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Naval Forces’ Defense Capabilities Against Chemical and Biological Warfare Threats C Additional Information on the Five Commodity Areas This appendix expands on the information presented in Chapter 4 about the five commodity areas of the Joint Chemical and Biological Defense (CBD) Program: contamination avoidance, individual protection, collective protection, decontamination, and modeling and simulation. CONTAMINATION AVOIDANCE Consistent with the Joint CBD Program’s organization of the science and technology associated with contamination avoidance, the following discussion is divided into subsections on chemical and biological point detection and standoff detection. Point and standoff detection require mostly distinct science and technology, albeit with some overlaps. For instance, optical spectrometry may be useful in both point and standoff applications. Within those divisions, sensors for chemical and biological agents are discussed separately because each one usually requires different science and technology. Chemical Point Detection Modern chemical warfare (CW) agents are produced as solids or liquids, depending on the application. Liquids can be volatile, such as sarin (GB), which converts to vapor form quickly, or nonvolatile, such as VX (O-ethyl S-diisopropylaminoethyl methylphosphonothiolate), which emits almost no vapor at standard temperatures. Liquids can also be sprayed into the air as aerosols or fixed on a solid matrix such as silicone particles (dusty agents), or perhaps be fixed on soil particles. In these cases, volatile agent droplets or volatile agents
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Naval Forces’ Defense Capabilities Against Chemical and Biological Warfare Threats loaded on inert particles will still emit a vapor signature. Solid agents, such as BZ (3-quinuclidinyl benzilate), will often be aerosolized as an inhalable powder. Many of the techniques for delivering solids are designed to defeat the standard vapor-detection devices used by most military forces. Liquid agents can also leave ground contamination. Agents such as mustard and VX are designed for use in terrain denial; they persist in the environment because of their low volatility. Precursors and by-products can be found in any of these physical forms. Unfortunately, because the response to direct exposure to CW agents is typically very fast and violent, humans are excellent detectors for the presence of such substances in the immediate environment. It is certainly preferable to be able to detect the presence of CW agents through some other form of interaction. There are numerous other physical mechanisms that can be exploited to produce robust detection, classification, and identification signatures. Although CW agents can appear in many different physical forms—vapors, solids, or liquids, with or without inert co-components—such chemical substances typically have distinctive mass, chemical, and electromagnetic (EM) properties that can be measured. The electromagnetic interactions, which probe the energy-level structure of the chemical molecules, are particularly useful, leading to various forms of classical spectrometry, which are known to be capable of both excellent sensitivity and specificity. In addition, because of the propagation properties of EM waves, spectroscopic approaches can be successfully applied both locally, for point detection, and remotely, for standoff detection. The mass and chemical and physical interaction properties of CW agents are also quite distinctive and can permit sensitive detection, classification, and identification. Sensors based on such properties require that physical samples of the suspected agent be placed into intimate contact with the measurement equipment, however, and so they are suitable only as point detectors. The two popular forms of mass-based CW point detection—ion mobility spectrometry (IMS) and mass spectrometry (MS)—utilize similar principles. The unknown CW agent is collected and ionized in some way, and the ions are allowed to propagate under the influence of an electric field to a collector. Ions with different mobilities arrive at the collector at different times, and the timedependent collection current provides a signature which depends both on the specific ions that are present (i.e., position time of arrival peaks) and the numbers of each (i.e., signal level). The fundamental difference between the two techniques lies in the properties of the propagation medium. IMS uses local ambient air at atmospheric pressure, while MS uses a vacuum. As compared with the MS technique, the atmospheric pressure ion chemistry associated with the IMS technique greatly modifies the distribution of ion fragments or clusters that are generated by the ionization process, as well as the mobilities of the resulting fragments. As a result, the signatures and sensitivities of the two approaches are typically quite different—although signatures unique to individual CW agents can be obtained from each. Typically, the IMS approach is less sensitive, but it can be
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Naval Forces’ Defense Capabilities Against Chemical and Biological Warfare Threats significantly less expensive and provide faster response without the vacuum requirements of MS, and is better suited for the generation of compact designs. IMS is a well-developed point detection technology used in most recently fielded battlefield point CW detectors. A summary of Department of Defense (DOD) programs in chemical point sensing is provided in Table C.1. TABLE C.1 Chemical Point Sensing Programs of the Department of Defense Name Description ABC-M8 ABC-1-58 ABC-M8 chemical agent detector paper detects liquid chemical agents. It is used whenever chemical agents are suspected. Every soldier carries a booklet of ABC-M8 paper in the mask carrier. Each booklet contains 25 sheets of paper. This paper turns colors when it touches a chemical agent. V-type nerve agent turns the paper dark green, G-type nerve agent turns it yellow, and a blister agent turns it red. Night operations cause problems, because ABC-M8 paper must be read in white light. Since ABC-1-58 paper is used to check suspected surface areas for contamination, it can be brought into a white light area for reading. During night reconnaissance operations, the monitor can take several samples, marking each one, and then bring them back to the vehicle for reading. The paper is used by blotting it on the suspected contaminated surface. ACADA The automatic chemical agent detector/alarm (ACADA) is an advanced pointsampling, chemical agent alarm system capable of detecting, warning, and identifying standard blister and nerve agents simultaneously. The ACADA is man-portable, operates independently after system startup, and provides an audible and visible alarm. It is used by Army, Navy, Air Force, and Marine Corps units. ACADA replaces the M8A1 alarm as an automatic point detector and augments the improved chemical agent monitor (ICAM; see below) as a survey instrument. It provides its warning automatically, using the multiple integrated chemical agent alarm, to communicate with battlefield data transfer and warning systems. ACADA does not require a specific military operator. Weight: 24 lb (complete with carrying case, battery pack, and M42 remote alarm). Size: 7 in. × 7 in. × 14 in. detector and battery box (14 lb). Detection capability: Nerve and blister agents. Battery life: Approximately 15 hours at 70°F. ACADA uses the IMS technology of Graseby Dynamics, Ltd., and operates continuously. Beaglette The Beaglette is a Naval Research Laboratory (NRL) program outside the Joint Chemical and Biological Defense (CBD) Program. The concept is based on the larger point chemical agent detector (pCAD; see below) and offers the potential for a disposable, matchbox-sized system (with polymer-coated surface acoustic wave (SAW) sensors) with true real-time agent detection capabilities with subsecond equilibrated agent responses; robust performance for distributed, or personnel, or miniature unmanned aerial vehicle (UAV) applications in an environment with dynamically changing humidity/temperature; fabricated with
