first responders 
use do not provide accurate information because of this equipment's 
high level of false positives. In addition, BioWatch, the nationwide 
environmental monitoring system, does not enable first responders to 
obtain immediate real-time information about the effects of biological 
pathogens released in the atmosphere. 

Current Radiological and Nuclear Detection Equipment First Responders 
Use Cannot Detect the Dispersion of Releases in the Atmosphere: 

While equipment first responders use for detecting radiological and 
nuclear materials can detect the presence of significant amounts of 
these materials, they cannot predict their dispersion in the 
atmosphere. In addition, current handheld, compact devices such as 
dosimeters and pagers are not able to detect low energy beta radiation 
from some isotopes and are not capable of handling rugged and harsh 
environments. DHS's Domestic Nuclear Detection Office (DNDO) is 
responsible for acquiring and supporting the deployment of radiation 
detection equipment. However, this office has primarily emphasized 
developing and deploying radiation detection equipment to secure cargo 
container shipments at U.S. ports of entry to prevent smuggling 
radioactive material into the United States. DNDO's Chief of Staff told 
us that it does not consider its mission to include the development of 
radiological detection equipment for local first responders to use in 
identifying the release of radiological materials in the atmosphere. It 
does not evaluate radiological detection equipment for first responder 
use in consequence management. 

We surveyed federal agencies involved with CBRN defense about their 
mission in relation to radiological detection equipment for first 
responders. DHS, DOD, DOE, EPA, NIST, and NOAA responded that they do 
not have specific missions to develop, independently test, and certify 
detection equipment for use by first responders in detecting 
radiological materials in the atmosphere. However, DOD and DOE program 
officials said that first responders can certainly use radiological 
detection equipment DOD and DOE develop for other missions. In 
addition, agencies such as DOE and EPA have some capability for 
tracking airborne radiological materials--a capability that first 
responders do not have. For example, we previously reported that DOE 
can deploy teams that use radiation monitoring equipment, including 
sensors mounted on aircraft and land vehicles, to detect and measure 
radiation contamination levels and provide information to state and 
local officials on what areas need to be evacuated.[Footnote 12] EPA 
also has its RadNet system for airborne radiation monitoring.[Footnote 
13] 

Current Chemical Detection Equipment First Responders Use Cannot Detect 
Harmful Concentrations: 

According to DHS S&T's CB Division, significant investments have been 
made toward the detection of chemical agents, largely led by DOD 
investments, followed up by investments in the private sector to 
exploit the marketplace. As a result, a number of options are available 
for detecting these materials as vapor and liquids. However, according 
to DHS S&T, current detectors can be used for rapid warning of 
chemicals (warfare agents and TICs) as vapor but are considered 
generally inadequate to provide information on the presence of chemical 
warfare agents at less than lethal but still potentially quite harmful 
levels--that is, higher than permissible exposure levels. DHS S&T 
acknowledged that improvements are needed to meet sensitivities 
necessary for real-time protection of the population and for 
eliminating a tendency for high false-alarm rates. Improvements are 
also needed in the selectivity of most common chemical detector 
platforms. Anecdotal information led DHS S&T to make the following 
general observations with regard to currently available detectors and 
their ranking for performance for first responders' use: 

* Mass spectrometer devices are the most sensitive chemical detectors 
but are significantly costly and least frequently used by first 
responders. These devices are also significantly heavier and larger, so 
that they are typically bench-top, laboratory devices and not robust 
handheld detectors that are more suitable for field deployment. 

* Ion mobility spectrometers (IMS) and surface acoustic wave (SAW) 
devices are next in selectivity but encounter frequent false positive 
responses and are susceptible to interference by common materials such 
as cleaners, pesticides, paint fumes, fire-fighting foams, and 
combustion products. Hazmat teams and other responders use both types, 
and they are used in protecting occupants of buildings, transit 
systems, and the like. 

However, DHS S&T has assessed the sensitivity of IMS and SAW for V and 
G nerve agents as being in the low parts per billion (ppb) range-- 
approximately 2 ppb to 20 ppb--while the limit of detection is higher-
-at 200 ppb to 300 ppb--for blister agents such as mustard and 
lewisite. According to DHS S&T, these sensitivities would detect some 
agents at concentrations immediately dangerous to life and health but 
would not easily detect other agents such as VX at concentrations that 
are immediately dangerous to life and health. DHS S&T stated that first 
responders could use IMS, SAW, and similar devices to monitor a 
condition that is changing from dangerous to tolerable if the detectors 
were used to provide guidance on the use of personal protective 
equipment but cannot be used for rapid warning of dangerous conditions. 

Photo-ionization, flame-ionization, and flame photometric detectors-- 
according to DHS S&T, prone to false positive alarms--can be improved 
if chromatographic separation techniques are incorporated before 
analyte streams are presented. However, DHS S&T officials state that 
few current detectors first responders use have this technology. 

DHS S&T officials stated that the limitations noted for detectors of 
chemical warfare agents (cost and size; propensity for false positive 
alarms) also apply to TICs, many of which can be detected by IMS and 
SAW devices commonly in use. DHS S&T stated that electrochemical cells 
(and a variety of slower responding detector tubes) are used to fill 
the gaps in detection presented by IMS and SAW devices and expand the 
number of TICs that can be detected. Detection sensitivity of the 
electrochemical cells can range from ppb to low parts per million (ppm) 
concentration ranges. In general terms, TICs can be detected at 
concentrations considerably less than immediately dangerous, ranging in 
times from seconds to a few minutes, depending on the detector. DHS 
officials stated that these observations are based on an examination of 
manufacturers' claims that in some cases have been independently tested 
and evaluated. 

First Responders' Handheld Biological Detectors Are Ineffective: 

During the emergency response phase of a suspected exposure to a 
biological threat agent, the only tool most likely available to first 
responders would be HHAs. HHAs are small test strips that contain an 
antibody to a specific biological agent. The assays require a 
suspension of the suspect sample in a liquid supplied with the test 
assay. Applying the liquid suspension to the strip yields a result in 
approximately 15 minutes. A quality control test is built into all the 
strips to indicate whether the assay materials are working properly. 

However, according to officials in DHS S&T, HHAs do not have the 
sensitivity to detect the atmospheric concentrations of agents that 
pose health risks without large volume air collectors. A 2002 
memorandum from the White House Office of Science and Technology Policy 
(OSTP) recommended against first responders' using HHAs. It stated 
that: 

"Recent scientific evaluation of these commercially available detection 
systems concludes that this equipment does not pass acceptable 
standards for effectiveness. Specifically, Bacillus anthracis detection 
thresholds for these devices are well above the minimum level that can 
infect personnel, and are not suitable for determining biological 
determinants of personnel, rooms, or pieces of equipment. Many devices 
have been shown to give a significant number of false positives, which 
could cause unnecessary medical interventions with its own 
risk."[Footnote 14] 

OSTP's recommendation was based on a joint evaluation study by the 
Centers for Disease Control and Prevention (CDC) and the Federal Bureau 
of Investigation (FBI). Manufacturers of HHAs have expressed concern 
regarding the study's methods, objectivity, and overall quality. 

According to DHS S&T officials, since the 2002 OSTP guidance, DHS has 
sponsored the development of standards for HHA detection of Bacillus 
anthracis through AOAC International, AOAC testing of a number of HHAs, 
and the development and propagation of ASTM International (originally 
known as the American Society for Testing and Materials) standards for 
sampling of white powders.[Footnote 15] ASTM International developed 
standard E2458, Standard Practices for Bulk Sample Collection and Swab 
Sample Collection of Visible Powders Suspected of Being Biological 
Agents from Nonporous Surfaces, published in 2006. This standard was 
developed by CDC, DHS, EPA, the FBI, and state and local hazmat 
specialists. 

DHS S&T officials noted that a biological attack is likely to be 
covert, and since no visible signatures or odors are associated with a 
release and people do not immediately fall ill, there will be no 
indicators for a first responder to know there was an attack. First 
responders for biological events are not likely to appear on the scene 
until well after the primary release cloud has dispersed. Therefore, 
all characterization is likely to be after the atmospheric release 
cloud has passed. The hazards first responders will encounter are 
surface contamination and any possible reaerosolization. In that case, 
S&T officials stated, the information to characterize the affected 
region is likely to come from environmental sampling (for example, 
BioWatch, surface sampling, or native air collectors) coupled with 
plume modeling and, as disease progresses, epidemiological information. 

BioWatch Does Not Provide First Responders Real-Time Detection of 
Biological Pathogens: 

BioWatch is a nationwide environmental monitoring system for selected 
biological pathogens but does not provide first responders real-time 
detection of them. Under the current BioWatch system, a threat agent is 
not identified until several hours to more than a day after the release 
of the agent, and the system does not determine how much material was 
released. DHS BioWatch officials said that the system gives a 
qualitative rather than quantitative assessment of the release of 
biological material. 

BioWatch is funded and managed by DHS and coordinated with CDC and EPA. 
LANL and LLNL provide technical support. BioWatch was designed to 
detect the release of biological pathogens in the air through aerosol 
collector units installed in several major U.S. cities. The units 
collect airborne particles on filters, which are transported to 
laboratories for analysis. Set up very quickly in early 2003, according 
to DHS BioWatch Program officials, more than 30 jurisdictions now 
participate in BioWatch. DHS spending for the BioWatch program during 
fiscal years 2005 to 2007 was about $236 million.[Footnote 16] 

The BioWatch network of sampling units collects aerosol samples daily 
(fig. 1). Each aerosol collector has a single filter that traps aerosol 
particles. Couriers collect the air filters every 24 hours and deliver 
them to state or local public health laboratories, where they are 
tested for the presence of the genetic material of six specific 
biothreat pathogens. The BioWatch Laboratory assay, however, cannot 
differentiate between infectious and noninfectious agents (that is, 
live or dead germs). 

Figure 1: A BioWatch Aerosol Collector: 

This figure is a photograph of a BioWatch aerosol collector. 

[See PDF for image] 

Source: DHS. 

[End of figure] 

First responders cannot use BioWatch to immediately determine an 
adequate response. While BioWatch is a detect-to-treat system designed 
to detect a biological attack in advance of symptoms arising within a 
population, it cannot help first responders make immediate medical 
intervention decisions. BioWatch is not intended to detect a release 
while it is in progress. It is intended to detect a release as soon 
after an event as practical and before the onset of symptoms so as to 
speed the delivery of medical countermeasures. DHS officials stated 
that BioWatch was not intended as a tool for first responders. A 
confirmed laboratory test result from a BioWatch sample, known as a 
"BioWatch Actionable Result," is a data point used by the local 
Director of Public Health and BioWatch Advisory Committee to determine 
if the result has public health significance and, if it does, what 
actions are necessary to address a potential problem. If a response is 
necessary, the local jurisdiction's Incident Management System is used 
to determine the nature and logistics of the response. First responders 
may or may not be deployed. 

The current BioWatch system can detect an aerosol attack with specific 
threat agents within several hours to more than 1 day after the release 
of the agents. This period of time includes the sample collection cycle 
of 24 hours, transportation to public health laboratories, and 
laboratory analysis to identify and confirm the agents used. According 
to DHS BioWatch officials, in general, symptoms would not develop until 
days to weeks after an attack. 

However, experts have emphasized the importance of "real-time 
detection" of biological agents as an element of an effective 
biological detection system.[Footnote 17] The system should rapidly 
recognize the release of likely biological agents before the onset of 
clinical illness. Without the benefit of real-time biological 
detection, a terrorist biological attack cannot be detected until the 
clinical analysis of the initial outbreak of patients' demonstrating 
symptoms and early fatalities. This delayed detection will allow 
disease to progress rapidly within the population and grow to 
potentially epidemic proportions. Real-time detection enables first 
responders to take action to limit the number of people exposed to the 
agent, allowing time to warn others before they are exposed and reduce 
the number of infections. Real time has been defined as 30 seconds or 
less from the time potential material reaches the device until an alarm 
is triggered.[Footnote 18] 

DHS officials stated that public health officials in the jurisdictions 
where BioWatch collectors are located can and plan to use BioWatch 
information immediately to make decisions about responses. They noted 
that a wide range of decisions is possible and that a specific course 
of action depends on such factors such as current intelligence about 
threats, the type of agents detected, the amount detected, the number 
of BioWatch collectors affected, and information from medical 
surveillance systems. BioWatch is moving toward next- generation 
technology, which will provide autonomous collection and detection and 
better time resolution than current BioWatch collector units. 

CBRN Detection Equipment Has Few Performance Standards and Is Not 
Independently Tested to Validate Manufacturers' Claims: 

First responders are hampered by the slow development of CBRN equipment 
detection standards. The CBRN detection equipment that first responders 
and other DHS grantees buy with DHS grant funds must comply with 
equipment performance standards adopted by DHS. However, DHS has 
adopted very few standards for this equipment, and the adoption of 
accepted standards has lagged behind the pace at which new products 
enter the market. In addition, according to our survey of federal 
agencies, DHS has the primary mission to develop, independently test, 
and certify CB detection equipment for first responders' use. However, 
DHS does not independently test and validate whether commercially 
available CBRN detection equipment can detect specific agents at 
specific target sensitivities claimed by the manufacturers. 

DHS Grant Funds Allow First Responders to Acquire CBRN Detection 
Equipment: 

DHS's grant funding to states allows first responders to purchase 
commercially available CBRN detection equipment. First responders may 
use DHS's major grant funding under the State Homeland Security Program 
(SHSP) and Urban Areas Security Initiative (UASI) to buy equipment from 
the 21 categories on DHS's authorized equipment list. Detection 
equipment, category 7, is available for CBRN detection. For biological 
detection, for example, this includes field assay kits, protein test 
kits, DNA and RNA tools, and biological sampling kits, but descriptions 
and features, models and manufacturers, and operating considerations 
are not identified. 

In the states we visited, we obtained information on detection 
equipment bought with DHS grant funds in 2003-2005. For example, in 
Seattle and the state of Washington, state agencies, hazmat teams, and 
local fire departments in 11 counties acquired CBRN detection equipment 
with about $3.2 million of SHSP and UASI grant funds in 2004-2005. 
Seattle alone purchased CBRN detection equipment, mostly chemical 
detection equipment, at a cost of about $500,000, primarily with UASI 
grants. According to the Assistant Chief of the Seattle Fire 
Department, about 20 to 26 hazmat teams served nine counties, varying 
widely in composition and equipment, with small populations and rural 
teams not having the capabilities of those in urban areas. Connecticut 
spent about $1.8 million in DHS grants for CBRN detection equipment in 
2003-2005. 

DHS Has Adopted Few Performance Standards for CBRN Detection Equipment: 

The purpose of standards for equipment is to ensure that equipment 
meets a minimum level of performance, functionality, adequacy, 
durability, sustainability, and interoperability. Adopting uniform 
standards for equipment helps first responders in procuring and using 
equipment that is safe, effective, and compatible. DHS works with a 
number of federal agencies and private organizations in developing 
standards for CBRN detection equipment, including NIST and 
IAB.[Footnote 19] DHS's Standards Subject Area Working Groups and these 
organizations work, in turn, with standards development organizations 
such as ASTM and the National Fire Protection Association. 

