Homeland Security: First Responders' Ability to Detect and Model Hazardous Releases in Urban Areas Is Significantly Limited
Published: 2008-06-27T00:00:00

Fast Facts:

Highlights:
section_title: Why GAO Did This Study
paragraphs: 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.
section_title: What GAO Found
paragraphs: 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. DHS's 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 responders' CB detection equipment, but its testing and certification cover equipment DHS develops, not what first responders buy. Interagency studies show that federal agencies' models to track the atmospheric release of CBRN materials have major limitations in urban areas. DHS's national TOPOFF exercises have demonstrated first responders' confusion over competing plume models' contradictory results. The Interagency Modeling and Atmospheric Assessment Center (IMAAC), created to coordinate modeling predictions, lacks procedures to resolve contradictory predictions. 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.

section_title: Letter
paragraphs: 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. 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. 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. 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. 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.
subsections: section_title: Background
paragraphs: 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.” 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.”
subsections: section_title: Government Responsibilities for Responding to CBRN Events
subsections: section_title: State and Local Responsibilities
paragraphs: 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.
section_title: Federal Responsibilities
paragraphs: 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. 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.
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. 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.
section_title: First Responders’ Challenges in CBRN Events
paragraphs: 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.
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. 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.
section_title: Tools Used to Identify and Track CBRN Materials
paragraphs: 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.
section_title: CBRN Detection Equipment Has Significant Limitations for First Responders’ Use
paragraphs: 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.
subsections: section_title: Current Radiological and Nuclear Detection Equipment First Responders Use Cannot Detect the Dispersion of Releases in the Atmosphere
paragraphs: 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. EPA also has its RadNet system for airborne radiation  monitoring.
section_title: Current Chemical Detection Equipment First Responders Use Cannot Detect Harmful Concentrations
paragraphs: 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.
section_title: First Responders’ Handheld Biological Detectors Are Ineffective
paragraphs: 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. “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.”
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. 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.
section_title: BioWatch Does Not Provide First Responders Real-Time Detection of Biological Pathogens
paragraphs: 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.
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).
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. 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.
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.
section_title: CBRN Detection Equipment Has Few Performance Standards and Is Not Independently Tested to Validate Manufacturers’ Claims
paragraphs: 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.
subsections: section_title: DHS Grant Funds Allow First Responders to Acquire CBRN Detection Equipment
paragraphs: 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.
section_title: DHS Has Adopted Few Performance Standards for CBRN Detection Equipment
paragraphs: 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. 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. 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.
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.
However, DHS has not adopted any standards for CB detection  equipment. 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.
section_title: DHS Has the Primary Mission to Develop, Independently Test, and Certify First Responders’ Chemical and Biological Detection Equipment
paragraphs: 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.
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.
section_title: DHS Is Not Independently Testing Manufacturers’ Claims about CBRN Detection Equipment
paragraphs: 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. 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. 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).
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.
section_title: Plume Models for Analyzing Urban Dispersion of CBRN Agents Have Limited Capabilities
paragraphs: 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.
subsections: section_title: Nonurban Plume Models Have Limitations for Emergency Response to CBRN Events in Urban Environments
paragraphs: 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.
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. 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.
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. 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. 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. 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.
section_title: TOPOFF 2 Revealed Weaknesses in Coordinating Plume Modeling Efforts
paragraphs: 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.
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. 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.  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. 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. 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.
section_title: The Creation of the Interagency Modeling and Atmospheric Assessment Center
paragraphs: 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.
section_title: TOPOFF 3 Revealed Continuing Problems in Coordinating Plume Modeling Results
paragraphs: 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.
section_title: TOPOFF 4 Shows Improvements in Coordinating Plume Modeling but Difficulties in Interpreting Results
paragraphs: 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.
section_title: Urban Plume Models Give Variable Predictions
paragraphs: 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.
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. 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. 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. 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. 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. The urban HPAC model slightly overpredicted at  most distances; another evaluation of HPAC found consistent mean  overpredictions of about 50 percent. 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.
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. 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.  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. 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. 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.
section_title: Urban Plume Models Have Limitations for Estimating the Source Term of Toxic Industrial Chemical Releases
paragraphs: 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. 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. 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.
section_title: Data Gaps on How CBRN Releases Affect Urban Populations Are Significant
paragraphs: 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.
subsections: section_title: Urban Databases Have Significant Gaps
paragraphs: 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.  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. 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.
section_title: Data Are Insufficient on How Exposure to CBRN Materials Affects Health
paragraphs: 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.
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.
section_title: Conclusions
paragraphs: 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.
section_title: Recommendations for Executive Action
paragraphs: 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.
section_title: Agency Comments and Our Evaluation
paragraphs: 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 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.
section_title: Appendix I: Scope and Methodology
paragraphs: 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.
section_title: Appendix II: Chemical, Biological, and Radiological Agents
paragraphs: High fever, chills,  headache, spitting up  blood, and toxemia,  progressing rapidly to  shortness of breath and  cyanosis (bluish  coloration of skin and  membranes)
section_title: Appendix III: Comments from the Department of Homeland Security
section_title: Appendix IV: Comments from the Department of Commerce