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Naval Forces’ Defense Capabilities Against Chemical and Biological Warfare Threats Name Description commercial off-the-shelf components; and having low-power operation with no consumables. Current or projected system capabilities include these: Chemical agent vapor detection with low parts per billion limits; High discrimination for diesel, gasoline, and the like; System power: 0.1 W continuous; Weight: 0.1 lb (palm-sized system); Zero warm-up time for efficient intermittent operation; Wireless link; and Compatibility with other sensors. CAAS The chemical agent alarm system (CAAS; also known under the designation M8A1), through IMS techniques, detects the presence of nerve agents (tabun (GA), sarin (GB), soman (GD), O-ethyl S-diisopropylaminoethyl methylphosphonothiolate (VX)) and supplies visible and audible alarms. This mature system has been available for a long time. More than 40,000 M8A1 systems have been fielded by the U.S. Army and many foreign countries. CAM The chemical agent monitor (CAM) is a product of Graseby Dynamics, Ltd. It is a handheld, portable detector specifically designed to assess the extent of chemical dispersal and the contamination of personnel, vehicles, and equipment, and to confirm when an area is clear of contamination. It is based on Graseby’s mature IMS technology; detects nerve, blister, blood, and choking agents; is programmable to cover other agents or simulated agents for training; and is capable of 14-hour continuous battery operation. More than 50,000 units are in service worldwide. A few vapors present in the atmosphere can, in some circumstances, give a false response in CAM. The situations most likely to give a false response are those in enclosed spaces or when sampling is done near strong vapor sources (dense smoke). Some of the types of vapors that have been found to give false readings include these: Aromatic vapors. Included in this category are groups of materials such as perfumes and food flavorings. Some brands of aftershave and perfume can give a response in G mode (for detecting nerve agents) when CAM is held close to the skin—for example, as in casualty-handling procedures. Some sweets, such as peppermints and cough lozenges, and menthol cigarettes can cause a response in G mode if the breath is exhaled directly into the CAM inlet. Cleaning compounds. Some cleaning compounds and disinfectants contain additives that give them a pleasant smell. Some of these additives, such as menthol and methyl salicylate can give false responses in the H mode (for detecting blister agents). Ammonia gives a false response in the G mode. Many cleaning materials are spread over large surface areas and therefore provide a considerable vapor source, particularly in enclosed spaces. Smoke and fumes. The exhaust from some rocket motors and the fumes from some munitions can give responses. Since monitoring with CAM in these situations is unrealistic, few problems should arise.
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Naval Forces’ Defense Capabilities Against Chemical and Biological Warfare Threats Name Description ICAD The Marine Corps-issued individual chemical agent detector (ICAD) includes two electrochemical sensors, each of which is covered by a thin diffusion membrane. One sensor is sensitive to nerve agents (GA, GB, GD: 0.5 mg/m3 in 120 seconds); blood agents (cyanide (AC): 250 mg/m3 in 120 seconds); and choking agents (CG: 25.0 mg/m3 in 15 seconds). The other sensor detects blister agents (H, lewisite (L): 10.0 mg/m3 in 30 seconds). Chemical agents in the air diffuse through the membranes on the faces of the ICAD sensors and are collected by the electrolyte behind the membranes. The chemical agent concentrations in the electrolyte are measured by multiple-electrode electrochemical sensor systems. When the concentration reaches a preset threshold level, an audio alarm sounds and a light-emitting diode comes on. ICAM The improved chemical agent monitor (ICAM) is a product of the Joint CBD Program. Based on IMS technology, the ICAM upgrades the CAM with improved reliability and maintainability. It is a handheld device for real-time detection of low levels of nerve and mustard vapors and is capable of both day and night operation. More than 6,000 ICAMs have been procured to date. ISCAD The IMS/SAW chemical agent detector (ISCAD) is an NRL program outside the Joint CBD Program. It strives for ultralow false-alarm rates by integrating two CW point detection technologies (IMS and SAW) that have orthogonal principles of operation. The objective is a handheld chemical detector with subsecond equilibrated chemical detection at threat levels for survey mode and vehicular applications. The ISCAD incorporates NRL’s pCAD, which dramatically improves SAW signal kinetics and tolerance to environmental effects. JCAD The joint chemical agent detector (JCAD) is a handheld, pocket-sized detector capable of automatically detecting, identifying, and quantifying chemical agents onboard ships and aircraft and for individual warfighter applications. Its operating principles are based on NRL’s pCAD SAW-based detector. Production is scheduled for FY 2004 and beyond. M256 The M256 series chemical agent detector kit is capable of detecting both liquid and vapor concentrations of chemical agents. It detects chemical agents in the following concentrations—nerve (G series: 0.005 mg/m3; VX: 0.02 mg/m3 within 15 minutes), blister (H: 2 mg/m3 to 12 mg/m3 within 10 minutes), and blood agents (AC: 7 mg/m3 within 10 minutes). The M256 kit is issued at the squadron level, so every squadron has the capability of detecting and classifying chemical agents. The M256 series contains ABC-M8 chemical agent detector paper for liquids and samplers/detectors for vapors. An improved M256 detector kit will also be capable of detecting T2 mycotoxin. M256 series samplers/detectors are used primarily to determine the type of chemical agents present. For example, a unit may have noticed an attack or the alarm may have sounded; the M256 series is then used to check if there is a chemical agent present and to identify the agent. The M256 series also causes operational security problems during hours of limited visibility. A white light is needed to read both the ABC-M8 paper and