DHS's S&T directorate is the focal point for adopting CBRN detection 
equipment standards. According to a 2006 DHS Office of Inspector 
General report on DHS's adoption of equipment standards, S&T can adopt 
standards that apply to equipment first responders purchase with DHS 
grant funds, but it cannot develop mandatory standards for equipment 
because it has no authority to regulate the first responder 
community.[Footnote 20] In addition, DHS S&T has no regulatory 
authority to compel first responders to purchase equipment not 
purchased with federal funds that conforms to S&T adopted standards or 
to order manufacturers not to sell equipment that does not meet these 
standards. NIST's OLES identifies needed performance standards and 
obtains input from others, such as IAB.[Footnote 21] 

As of October 30, 2007, DHS had adopted 39 total standards, but only 4 
of them were for CBRN detection equipment. In February 2004, it adopted 
4 standards for radiation and nuclear detection equipment. These 
standards address first responders' priorities for personal radiation 
detection and devices for detecting, interdicting, and preventing the 
transport of radioactive material rather than the detection of the 
atmospheric spread of radiation materials. Table 2 shows standards DHS 
adopted for radiation and nuclear detection equipment. 

Table 2: DHS's Radiation and Nuclear Detection Equipment Standards: 

Standard: Performance criteria for alarming personal radiation 
detectors for homeland security; 
Requirement: Design and performance criteria and testing methods for 
evaluating performance; 
Function: Pocket-sized instruments carried on the body to detect the 
presence and magnitude of radiation. 

Standard: Radiation detection instrumentation for homeland security; 
Requirement: Design and performance criteria, test and calibration 
requirements, and operating instruction requirements; 
Function: Portable radiation detection instruments to detect photon-
emitting radioactive substances for detection, interdiction, and hazard 
assessment. 

Standard: Performance criteria for handheld instruments for detecting 
and identifying radionuclides; 
Requirement: Test procedures and radiation response requirements and 
electrical, mechanical, and environmental requirements; 
Function: Instruments to detect and identify radionuclides, gamma dose 
rate measurement, and indication of neutron radiation. 

Standard: Evaluation and performance of radiation detection portal 
monitors for use in homeland security; 
Requirement: Testing and evaluation criteria; 
Function: Radiation detection portal monitors to detect and interdict 
radioactive materials that could be used for nuclear weapons or 
radiological dispersal devices. 

Source: DHS. 

[End of table] 

However, DHS has not adopted any standards for CB detection 
equipment.[Footnote 22] The remaining standards address personal 
protective equipment such as respirators and protective clothing. NIST 
officials told us that it generally takes 3 to 5 years for an equipment 
standard to achieve full consensus from the network of users, 
manufacturers, and standards development organizations before final 
publication. DHS, however, noted that standards for radiation detection 
equipment and powder sampling were developed in 12 to 18 months. 

DHS Has the Primary Mission to Develop, Independently Test, and Certify 
First Responders' Chemical and Biological Detection Equipment: 

We surveyed major federal agencies involved with CBRN defense about 
their missions to develop, independently test, and certify CBR 
detection equipment for first responders' use. To certify CBR detection 
equipment is to guarantee a piece of equipment as meeting a standard or 
performance criterion into the future. Certification must be based on 
testing against standards. According to DHS, certification is the 
attestation that equipment has been tested against standards using 
approved testing protocols by an accredited test facility. Table 3 
shows agency responses to our survey, in which we found that only DHS 
indicated it has the missions to develop, independently test, and 
certify CB detection equipment for first responders' use. 

Table 3: Agency Missions to Develop, Independently Test, and Certify 
CBR Detection Equipment for First Responders' Use: 

[See PDF for image] 

Source: GAO. 

[End of table] 

According to DHS, DHS's components, principally the Federal Emergency 
Management Agency (FEMA) and the Office of Health Affairs, in 
conjunction with IAB, identify first responders' needs for CB detection 
equipment. However, DHS officials stated that their mission to test and 
certify CB detection equipment is limited to equipment that DHS is 
developing for first responders; it does not extend to detection 
equipment they purchase from commercial manufacturers. 

DHS Is Not Independently Testing Manufacturers' Claims about CBRN 
Detection Equipment: 

DHS does not independently test and validate whether commercially 
available CBRN detection equipment can detect specific agents at 
specific target sensitivities claimed by the manufacturers. Although 
manufacturers may test equipment in a controlled laboratory environment 
using simulants, live agent testing and field testing by independent 
authorities provides the best indication of performance and 
reliability. 

DHS S&T acknowledged that it does not have a testing program to 
independently test the performance, reliability, and accuracy of 
commercial CBRN detection equipment and determine whether specific, 
currently available detectors can detect at specific target 
sensitivities. No organized DHS evaluation and qualification program 
now guides and informs first responders on their purchases of chemical, 
biological, and radiological detection equipment. DHS relies on 
manufacturers' claims and anecdotal information in the open literature; 
it has not routinely tested or verified manufacturers' claims regarding 
equipment's ability to detect hazardous material at specific 
sensitivities. 

DHS stated that test data may be found for some systems examined under 
its earlier Domestic Preparedness Program or other agency programs such 
as EPA's Environmental Technologies Verification Program.[Footnote 23] 
However, we have not independently evaluated what, if any, CBRN 
technologies they have evaluated. Moreover, the testing is often at the 
anecdotal level since few copies of a given detector model are tested 
in these programs. DHS further stated that because the manufacturers' 
claims and, where available, limited testing data for different models 
of the detector systems are quite varied, compiling data at a 
reasonable confidence level would require a substantial current market 
survey. 

DHS S&T officials said that manufacturers have asked DHS to establish a 
process for validating biodetection equipment. One official said that 
first responders are purchasing biodetection equipment that is "junk" 
because there are no standards and testing programs. Local and state 
first responders we interviewed also said that they often test and 
validate manufacturers' claims on their own. For example, Washington 
State Radiation Protection officials said that in one instance they 
tested one brand of new digital dosimeters they were planning to 
purchase against those they already used. They found that the brand 
tested consistently read only 40 percent of what their current 
dosimeters and instruments read. 

DHS has two programs in place to provide first responders with 
information about CBRN detection equipment. One program, DHS's System 
Assessment and Validation for Emergency Responders (SAVER) program, 
assesses various commercial systems that emergency responders and DHS 
identify as instrumental in their ability to perform their jobs. The 
assessments are performed through focus groups of first responders who 
are asked for their views on the effectiveness of a given technology 
based on a set of criteria.[Footnote 24] The criteria address the 
equipment's capability, usability, affordability, maintainability, and 
deployability. However, DHS officials acknowledged that SAVER neither 
conducts independent scientific testing to determine the extent to 
which the equipment can detect actual chemical warfare agents nor tests 
or verifies manufacturers' claims regarding the equipment's ability to 
detect given hazardous material at specific sensitivities. As of 
October 2007, SAVER had conducted assessments of IMS chemical 
detectors, multisensor meter chemical detectors, photo-ionization and 
flame-ionization detectors, radiation pagers, and radiation survey 
meters, but it had not tested or verified manufacturers' claims 
regarding commercial off-the-shelf CBRN detection equipment's ability 
to detect given hazardous material at specific sensitivities. We have 
not independently evaluated the SAVER assessments. 

The other information source for first responders is DHS's RKB, a Web- 
based information service for the emergency responder community. RKB is 
a one-stop resource that links equipment-related information such as 
product descriptions, standards, operational suitability testing, and 
third-party certifications. As of October 2007, it included 1,127 
certifications for equipment on DHS's authorized equipment list and 268 
reports of operational suitability testing of CBRN equipment by such 
organizations as the U.S. Army's Edgewood Chemical Biological Center 
(ECBC).[Footnote 25] 

Information available to first responders on CBRN detection equipment 
sensitivities comes largely from vendors' claims, either directly from 
a vendor or through vendor-maintained specification sheets on the RKB, 
reference guides NIST has developed, and reference guides ECBC has 
developed. The information in the guides is based on literature 
searches and market surveys and includes manufacturers' statements on 
product capabilities. However, the guides do not contain any testing 
data that would validate the manufacturers' claims. The guides, 
recently incorporated on DHS's SAVER Web site, also have not kept pace 
with emerging technology. They include the 2007 ECBC biological 
detector market survey, the 2005 NIST biological agent detection 
equipment guide, and the 2005 NIST chemical agent detection equipment 
selection guide. 

Plume Models for Analyzing Urban Dispersion of CBRN Agents Have Limited 
Capabilities: 

Federal agencies such as DHS, DOD, DOE, and EPA have developed several 
nonurban plume models for tracking the atmospheric release of CBRN 
materials. Interagency studies, however, have concluded that these 
models have major limitations for accurately predicting the path of 
plumes and the extent of contamination in urban environments. Current 
models commonly used in emergency response do not have the resolution 
to model complex urban environments, where buildings and other 
structures affect wind flow and the structure and intensity of 
atmospheric turbulence. DHS's national TOPOFF exercises have also 
demonstrated that the use of several competing models, using different 
meteorological data and exercise artificiality, can produce 
contradictory results, causing confusion among first responders. 

Evaluations and field testing show that urban plume models federal 
agencies have developed specifically for tracking the release of CBRN 
materials in urban areas have some of the same limitations as the older 
models used for emergency response. The new models show much 
variability in their predictions, and obtaining accurate source term 
data on the release of TICs is also a problem. 

Nonurban Plume Models Have Limitations for Emergency Response to CBRN 
Events in Urban Environments: 

When using information from nonurban plume models in CBRN events, first 
responders may have to choose from the multiple models that various 
agencies support for tracking the release of CBRN materials. Several 
federal agencies operate modeling systems, including DHS, DOD, DOE, 
EPA, NOAA, and the Nuclear Regulatory Commission. U.S. interagency 
studies, however, have concluded that these models have major 
limitations. For example, according to OFCM, in the Department of 
Commerce, most of the more than 140 documented modeling systems used 
for regulatory, research and development, and emergency operations 
purposes, and for calculating the effects of harmful CBRN materials, 
are limited in their ability to accurately predict the path of a plume 
and the extent of contamination in urban environments. Table 4 shows 
examples of models that federal agencies and first responders have 
developed and used to predict the path of the plume for multiple CBRN 
materials. 

Table 4: Six CBRN Models Federal Agencies and First Responders Use: 

Agent modeled: Chemical, biological, radiological, nuclear; 
Model: * HPAC: Hazard Prediction and Assessment Capability; 
* SCIPUFF: Second- order Closure Integrated Puff; 
Agency: Defense Threat Reduction Agency. 

Agent modeled: Chemical, biological, radiological, nuclear; 
Model: LODI: Lagrangian Operational Dispersion Integrator; 
Agency: * Department of Energy; 
* Lawrence Livermore National Laboratory/National Atmospheric Release 
Advisory Center. 

Agent modeled: Chemical; 
Model: * ALOHA: Areal Locations of Hazardous Atmospheres; 
* CAMEO: Computer-Aided Management of Emergency Operations; 
Agency: * Environmental Protection Agency; 
* National Oceanic and Atmospheric Administration. 

Agent modeled: Chemical; 
Model: HYSPLIT: Hybrid Singe-Particle Lagrangian Integrated Trajectory; 
Agency: National Oceanic and Atmospheric Administration. 

Agent modeled: Radiological; 
Model: HOTSPOT; 
Agency: * Department of Energy; 
* Lawrence Livermore National Laboratory. 

Agent modeled: Radiological, nuclear; 
Model: RASCAL: Radiological Assessment System for Consequence Analysis; 
Agency: Nuclear Regulatory Commission. 

Source: OFCM. 

[End of table] 

OFCM provides the coordinating structure for federal agencies involved 
in modeling and has established interagency forums and working groups 
that have developed studies evaluating models available to address 
homeland security threats. In an August 2002 study, OFCM and other 
agencies evaluated 29 modeling systems used operationally by either 
first responders or federal agencies.[Footnote 26] The study concluded 
that (1) few models had been tested or validated for homeland security 
applications; (2) their ability to predict the dispersal of chemical, 
biological, or radiological agents through urban buildings, street 
canyons, and complex terrain was not well developed; and (3) they could 
provide only a rudimentary description of the nocturnal boundary layer 
and not the more complex turbulence resulting from complex buildings, 
terrain, and shorelines.[Footnote 27] 

According to DOD officials, many of these models were not developed for 
emergency response. For example, DOD developed HPAC as a model for 
counterproliferation purposes, but first responders also use 
it.[Footnote 28] In addition, DOD officials said that some of the 
deficiencies OFCM noted have been somewhat addressed with the 
development of urban plume models. (We discuss urban plume models later 
in the report.) 

A 2003 National Research Council (NRC) study on modeling capabilities 
reached essentially the same conclusions, stating that plume models in 
operational use by various government agencies were not well designed 
for complex natural topographies or built-up urban environments and 
that, likewise, the effects of urban surfaces were not well accounted 
for in most models.[Footnote 29] No one model had all the features 
deemed critical--(1) confidence estimates for the predicted dosages, 
(2) accommodation of urban and complex topography, (3) short execution 
time for the response phase, and (4) accurate if slower times for 
preparedness and recovery. Both fast execution response models and 
slower, more accurate models needed further development and evaluation 
for operational use in urban settings, according to NRC. 

In urban areas, buildings and street canyons separating them often 
cause winds that are almost random, making it exceedingly difficult for 
models to predict or even describe how CBRN materials are dispersed 
when released. Buildings create complex wind and turbulence patters in 
urban areas, including updrafts and downdrafts; channeling of winds 
down street canyons; and calm winds or "wake" regions, where toxic 
materials may be trapped and retained between buildings. Since most 
existing models have little or no building awareness, they could be 
misapplied in urban settings with fatal consequences. According to LLNL 
modeling experts, misinterpretation of modeling results is a key issue 
facing first responders. Many users assume that models are more 
accurate than warranted, because of the impression left by model 
predictions showing that individual buildings may actually not be 
accurately predicting fine-scale features, like the location of hot 
spots and plume arrival and departure times. 

Obtaining information on the source term, or the characteristics of 
CBRN materials released, is also a problem with current models, 
especially in complex urban environments. When modeling is used in an 
emergency, characterizing the source term and local transport is 
typically the greatest source of uncertainty. First responders' key 
questions are, What was released, when, where, and how much? Locating 
the source and determining its strength based on downwind concentration 
measurements is complicated by the presence of buildings that can 
divert flow in unexpected directions. Answers may not be available or 
may be based on uncertain and incomplete data that cannot be confirmed. 
For example, evidence of the release of a biological agent may not be 
known for days or weeks, when the population begins to show symptoms of 
exposure, becomes ill, and is hospitalized. 

Information from four basic categories of models is available to first 
responders today: 

1. Gaussian plume or puff models, widely used since the 1940s, can be 
run quickly and easily by nonspecialists. They typically use only a 
single constant wind velocity and stability class to characterize 
turbulence diffusion. They can be reasonably reliable over short ranges 
in situations involving homogeneous conditions and simple flows, such 
as unidirectional steady state flow over relatively flat terrain. The 
CAMEO/ALOHA model is a Gaussian plume model that has been widely 
distributed to first responders. 

2. Lagrangian models (puff and particle) provide more detailed 
resolution of boundary layer processes and dispersion. Puff models 
represent plumes by a sequence of puffs, each of which is transported 
at a wind speed and direction determined by the winds at its center of 
mass. Lagrangian particle models use Monte Carlo methods to simulate 
the dispersion of fluid marker particles.[Footnote 30] These models can 
capture plume arrival and departure times and peak concentrations. 
Examples of models in this category include HPAC (puff model), HYSPLIT 
and LODI (particle models). 