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Naval Forces’ Defense Capabilities Against Chemical and Biological Warfare Threats Name Description the sampler/detector. The light must be shielded from enemy observation using a poncho or other suitable covering. M272 The M272 water-testing kit for chemical agents is a lightweight portable kit that will detect and identify harmful amounts of chemical warfare agents when present in raw and treated water. The kit will detect AC to 20 mg/liter, mustard (HD) to 2.0 mg/liter, L to 2.0 mg/liter, and nerve agents (both G and V series) to 0.02 mg/liter. Water containing agents in less than these concentrations is permissible for short-term (up to 7 days) use, in cold or warm regions, with up to 5 quarts per person per day usage. These kits are usually found in chemical reconnaissance units, medical units, and units with water-purification or transportation missions. M8A1 M8A1 is another designation for the CAAS. M9 Chemical agent detector paper M9 is the most widely used method of detecting liquid chemical agents. It is more sensitive and reacts more rapidly than ABCM8 paper does. M9 paper reacts to chemical agents by turning a red or reddishbrown color. To use M9 detector paper, it is put on opposite sides of the body: if one is right-handed, a strip of M9 paper is put around the right upper arm, left wrist, and right ankle; if one is left-handed, the M9 paper is put around the left upper arm, right wrist, and left ankle. It is also attached to large pieces of equipment (e.g., air-conditioning systems, shelter or van entrances, or vehicles). When attached to equipment, it must be placed in an area free from dirt, grease, and oil. This is especially important, since petroleum products and DS2 (decontaminating solution containing diethylenetriamine, 2-methoxyethanol, and sodium hydroxide) also cause the paper to change color. M9 paper is especially useful in detecting on-target attacks and in keeping soldiers from entering contaminated areas. Whenever a pink, red, reddishbrown, or purple color appears on the paper, the presence of chemical agents is suspected. As soon as M9 paper indicates the presence of chemical agents, soldiers and units must take protective action to keep from becoming grossly contaminated. The results of the M9 paper should be confirmed with the M256 kit. Night operations present some problems when using M9 paper. Color changes do not show up when a flashlight with a red filter is used to read the paper; white light must be used. This could cause some serious operations security problems, especially for front-line troops. Commanders must realize that there is a risk if they do not establish procedures for checking M9 paper for color changes. To check it, soldiers can be rotated into a white-light area, or the M9 paper can be collected periodically for reading. MIME The metal-insulator metal-ensemble (MIME) chemi-resistor is an NRL project outside the Joint CBD Program. It represents a new development in solid-state chemical vapor sensors and is still in an early phase of research and
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Naval Forces’ Defense Capabilities Against Chemical and Biological Warfare Threats Name Description development (R&D). The MIME chemical sensor is composed of nanometersized gold particles encapsulated by a monomolecular layer of an alkanethiol surfactant. These nanoclusters are self-assembled onto a micron- or nanometerscale electrode. This sensor operates by reversible absorption of vapors into the organic monolayer, which causes a very large modulation in the tunneling current between clusters in the deposition. Response times are controlled by vapor diffusion, which is extremely fast for monolayers. Selectivity depends on an array of variably responding sensor elements, which are produced by chemical functionalization of the alkanethiol. Current or projected capabilities include these: “Electronic nose” chemical vapor detection, Parts per billion chemical agent simulant detection, and Response and recovery times <1 sec. An entire detection system may be packaged within the volume of a wristwatch. pCAD The point chemical agent detector (pCAD) represents the pioneering NRL SAW-based CW-agent point-sensor concept that is being incorporated into the JCAD sensor of the Joint CBD Program. The pCAD provided for the first time true real-time agent detection capabilities with subsecond equilibrated agent responses. It offers robust performance for ground and unmanned aerial vehicle applications in an environment with dynamically changing humidity and temperature; a palm-sized system fabricated with commercial off-the-shelf components; and low-power operation with no consumables. The operating principle is based on polymer-coated SAW devices that selectively and reversibly absorb chemical agents. The resulting shift in SAW signal frequency provides detection capability. SAW-array pattern analysis provides identification of the agent. Novel system design provides accelerated signal kinetics and immunity from environmental effects due to humidity and temperature. Current or projected system capabilities include these: Chemical agent vapor detection with low parts per billion limits; High discrimination for diesel, gasoline, and the like; System power: 0.5 W continuous; Weight: 0.5 lb (palm-sized system); Zero warm-up time for efficient intermittent operation; Wireless link; and Successful preliminary ground and UAV flight tests.
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Naval Forces’ Defense Capabilities Against Chemical and Biological Warfare Threats Chemical- and physical-reaction-based point detectors exploit several different principles. Perhaps the most basic, and the first to be exploited in the context of CW agent detection, is the change in color of various solutions and substrates when they interact with the agents. Detection papers (e.g., ABC-M8 and M9) have reagent coatings that selectively change color when exposed to specific CW agents. Color-change detectors can detect nerve, blister, and blood agents. Chemoselective hydrogen-bonded acid polymers are at the heart of many “electronic nose” chemical point detection sensor systems. These polymers selectively adsorb chemical agents or explosives over extended periods of time (minutes, hours, days). Relatively thick polymer films and/or hyperporous structures allow rapid vapor sorption. Material properties are selected to allow vapor sorption, but not desorption, at ambient conditions. Heating allows the trapped agent to be released for analyses. The adsorption of the agent into the polymer can have a number of measurable physical effects, the simplest of which is an increase in overall mass of the element. If these polymer elements are coated on the surface of a surface acoustic wave (SAW) oscillator, the changes in mass can be detected as changes in frequency of the SAW signal. The use of multiple polymers, which respond in different ways to a given chemical agent, permits agent identification through pattern-matching techniques. This is the principle of operation behind a series of CW point detection sensors. SAW technology was, in fact, pioneered by the Naval Research Laboratory (NRL) and has been selected for the next-generation chemical point detector (the joint chemical agent detector, or JCAD). Another approach commonly used in the civilian and academic worlds is chromatography. Chromatography involves dissolving a sample in a so-called mobile phase, which may be a liquid or a gas. The mobile phase is then forced over a static component known as the stationary phase. Generally the sample will have differing solubilities in each phase. A component that is quite soluble in the stationary phase will take longer to travel through the apparatus than a component that is not. As a result of these differences, sample components will become separated from each other. Techniques such as high-performance liquid chromatography and gas chromatography use columns—narrow tubes packed with the stationary component through which the mobile component is forced. The sample is transported through the column by the continuous addition of the mobile phase; the different components of the sample emerge at different times. Chromatographic separations can be carried out using a variety of transport and stationary phases, including liquids, volatile gases, paper, and immobilized silica on glass plates. Coupling a detection scheme at the exit of the separation produces the sensor. Such sensors have found wide application in the laboratory and for environmental measurements. As does mass spectrometry, chromatography offers high sensitivity and good specificity for the detection of CW agents in many forms.
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Naval Forces’ Defense Capabilities Against Chemical and Biological Warfare Threats Work on systems using microfabricated columns to implement miniature gas and liquid chromatography sensors for the detection of pollutants (e.g., toxic industrial chemicals or CW agents) has been going on for some time, but it has been historically challenged by difficult implementation issues. Recent progress, however, is suggesting that microchromatographic techniques may form the basis for the next-generation detector after JCAD. Biological Point Detection As noted in Chapter 4 of this report, at least six approaches are being used for the detection and identification of biological agents: Nucleic acid sequence detection and identification, Binding affinity and specificity using natural antibodies to target antigens, Ligands and artificial antibodies for binding affinity and specificity, Response of living cells or tissue to pathogen or toxin exposure, Chemical analysis, and Culture-based approaches including microscopy. Numerous measurement approaches use these basic six “signatures.” For instance, a binding event between the target agent and the test probe can be measured using the differences in mass among the individual molecules and the bound complex. Alternatively, an optical label can be attached to the probe and detection achieved after separation of the molecular complex by physical filtering from the labeled probe. Each of the six basic signatures has resulted in numerous instrument prototypes and concepts for detection and identification. Immunological approaches (i.e., antibody assays) have been available for some time. Their principal limitation is the lack of specificity of the antibody; that is, very few antibodies bind exclusively to one target molecule. This can lead to false positives from the detector. Several approaches are being investigated to improve the performance of immunological sensors, including the design of artificial antibodies with greater specificity, the use of multiple antibodies that bind to different parts of the target molecule, and the use of a network of detectors that allow spatial comparisons among the sensors to help discriminate between a false positive and the presence of a biological agent. Nucleic acid–based approaches are both sensitive and specific, and have been fielded as part of demonstrations and tests. Nucleic acid approaches cannot detect purified biological toxins but may be able to identify associated residues from the organism. The time required to perform a nucleic acid test is decreasing, and for some instruments it is now less than 10 minutes. Instrument packaging is also being dramatically reduced; currently, suitcase-sized systems can be purchased. A nucleic acid approach to medical diagnostics is also showing promise
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Naval Forces’ Defense Capabilities Against Chemical and Biological Warfare Threats (see Chapter 5). On the other hand, inhibition from metals, salts, and other factors affect detection and can lead to significant sample preparation issues in various environments. Nucleic acid detection instrumentation can be expensive. Ideally, a single sensor would be available to detect and identify both chemical and biological threats. The potential for integrating chemical and biological point detection was presented to the committee for a system based on mass spectrometry (signature 4 in the list at the beginning of this section). Mass spectrometry is arguably the “gold standard” for chemical testing. Even though the mass spectrometer approach has promise, progress for biodetection has been limited such that the near-term potential to perform both types of tests in one sensor should not be expected. Even if the detection capability can be developed, the mass spectrometer will require different “front ends” with separate optimization for chemical and biological targets. In the near term, a single instrument will not be able to adequately detect and identify both chemical and biological agents. Mass spectrometry has some promise in this area but will require a long-term investment. It is likely that different sample preparations will be required for chemical and biological samples. The sensors proposed and used for contamination avoidance should have utility in decontamination. The committee is not aware, however, of any assessment aimed at finding out how well the sensors developed for contamination avoidance can support decontamination and resumption of operations. There are also opportunities to leverage sensor investments with water and food safety. The DOD development of a sensor for water safety (joint chemical/biological agent water monitor) is at an early stage, with planned entry into development in FY 2005. Several references provide descriptions and status reports of biological point detection systems within the DOD.1 Table C.2 offers a summary. There are significant investments and progress being made in similar sensors in other parts of the government—for example, the National Science Foundation, Department of Energy (DOE), and National Aeronautics and Space Administration—and in industry (HAZMAT and medical diagnostics). The committee did not attempt a catalog of all of these activities, but acknowledges that the Joint CBD Program is continuously monitoring progress in these other efforts and is importing promising technologies when appropriate. 1 National Research Council. 2000. Strategies to Protect the Health of Deployed U.S. Forces: Detecting, Characterizing, and Documenting Exposures, Board on Army Science and Technology, National Academy Press, Washington, D.C.