3. Computational fluid dynamics (CFD) are first principles physics 
models that simulate the complex flow patterns created in urban areas 
by large buildings and street canyons. CFD models provide the highest 
fidelity transport and diffusion simulations but are computationally 
expensive compared to Gaussian or Lagrangian models. They can take 
hours or days to run on a large computer. However, CFD models can 
capture plume arrival and departure times and peak concentrations. 

4. Empirical urban models are derived from wind tunnel and field 
experiment data. These models incorporate urban effects by explicitly 
resolving buildings. Such models are not considered as accurate as CFD 
models because of their empirical basis, particularly for the highest 
temporal and spatial resolutions and near-source regions. They need to 
be carefully validated. Examples include the Urban Dispersion Model and 
the Quick Urban and Industrial Complex dispersion modeling system. 

For example, EPA and NOAA developed the CAMEO/ALOHA model specifically 
for first responders' use. Widely used by state and local first 
responders, it originated as an aid in modeling the release of TICs but 
has evolved over the years into a tool for a broad range of response 
and planning. CAMEO is a system of software applications used to plan 
for and respond to chemical emergencies and includes a database with 
specific emergency response information for over 6,000 chemicals. ALOHA 
can plot a gas plume's geographic spread on a map. It employs an air 
dispersion model that allows the user to estimate the downwind 
dispersion of a chemical cloud based on the toxicological and physical 
characteristics of the released chemical, atmospheric conditions, and 
specific circumstances of the release. 

However, like any model, CAMEO/ALOHA cannot be more accurate than the 
information given to it to work with. Even with the best possible input 
values, CAMEO/ALOHA can be unreliable in certain situations, such as at 
low wind speeds, very stable atmospheric conditions, wind shifts and 
terrain steering effects, and concentration patchiness, particularly 
near the spill source of a release. CAMEO/ALOHA does not account for 
the effects of byproducts from fires, explosions, or chemical 
reactions; particulates; chemical mixtures; terrain; and hazardous 
fragments. It does not make predictions for distances greater than 6.2 
miles (10 kilometers) from the release point or for more than an hour 
after a release begins, because wind frequently shifts direction and 
changes speed. 

TOPOFF 2 Revealed Weaknesses in Coordinating Plume Modeling Efforts: 

That using several competing models supported by different agencies can 
produce contradictory results and confuse first responders was 
highlighted during DHS's TOPOFF 2003 and 2005 exercises. The TOPOFF 
exercises are biennial, congressionally mandated, national 
counterterrorism exercises designed to identify vulnerabilities in the 
nation's domestic incident management capability. They test the plans, 
policies, procedures, systems, and facilities of federal, state, and 
local response organizations and their ability to respond to and manage 
scenarios depicting fictitious foreign terrorist organizations 
detonating or releasing simulated CBRN agents at various locations in 
the United States. One important aim is to identify any seams, gaps, 
and redundancy in responsibilities and actions in responding to the 
simulated attacks. DHS's after-action reports for each exercise showed 
continuing problems in the coordination of federal, state, and local 
response and in information sharing and analysis. The four TOPOFF 
exercises conducted 2000-07 are summarized in table 5. 

Table 5: Top Officials Exercises 1-4, 2000-2007: 

Table: Top Officials Exercises 1ï¿½4, 2000ï¿½2007: 

Exercise: 1; 
Date: May 20ï¿½24, 2000; 
Place: Portsmouth, N.H;
Type of agent release simulated: Mustard gas. 

Exercise: 1; 
Date: May 20ï¿½24, 2000; 
Place: Denver, Colo;
Type of agent release simulated: Pneumonic plague. 

Exercise: 1; 
Date: May 20ï¿½24, 2000; 
Place: Washington, D.C;
Type of agent release simulated: Radiological dispersion device. 

Exercise: 2; 
Date: May 12ï¿½16, 2003; 
Place: Chicago, Ill;
Type of agent release simulated: Pneumonic plague. 

Exercise: 2; 
Date: May 12ï¿½16, 2003; 
Place: Seattle, Wash;
Type of agent release simulated: Radiological dispersion device. 

Exercise: 3; 
Date: April 4ï¿½8, 2005; 
Place: New London, Conn;
Type of agent release simulated: Mustard gas. 

Exercise: 3; 
Date: April 4ï¿½8, 2005; 
Place: New Jersey;
Type of agent release simulated: Pneumonic plague. 

Exercise: 4; 
Date: October 15ï¿½20, 2007; 
Place: Guam;
Type of agent release simulated: Radiological dispersion device. 

Exercise: 4; 
Date: October 15ï¿½20, 2007; 
Place: Phoenix, Ariz;
Type of agent release simulated: Radiological dispersion device. 

Exercise: 4; 
Date: October 15ï¿½20, 2007; 
Place: Portland, Ore;
Type of agent release simulated: Radiological dispersion device. 

Source: DHS. 

[End of table] 

TOPOFF 2, 3, and 4 used plume models. In TOPOFF 2, on May 12-16, 2003, 
federal, state, local, and Canadian responders, leaders, and other 
authorities reacted to a fictitious foreign terrorist organization's 
detonation of a simulated radiological dispersal device, or dirty bomb, 
in Seattle.[Footnote 31] It showed the federal government's inability 
to coordinate and properly use atmospheric transport and dispersion 
models. According to DHS internal reports, critical data collection and 
coordination challenges significantly affected the response to the 
attack in Seattle and the ability to get timely, consistent, and valid 
information to top officials. 

During the exercise, different federal, state, and local agencies and 
jurisdictions used different plume models to generate predictions, 
which led to confusion and frustration among the top officials. Seattle 
and Washington state officials told us that federal agencies provided 
modeling results not based on the preplanned series of scenario events 
exercise planners had established. They said that some of the data used 
to create the differing models had been made up in order to drive a 
federal agency's objectives for the exercise and bore no relationship 
to data that responders gathered at the scene. 

For example, Seattle City Emergency Management officials from the fire 
and police departments said that the city was operating on readings it 
received from the Federal Radiological Monitoring and Assessment Center 
(FRMAC) while the state modeled a larger area for the plume.[Footnote 
32] Washington state officials also said that the deposition data 
received from field teams were not consistent with the National 
Atmospheric Release Advisory Center's (NARAC) plume modeling 
predictions.[Footnote 33] NARAC modeling experts, however, stated that 
NARAC provided plume model predictions and worked with FRMAC to update 
model predictions as data became available. NARAC plumes were later 
found to be consistent with the ground truth used in the exercise. They 
attributed the disparity of data from the field to plume modeling 
predictions to exercise artificiality and the improper generation and 
interpretation of simulated exercise data for state-deployed field 
teams. 

Washington State Emergency Management officials stated that the 
"canned" weather patterns factored into the model conflicted with real- 
time weather reports. Running counter to typical norms, they went 
almost directly against the prevailing winds and "straight as an arrow" 
where the terrain would certainly have diverted their path. Confusion 
resulted from models being generated using different meteorological 
inputs. The resulting plume models were contradictory. NARAC/IMAAC 
modeling experts stated that the exercise called for the ground truth 
scenario to be based on the canned winds and that contradictory results 
were obtained by exercise players who did not use the ground truth 
scenario canned weather.[Footnote 34] However, NOAA modeling experts 
said that the ability of the TOPOFF exercises to identify gaps in plume 
modeling was limited by the use of canned weather patterns. In a real 
situation, the models would be run with current weather data. 

Further, in TOPOFF 2, coordination was lacking between state and local 
and federal plume modeling. For example, the Seattle Emergency 
Operations Center contacted NARAC after the explosion, as called for in 
the exercise scenario, to have it generate a prediction of where the 
plume would travel. NARAC's product (shown in fig. 2) was provided to 
the Seattle, King County, and Washington State emergency operations 
centers, as well as to FEMA and other federal agencies. However, the 
Washington State Department of Health also generated a plume prediction 
with a HOTSPOT modeling program, adding to the confusion. In addition, 
several federal agencies developed their own plume predictions to make 
internal assessments concerning assets that might be required. As a 
result, while Seattle, King County, Washington State, and federal 
officials all had access to NARAC plume modeling results, state and 
federal agencies still chose to use other available models for 
information from which to make their preliminary decisions. 

Figure 2: NARAC's TOPOFF 2 Plume Prediction: 

This figure is a map of NARAC's TOPOFF 2 plume prediction. 

[See PDF for image] 

Source: NARAC, LLNL. 

[End of figure] 

The Creation of the Interagency Modeling and Atmospheric Assessment 
Center: 

The confusion over the use of multiple modeling tools in TOPOFF 2 led 
DHS to establish IMAAC in 2004 as an interagency center responsible for 
producing, coordinating, and disseminating predictions for airborne 
hazardous materials. NARAC is the designated interim provider of IMAAC 
products. According to NARAC and IMAAC program officials, IMAAC's goals 
are to provide one point of contact for decision makers, eliminate 
confusing and conflicting hazard predictions, and distribute "common 
operating picture" predictions to federal, state, and local agencies 
with key information such as plume hazard areas, expected health 
effects, protective action recommendations (such as for sheltering or 
evacuation), and the affected population. NARAC and IMAAC staffs are 
available 24 hours a day, 7 days a week, to provide support and 
detailed analyses to emergency responders. 

IMAAC does not replace or supplant the atmospheric transport and 
dispersion modeling activities of other agencies whose modeling 
activities support their missions. However, IMAAC provides a single 
point for the coordination and dissemination of federal dispersion 
modeling and hazard prediction products that represent the federal 
position during actual or potential incidents requiring federal 
coordination. IMAAC aims to draw on and coordinate the best available 
capabilities of participating agencies. It entered into a memorandum of 
understanding with several agencies in December 2004, including DOD, 
DOE, EPA, and NOAA, on their roles and responsibilities for supporting 
and using IMAAC's analyses and products. According to NARAC and IMAAC 
operations staff, NARAC and IMAAC can provide an automated prediction 
for CBRN events within 5 to 15 minutes. 

TOPOFF 3 Revealed Continuing Problems in Coordinating Plume Modeling 
Results: 

TOPOFF 3, conducted April 4 to April 8, 2005, simulated the release of 
mustard gas and a high-yield explosive in New London, Connecticut. 
Despite the creation of IMAAC and its mission to coordinate the best 
available modeling capabilities of federal agencies, TOPOFF 3 revealed 
continuing problems in coordinating the results of competing modeling 
outputs. Exercise results from DHS internal reports indicated that 
IMAAC did not appear to have adequate procedures for dealing with 
discrepancies or contradictions in inputs or modeling requests from 
various agencies. Although numerous modeling analyses and predictions 
were continually refined and confirmed as evidence and field 
measurements were collected, conflicting and misleading data other 
agencies submitted on the source of attack and hazard areas resulted in 
confusion. 

According to NARAC and IMAAC operations officials, however, IMAAC was 
continuously in contact with state and local responders to resolve 
discrepancies in modeling inputs and requests and to correct 
misinformation. IMAAC provided its first modeling analysis 49 minutes 
after it was notified of a truck bomb explosion near a large public 
gathering in New London, Connecticut. The modeling prediction had 
estimated that a 55-gallon drum of mustard agent could be released in a 
small explosion involving a small truck and that the public could 
suffer serious health effects. Connecticut officials said that initial 
modeling was done when the hazmat teams arrived at the explosion site; 
NARAC and IMAAC were contacted after 30 minutes, and the hazmat team 
gave NARAC input. The NARAC modeling analysis was reviewed, but 
information received from the FBI resulted in tweaks to the model. 

A second IMAAC modeling analysis more than 2 hours after the explosion 
determined that the truck explosion had not caused the observed blister 
agent effects. Instead, reports of a small aircraft flying over the New 
London City Pier area had led IMAAC to develop another analysis that 
concluded that only an airplane's release could have caused the 
casualties. In fact, about 2 hours before the truck explosion, a small 
aircraft had flown over the New London City Pier, releasing mustard in 
a gaseous form over the area. IMAAC operations officials stated that 
they determined that the bomb could not have caused the mustard gas 
casualties based on (1) information that exposure victims were 
reporting at the time of the explosion and (2) its own analysis that 
the size of the truck bomb explosion would have destroyed virtually all 
chemicals that might have been associated with the bomb. 

Five hours after the explosion, IMAAC developed a third modeling 
analysis, based on the small aircraft's dumping the mustard agent, 
estimating that the public gathering at the pier would develop 
significant skin blistering, consistent with the casualty reports. 
IMAAC refined this prediction, based on field data received from state 
and local responders, and a fourth modeling analysis 10 hours after the 
explosion predicted significant skin exposures and some inhalation 
effects. 

NARAC and IMAAC officials stated that IMAAC continuously informed users 
that its analyses showed that the plane, and not the bomb, was the only 
source of contamination consistent with available data but was unable 
to correct other agencies' misperceptions. Several other agencies 
insisted that the source of the blister agent was the truck bomb. IMAAC 
continued during the next day to receive contradictory requests for 
products that did not incorporate dispersion from an airplane. The 
Connecticut Department of Environmental Protection requested an updated 
model run, based on a ground release, and DHS's S&T instructed IMAAC to 
produce model runs that did not include the airplane. The Connecticut 
Joint Field Office also sought plume products that assumed either an 
air or a ground release but not both. In addition, considerable 
misleading information came from the field, according to IMAAC 
operations, as additional field measurements were collected. This 
misinformation resulted from state officials' claim that the FBI had 
determined that the plane contained no chemicals. However, with 
additional field data, IMAAC conducted another modeling analysis that 
confirmed that a release from the aircraft was the only plausible 
source. On the third day, IMAAC, with the full set of 158 field 
measurements, again confirmed that the airplane's release was the 
source. 

According to Connecticut officials, contradictory data and analysis 
caused confusion regarding the hazard area and whether to shelter the 
population in place or evacuate. They stated that they received 
definitive analyses from IMAAC that would allow people to evacuate 
their premises. While weather forecasts indicated that rainfall would 
wash away any mustard gas on the ground, EPA disagreed, interpreting 
its own data as showing more contamination on the ground. EPA could 
not, however, explain the origin of these data, and NARAC and IMAAC had 
no knowledge of them. The issue was finally resolved by deciding not to 
use the EPA data. 

Exercise results from DHS internal reports concluded that IMAAC did not 
appear to have adequate procedures for dealing with discrepancies or 
contradictions in inputs or modeling requests from various agencies. 
Among the recommendations made were that IMAAC (1) clarify processes 
for receiving and reviewing other modeling products, (2) establish a 
protocol for other modeling agencies to distribute to their consumers 
on the purpose of IMAAC's product and guidelines for redistribution, 
and (3) develop procedures on how IMAAC should handle discrepancies in 
data inputs or product requests. 

IMAAC officials do not concur with the exercise findings and 
conclusions regarding the effectiveness of its federal plume modeling 
coordination during the exercise. They state that significant progress 
was demonstrated during TOPOFF 3 in coordinating federal plume modeling 
despite the fact that TOPOFF 3 was conducted in April 2005, less than a 
year after IMAAC's creation and the interagency agreement on its roles. 
They further state that IMAAC successfully coordinated the federal 
plume modeling to federal, state, and local agencies. There were no 
"dueling federal plume models with inconsistent results," as were 
observed during TOPOFF 2. However, the exercise did demonstrate a need 
for procedures for dealing with conflicting modeling requests for 
various agencies. IMAAC officials state that its procedures now call 
for an IMAAC Operations Coordinator to coordinate modeling requests and 
tasking. 