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Naval Forces’ Defense Capabilities Against Chemical and Biological Warfare Threats TABLE C.2 Biological Point Detection Systems of the Department of Defense Name Description BAWS The bio-aerosol warning sensor (BAWS) is an ultraviolet (UV) fluorescence detector using laser illumination. BAWS units are planned to be integrated into the joint biological point detection system (JBPDS) as a trigger for the presence of a 1- to 10-micron-sized biological particle. BIDS The Biological Integrated Detection System (BIDS) is a vehicle-based collection of components with upgrade capacity. Integration into JBPDS is planned toward fully automated, broad-spectrum biological detection and identification.a Tens of units were produced for the Chemical Company. BSPS The Biological Sample Preparation System (BSPS) for biological identification is two different approaches: proteomic and genomic. The proteomic approach uses sonication and high-performance liquid chromatography separation as a front end to mass spectrometry. In FY 2000, about 2-ft3-size implementations of the front end were demonstrated. Enzymatic digests have been used to do protein-based identification. The genomic approach uses polymerase chain reaction (PCR) as the detection mechanism and has shown a 100 colonyforming unit/ml limit of detection for several threat organisms in less than 20 minutes. CASPOD The Contamination Avoidance at Sea Ports of Debarkation (CASPOD) advanced concept technology demonstration (ACTD) has been newly initiated by the Joint CBD Program. CBIS The Chemical and Biological Individual Sampler (CBIS) ACTD has begun with chemical detection only, using commercial off-the-shelf technology. The scenario for the ACTD has not yet been determined. CBMS The chemical biological mass spectrometer (CBMS) uses infrared pyrolyzer followed by tandem mass spectrometry.b The CBMS was originally intended for the next-generation BIDS. It is being evaluated as a joint chemical/ biological agent water monitor. IBAD The interim biological agent detector (IBAD) is composed of a particle-size sorter/counter, a wet cyclone sampler, a manual identifier, and a flow-through colorimetric ticket assay. Agent identification occurs within 20 minutes. JBAIDS The Joint Biological Agent Identification and Diagnosis System (JBAIDS) has demonstrated PCR-based systems to quickly and reliably identify multiple (at least 8) biological organisms. It is moving to the acquisition phase. Smart Cycler™ XC and Rapid/LightCycler were part of Block I concept technologies. JBPDS The Joint Biological Point Detection System (JBPDS) is in development to replace and outperform the Army BIDS and Navy IBAD systems. It is planned to enter development of Block II in FY 2004. JBPDS comprises trigger, sampler, detection, and identification subsystems to meet Joint Operational Requirements Document (JORD) specifications. It is designed to be able to identify multiple BW agents in less than 15 minutes, at 1 ACPLA sensitivity, and have less than 2 percent error in identification.c Generic UV laser-induced fluorescence detection capability (BAWS) improves system performance while reducing operations and support costs.
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Naval Forces’ Defense Capabilities Against Chemical and Biological Warfare Threats ture or remove contamination from the air. Individual protective garments currently fielded include the chemical protective overgarment (CPO), battle dress overgarment (BDO), and Saratoga suits. Technology development efforts for outerwear focus on enhanced, semipermeable fabrics to reduce heat and respiratory loads; toughening of garments; and development of self-decontaminating, or reactive, fibers. The Joint CBD Program currently funds research, development, and testing for both individual and collective protection. This includes the Joint Services Program mask with end-of-service-life indication and limited protection against toxic industrial chemicals; the next-generation general-purpose mask intended to reduce respiratory and thermal stress while offering enhanced protection and comfort; and the joint services chemical environment survivability disposable mask that offers up to 6 hours of protection. New-generation garments are also under development in the Joint CBD Program. These include the lighter-weight and lower-thermal-stress suit (JCE-I); the JCE-II suit that promises even lower weight, lower thermal stress, and a self-decontaminating feature; and the JSCESS suit that is a single-use, minimum-weight and -volume garment. Collective protection systems under development include the chemical/biological protective shelter, which is a lightweight, truck-mounted shelter that provides a clean working area for medical, combat service, and support personnel for up to 72 hours. The chemically protected deployable medical system is a chemically hardened, air-transportable hospital unit. Collective protection retrofits and the shipboard collective protection equipment (SCPE) project are focused on extending the lifetime of shipboard high-efficiency particulate air filters for protection systems based on overpressurization with clean air. DECONTAMINATION In the committee’s opinion—and as stated many times throughout this report, attacks with chemical or biological agents or toxic industrial chemicals (TICs) will occur, and some of them will be successful. It is a nearly impossible problem to protect fully against contamination by a determined adversary armed with a chemical or biological weapon in many asymmetric scenarios. Although improved CW or BW detection sensors have value for providing an increased warning capability, they should not be relied upon as an effective defensive strategy to avoid attack. Similarly, the nature of many of these scenarios is such that it would be impossible to avoid contamination by quickly fleeing the area. Because of these limitations, the probability of contamination resulting from an asymmetric attack is far from zero. Attacks with CW or BW agents or TICs will occur, and some of them will be successful. The operational goal then becomes achieving a quick recovery to operational status, which in turn requires wellplanned decontamination operations, which in turn will require significant im-
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Naval Forces’ Defense Capabilities Against Chemical and Biological Warfare Threats provements in decontamination agents, methods, technical understanding, training, and doctrine. Methods and Materials Some currently fielded decontamination materials and equipment are described in detail in a separate National Research Council/Institute of Medicine publication.2 A brief description of current decontamination programs under the auspices of the Joint CBD Program is provided in Box C.1. (The associated time lines for testing, acquisition, and fielding can be found in the publication entitled Joint Service Chemical and Biological Defense Program—FY00-02 Overview.3) Box C.1 also includes a listing of other federally funded research and development efforts related to decontamination. Standards In addition to the decontamination approaches themselves, effective decontamination requires reducing exposure to the toxic compound or biological agent to a level that is considered safe for personnel. In managing the consequences of an attack, it is important to distinguish between the two agent types. Chemical agents can have both acute, immediate effects and more chronic (long-term) effects that may not manifest themselves for months or years. Some biological agents create morbidity within hours, while others take days or weeks. It is critical to have expert advice as to the range of possible effects as well as the chemical and biological nature of the agents in question. Little is known about the effects of long-term exposure to low levels of chemical or biological agents. Understanding this is important for those target areas that have large in-place populations such as harbors and bases, where return to a safe level may mean safe for long-term exposure or a level dictated by civil regulations. These facilities depend on a continuous and complicated free flow of people and materiel for effective naval operations. A return to normal operations may require a more thorough and possibly more complex decontamination process than that required in battlefield scenarios. In most situations, rapid resumption of operations will depend on effective decontamination of installations, personnel, and equipment. This is especially true for persistent chemical agents and spore-forming bacteria and some viruses. 2 Institute of Medicine and Board on Environmental Studies and Toxicology, National Research Council. 1999. Chemical and Biological Terrorism: Research and Development to Improve Civilian Medical Response, National Academy Press, Washington, D.C., pp. 239-240. 3 Johnson-Winegar, Dr. Anna, Deputy Assistant to the Secretary of Defense for Chemical/Biological Defense. 2000. Joint Services Chemical and Biological Defense Program, FY00-02 Overview, Washington, D.C.
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Naval Forces’ Defense Capabilities Against Chemical and Biological Warfare Threats BOX C.1 Joint Service and Other Agency Programs in Decontamination Joint Service Programs Joint Services Fixed Site Decontamination (JSFSD). This effort is geared toward ports of entry, airfields, logistics nodes, and command and control centers. The goal is removal, neutralization, or elimination of chemical/biological agents and toxic industrial materials by employing a family of decontamination reagents and applicator systems. Decontamination of wide areas, facilities, key equipment, and personnel are all considerations. The program focuses on the use of new decontamination reagents that can be employed with existing applicators. A second aspect deals with the development of new applicators. The third aspect of the program is concerned with applicators for use on skin and in open wounds. Joint Services Sensitive Equipment Decontamination (JSSED). This effort primarily focuses on nonaqueous decontamination technologies for chemical/biological agents. Three separate capabilities are under development. First, techniques for decontamination of small, high-value, sensitive equipment or components are being examined. Included are examination of supercritical solvents, glow discharge plasmas, catalyst (nanoparticle) solvent wash systems, and thermally accelerated weathering. Second, vehicle interiors that house sophisticated electronic materials (aircraft, tanks, and so on) are to be examined. Included are exterior surfaces that cannot be subjected to the more aggressive decontamination solutions currently fielded, such as DS2. Third, in the out years, the issue of “onthe-move” decontamination will be addressed. Included is the decontamination of vehicles while they are in operation or flight. Modular Decontamination System (MDS). This technology development program has as a primary goal minimizing the spread of contamination on the battlefield through the use of small, modular decontamination stations. The system under development includes a decontamination reagent pump and high-pressure applicators. This unit is essentially a compact, high-pressure washer unit capable of delivering a limited set of liquid-phase decontamination reagents (DS2, common bleach, formalin, or even diesel fuel, should that be the only liquid available). Sorbent Decontamination. The sorbent program includes development of personal wipedown systems and spraydown operations. The objective is to improve upon the carbonaceous and ion exchange mixes in current use and to eliminate DS2 from the spraydown operations. A stable, environmentally acceptable, noncorrosive sorbent that is effective over a wide temperature range will permit decontamination of personal equipment, key areas of vehicles, and weapon systems. Short-term objectives include development of carbon cloth technology for the removal of contamination from skin. Longer-term objectives include testing and procurement of sorbent-based decontamination kits for field use.
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Naval Forces’ Defense Capabilities Against Chemical and Biological Warfare Threats Other Decontamination Programs In addition to the joint service programs listed above, current research and development efforts are being undertaken through 6.1 efforts supported by the Army Research Office, through the Technical Support Working Group, as part of the biodefense program at the Defense Advanced Research Projects Agency, and at the Department of Energy national laboratories. These efforts are listed below. Army Research Office—Chemical Sciences Division Novel Surfactants and Microemulsions (Menger, Emory University) Simultaneous Signal and Decontamination (Jaeger, University of Wyoming) Polyoxometalates (Hill, Emory University) Nanoparticles (Klabunde, Kansas State University) Artificial Metallo-phosphoesterases (Chin, McGill University) Ester Metathesis (Gagne, University of North Carolina) Metal Catalyzed Degradation (Moss, Rutgers University) Solar-driven Photooxidation (Yates, University of Pittsburgh) Chemistry of Mild Wide Spectrum Decontamination (Bunton, University of California, Santa Barbara) Enzyme Catalysis (Leblanc, University of Miami, Coral Gables) Meso and Microporous Materials (Landry, University of Vermont) New Chemical Catalysts (Chen, University of South Carolina) Technical Support Working Group Mass Decontamination Protocols (Technical Support Working Group/ Public Health Service) Mass Decontamination Protocols (Technical Support Working Group/ Public Health Service) Defense Advanced Research Projects Agency Antimicrobial Nanoemulsions (Baker, University of Michigan) Enzymatic Decontamination (Maxygen) Department of Energy Gel-based Catalytic Oxidant System (Raber, Lawrence Livermore National Laboratory) Foam-based Oxidant/Additive System (Tucker, Sandia National Laboratories) Atmospheric Pressure Plasma Jet (Herrmann, Los Alamos National Laboratory) Gas Phase Decontamination (Currier, Los Alamos National Laboratory) How Clean Is Safe (Sorenson, Oak Ridge National Laboratory) How Clean Is Clean (Raber, Lawrence Livermore National Laboratory)
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Naval Forces’ Defense Capabilities Against Chemical and Biological Warfare Threats For biological attacks, there currently are no guidance documents or performance standards that could be used by the Navy to decontaminate its operations to levels suitable for resuming its operations and protecting its human and material resources. Guidance for chemical agent exposure has been recently addressed by the Joint Staff4; it admits to a limited understanding of safe exposure levels and to the need for the individual commander to accept some level of risk appropriate for his or her own situation. In the commercial world, the acceptable risk levels that are used by regulatory agencies for setting standards for managing chemical and biological disease outbreaks are small, but not zero—typically on the order of 1 casualty in 105 or 106 (i.e., a fatality rate of 1 in 100,000 or 1 in 1 million.) In military operations, it is impossible to have zero risk, and indeed, the acceptable risk level in most cases may well be higher than that set for civilian operations. Determining the appropriate level of decontamination for a situation is the result of assessment and decision making based on all of the risks. Setting the appropriate risk levels and decontamination specifications is an area in need of Navy doctrine. Once established, that doctrine could then lead to the development of testing and performance standards to be used for field decontamination, as well as to base and long-term equipment decontamination procedures. The Navy must be able to provide doctrine, guidelines, and expertise in this area. Agent Fate Studies The test protocol established by Edgewood Chemical and Biological Command (ECBC) for establishing chemical agent interactions with substrates is summarized in Box C.2. MODELING AND SIMULATION Chemical Modeling The emphasis in chemical agent modeling appears to be on using plume models to predict the spread and concentration levels of a chemical release. However, the accuracy of such predictions is highly dependent on knowledge of the precise location and magnitude of the chemical release, the physical characteristics of the plume (e.g., the initial particle-size distribution), and detailed knowledge of the stochastic nature of local atmospheric dispersion. In reality, these parameters are likely to be poorly known in any cleverly executed asym- 4 Hawkins, MAJGEN James A., USAF, Vice Director, Joint Staff. 2002. Memorandum for Distribution List re: Chemical Warfare (CB) Agent Exposure Planning Guidance (with two enclosures), MCM-0026-02, Office of the Chairman, Joint Chiefs of Staff, Washington, D.C., April 29.