IMAAC officials said that they were unable to obtain a copy of the 
internal DHS report on exercise results from TOPOFF 3 and were not 
given an opportunity to provide input and review and correct the 
contents of the report. An official in FEMA's National Exercise 
Division said that TOPOFF 3 had an established process for obtaining 
comments from each of the participating agencies and from participants 
within DHS. However, the official could not explain why IMAAC was not 
given a copy of the report and a chance to provide comments. 

An IMAAC Technical Working Group developed the first version of its 
standard operating procedures in December 2005. However, it described a 
generalized concept of operations that does not specify procedures for 
coordinating modeling inputs from other agencies or procedures for CBRN 
incidents. The initial procedures identified as a key issue the need to 
clarify the type and scale of what would constitute a major CBRN 
incident that qualifies for IMAAC assistance. The procedures described 
the various levels of engagement and notification for activation of 
IMAAC but did not define the type and scale of what constitutes an 
incident qualifying for IMAAC assistance. 

IMAAC's director said that the use of plume modeling during TOPOFF 2 
and 3 primarily showed the lack of coordination among the participants 
on how to use technology. State and local responders are not required 
to use IMAAC plots, and IMAAC does not become the single federal point 
for coordinating and disseminating federal dispersion modeling and 
hazard prediction products until a significant CBRN event is declared. 
Agreement must be obtained from all federal agencies before a 
coordinated response can be implemented. 

* Although officials from DHS's S&T stated that the concept of 
operations and specific procedures for CBRN incidents were to be 
completed by the end of 2006, IMAAC's standard operating procedures 
have not yet been revised to (1) develop common/joint IMAAC emergency 
response practices with federal, state, and local agencies for dealing 
with contradictory plume modeling information from other agencies 
during a CBRN event; (2) refine the concept of operations for chemical, 
biological, and radiological releases; and (3) delineate the type and 
scale of major CBRN incidents that would qualify for IMAAC assistance. 

The issue of how a significant CBRN incident is to be defined was 
clarified in the 2006 National Response Plan Notice of Change, and the 
new IMAAC activation language has been changed to support "incidents 
requiring federal coordination." NARAC and IMAAC officials noted that 
while these procedures are important, they would not have affected the 
confusing field information in TOPOFF 3. In addition, operating 
procedures were meant to cover only the interim period, until the 
permanent configuration of IMAAC has been determined. 

TOPOFF 4 Shows Improvements in Coordinating Plume Modeling but 
Difficulties in Interpreting Results: 

TOPOFF 4 was conducted October 15-19, 2007, and used a radiological 
dispersal device scenario that included coordinated attacks in Guam, 
Portland, Oregon, and Phoenix, Arizona. On April 10, 2008, FEMA 
released its initial analysis and impressions of the exercise in an 
"After Action Quick Look Report." Regarding plume modeling conducted 
during the exercise, the report stated that IMAAC provided consequence 
predictions and that there were no "dueling plume models," as was 
observed during TOPOFF 2. According to the report, the processes 
established after TOPOFF 2 to minimize differences in plume modeling 
outputs and provide one source for consequence predictions appeared to 
be effective. IMAAC models were requested and used in all venues and 
decision makers appeared to understand that the model was only a 
prediction and would be periodically upgraded as actual data were 
collected and analyzed. 

However, the report noted that while most federal, state, and local 
agencies were familiar with IMAAC and its responsibility for producing 
consequence predictions, they had difficulty interpreting the plume and 
consequence models predicting radiation dispersal. Local decision 
makers had to rely on state and local subject matter experts during the 
first 24 to 48 hours of the response for immediate protective action 
recommendations. The report stated that it proved to be a challenge to 
get that expertise to key state and local decision makers during the 
exercise. 

The Chief of the Exercise Division at DHS stated that a better format 
was needed for decision makers, such as governors and mayors without 
scientific backgrounds, to use to interpret model predictions and 
communicate these predictions to the public. 

Urban Plume Models Give Variable Predictions: 

Model evaluations and field testing show that plume models federal 
agencies have developed specifically for tracking the release of CBRN 
materials in urban areas have some of the same limitations as the older 
models used for emergency response. Few models have been sufficiently 
validated against meaningful urban tests, and these models are not yet 
used regularly in emergency response applications. The urban models 
show much variability in their predictions, and obtaining accurate 
source term data is also a problem. Three such models are the Urban 
Dispersion Model (UDM), Quick Urban and Industrial Complex (QUIC) 
dispersion modeling system, and CT-Analyst.[Footnote 35] 

UDM, a component of the DTRA HPAC modeling suite shown in table 4, is a 
Gaussian puff model designed to calculate the flow of dispersion around 
obstacles in an urban environment. According to modeling experts, 
Gaussian models are fast (less than a second), but their precision is 
poor. DTRA entered into a cooperative agreement in fiscal year 2000 
with the United Kingdom's Defence Science and Technology Laboratory and 
Defence Research and Development Canada to develop UDM. The program's 
objective was to enhance HPAC models in an urban domain. 

In fiscal year 2000, the UDM program's first year, it developed an 
initial urban modeling capability; it implemented a special version of 
HPAC in fiscal year 2001, added three new urban modeling components and 
conducted two dispersion experiments in fiscal year 2002, conducted the 
largest urban dispersion experiment in history in collaboration with 
DHS and performed independent verification and validation of the urban 
modules in fiscal year 2003, and included operational urban 
capabilities in fiscal year 2004.[Footnote 36] UDM combines the 
standard HPAC developed for rural environments with urban canopy wind 
and turbulence profiles, urban dispersion models, and an urban flow 
model. It was used at the 2001 U.S. presidential inauguration, 2002 
Salt Lake Winter Olympics, 2004 Democratic and Republican conventions 
in Boston and New York City, and other high- profile events. 

UDM was subjected to a validation and verification program that 
compared model predictions against a comprehensive selection of 
measurements drawn from a database of field experiment trials. It was 
compared with three different field trials covering ranges from tens of 
meters to kilometers. Model predictions showed a typical error of 
greater than 50 percent of the mean, and more than 54 percent of the 
predictions were within a factor of 2.[Footnote 37] However, the field 
trials also showed a trend toward underprediction at close-in distances 
and overprediction at greater distances from the source. The model was 
found to overestimate plume width with increasing distance and, as a 
result, to underestimate plume concentration. 

The QUIC dispersion modeling system produces a three- dimensional wind 
field around buildings, accounts for building-induced turbulence, and 
contains a graphic user interface for setup, running, and 
visualization. QUIC has been applied to neighborhood problems in 
Chicago, New York City, Salt Lake City, and Washington, D.C. QUIC has 
medium speed (1 to 10 minutes) and fair accuracy, according to modeling 
experts. 

The Naval Research Laboratory and other groups have developed models, 
like CT-Analyst, that use CFD for fast-response applications. According 
to LLNL modeling experts, CFD models provide the highest fidelity 
simulations of the transport and diffusion of hazardous materials but 
are computationally more expensive and slow to operate. They can 
capture transient phenomena, such as plume arrival and departure times 
and peak concentrations. Accurate knowledge of peak concentrations is 
critical for determining the effect of many chemical releases, for 
which the health effects depend on instantaneous or short-term peak 
exposures rather than time-integrated dose. CFD models can predict the 
variation of concentrations over small (1-second) time scales and over 
small grid volumes (about 1 cubic meter). 

Evaluations and field testing have shown an unpredictable range of 
uncertainty in urban dispersion models' analyses.[Footnote 38] A series 
of urban field experiments have been sponsored by a number of agencies 
since 2000. In October 2000, DOE sponsored a meteorological and tracer 
field study of the urban environment and its effect on atmospheric 
dispersion. Called Urban 2000, the study included seven intensive 
nightlong operation periods in which extensive meteorological 
measurements were made and tracer gases of sulfur hexafluoride and 
perfluorocarbon were released and tracked across Salt Lake 
City.[Footnote 39] Led by DOE and several DOE National Laboratories, 
the study covered distances from the source ranging from 10 meters to 6 
kilometers. DTRA, U.S. Army Dugway Proving Ground, and NOAA also 
participated. 

In one evaluation of six urban dispersion models using the Salt Lake 
City field data, it was found that while the six models did a good job 
of determining the observed concentrations and source term, there were 
indications of slight underpredictions or overpredictions for some 
models and some distances.[Footnote 40] The urban HPAC model slightly 
overpredicted at most distances; another evaluation of HPAC found 
consistent mean overpredictions of about 50 percent.[Footnote 41] For 
HPAC model predictions of the lateral distance scale of concentration 
distribution, HPAC predicted within a factor of 2 only about 50 percent 
of the time.[Footnote 42] 

In another 2003 evaluation, conducted by the Institute for Defense 
Analyses (IDA), it was found that, in general, urban HPAC overpredicted 
the observed concentrations and dosages of URBAN 2000.[Footnote 43] Of 
20 model configurations examined (four model types each considered with 
five weather input options), 19 led to overpredictions of the total 
observed concentration or dosage. The IDA study concluded that the 
general overprediction of the URBAN 2000 observations by the Urban HPAC 
suite is a relatively robust conclusion. HPAC predictions of 30-minute 
average concentrations or the 2-hour dosage were plagued, in general, 
by substantial overpredicitons. Model predictive performance was also 
degraded at the longer downwind distances. 

An evaluation of QUIC found that the model predicted concentrations 
within a factor of 2 of the measurements 50 percent of the 
time.[Footnote 44] According to LANL modeling experts, QUIC performed 
reasonably well, slightly underestimating the decay of the 
concentrations at large distances from the source. However, it also 
significantly underpredicted lower concentrations at large distances 
downwind. 

A field study called Joint Urban 2003 and sponsored by DHS, DOE, and 
DTRA was conducted in Oklahoma City in July 2003. Its objectives were 
similar to those of URBAN 2000. The study included a series of 
experiments to determine how air flows through the urban area both day 
and night and to learn about the concentrations in the air of sulfur 
hexafluoride and perfluorocarbon. 

A 2006 IDA study that used the Joint Urban 2003 data to assess the 
Urban HPAC capabilities found significant differences in model 
performance, depending on time of day. Daytime performance was better 
than nighttime for meteorology inputs but with a large day-night 
discrepancy.[Footnote 45] The urban subcomponents of the HPAC model, 
the urban canopy, urban dispersion model, and urban wind field module 
all tended to underpredict at day and overpredict at night. A 2007 IDA 
study confirmed that there was a substantial difference in the 
performance of Urban HPAC as a function of day and night.[Footnote 46] 
For all meteorology inputs IDA used, daytime releases tended to be 
underpredicted and nighttime releases tended to be overpredicted. 

LANL found that QUIC model predictions of Joint Urban 2003 tracer 
releases underestimated concentrations up to a factor of 10. An LLNL 
assessment of the performance of CFD models that also used data from 
Joint Urban 2003 found that CFD models did not capture the effects of 
turbulence and winds caused by nocturnal low-level jets--that is, winds 
during the night at altitudes of 400 meters above ground. Turbulence 
generated by these low-level jets can induce mixing that reaches the 
surface, thereby influencing the dispersion of hazardous materials. 

The New York City Urban Dispersion Program conducted field studies in 
March 2005 and August 2005 that evaluated seasonal variations in the 
New York City area. The aim was to learn about the movement of 
contaminants in and around the city and into and within buildings and 
to improve and validate computer models that simulate the atmospheric 
movement of contaminants in urban areas. Inert perfluorocarbon and 
sulfur hexafluoride were released to track air movement. More than 200 
samplers collected tracer samples at more than 30 locations. 

Results from the New York City field experiments found that first 
responders should always use wind directions measured at the tops of 
tall buildings for making approach and evacuation decisions and that 
ready availability of building-top winds is essential. According to 
NOAA modeling experts, however, such data are not always routinely 
available. NARAC modeling experts also said that wind speeds will not 
necessarily reflect the complex flows that occur at ground and building 
levels, where the wind may be moving in completely different 
directions. In addition, the experiment found that first responders 
should be aware that: 

* hazardous clouds may be encountered one to two blocks upwind from a 
known or suspected release site, 

* the roofs of nearby tall buildings for street-level releases should 
not be considered safe havens because of the rapid vertical dispersion 
around buildings, and: 

* wind sensors should not be automatically located with CBRN detectors 
and winds should not be measured adjacent to CBRN detectors in street 
canyons in order to interpret the direction or extent of a release 
location. 

According to modeling experts, urban modeling systems require 
additional field evaluation. NOAA's modeling experts have noted that 
even after several field studies and evaluations have been conducted, 
very limited data are available to evaluate models under varying urban 
and meteorological conditions and to lead the improved simulations of 
difficult situations such as light winds and at the interface with the 
environment of buildings, subways, and the like. They believe that 
additional tracer studies should be conducted to address these issues. 
LLNL modeling experts stated that funding is not sufficient to make use 
of all the data generated by field studies in order to improve 
understanding of key urban processes, evaluate model performance, and 
build improved urban models. 

Urban Plume Models Have Limitations for Estimating the Source Term of 
Toxic Industrial Chemical Releases: 

According to unclassified assessments, the most likely type of toxic 
chemical attack on the United States would involve dual-use chemicals 
from industrial sources. The 13 highest-priority TICs are inhalation 
toxics that are shipped in large quantities; the most dangerous are 
those with low boiling points that are transported as pressurized 
liquids. According to modeling experts, the highest- priority TICs from 
the perspective of rail or truck transport are ammonia, chlorine, and 
sulfur dioxide. They are stored and shipped as pressurized liquefied 
gases, have low boiling points, and result in dense two-phase (gas and 
liquid) clouds. Recent rail accidents have shown that these chemicals, 
released as a dense, two-phase cloud of gas and small but visible 
aerosol drops, would spread initially in all directions and follow 
terrain slopes. Modeling experts believe that this area needs 
improvement in source emissions models. 

Source emissions formulas and models included in comprehensive, widely 
used models such as HPAC have been extensively reviewed. A study for 
the Defense Advanced Research Projects Agency, for example, indicated 
that while HPAC provides some source emissions algorithms for 
industrial chemical release scenarios, many emissions scenarios remain 
difficult to model.[Footnote 47] It is difficult to model emissions 
scenarios such as the quick release of pressurized liquid ammonia or 
chlorine from a rail car or tanker truck, the plume from a burning 
pool, the geometry and physical and chemical characteristics of a 
boiling liquid expanding vapor explosion or an intentional explosion, 
and any release in complex terrain. The 2007 version of HPAC does not 
consider two-phase releases. In addition, sufficient field data for 
most real scenarios do not exist because it is too dangerous to carry 
out a full-size experiment such as the release of the total contents of 
a rail car carrying chlorine or the explosion of a large propane 
storage tank.[Footnote 48] Available source emissions algorithms are 
based on theory and on small-scale field and laboratory experiments. 

LANL, the developer of QUIC, has been working to enhance QUIC's ability 
to address dense gas two-phase releases in the midst of buildings. LANL 
has also been enhancing QUIC's ability to deal with other issues that 
arise with chemical, biological, and radiological releases in cities: 
multiple-particle size releases and their deposition characteristics on 
building surfaces, the buoyant rise of particles after an explosive 
release of material, and the influence of building-induced winds on 
buoyant rise and dispersion. DHS and DTRA are also investigating 
critical data and physics gaps for chemical source term models that 
need to be solved in order to develop appropriate source term models. 
In addition, NARAC is improving the capability of its CFD urban model, 
FEM3MP, to combine complex source terms, dense gas effects, chemical 
reactions, and building-scale effects. 

DOD's development of the Joint Effects Model relies on the ability to 
extract and derive key information on CBRN source term from available 
CBRN and meteorological sensors and to use this information to predict 
the CBRN downwind hazard. According to DTRA, the Joint Effects Model 
will provide the military with a single validated ability to predict 
and track CBRN and TIC effects, as well as estimates of the source 
location and source term and the ability to make refined dispersion 
calculations. It was scheduled for full operation by fiscal year 2009, 
and the second increment of JEM, scheduled to be operational by fiscal 
year 2011, will include the ability to predict hazard areas and effects 
for urban areas. 

Data Gaps on How CBRN Releases Affect Urban Populations Are 
Significant: 

Urban plume models rely, as we have shown, on a wide range of data, but 
the difficult challenges in modeling the transport and dispersion of 
CBRN materials in complex urban settings have shown significant gaps in 
the data on how CBRN releases would affect urban populations. First, 
exposure rates the population would experience in an urban environment 
would be affected by the physical environment and where people work and 
live. Existing urban databases, however, have significant gaps in both 
quantity and quality of information on land use and complex urban 
terrain; knowledge as to where critical populations are located is also 
needed to focus predictions. Second, scientific research on the health 
effects of low-level exposure to CBRN material on civilian populations 
is lacking, especially for vulnerable populations at risk. 

Urban Databases Have Significant Gaps: 

Urban land use type--residential, commercial, industrial--is used in 
meteorological models to assign building structure and composition 
parameters and other surface characteristics to the underlying terrain. 
Mesoscale meteorological models and many atmospheric plume models do 
not have the spatial resolution to simulate the fluid dynamics near and 
around buildings and other urban land features. Urban canopy parameters 
have been developed to allow plume models to simulate the effects of 
buildings and urban land features on plume transport and dispersion, 
wind speed and direction, and turbulent mixing. 

Accurate urban land use definition is therefore an important component 
in modeling efforts. The ability to conduct modeling in urban areas, 
however, is typically limited to the use of a single or simplistic set 
of land use categories that do not provide explicit information on the 
effect of buildings and surfaces on the flow and transport of hazardous 
substances in the air. Determining the structure and composition of 
urban areas has resulted in the development of large datasets of high-
resolution urban features for many of the nation's largest cities. The 
National Building Statistics Database, for example, contains data for 
17 U.S. cities at a 250-meter grid cell resolution. This database 
contains mean building heights and other such statistics. It also 
contains high-rise district footprints for 46 of the most populous 
cities. In addition, the National Geospatial-Intelligence Agency and 
the U.S. Geological Survey have created a database of urban building 
footprints and heights in various cities. 

Several efforts have been made to improve urban databases for urban 
plume modeling, such as creating a database for day and night 
populations. Geographic information that includes population density 
data is essential for a fast, effective first response to disasters and 
is the common thread in all planning, response, and recovery 
activities. Using geographic information systems and remote sensing, 
ORNL developed LandScan, a global population distribution model, 
database, and tool from census and other spatial data. LandScan is a 
collection of the best available census counts for each U.S. county and 
four key indicators of population distribution--land cover, roads, 
slope, and nighttime lights. Census tracts are divided into 1-kilometer 
grid cells, and each cell is evaluated for the likelihood of its being 
populated on the basis of the four indicators. The total population for 
each tract is then allocated to each cell, weighted to the calculated 
likelihood of being populated. ORNL's LandScan 2006 developed a high- 
resolution daytime population database. 

According to DTRA, DOD efforts have added the number and quality of 
city databases available to 75 cities in the continental United States, 
with new ones added periodically. DTRA officials stated that 
enhancements in the UDM suite of urban domain characterizers have 
significantly improved the overall urban transport and dispersion 
modeling capability. 

According to NOAA weather experts, the standard national meteorological 
observing network does not provide sufficient spatial resolution to 
resolve local conditions that influence urban plumes. While a number of 
"mesonets" provide meteorological observations with relatively high 
spatial resolution over a limited domain, the quality of data from them 
varies significantly, according to NOAA officials.[Footnote 49] They 
stated that to provide reliable data for plume predictions, mesonet 
design should be considered, the quality of data from relevant mesonets 
should be characterized, and appropriate data screening and 
transformation approaches should be developed. Research is required to 
determine how best to incorporate urban mesonet data into plume models. 

Establishing Urban test beds has been proposed as a way to provide 
critical data to improve urban plume modeling. An Urban test bed is a 
multifunctional infrastructure of atmospheric instruments that provide 
continuous, multiyear measurement and archival environmental data 
across a metropolitan area and through the atmospheric boundary layer. 
An Urban test bed would be used to support improvements in a range of 
activities from scientific research to user applications. In a 
September 2004 study, OFCM and other agencies recommended the 
implementation of multiple Urban test beds.[Footnote 50] Urban test 
beds would provide (1) long term, continuous, high-resolution, 
meteorological observations of the urban domain and (2) long-term 
measurement and archiving of measurement data on atmospheric processes 
and modeling in urban environments. NOAA has implemented a dispersion 
measurement test bed called DCNet in Washington, D.C., to provide 
dispersion computations for planning and possible response. 

According to LLNL modeling experts, a major issue has been how to 
provide cost-effective access to building, land use, population, and 
other geographic databases as well as local meteorological data, 
establish common formats for databases, and enforce quality assurance 
standards. 

Data Are Insufficient on How Exposure to CBRN Materials Affects Health: 

Significant gaps exist in first responders' information for determining 
the effects of exposure to CBRN materials on heterogeneous urban 
populations. Scientific research on the effects of low-level exposure 
to CBRN material on civilian populations is severely lacking, 
especially for vulnerable populations such as elderly people, children, 
and individuals with compromised immune systems. A dose that may not be 
lethal for a healthy young adult might be lethal for such persons. For 
example, in the 2001 anthrax attack, many postal workers exposed to 
high concentrations over a prolonged period did not develop anthrax 
disease, while an elderly woman in Connecticut with a compromised 
immune system died, presumably from inhaling very few spores. Data are 
needed on exposure and dose assessments to identify vulnerable 
populations and how to adjust individual and population postevent 
activities and behavior to reduce numbers of casualties. 

Knowing health effects from exposure to chemical agents depends on a 
hierarchy of EPA-published chemical exposure limits and chemical dose-
response relationships as used in modeling. EPA has assigned three 
acute exposure guideline levels (AEGL) to TICs that could represent 
dangerous inhalation exposure from releases to air by accident or 
terrorist action. AEGLs are threshold exposure limits for the general 
public and apply to emergency exposure periods ranging from 10 minutes 
to 8 hours. They are intended to help protect most people in the 
general population, including those who might be particularly 
susceptible to the deleterious effects of chemical substances, and are 
expressed as an airborne concentration in parts per million or 
milligrams per cubic meter. However, dose response parameters for the 
general population do not exist for most CB warfare agents believed to 
pose a threat to civilians. For radiological exposures, DHS and EPA 
provide Protective Action Guidelines that identify the radiation levels 
at which state and local officials should take various actions to 
protect human health during an accident. 

At AEGL-1, the general population, including susceptible individuals, 
could experience notable discomfort, irritation, or certain 
asymptomatic nonsensory effects. The effects are not disabling and are 
transient and reversible when exposure ceases. At AEGL-2, the 
experience could be irreversible or could consist of other serious, 
long-lasting adverse health effects or an impaired ability to escape. 
At AEGL-3, the experience would be life-threatening or fatal. 

For chemicals for which AEGLs have not been established, the Emergency 
Response Planning Guidelines of the American Industrial Hygiene 
Association are used. If neither EPA nor the Association has 
established a value for a chemical, then DOE's temporary emergency 
exposure limits are used. 

AEGLs and other estimates attempt to describe the lower end of the dose 
response curve for particular chemical agents. Dose response parameters 
for the general population do not exist for most CB warfare agents 
believed to pose a threat to civilians. LLNL modeling experts stated 
that for chemical weapon and biological agents, they determine health 
effects levels from literature reviews. Toxicity estimates for the 
general population are required for hazard prediction models. Data are 
needed on exposure and dose assessments to identify populations at risk 
from primary or secondary contact and how to adjust individual and 
population postevent activities and behavior to reduce casualties. 
According to the Armed Forces Medical Intelligence Center, 50 percent 
lethal concentrations and dosages are unknown for most chemicals, and 
detailed information on high-volume chemicals and processes is not 
widely available.[Footnote 51] 

Little scientific research has been done on the effects of low-level 
exposure to CBRN material on civilian populations, especially 
vulnerable populations at risk. ECBC has the task of providing human 
chemical warfare agent toxicity estimates for the general population, 
together with supporting analyses. According to ECBC studies, most of 
the available toxicological data underlying human toxicity estimates 
for chemical warfare agents were generated in support of chemical 
weapons development for offensive battlefield deployment against 
military personnel, who at the time of the studies were nearly all 
male. Thus, the available human data represent a very limited segment 
of the population--relatively young, fit male soldiers. Using military 
values for civilian scenarios would therefore result in the 
underestimation of civilian casualties and the overall threat to 
civilian populations from potential or actual releases. ECBC has been 
developing mathematical models to estimate general population toxicity 
values from previously established military values. For example, figure 
3 shows dose response curves for the fraction of a healthy military 
population and of the general population that would be killed by a 2- 
minute exposure to sarin. 

Figure 3: Dose Response for Healthy and General Population Exposures to 
Sarin: 

This figure is a combination line graph showing dose response for 
healthy and general population exposures to sarin. The X axis 
represents the dose, and the Y axis represents the fraction of 
population. 

[See PDF for image] 

Source: LLNL, DOE. 

[End of figure] 

Conclusions: 

Despite several initiatives and investments DHS and other agencies have 
undertaken since 2001, first responders do not have effective tools to 
respond to events involving the release of CBRN materials in urban 
areas. Detection systems are limited in their ability to provide the 
timely and accurate information first responders need about the release 
of CBRN materials in urban areas to make decisions on expected health 
effects and protective action--for example, sheltering and evacuation. 
Existing nonurban and urban plume models for emergency response to CBRN 
events have several limitations as a primary tool for tracking the 
release of CBRN materials in urban areas and for making decisions about 
handling them. National TOPOFF exercises have also shown the problems 
and confusion that could occur to first responders' responses to CBRN 
events from disparate modeling inputs and results. In addition, more 
data are needed about the effects of hazardous materials in built-up 
urban environments. Continued improvements are needed in urban building 
and population databases and for understanding the health effects from 
concentrations of hazardous substances, especially on vulnerable 
populations, so that first responders are properly prepared for 
addressing airborne releases of harmful materials in urban areas. 

Led by DHS, ongoing federal efforts have attempted to improve the 
capabilities of detection systems and models so that first responders 
can accurately identify CBRN materials released in urban environments, 
the extent of their dispersion, and their effect on urban populations. 
For detection equipment, one shortcoming that should be addressed is 
the lack of emphasis on the development of detection equipment that 
first responders can use to detect radiological materials in the 
atmosphere. DHS has recognized the threat of a terrorist attack 
involving the explosion of radiological dispersal devices--or dirty 
bombs--and has used this as a scenario in TOPOFF exercises. However, 
DHS's development of radiation detection equipment has largely focused 
on the interdiction of radioactive material rather than on detecting 
the release of radioactive material into the atmosphere in urban areas. 
We found that agencies such as DHS, DOD, EPA, NIST, and NOAA do not 
have missions to develop, independently test, and certify equipment for 
detecting radiological materials in the atmosphere. 

Another shortcoming is the lack of a formal DHS system to independently 
test and validate the performance, reliability, and accuracy of CBRN 
detection equipment that first responders acquire. While DHS indicated 
it has missions to develop, independently test, and certify CB 
detection equipment for first responders' use, its testing and 
certification are limited to equipment DHS is developing and does not 
extend to equipment developed by commercial manufacturers. As we have 
noted, DHS has no evaluation and qualification program that guides and 
informs first responders on the veracity of manufacturers' claims about 
the performance of their CBRN detection systems. DHS has no control 
over what manufacturers can sell to first responders and cannot order 
first responders not to purchase a certain piece of equipment, unless 
purchased with federal funds. A formalized process needs to be 
established for the evaluation and validation of manufacturers' claims 
regarding commercial biodetection equipment. 

While existing urban plume models have several limitations as a primary 
tool for tracking the release of CBRN materials in urban areas, the 
TOPOFF exercises demonstrated the larger problem of confusion among 
first responders about the timing, value, and limitations of plume 
models and other analyses following a CBRN event. At best, models can 
give a close approximation and can help inform a decision maker on the 
probable plume. The TOPOFF exercises demonstrated that plume model 
results developed without the incorporation of field data are only 
estimates that should be used for guidance but are not an accurate 
rendition of the actual situation facing first responders. Plume models 
are most effectively used to provide early estimates of potentially 
contaminated areas in combination with data gathered from the field. 
These data, in turn, are used to update plume model predictions. 

The major weakness of these models is that any real source release is 
nearly always more complicated than the simple scenarios studied in the 
field and wind tunnel experiments they are based on. Real sources tend 
to vary in time and space and to occur when the atmosphere is variable 
or rapidly changing. A small change in wind direction or height of 
release can result in a different or a more or less populated area 
being affected. During the TOPOFF exercises, first responders and 
decision makers used plume model predictions as real- time information 
on which to base decisions. 

In addition, the TOPOFF 2 and 3 exercises demonstrated that while IMAAC 
is designated the focal point for coordinating and disseminating 
modeling products, it does not have adequate procedures to deal with 
discrepancies or contradictions from competing models from various 
agencies. DHS's preliminary assessment of the TOPOFF 4 exercise found 
improvement in IMAAC's coordination of federal plume modeling to 
minimize differences in model outputs and provide one source for 
consequence predictions. However, IMAAC Operations officials said the 
key to "deconflicting" plume modeling information is to have procedures 
that are coordinated and integrated with those of first responders and 
other local emergency response agencies. IMAAC also does not have a 
concept of operations or specific procedures for significant CBRN 
incidents. A key issue is the need to clarify the type and scale of 
what major incident could constitute a potentially significant CBRN 
event and qualify for IMAAC assistance. 

Recommendations for Executive Action: 

We recommend that the Secretary of Homeland Security: 

* reach agreement with DOD, DOE, EPA, and other agencies involved with 
developing, testing, and certifying CBRN detection equipment on which 
agency should have the missions and responsibilities to develop, 
independently test, and certify detection equipment that first 
responders can use to detect hazardous material releases in the 
atmosphere; 

* ensure that manufacturers' claims are independently tested and 
validated regarding whether their commercial off-the-shelf CBRN 
detection equipment can detect given hazardous material at specific 
sensitivities; 

* refine IMAAC's procedures by working with other federal, state, and 
local agencies to (1) develop common/joint IMAAC emergency response 
practices, including procedures for dealing with contradictory plume 
modeling information from other agencies during a CBRN event; (2) 
refine the concept of operations for chemical, biological, and 
radiological releases; and (3) delineate the type and scale of major 
CBRN incidents that would qualify for IMAAC assistance; and: 

* in conjunction with IMAAC, work with the federal plume modeling 
community to accelerate research and development to address plume model 
deficiencies in urban areas and improve federal modeling and assessment 
capabilities. Such efforts should include improvements to 
meteorological information, plume models, and data sets to evaluate 
plume models. 

Agency Comments and Our Evaluation: 

We obtained written comments on a draft of this report from DHS and the 
Department of Commerce. DHS concurred with our recommendations but 
stated that GAO should consider other scenarios as alternative ways of 
looking at the present national capabilities for CBRN response and the 
current status of testing and certifying detection equipment. DHS 
stated that in one alternative scenario, first responders, in the event 
of a terrorist attack, will use a variety of prescreening tools, and 
they will be assisted immediately by state and federal agencies that 
will bring the best available state-of-the-art CBRN detection 
equipment. 

In our report, we have considered scenarios in which first responders 
are on the scene before federal assets arrive, not knowing what 
hazardous materials (including CBRN agents) have been released, either 
accidentally or by terrorist acts. In these situations, it is the first 
responder who has to first determine what was released and what tools 
to use to make that determination before receiving assistance from 
state and federal agencies. 

By DHS's own assessments, these state-of-the-art CBRN detection tools 
have significant limitations. DHS acknowledged that first responders do 
not now have any equipment that can detect the dispersion of 
radiological and nuclear materials in the atmosphere. DHS's S&T 
Directorate assessed that while current detectors can be used for rapid 
warning of chemicals in the vapor phase, they are generally considered 
inadequate to provide information on the presence of chemical threat 
agents at less than lethal but still potentially harmful levels. 
According to DHS's S&T, HHAs, the tool that first responders would use 
to detect biological threat agents, do not have the sensitivity to 
detect the atmospheric concentrations of agents that pose health risks. 
Moreover, the detection of biological agent aerosols and particulates 
through the current BioWatch sample collection and laboratory analysis 
process is time-consuming and labor intensive, with final confirmation 
occurring long after initial exposure. 

With respect to testing and validation of commercial CBRN detection 
equipment available for first responder use, DHS stated that there is 
no legislative requirement that such equipment for homeland security 
applications meet performance standards. DHS also believes that it will 
never be feasible for the federal government to fund testing of all 
commercial detectors without first assessing their potential merits for 
detection of CBRN agents because of the very large number of hazardous 
CBRN agents and the expense of testing detectors against these agents. 

While there is no legislative requirement that CBRN detection equipment 
for homeland security meet performance requirements, we noted in our 
report that DHS does require that commercial detection equipment first 
responders purchase with DHS grant funds comply with equipment 
performance standards adopted by DHS. However, DHS has adopted few 
performance standards for CBRN detection equipment. Without such 
standards, first responders may purchase detection equipment that does 
not detect harmful levels or whose performance varies. Without 
standards, there would be no way to ensure the reliability of the 
equipment's detection capabilities. 

As we indicated in our report, DHS had adopted only four standards for 
radiation and nuclear detection equipment as of October 30, 2007. DHS 
acknowledged that current testing is mainly limited to DHS and DOD CBRN 
detection systems under development, and it has no process to validate 
the performance of commercial CBRN detection equipment. However, we are 
not recommending that DHS test all available commercial detection 
equipment. We are recommending that DHS independently test and evaluate 
detection equipment first responders purchase using DHS grant funds. 
(DHS's comments appear in appendix III.) 

In DOC's general comments on our draft report, DOC stated that it 
believed that even with the implementation of our recommendations aimed 
at improving IMAAC operations, the plume models will still have several 
limitations as a primary tool for tracking the release of CBRN 
materials in urban areas. To improve information available for 
emergency managers, DOC suggested offering a recommendation that DHS 
work with the federal plume modeling community to accelerate research 
and development to address plume model deficiencies in urban areas. 
Such efforts should include improvements to meteorological information, 
plume models, and data sets to evaluate plume models. DOC acknowledged 
that these improvements would be likely to take several years, but work 
should be initiated while IMAAC is instituting improvements. 

We believe that DOC's recommendation has merit and have included it in 
our final report for DHS's consideration. 

DOC also stated that it believed that IMAAC should be working to 
improve federal modeling and assessment capabilities and to enhance the 
national scientific capability through cooperation among the federal 
agencies for incidents of national significance. IMAAC and the 
atmospheric transport and diffusion community should support OFCM in 
developing a joint model development and evaluation strategy. 

We also agree that IMAAC should continue to improve federal modeling 
and assessment capabilities with OFCM and other federal agencies 
involved with modeling terrorist-related or accidental releases of CBRN 
materials in urban areas. This is included in our recommendation. In 
technical comments on our draft report, IMAAC operations staff at LLNL 
stressed that improvements to plume modeling information and 
predictions are best achieved by establishing trusted working 
relationships with federal, state, and local agency operations centers 
and deployed assets. 

DOC also stated that the inference in our report that IMAAC will be 
providing a single dispersion solution is misleading. IMAAC, as a 
federal entity, provides a recommendation to the local incident 
commander and the commander decides what information to use. This stems 
from the basis that all events are local in nature. DOC stated that it 
believed that the report should also highlight the need to promote an 
aggressive program of educating first responder and local incident 
commanders in the use of dispersion models. 

We clarified our discussion in the report about the role of IMAAC in 
order to remove any inference that it was expected to provide a single 
dispersion solution. We noted in our draft report that IMAAC does not 
replace or supplant the atmospheric transport and dispersion modeling 
activities of other agencies whose modeling activities support their 
missions. IMAAC provides a single point for the coordination and 
dissemination of federal dispersion modeling and hazard prediction 
products that represent the federal position during actual or potential 
incidents requiring federal coordination. We also noted in our 
conclusions that TOPOFF exercise results demonstrated the larger 
problem of the confusion among first responders' awareness about the 
timing, value, and limitations of plume models and other analyses 
following a CBRN event. We agree that an aggressive program for 
educating first responders on the use of dispersion models is needed. 

DOC also commented on our discussion about the confusion from the 
models produced during the TOPOFF 2 exercise. DOC noted that the 
confusion resulted from models being generated using different 
meteorological inputs--real weather versus "canned" weather. We noted 
in our draft report that one major cause for the confusion was the use 
of different meteorological inputs in the modeling conducted during 
TOPOFF 2. (DOC's comments appear in app. IV.) 

We also received technical comments from DHS and DOC, from DOD, and 
from DOE (LLNL), and we made changes to the report where appropriate. 
Technical comments we received from LLNL, in particular, proposed 
broadening the recommendation related to revising IMAAC standard 
operating procedures to deal with contradictory modeling inputs. IMAAC 
operations staff at LLNL believed that integrating procedures with 
other emergency response agencies are the key to clarifying plume 
modeling information. They stated that their experience has shown that 
refining IMAAC's standard operating procedures is relatively 
ineffective unless this is coordinated with the development of joint 
operating procedures with other agencies, leading to the incorporation 
of IMAAC into these agencies' standard operations. We agreed and have 
revised our recommendation accordingly. 

We are sending copies of this report to the Secretaries of Commerce, 
Defense, Energy, and Homeland Security and others who are interested. 
We will also provide copies to others on request. In addition, the 
report will be available at no charge on GAO's Web site at [hyperlink, 
http://www.gao.gov]. 

If you or your staff have any questions regarding this report, please 
call me at (202) 512-2700. Key contributors to this assignment were 
Sushil Sharma, Assistant Director, Jason Fong, Timothy Carr, and Penny 
Pickett. James J. Tuite III, a consultant to GAO during our engagement, 
provided technical expertise. 

Signed by: 

Nancy R. Kingsbury, Managing Director: 

Applied Research and Methods: 

List of Requesters: 

The Honorable Robert C. Byrd: 
Chairman: 
Committee on Appropriations: 
United States Senate: 

The Honorable Joseph I. Lieberman: 
Chairman: 
Committee on Homeland Security and Governmental Affairs: 
United States Senate: 

The Honorable Susan M. Collins: 
Ranking Member: 
Committee on Homeland Security and Governmental Affairs: 
United States Senate: 

The Honorable John D. Dingell, Jr. 
Chairman: 
Committee on Energy and Commerce: 
House of Representatives: 

The Honorable David E. Price: 
Chairman: 
Subcommittee on Homeland Security: 
Committee on Appropriations: 
House of Representatives: 

The Honorable Bart T. Stupak: 
Chairman: 
Subcommittee on Oversight and Investigations: 
Committee on Energy and Commerce: 
House of Representatives: 

The Honorable Christopher Shays: 
Ranking Member: 
Subcommittee on National Security and Foreign Affairs: 
Committee on Oversight and Government Reform: 
House of Representatives: 

[End of section] 

Appendix I: Scope and Methodology: 

To assess the capabilities and limitations of chemical, biological, 
radiological, and nuclear (CBRN) detection equipment, we interviewed 
federal program officials from the (1) Science and Technology 
directorate of the Department of Homeland Security (DHS) and its 
Homeland Security Advanced Research Projects Agency; (2) the Defense 
Threat Reduction Agency and the Joint Program Executive Office for 
Chemical and Biological Defense in the Department of Defense (DOD); and 
(3) the Department of Energy's (DOE) Lawrence Livermore National 
Laboratory (LLNL), Los Alamos National Laboratory, and Oak Ridge 
National Laboratory. 

We also met with program officials from DHS's Responder Knowledge Base 
(RKB) and the Department of Commerce's (DOC) National Institute of 
Standards and Technology's Office of Law Enforcement Standards (OLES) 
to obtain information on equipment standards and the testing of CBRN 
detection equipment. We reviewed DHS, DOD, and DOE detection programs 
in place and being developed, as well as these agencies' studies on 
CBRN detection systems. We attended conferences and workshops on CBRN 
detection technologies. 

To obtain information on detection equipment standards and the testing 
of CBRN detection equipment for first responders, we met with program 
officials from DHS's RKB and OLES. We also interviewed local responders 
in Connecticut, New Jersey, and Washington on their acquisition of CBRN 
detection equipment. We chose these states because of their 
participation in DHS-sponsored Top Officials (TOPOFF) national 
counterterrorism exercises. In addition, we interviewed members of the 
InterAgency Board for Equipment Standardization and Interoperability 
(IAB). IAB, made up of local, state, and federal first responders, is 
designed to establish and coordinate local, state, and federal 
standardization; interoperability; compatibility; and responder health 
and safety to prepare for, train for and respond to, mitigate, and 
recover from any CBRN incident. 

To assess the limitations of plume models, we interviewed modeling 
experts from DHS, DOD, DOE's national laboratories, DOC's National 
Oceanic and Atmospheric Administration, and the Office of the Federal 
Coordinator for Meteorological Service and Supporting Research (OFCM) 
in the Department of Commerce. We also interviewed operations staff of 
the Interagency Modeling and Atmospheric Assessment Center (IMAAC) at 
LLNL. IMAAC consolidates and integrates federal efforts to model the 
behavior of various airborne releases and is the source of hazards 
predictions during response and recovery. We also interviewed local 
responders in Connecticut, New Jersey, and Washington regarding the use 
of plume models during the TOPOFF 2 and TOPOFF 3 exercises. 

We reviewed documentation on the various plume models and reports and 
studies evaluating models available for tracking CBRN releases in urban 
environments and studies identifying future needs and priorities for 
modeling homeland security threats. We attended several conferences and 
users' workshops sponsored by the American Meteorological Society, DOD, 
OFCM, and George Mason University, where modeling capabilities were 
evaluated. We also reviewed DHS internal reports on lessons learned 
from the use of modeling during the TOPOFF national exercises. 

To determine what information first responders have for determining the 
effects of exposure to CBRN materials on heterogeneous civilian 
populations, we reviewed agency documentation and studies on urban land 
use and population density. We also reviewed documentation on acute 
exposure guideline levels published by the Environmental Protection 
Agency and other organizations. In addition, we reviewed studies on 
human toxicity estimates by the U.S. Army and DOE's national 
laboratories. 

We conducted our review from July 2004 to January 2008 in accordance 
with generally accepted government auditing standards. 

[End of section] 

Appendix II: Chemical, Biological, and Radiological Agents: 

Table 6: Chemical Warfare Agents: 

Class: Blister; 
Signs and symptoms: First irritates cells, then poisons them; 
conjunctivitis (pink eye); reddened skin, blisters; nasal irritation; 
inflammation of throat and lungs; 
Name and symbol: Ethyldichloroarsine (ED); 
Persistence: Moderate; 
Rate of action: Immediate irritation; delayed blistering; Eye and skin 
toxicity: Vapor harmful on long exposure; liquid blisters. 

Class: Blister; 
Signs and symptoms: First irritates cells, then poisons them; 
conjunctivitis (pink eye); reddened skin, blisters; nasal irritation; 
inflammation of throat and lungs; 
Name and symbol: Lewisite (L); 
Persistence: Days; rapid hydrolysis with humidity; 
Rate of action: Rapid; 
Eye and skin toxicity: Severe eye damage; skin less so. 

Class: Blister; 
Signs and symptoms: First irritates cells, then poisons them; 
conjunctivitis (pink eye); reddened skin, blisters; nasal irritation; 
inflammation of throat and lungs; 
Name and symbol: Methyldichloroarsine (MD); 
Persistence: Low; 
Rate of action: Rapid; 
Eye and skin toxicity: Eye damage possible; blisters. 

Class: Blister; 
Signs and symptoms: First irritates cells, then poisons them; 
conjunctivitis (pink eye); reddened skin, blisters; nasal irritation; 
inflammation of throat and lungs; 
Name and symbol: Mustard (H, HD); 
Persistence: Very high; days to weeks; 
Rate of action: Delayed hours to days; 
Eye and skin toxicity: Eyes very susceptible; skin less so. 

Class: Blister; 
Signs and symptoms: First irritates cells, then poisons them; 
conjunctivitis (pink eye); reddened skin, blisters; nasal irritation; 
inflammation of throat and lungs; 
Name and symbol: Nitrogen mustard (HN-1, -2, -3); 
Persistence: HN-1, - 3, very high, days to weeks; HN-2, moderate; 
Rate of action: HN-1, -2, delayed 12 hours or more. HN-3, serious 
effects, same as HD; minor effects sooner; 
Eye and skin toxicity: HN-1, eyes susceptible to low concentration, 
skin less so. HN-2, toxic to eyes; blisters skin. HN-3, eyes very 
susceptible; skin less so. 

Class: Blister; 
Signs and symptoms: First irritates cells, then poisons them; 
conjunctivitis (pink eye); reddened skin, blisters; nasal irritation; 
inflammation of throat and lungs; 
Name and symbol: Phenyldichloroarsine (PD); 
Persistence: Low-moderate; Rate of action: Rapid; 
Eye and skin toxicity: 633 mg-min/m[3] produces eye damage; less toxic 
to skin. 

Class: Blister; 
Signs and symptoms: First irritates cells, then poisons them; 
conjunctivitis (pink eye); reddened skin, blisters; nasal irritation; 
inflammation of throat and lungs; 
Name and symbol: Phosgene oxime (CX); 
Persistence: Low, 2 hours in soil; 
Rate of action: Immediate effects on contact; 
Eye and skin toxicity: Powerful irritant to eyes and nose; liquid 
corrosive to skin. 

Class: Blood; 
Signs and symptoms: Skin cherry red or 30% cyanosis (bluish 
discoloration from lack of oxygen); gasping for air; seizures before 
death; 
Name and symbol: Arsine (SA); 
Persistence: Low; 
Rate of action: 2 hours to 11 days; 
Eye and skin toxicity: None. 

Class: Blood; 
Signs and symptoms: Skin cherry red or 30% cyanosis (bluish 
discoloration from lack of oxygen); gasping for air; seizures before 
death; 
Name and symbol: Cyanogen chloride (CK); 
Persistence: Evaporates rapidly and disperses; 
Rate of action: Very rapid; 
Eye and skin toxicity: Low; tears and irritation. 

Class: Blood; 
Signs and symptoms: Skin cherry red or 30% cyanosis (bluish 
discoloration from lack of oxygen); gasping for air; seizures before 
death; 
Name and symbol: Hydrogen cyanide (AC); 
Persistence: Extremely volatile; 1-2 days; 
Rate of action: Very rapid; 
Eye and skin toxicity: Moderate. 

Class: Nerve; 
Signs and symptoms: Salivation, lacrimation (tearing), urination, 
defecation, gastric disturbances, vomiting; 
Name and symbol: Cyclosarin (GF); Persistence: Moderate; 
Rate of action: Very rapid; 
Eye and skin toxicity: Very high. 

Class: Nerve; 
Signs and symptoms: Salivation, lacrimation (tearing), urination, 
defecation, gastric disturbances, vomiting; 
Name and symbol: Sarin (GB); 
Persistence: Low; 1-2 days; evaporates with water; 
Rate of action: Very rapid; Eye and skin toxicity: Very high. 

Class: Nerve; 
Signs and symptoms: Salivation, lacrimation (tearing), urination, 
defecation, gastric disturbances, vomiting; 
Name and symbol: Soman (GD); 
Persistence: Moderate; 1-2 days; 
Rate of action: Very rapid; 
Eye and skin toxicity: Very high. 

Class: Nerve; 
Signs and symptoms: Salivation, lacrimation (tearing), urination, 
defecation, gastric disturbances, vomiting; 
Name and symbol: Tabun (GA); 
Persistence: Low; 1-2 days if heavy concentration; 
Rate of action: Very rapid; 
Eye and skin toxicity: Very high. 

Class: Nerve; 
Signs and symptoms: Salivation, lacrimation (tearing), urination, 
defecation, gastric disturbances, vomiting; 
Name and symbol: VX; 
Persistence: Very high; 1 week if heavy concentration; as volatile as 
oil; 
Rate of action: Rapid; 
Eye and skin toxicity: Very high. 

Source: Analytic Services Inc., Central Intelligence Agency, and 
Edgewood Chemical Biological Center. 

[End of table] 

Table 7: Biological Warfare Agents: 

Agent: Bacterium: Anthrax; 
Possible means: of delivery: Aerosol; 
Time: Incubation 1-5 days; 
symptoms in 2-3 days; 
Symptoms: Fever, malaise, fatigue, cough, and mild chest discomfort, 
followed by severe respiratory distress; 
Lethality: 3-5 days; 
shock and death 24-36 hours after symptoms; 
Stability: Spores are highly stable. 

Agent: Bacterium: Brucellosis; 
Possible means: of delivery: Aerosol, expected to mimic a natural 
disease; 
Time: Rate of action usually 6-60 days; 
Symptoms: Chills, sweats, headache, fatigue, joint and muscle pain, and 
anorexia; 
Lethality: Weeks to months; 
Stability: Organisms are stable for several weeks in wet soil and food. 

Agent: Bacterium: Cholera; 
Possible means: of delivery: Sabotaged food and water supply; 
aerosol; 
Time: Sudden onset after 1-5 days incubation; 
Symptoms: Initial vomiting and abdominal distention, with little or no 
fever or abdominal pain, followed rapidly by diarrhea; 
Lethality: One or more weeks; 
low with treatment; 
high without treatment; 
Stability: Unstable in aerosols and pure water; 
more stable in polluted water. 

Agent: Bacterium: Plague; 
Possible means: of delivery: Contaminated fleas, causing bubonic type, 
or aerosol, causing pneumonic type; 
Time: Rate of action 2-3 days; 
incubation 2-6 days bubonic, 3-4 days pneumonic; 
Symptoms: High fever, chills, headache, spitting up blood, and toxemia, 
progressing rapidly to shortness of breath and cyanosis (bluish 
coloration of skin and membranes); 
Lethality: Very high; 
Stability: Extremely stable but highly transmissible. 

Agent: Bacterium: Q fever; 
Possible means: of delivery: Dust cloud from a line or point source; 
Time: Onset may be sudden; 
Symptoms: Chills, headache, weakness, malaise, and severe sweats; 
Lethality: Very low; 
Stability: Stable. 

Agent: Bacterium: Tularemia; 
Possible means: of delivery: Aerosol; 
Time: Rate of action 3-5 days; 
incubation 1-10 days; 
Symptoms: Fever, chills, headache, and malaise; 
Lethality: 2 weeks moderate; 
Stability: Not very stable. 

Agent: Bacterium: Typhoid; 
Possible means: of delivery: Sabotaged food and water supply; 
Time: Rate of action 1-3 days; 
incubation 6-21 days; 
Symptoms: Sustained fever, severe headaches, and malaise; 
Lethality: Moderate if untreated; 
Stability: Stable. 

Agent: Bacterium: Typhus; 
Possible means: of delivery: Contaminated lice or fleas; 
Time: Rate of action 6-15 days; 
onset often sudden, terminating after about 2 weeks of fever; Symptoms: 
Headaches, chills, prostration, fever, and general pain; Lethality: 
High; Stability: Not very stable. 

Agent: Toxin: Botulinum; 
Possible means: of delivery: Sabotaged food and water supply; 
aerosol; 
Time: Rate of action 12-72 hours; 
incubation hours to days; 
Symptoms: Blurred vision; 
photophobia; 
skeletal muscle paralysis and progressive weakness that may culminate 
abruptly in respiratory failure; 
Lethality: High; 
Stability: Stable. 

Agent: Toxin: Ricin; 
Possible means: of delivery: Aerosol; 
Time: Rate of action 6-72 hours; 
Symptoms: Rapid onset of nausea, vomiting, abdominal cramps, and severe 
diarrhea with vascular collapse; 
Lethality: High; 
Stability: Stable. 

Agent: Virus: Ebola; 
Possible means: of delivery: Aerosol; 
direct contact; 
Time: Rate of action: sudden; 
Symptoms: Malaise, headache, vomiting, diarrhea; 
Lethality: High: 7-16 days; 
Stability: Unstable. 

Agent: Virus: Marburg; 
Possible means: of delivery: Aerosol; 
direct contact; 
Time: Rate of action 7-9 days; 
Symptoms: Malaise, headache, vomiting, diarrhea; 
Lethality: High; 
Stability: Unstable. 

Agent: Virus: Smallpox; 
Possible means: of delivery: Airborne; 
Time: Rate of action 2-4 days; 
incubation 7-17 days; 
Symptoms: Malaise, headache, vomiting, diarrhea, small blisters on 
skin, bleeding of skin and mucous membranes; 
Lethality: High; 
Stability: Stable. 

Agent: Virus: Venezuelan; equine; encephalitis; 
Possible means: of delivery: Airborne; 
Time: Sudden rate of action; 
incubation 1-5 days; 
Symptoms: Headache, fever, dizziness, drowsiness or stupor, tremors or 
convulsions, muscular incoordination; 
Lethality: Low; 
Stability: Unstable. 

Agent: Virus: Yellow fever; 
Possible means: of delivery: Aerosol; 
Time: Sudden rate of action; 
incubation 3-6 days; 
Symptoms: Malaise, headache, vomiting, diarrhea; 
Lethality: High; 
Stability: Unstable. 

Source: Analytic Services Inc., Central Intelligence Agency, and 
Edgewood Chemical Biological Center. 

[End of table] 

Table 8: Radiological Warfare Agents: 

Radioactive isotope: Americium-241; 
Respiratory absorption and retention: 75% absorbed; 10% retained; 
Gastrointestinal absorption and retention: Minimal, usually insoluble; 
Skin wound absorption: Rapid in first few days; 
Primary toxicity: Skeletal deposition; marrow suppression; hepatic 
deposition. 

Radioactive isotope: Cesium-137; 
Respiratory absorption and retention: Completely absorbed; follows 
potassium; 
Gastrointestinal absorption and retention: Completely absorbed; follows 
potassium; 
Skin wound absorption: Completely absorbed; follows potassium; 
Primary toxicity: Renal excretion; beta and gamma emissions. 

Radioactive isotope: Cobalt-60; 
Respiratory absorption and retention: High absorption; limited 
retention; 
Gastrointestinal absorption and retention: Less than 5% absorption; 
Skin wound absorption: Unknown; 
Primary toxicity: Gamma emitter. 

Radioactive isotope: Iodine-131; 
Respiratory absorption and retention: High absorption; limited 
retention; 
Gastrointestinal absorption and retention: High absorption; limited 
retention; 
Skin wound absorption: High absorption; limited retention; 
Primary toxicity: Thyroid ablation carcinoma. 

Radioactive isotope: Plutonium-238 and Plutonium-239; 
Respiratory absorption and retention: Limited absorption; high 
retention; 
Gastrointestinal absorption and retention: Minimal, usually insoluble; 
Skin wound absorption: Limited absorption; may form nodules; 
Primary toxicity: Local effects from retention in lung. 

Radioactive isotope: Polonium 210; 
Respiratory absorption and retention: Moderate absorption; moderate 
retention; 
Gastrointestinal absorption and retention: Minimal; Skin wound 
absorption: Moderate absorption; 
Primary toxicity: Spleen, kidney. 

Radioactive isotope: Strontium-90; 
Respiratory absorption and retention: Limited retention; 
Gastrointestinal absorption and retention: Moderate absorption; 
Skin wound absorption: Unknown; 
Primary toxicity: Bone, follows calcium. 

Radioactive isotope: Uranium-235 and Uranium-238; 
Respiratory absorption and retention: High absorption; high retention; 
Gastrointestinal absorption and retention: High absorption; 
Skin wound absorption: High absorption; skin irritant; 
Primary toxicity: Renal, urinary excretion. 

Source: Armed Forces Radiobiology Research Institute, Medical 
Management of Radiological Casualties Handbook, 2nd ed. (Bethesda, Md.: 
April 2003), app. B. 

[End of table] 

[End of section] 

Appendix III: Comments from the Department of Homeland Security: 

U.S. Department of Homeland Security: 
Washington, DC 20528: 
[hyperlink, http://www.dhs.gov]: 

Homeland Security: 

April 16, 2008: 

Ms. Nancy Kingsbury: 
Managing Director, Applied Research & Methods: 
U.S. Government Accountability Office: 
441 G Street, NW: 
Washington, DC 20548: 

Dear Ms. Kingsbury: 

RE: Draft Report GAO-08-180, Homeland Security: First Responders' 
Ability to Detect and Model Hazardous Releases in Urban Areas Is 
Significantly Limited (GAO Job Code 460570) 

The Department of Homeland Security (DHS) appreciates the opportunity 
to review and comment on the draft report referenced above. The 
Government Accountability Office (GAO) makes three recommendations to 
the Secretary of Homeland Security. Officials within DHS's Science and 
Technology Directorate agree with the recommendations. However, we 
believe GAO should consider other scenarios as alternate ways of 
looking at the present national capabilities for chemical, biological, 
radiological, or nuclear (CBRN) response and the current status of 
testing and certification of detection equipment. 

With respect to CBRN detection equipment and the validation of such 
equipment, the report suggests that in response to a CBRN attack all 
first responders (presumably fire fighters, HAZMAT teams and local law 
enforcement) will be called upon to assess the extent of contamination 
using detectors that are capable of detecting all potential CBRN agents 
at concentrations that are below those hazardous to themselves and the 
general public. 

The report also appears to suggest that any and all CBRN detection 
equipment designed by entrepreneurial manufacturers for sale to first 
responders should be validated by the federal government. 

There are, however, alternative ways of looking at the present national 
capabilities for CBRN response. In one alternative scenario, in the 
event of a terrorist attack, first responders will use a variety of 
prescreening tools, and they will be assisted immediately by state and 
federal agencies that will bring the best available state-of-the-art 
CBRN detection equipment. First responders receive training now 
primarily in the detection and identification of chemical and 
biological (CB) agents in the form of suspicious packages 
and other visible threats. Detection schemes for aerosols and 
particulates rely on sample collection and subsequent analysis by 
trained laboratory personnel. 

The draft report also seems to imply that the federal government should 
test all CBRN detection equipment sold to first responders. There is 
not a current legislative requirement that CBRN detection equipment for 
homeland security applications meet performance standards. However, 
both the Department of Defense (DOD) and DHS have committed 
considerable federal resources to building a next generation of CBRN 
detection systems that will enhance the security of the nation. These 
CBRN detection systems are being deployed on a risk-based priority 
basis across the nation. 

DHS has made significant progress in supporting the development of 
consensus standards and test protocols. Working with our interagency 
partners, we are continuing to support the development of new standards 
and protocols as needs arise. The voluntary consensus standards that 
are being developed for detectors used for CBRN agents--by ASTM 
International for chemical agents, by AOAC International for biological 
agents. and by the Institute of Electrical and Electronic Engineers for 
radiological and nuclear materials--are gaining acceptance by the 
manufacturers, the first responders and the public health community. 
The detector testing currently taking place, as the draft report notes, 
is mainly limited to systems under development by DOD and DHS but these 
systems were selected from numerous proposals and are a good 
representation of the best available technology. The standards and test 
protocols under development now by the federal government and the 
"voluntary standards" community are intended to build an enduring 
capability for standards and testing that will encourage multiple 
manufacturers to engage in a pay-to-play product development venture. 
It will never be feasible for the federal government to fund testing of 
all commercial detectors without first assessing their potential merits 
for detection of CBRN agents because of the very large number of 
hazardous CBRN agents and the expense of testing detectors against 
these agents. 

Technical comments have been provided under separate cover. 

Sincerely, 

Penelope G. McCormack: 
Acting Director: 
Departmental GAO/OIG Liaison Office: 

[End of section] 

Appendix IV Comments from the Department of Commerce: 

THE SECRETARY OF COMMERCE: 
Washington, D.C. 20230: 

April 2, 2008: 

Ms. Nancy Kingsbury: 
Managing Director: 
Applied Research and Methods: 
U.S. Government Accountability Office: 
441 G Street, NW: 
Washington, D.C. 20548: 

Dear Ms. Kingsbury: 

Thank you for the opportunity to review and comment on the Government 
Accountability Office's draft report entitled Homeland Security: First 
Responders' Ability to Detect and Model Hazardous Releases in Urban 
Areas is Significantly Limited (GAO-08-180). I enclose the Department 
of Commerce's comments on the draft report. 

Sincerely, 

Signed by: 

Carlos M. Gutierrez: 

Enclosure: 
Department of Commerce: 

Comments on the Draft GAO Report Entitled "Homeland Security: First 
Responders' Ability to Detect and Model Hazardous Releases in Urban 
Areas is Significantly Limited" (GAO-08-180/March 2008):  

General Comments: 

The Department of Commerce (DOC) appreciates the opportunity to review 
this report on urban plume modeling. As the report contains no 
recommendations for DOC, we only have general and factual/technical 
comments, which are provided below. 

DOC believes, even with the implementation of GAO recommendations aimed 
at improving Interagency Modeling and Atmospheric Assessment Center 
(IMAAC) operations, the plume models will still have several 
limitations as a primary tool for tracking the release of chemical, 
biological, radiological, nuclear (CBRN) materials in urban areas. To 
improve the information available for emergency managers, we suggest 
you offer a recommendation that the Department of Homeland Security 
work with the federal plume modeling community to accelerate research 
and development to address plume model deficiencies in urban areas. It 
would be ideal if such efforts include improvements to meteorological 
information, plume models, and data sets to evaluate plume models. We 
acknowledge it would likely take several years to achieve results. 
Therefore, work should be initiated while the IMAAC is instituting 
improvements. 

DOC also believes the IMAAC should be working to improve federal 
modeling and assessment capabilities, and to enhance the national 
scientific capability through cooperation among the federal agencies 
for incidents of national significance. IMAAC and the atmospheric 
transport and diffusion community should support the Office of the 
Federal Coordinator for Meteorology to develop a joint model 
development and evaluation strategy. 

In addition, the inference that the IMAAC will be providing a single 
dispersion solution is misleading. The IMAAC, as a federal entity, 
provides a recommendation to the local Incident Commander and the local 
Incident Commander decides what information to use. This stems from the 
basis that all events are local in nature. While the draft report 
documents the difficulties for first responders to detect and 
characterize a release of hazardous material in an urban environment, 
it could also highlight a significant opportunity to promote an 
aggressive program of educating first responders and local incident 
commanders on the use of dispersion models. This program could address 
the different types of dispersion models and strengths and weaknesses 
of each type. It could also provide the overall state of dispersion 
modeling and the information needed by the modelers when responding to 
a request for a dispersion model. 

Finally, the report identifies "confusion" regarding the models 
produced for the Top Officials (TOPOFF) 2 exercise, which is repeated 
in various forms throughout the document. While there was confusion, 
the confusion resulted from models being generated using different 
meteorological inputs. One model was generated using real weather, and 
the second was generated using canned weather. Canned weather was used 
in order to meet exercise objectives and its use was approved during 
exercise planning conferences involving local, state, and federal 
officials. 

[End of section] 

Footnotes: 

[1] Anthrax in this report reflects common terminology. Technically, 
the word refers only to the disease caused by Bacillus anthracis, not 
the bacterium or its spores. 

[2] The Homeland Security Council is intended to ensure the 
coordination of all activities related to homeland security by 
executive departments and agencies and to promote the effective 
development and implementation of all homeland security policies. See 
also "Organization and Operation of the Homeland Security Council," 
Homeland Security Presidential Directive-1, The White House, 
Washington, D.C., Oct. 29, 2001. 

[3] Individuals responsible for protecting and preserving life, 
property, evidence, and the environment in the early stages of a 
terrorist attack, natural disaster, or other large-scale emergency are 
known as first responders or emergency response providers. They include 
"Federal, State, and local governmental and nongovernmental emergency 
public safety, fire, law enforcement, emergency response, and emergency 
medical (including hospital emergency facilities), and related 
personnel, agencies, and authorities." See 6 U.S. Code ï¿½101(6). 

[4] While we use CBRN for convenience, we do describe, later in the 
report, differences in the behavior and effects of these materials when 
they are released into the atmosphere. 

[5] The White House, Office of Homeland Security, The National Strategy 
for Homeland Security (Washington, D.C.: July 16, 2002), p. 2. 
[hyperlink, http://www.whitehouse.gov/homeland/book]. 

[6] The National Strategy for Homeland Security, p. ix. 

[7] Management of Domestic Incidents," Homeland Security Presidential 
Directive/HSPD-5, The White House, Washington, D.C., Feb. 28, 2003. 
[hyperlink, http://www.whitehouse.gov/news/releases/2003/02/20030228-
9.html]. 

[8] Effective March 22, 2008, DHS renamed the National Response Plan, 
calling it the National Response Framework. 

[9] National Preparedness," Homeland Security Presidential Directive/ 
HSPD-8, The White House, Washington, D.C., Dec. 17, 2003. [hyperlink, 
http://www.whitehouse.gov/news/releases/2003/12/20031217-6.html]. 

[10] An antimicrobial is a substance that kills or inhibits the growth 
of microbes such as bacteria, fungi, or viruses. 

[11] In the early hours of December 3, 1984, methyl isocyanate gas 
leaked from the Union Carbide plant in Bhopal, India. 

[12] GAO, Combating Nuclear Terrorism: Federal Efforts to Respond to 
Nuclear and Radiological Threats and to Protect Emergency Response 
Capabilities Could Be Strengthened, GAO-06-1015 (Washington, D.C.: 
Sept. 21, 2006). 

[13] RadNet is a national network of monitoring stations that regularly 
collect air, precipitation, drinking water, and milk samples for 
analysis of radioactivity. 

[14] John H. Marburger III, Director, "Purchase of Anthrax Detection 
Technologies," Memorandum for Federal Mail Managers and First 
Responders to Federal Mail Centers, Executive Office of the President, 
Office of Science and Technology Policy, Washington, D.C., July 19, 
2002. 

[15] AOAC International is an independent scientific association of 
analytical scientists with members throughout the world. AOAC provides 
validated methods, proficiency test samples, accreditation criteria, 
and scientific information to industry, government agencies, and 
academic institutions. See [hyperlink, http://www.aoac.org]. 

[16] DHS BioWatch officials provided cost data on the following program 
categories: Management, Oversight, and Program Control; Laboratory 
Operations; Field Operations; Studies and Analyses; National Security 
Special Events; New Technology Development and Transition, and Public 
Health Support-Outreach and ReachBack. 

[17] Laszlo Retfalvi and others, "The Challenges of Effective 
Biological Agent Detection in Homeland Security Applications" (paper, 
8th International Symposium on Protection against Chemical and 
Biological Warfare Agents, June 2004). 

[18] Retfalvi, p. 7. 

[19] LAB is a users' working group of responders from the federal 
government, various local and state governments, and private 
organizations. It is designed to establish and coordinate local, state, 
and federal standardization, interoperability, compatibility, and 
responder health and safety to prepare for, train, respond to, 
mitigate, and recover from incidents by identifying requirements for an 
all-hazards incident response, with a special emphasis on CBRNE issues 
(E representing explosives). 

[20] DHS, Office of Inspector General, Review of DHS' Progress in 
Adopting and Enforcing Equipment Standards for First Responders, OIG- 
06-30 (Washington, D.C.: March 2006). 

[21] OLES also serves as IAB's executive agent for implementing and 
administering first responder equipment standards. IAB has developed a 
strategic plan to identify, adopt, modify, and develop a common suite 
of first responder equipment standards. 

[22] A new standard for chemical warfare vapor detectors that DHS has 
not yet adopted--ASTM E2411-07, Standard Specification for Chemical 
Warfare Vapor Detector--would establish minimum performance 
requirements to detect, identify, and quantify the amount of chemical 
agent vapor in a threat environment. The instrument would be able to 
simultaneously detect multiple threat agents at or below levels that 
are immediately dangerous to life or health. The standard requires 
detection at the first level of EPA's acute exposure guidelines or 
lower. 

[23] According to EPA, its Environmental Technology Verification 
Program develops testing protocols and verifies the performance of 
innovative technologies that have the potential to improve the 
protection of human health and the environment. The goal of the program 
is to provide credible performance data for commercial-ready 
environmental technologies to speed their implementation for the 
benefit of purchasers, vendors, and the public. 

[24] The SAVER program is also supported by other organizations, 
including DHS's Center for Domestic Preparedness; DOE's Nevada Test 
Site; the Science Applications International Corporation; the Technical 
Support Working Group; the U.S. Army Soldier Systems Center, Natick, 
Massachusetts; and the U.S. Space and Naval Warfare Systems Center, 
Charleston, South Carolina. 

[25] DOD has also established the Non-Standard Equipment Review Panel 
that evaluates commercial off-the-shelf chemical and biological defense 
equipment DOD purchases for consequence management. The DOD panel has 
established partnerships with DHS's RKB and SAVER programs to share 
information and leverage existing resources. 

[26] OFCM, Atmospheric Modeling of Releases from Weapons of Mass 
Destruction: Response by Federal Agencies in Support of Homeland 
Security (Silver Spring, Maryland: Aug. 1, 2002). 

[27] The atmosphere near Earth's surface, called the boundary layer, is 
influenced by temperature, turbulence, air flow, and the like. It 
consists of a very turbulent mixed layer, a less turbulent residual 
layer, and a nocturnal, stable, sporadically turbulent boundary layer. 
Winds in the nocturnal boundary layer often accelerate at night. 

[28] Counterproliferation is the full range of military preparations 
and activities to reduce, and protect against, the threat posed by 
chemical, biological, and nuclear weapons and their associated delivery 
means. 

[29] NRC, Tracking and Predicting the Atmospheric Dispersion of 
Hazardous Material Releases: Implications for Homeland Security 
(Washington, D.C.: National Academies Press, 2003), p. 4. 

[30] A Monte Carlo method is a computational algorithm that relies on 
repeated random sampling to compute its results. Monte Carlo methods 
are often used when simulating physical and mathematical systems. 

[31] NRC defines "dirty bomb" as a weapon not of mass destruction but, 
rather, of "mass disruption," combining a conventional explosive, such 
as dynamite, with radioactive material that, "depending on the scenario 
. . . could create fear and panic, contaminate property, and require 
potentially costly cleanup." See "Fact Sheet on Dirty Bombs," U.S. 
Nuclear Regulatory Commission, Washington, D.C. [hyperlink, 
http://www.nrc.gov/reading-rm/doc-collections/fact-sheets/dirty-
bombs.html]. 

[32] The mission of FRMAC, part of DOE's National Nuclear Security 
Administration, is to coordinate and manage all federal radiological 
monitoring and assessment activities during major radiological 
emergencies within the United States in support of state, local, and 
tribal governments. 

[33] The mission of NARAC, at LLNL, the DHS and DOE operational support 
and resource center for plume modeling, is to provide timely and 
credible assessment advisories to emergency managers for hazardous 
releases to the atmosphere in order to help minimize exposure of the 
populations at risk. 

[34] Ground truth, as we indicated earlier, refers to information 
collected on location to verify modeling. It relates the model 
simulation to real features and materials on the ground. 

[35] Other urban plume models include the FEM3MP, a CFD urban model 
developed by LLNL; CFD-Urban, developed by CFD Research Corporation; 
FLUENT-EPA, a commercial model adapted by EPA; and FLACS/FEFLO-Urban. 
However, these CFD models are too slow to be used for real-time 
emergency response. 

[36] The goal of verification and validation is a model that can 
accurately predict the performance of the real-world system that it 
represents, or to predict the difference in performance between two 
scenarios or two model configurations. DOD Instruction 5000.61 
describes the requirements and procedures for the verification, 
validation, and accreditation of DOD models and simulations. See "DOD 
Modeling and Simulation (M&S) Verification, Validation, and 
Accreditation (VV&A)," DOD Instruction 5000.61, Under Secretary of 
Defense (Acquisition, Technology, and Logistics), May 13, 2003. 

[37] D.R. Brook and others, "Validation of the Urban Dispersion Model 
(UDM)," International Journal of Environment and Pollution 20, nos. 1- 
2 (May 10, 2004): 11-21. 

[38] A model evaluation usually has three main components: (1) an 
assessment of the model's physics, (2) an operational performance 
evaluation with field data, and (3) operational testing against real- 
world events. The physics is assessed from a scientific review and 
comparison of the model with data from intensive field experiments, as 
well as numeric and laboratory simulations. Data in the operational 
evaluation can be from intensive experiments or routine monitoring 
networks. Operational testing evaluates the usability, efficiency, 
consistency, and robustness of models for operational conditions. A 
central issue is how well models can be evaluated in the presence of a 
large natural variability in concentration from atmospheric turbulence. 
According to modeling experts, two major limitations of many model 
evaluations and field experiments are a lack of information on the 
vertical distribution of concentration and the random variability or 
inherent uncertainty in concentration. 

[39] Sulfur hexafluoride and perfluorocarbon are stable, colorless, 
odorless gases used extensively and safely since the mid-1960s as 
atmospheric tracers. At the low concentrations used for atmospheric 
studies, sulfur hexafluoride tracer gas has no known environmental 
effect or health risk. It is easily detected, easily handled, and 
relatively inexpensive. 

[40] Steven Hanna and others, "Use of Urban 2000 Field Data to 
Determine Whether There Are Significant Differences between the 
Performance Measures of Several Urban Dispersion Models" (paper, Fifth 
Conference on Urban Environment, American Meteorological Society, 
Vancouver, British Columbis, August 2004). 

[41] Joseph C. Chang and others, "Use of Salt Lake City URBAN 2000 
Field Data to Evaluate the Urban Hazard Prediction Assessment 
Capability (HPAC) Dispersion Model, "Journal of Applied Meteorology 44, 
no. 4 (2005): 485-501. 

[42] NARAC modeling experts state that model predictions within a 
factor of 2, approximately 50 percent of the time, if proper input and 
boundary condition data is available, is an acceptable level of 
accuracy. However, they acknowledge that the inaccuracy of model inputs 
is often the primary limitation on how well the models perform. 

[43] Steve Warner, Nathan Platt, and James F. Heagy, "Comparisons of 
Transport and Dispersion Model Predictions of the URBAN 2000 Field 
Experiment," Journal of Applied Meteorology 43:6 (June 2004): 829-46. 

[44] Akshay Gowardhan and others, "Evaluation of QUIC Urban Dispersion 
Model Using the Salt Lake City URBAN 2000 Tracer Experiment Data--IOP 
10" (paper, 6th American Meteorological Society Symposium on the Urban 
Environment and the 14th Joint Conference on the Applications of Air 
Pollution Meteorology with the Air and Waste Management Association, 
Atlanta, Georgia, February 2006). 

[45] Jeffry Urban and others, "Assessment of HPAC Urban Capabilities 
Using Joint Urban 2003 Field Trial Data" (paper, 10th Annual George 
Mason University Conference on Atmospheric Transport and Dispersion 
Modeling, Fairfax, Virginia, August 2006). 

[46] IDA, Comparisons of Transport and Dispersion Model Predictions of 
the Joint Urban 2003 Field Experiment (Alexandria, Virginia: 2007). 

[47] Hanna Consultants, Source Term Estimation Methods for Releases of 
Hazardous Chemicals to the Atmosphere Due to Accidental and Terrorist 
Incidents at Industrial Facilities and during Transportation 
(Kennebunkport, Maine: 2005). 

[48] DOE operates the Nonproliferation Test and Evaluation Complex at 
the Nevada test site, which can conduct open air testing of toxic 
hazardous materials and biological simulants. 

[49] A mesonet is a network of automated weather stations designed to 
observe mesoscale meteorological phenomena. 

[50] OFCM, Federal Research and Development Needs and Priorities for 
Atmospheric Transport and Diffusion Modeling (Silver Spring, Maryland: 
September 2004). 

[51] Lethal concentration is the concentration of a chemical in the air 
that would kill 50 percent of a group of test animals. Lethal dosage is 
the dosage that kills 50 percent of the animals tested. 

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