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Naval Forces’ Defense Capabilities Against Chemical and Biological Warfare Threats BOX C.2 Test Protocol for Chemical Agent Fate Studies The standard Edgewood Chemical and Biological Command (ECBC) testing protocol for chemical warfare agents includes three levels of tests: (1) laboratory tests are performed using live agents and/or surrogates, (2) larger-scale chamber tests are performed with either live agents and/or surrogates to correlate the live agent and surrogate results, and (3) final field tests are performed using surrogate agents. During these final tests, operational assessments of applicator performance and techniques, tactics, and procedures are made. Whenever possible, international and ASTM (American Society for Testing and Materials) standards are employed. Internationally accepted standards do not presently exist for biological agent testing. At the laboratory scale, tests may be performed in stirred reactor vessels typically involving 1 g of agent and 50 ml of decontamination reagent. These tests provide basic kinetics data and an indication of the product suite. Panel testing, offgassing, and contact hazard testing may also be performed to determine the ease with which contamination can be removed from a specified surface. The Department of Defense (DOD) standard challenge, developed during the Cold War, is still employed, namely, 10 grams of agent per square meter of surface. Adherence to this protocol is by DOD decree. Agent is typically allowed to dwell on the surface for 60 minutes prior to application of the decontamination reagent. This is a historical artifact related to the time required either to set up a field decontamination unit or to return from the field to an established decontamination site. Decontamination reagents are typically applied to the surface and rinsed off following a 30-minute contact time. The contact time may vary with specific customer requirements. ECBC personnel indicated that there is a current push toward reagents that will be effective following a 15-minute contact time. Analytical methods typically include nuclear magnetic resonance, gas chromatograph/mass spectrometer (GC/MS), flame photometric detector (FPD), and so on for CW work, while classical growth-based microbiological assays are employed for assessing decontamination efficacy for biological agents and surrogates. metric attack. The inaccuracies introduced from these poorly known sources may prove to be the limiting factor in making detailed, spatially resolved predictions. A common perception exists that chemical attacks appear to require large amounts of chemical materials to have significant, long-term effects over large areas. This increases the likelihood of an opponent’s employing industrial chemicals (TICs/TIMs (toxic industrial materials)) as the agent. This also suggests that commercial chemical installations near Navy bases or carried by commercial transportation (e.g., trucks, rail cars, freighters) may present the more significant chemical threat near bases and ports. Such sources could be remotely triggered by attacks with man-portable weapon systems, such as small rockets or placed charges, effectively providing a remote capability to generate a significant chemical attack. Such
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Naval Forces’ Defense Capabilities Against Chemical and Biological Warfare Threats attacks would require that the industrial facilities or transportation routes be upwind of the base. In addition to open-air dispersion at shore installations and bases, the Navy needs models to help understand dispersion around and within vessels. Efforts are under way to include recent results on agent fate in the models. However, there is a significant controversy regarding chemical agent fates. The Air Force approach estimates practical limits for operational decisions rather than pursuing an exhaustive study of detailed chemical fates. In principle this is an intriguing approach, as it adopts a more “operational” perspective on testing and evaluation. However, there are lingering questions in the community about the extent and accuracy of the data gathered in the Air Force-led study. Even if the inherent variability between substrate materials ultimately dictates that an indepth and detailed study be conducted, there is merit to the operational perspective that the Air Force adopted which should not be overlooked. Biological Modeling Biological modeling of agent transport and fate has apparently not received nearly the same level of attention as chemical agent modeling. The same considerations for open-air and enclosed-vessel/facility transport of agent are needed, but in addition, the biological problem introduces some unique requirements. Since people act as “amplifiers” for infectious biological agents, the concentrations of biological agents that raise concern can be much lower than the levels of chemical agents that cause concern. Consequently, the accuracy requirements for biological modeling may be much higher than those necessary for chemical modeling. The prediction problem is further complicated by the fact that low biological concentrations can occur over much larger geographic areas than are typically affected in chemical attacks. People and/or animals can also act as dispersion mechanisms (vectors) for the spread of biological agents. For infectious agents spread initially in an aerosol cloud, exposed personnel act as dispersive cells, moving randomly in many different directions and over great distances. This situation takes the modeling problem beyond simple physics, since personnel movement is driven by many factors, most of which cannot be modeled in any sort of predictive sense. The time lag between exposure to a biological agent and the appearance of symptoms is usually measured in days or more, in contrast to minutes to hours for chemical agents. This lag increases the uncertainty in the source term (location and time of release), further complicating the biological modeling problem even as it offers leeway for therapeutic intervention. Agents that settle, like anthrax spores, are more easily resuspended by various activities; again, these are processes that are not well understood and cannot therefore be modeled in any predictive sense.
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Naval Forces’ Defense Capabilities Against Chemical and Biological Warfare Threats There are currently no highly reliable in situ biological detectors that could be used to increase the accuracy of dispersion models in the early phases of an incident as there are with the chemical problem. Effectively, a biological attack is likely to be recognized following a disease outbreak. Because of the unpredictable, dispersive spread of biological agents by affected people, biological dispersion models may be applicable only in the early phases of an attack, to narrow the set of personnel likely to have been exposed during the initial release. The growing use of computers in the military and the trend toward using biometrics to identify legitimate military users will lead to a growing capability to “track” the movement of military personnel back in time. This ability to track, at least in a general sense, the movement of military and support personnel might aid in identifying the origin of an outbreak and the region of exposure. A few cases of symptoms appearing in a diverse group of personnel whose movements had coincided in a particular region a few days earlier might help provide an indication of an attack sooner than waiting for more widespread symptoms to appear. Such a “detect to track” capability based on modeling could help identify and confirm that a biological attack had occurred. Another concern for biological modeling is the use of genetically altered agents, or the introduction of harmful genes into normally occurring, innocuous organisms. Even if we were to develop robust biodetectors for the dangerous biological agents likely to be used as weapons today, such sensors may prove of little value against genetically altered agents in the future. To illustrate the many factors to be included in a model to aid in decision making in the event of an attack, the committee provides an example of the elements that might be a part of a discrete simulation of the event. The example is illustrative only and not necessarily exhaustive in the factors it includes, but serves to make the point. Consider a case in which an adversary releases a biological agent against a naval base in CONUS, with the goal of delaying the deployment of a task force. Here the parameter that best determines the effectiveness of the attack would likely be how long the deployment is delayed. Deployment delays can occur because key personnel are injured or killed and are deterred from working and time is required for their recovery or their replacement, or because time is required to decontaminate equipment. In this scenario, a major branch point occurs at the beginning of the attack. If sensors detect that an attack is occurring, personnel can take advantage of individual and collective protection with a concurrent reduction in casualties. Alternatively, sensors may fail to detect that an attack is under way, delaying detection until personnel start falling sick. Along this second branch, personnel losses and resulting deployment delays might be much higher. Since even technically sound sensor systems can fail to detect an attack for any number of reasons, there is always the possibility that a real event could follow either branch of this scenario.
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Naval Forces’ Defense Capabilities Against Chemical and Biological Warfare Threats Figure C.1 outlines how a simulation might be constructed to explore this scenario. The goal is to calculate delays that would be introduced into a deployment. The simulation begins with the question of whether any indications and warnings (I&W) of an attack are available before the attack actually begins. Questions related to where such I&W might originate are discussed below. Sensors will produce a finite number of false alarms, which require some time, tFA, to resolve. One can anticipate that there will invariably be some time delay, t5, associated with the total number of false alarms and the time needed to resolve them. For sensors with high false-alarm rates, t5 goes up. I&W might allow an attack to be stopped in progress, resulting in no delay to the deployment. Otherwise there is a major branch point designated as “Detect attack under way.” One possibility is that this detection occurs at time t1, based on the sensor capabilities, allowing personnel to get into individual and collective protection by some time t2, which is a function of when they get the warning, their proficiency from training, and the ease of obtaining and using protective equipment. Some number of personnel are exposed, Pe, and some fraction of these personnel become infected, Pi, which depends on the number exposed, the agent, and the effectiveness of any vaccines. The notional graph at the bottom indicates that there is some recovery time, trec, required for these infected personnel to be either cured and returned to duty or to be replaced by transfers. There is probably some minimum number of losses, Pmin, which would not stop deployment. Beyond that, there are time delays for recovery or replacement, which can be expected to accelerate at a rate greater than linear for a period of time as more and more personnel become incapacitated. Whether replacement is by recovery or transfer, there is also some minimum time delay, ttrans, that would be introduced. Of course, there may be different curves for transfer and recovery. Along this same branch, equipment has to be decontaminated and returned to operational status. This total time t4 depends on how much equipment is contaminated, the decontamination techniques used, and the ease with which personnel can work in protective equipment. The net result, if the simulation goes down this branch, is a delay, which is the maximum of either the personnel delay, t2 + trec, or the equipment delay, t4. The other possibility occurs when the sensors fail to detect the attack, because of sensor system failure or because they had been deactivated due to high false-alarm rates, and so on. For infectious agents, the number of exposed personnel, Pe, now depends on the initial number of people exposed to the agent and the number of additional people that they infect as they move around. Eventually enough personnel fall sick that the occurrence of an attack is recognized at time t3, which is probably days later than t1. As a result, the recovery time, trec, is much higher, as is the decontamination time, t6. Along this branch, the delay is the maximum of the personnel delay, t3 + trec, or the equipment delay time, t6. In this case, the personnel delay will likely be the controlling factor.
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Naval Forces’ Defense Capabilities Against Chemical and Biological Warfare Threats FIGURE C.1 Stochastic simulation for naval deployment delays caused by a biological attack. (See discussion in text.)
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Naval Forces’ Defense Capabilities Against Chemical and Biological Warfare Threats It should be noted that many of these times and the numbers of personnel exposed or infected are statistical in nature themselves and would vary from scenario to scenario. For example, there is likely to be significant variability in time t3 for inferring an attack by recognizing groups of infected individuals. As shown in the box at the bottom of the figure, one pass through the simulation will result in a deployment delay time that is one of the four possibilities. Running the simulation many times then gives a distribution of deployment delay times and an indication of where bottlenecks exist in restoring operational capability. This example has concentrated on a single parameter as the goal—minimizing deployment delays. Other end-goal parameters, such as minimizing the number of casualties, could also be simulated with only minor modifications. One could also explore coupled goals, such as minimizing deployment delays and minimizing casualties. Because these two factors are probably interrelated, some technique such as multiattribute decision theory is needed to combine them. For example, if decision makers can weight the relative importance of reduced casualties versus reduced deployment delays, a slightly modified simulation could be used which has this weighted combination of factors as the end goal.
Representative terms from entire chapter: