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--> 4— A Framework for Assessing Risk to Deployed Forces The proposed framework for risk assessment of threats to deployed U.S. forces is intended to organize risk-assessment activities. It is divided into several components, providing places for various analyses, and organized to illustrate the role of each activity and how it contributes to an overall analysis of risks to deployed forces. The object is to foster a systematic approach to recognizing and cataloging potential hazards, founded on examination of the various activities and settings of deployment. Each recognized scenario or sequences of events that could lead to potentially hazardous exposures is divided into components for analysis, and these analyses can then be applied in judging the likelihood that potentially hazardous exposures will indeed be encountered and, if encountered, the probabilities that adverse outcomes will be engendered. This information can then be used to consider modifications of procedures, equipment, and actions to avoid or mitigate risks with the awareness that actions taken with respect to one risk might affect others and might need to be weighed against the needs of the military mission. The framework puts great emphasis on recognition of potentially hazardous activities, including systematic processes to uncover previously unrecognized ones. It also emphasizes anticipatory analysis and contingency planning before actual deployment as a means for identifying preventive measures and allowing risks to be carefully analyzed before they actually arise. Finally, it provides for the collection of appropriate data before, during, and after actual deployments. The framework is characterized by three major enterprises—ongoing strategic baseline preparation and planning, specific deployment activi-
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--> ties, and post-deployment activities. These enterprises are characterized by separate modes of activity and analysis, but are connected to each other by their common application to achieving the goal of assessing risks to deployed forces and by their need to incorporate each other's results. The elements of the three enterprises are presented in Boxes 1, 2, and 3, and how these elements fit in the overall framework is illustrated in the form of a hierarchical tree diagram in Figures 1 to 6. Although a single tree encompasses the whole framework, owing to its complexity, it is necessary to represent the tree in a series of diagrams to indicate how the subparts are connected. Figure 1 presents the three major enterprises of the framework, Figures 2 to 4 depict the activities encompassed by the ongoing strategic planning enterprise, Figure 5 outlines activities to be undertaken during deployment, and Figure 6 illustrates the post-deployment enterprise. This chapter explains and elaborates upon each of the risk-assessment activities of the framework. Ongoing Strategic Baseline Preparation and Planning Ongoing strategic baseline planning comprises all of the activities and analyses concerned with preparation, through analysis, systematic investigation, risk-aware design of procedures and material, and contingency planning for threatening eventualities before they occur. As such it includes all activities concerned with recognizing potential threats, anticipating the circumstances under which they might arise, and assessing and characterizing each kind of threat qualitatively and quantitatively. The aim is to make a thorough examination of the processes, activities, and settings that might arise during deployment, to identify potential hazards (including previously unrecognized hazards), and to subject them to appropriate analyses. Although the present report does not explore risk management in depth, the ongoing preparations also include preventive measures such as setting exposure standards and modifying procedures to avoid or ameliorate risks. The activities are not tied to specific deployments, but represent the continuing development of information about potential deployment risks and exposures, organized through the framework so as to create an ever expanding and improving base of knowledge. This knowledge can be drawn on to increase the capability to avoid or mitigate risk and to refine doctrine and training so as to lead to safer deployments. That is, the first phase comprises ongoing, long-term activities aimed at increasing preparedness for risk mitigation issues in specific future deployments, since planning and preparation for specific deployments (which fall under a second, subsequent phase of activity, described below) must often be conducted at an accelerated pace.
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--> BOX 1 Ongoing Strategic Baseline Preparation and Planning Activities Identify Potential Threats Lists of known and suspected agents Battle injuries Chemicals, radiation Disease Stress Accidents Exposure High, intense Unusual, novel Persistent, cumulative Inventories of exposure associated with activities and settings Hazards associated with deployment per se — specific environments Hazards associated with missions (by type) — combat — operations other than war Hazards associated with places (by place) — terrain, climate, infrastructure — indigenous diseases — local environmental pollution — toxic industrial chemicals — adversaries Co-exposure pattern review Develop Priorities for Detailed Analysis Likely to occur Mission-critical Known threat Potential impact Special DOD responsibility Risk Analysis Probability of release Probability of exposure given release Probability of health effect given exposure — hazard identification — dose-response — risk characterization Recognition Environmental consequences Incorporation into Standard and Risk-Aware Planning (Risk Management) Design, doctrine Standards development — operational — emergency/crisis — cumulative Contingency plans Training Review BOX 2 Specific-Development Activities Deployment-Specific Planning Update with mission-specific information ''Before" biomarker samples During Deployment (continued) — concentration — concentration × time profile Vigilance for unsuspected exposures Sampling, archiving, record-keeping — biological samples — environmental samples — unit activities, positions — monitoring and detection activities Upon Arrival Surveillance sampling During Deployment Recognition of events and detection of exposures — detection Deployment-Termination Activities "After" biomarker samples
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--> BOX 3 Post-Deployment Activities Reintegration Post-deployment service Veterans Population Analyses of Associations Exposure reconstruction Epidemiological analyses Generate hypotheses and test with new toxicological studies Data Archiving Capture during-deployment data Implement deployment-specific follow-up systems Evaluate Lessons Learned Deeper understanding of known threats Study previously unanticipated threats Feedback to predeployment planning mode Ongoing Health Surveillance Individual examinations tied to deployment history Implement registries with triggers for deeper analysis Figure 1. The three enterprises of the proposed risk-assessment framework.
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--> Figure 2. Ongoing strategic baseline preparation. The numbers correspond to the figures, which provide more detail about the activity.
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--> Figure 3. Ongoing strategic baseline preparation (continued from Figure 2). The numbers correspond to the figures, which provide more detail about the activity.
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--> Figure 4. Ongoing strategic baseline preparation (continued from Figure 2). The numbers correspond to the figures, which provide more detail about the activity.
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--> Figure 5. Specific deployment activities. The numbers correspond to the figures, which provide more detail about the activity.
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--> Figure 6. Post-deployment activities. The numbers correspond to the figures, which provide more detail about the activity.
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--> This phase of analysis is clearly large and complex, containing many distinct components of activity (Figures 2 to 4). It is divided into four major steps: (1) identify potential threats; (2) develop priorities for detailed analysis; (3) conduct a risk analysis; and (4) incorporate understanding of risk into standards and risk-aware planning (i.e., risk management). Identify Potential Threats The first step is to identify potential threats, both the agents of harm and the circumstances, activities, and settings that might cause potential threats to be realized. The aim is to systematically sort through activities to identify potential sources of hazard, including ones that might not have been recognized in this setting, or at all. Unrecognized threats could include agents not previously listed as hazards or new properties of recognized hazardous agents (such as chronic toxicity from ongoing low-level exposure). Clearly, the task of sorting through the whole universe of deployment-associated activities and settings is daunting, and the call to identify all potential hazards, including novel ones, is idealistic in view of the scarcity of data that usually prevails. In practice, a series of screening exercises, described below, can be pursued. The point of setting such a challenging goal is to go beyond a focus on agents already on standard lists of hazardous agents and activities, or on the most obvious properties of those agents. This step is different from the traditional process of hazard identification, which focuses on marshaling and interpreting the evidence regarding the toxic potential of particular agents considered individually. It is also different from the usual process of identifying a list of potential agents of concern (as one might do in evaluating a toxic waste site), because it seeks to identify hazards rather than simply recognize potential exposure to a list of known hazards. Unlike a toxic waste site, where the exposures are there to be measured, the task here is to imagine potential exposure scenarios and the likelihood that they will occur during deployment. What needs to be examined is not just the agents and exposures, but the activities and settings that lead to exposures. The practical means that is recommended for pursuing this search for hazards is to conduct several different screening exercises in parallel, each based on a somewhat different rationale. The intent is that by approaching the common question from several different angles simultaneously, one increases the probability that situations in which potentially harmful exposures might arise are recognized as such. Examples of such approaches are to screen (1) by lists of known or suspected hazardous agents; (2) by exposure considerations; (3) by inventories of exposures
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--> associated with various activities or settings; and finally (4) by conducting a review of the hazards identified by the previous three methods. This last approach is used to identify likely patterns of co-exposure among agents that should be given special attention due to the possibility of accumulative or synergistic effects. Lists of Known or Suspected Agents Notwithstanding the advice not to rely solely on established lists of hazardous agents, it is wise to begin by consulting such lists for presence of agents associated with deployment tasks. Established sources of characterization of hazards could be consulted for several different kinds of threats, including battle injuries, chemicals and radiation, disease, physical and psychological stress, and accidents. A paper commissioned by the National Research Council (NRC) for this project (Rose 1999; abstracted in Appendix A), lists many infectious diseases that should be considered. In addition to the Department of Defense's (DOD's) own existing lists, hazardous agents can be sought from such sources as the U.S. Environmental Protection Agency (EPA) Integrated Risk Information System and Acute Emergency Guideline Levels for Hazardous Substances, the Agency for Toxic Substances and Disease Registry Toxicological Profiles, the Hazardous Substance Data Base, the American Conference of Governmental Industrial Hygienists documentation, the International Agency for Research on Cancer monographs, EPA Health Effects Assessment Summary Tables, the National Toxicology Program Annual Report on Carcinogens, and the State of California Proposition 65 list. The review of such lists should go beyond the properties that caused the agents to be listed, because listing might be prompted by the most sensitive among several toxicity end points or by a particularly prominent toxicity end point. The hazards that an agent might pose during deployment might be affected by likely exposure patterns that differ from those considered in the original listing. Similarly, the presence of an agent on some list of toxic compounds is not a substitute for full hazard identification. The object of this initial step is to recognize potential hazards for fuller consideration in the risk-analysis step. Exposure A second means of seeking potential hazards is to examine agents with notable exposure patterns. The aim of this process is to identify agents to which deployed troops are likely to be exposed, putting a premium on the need to understand their potential hazardousness. The thinking here is similar to that applied to the current discussion about
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--> data immediately available and whatever store of knowledge and analysis has been assembled beforehand. Procedures for gathering and assembling appropriate information and archived analyses, and for using these to make sound decisions, need to be established as a part of preparedness. The Army's 1998 Risk Management Field Manual (FM 100-14) is an example of this kind of preparation. Development of Standards The foregoing design activities are aimed at optimizing ways to modify actions and material to avoid as much risk as is feasible, and to deal with the risk that cannot be avoided. Another risk-management approach is to define exposure standards that are deemed to achieve some specified degree of protection, and then to screen activities to assure that these standards are met. Although it is unwise to rely on standards alone as a means of controlling risks to military personnel, setting exposure standards is important in establishing a benchmark for protection of health against expected risks. It provides a straightforward means of defining health-protection goals, monitoring activities to assure that those goals are achieved, and allowing for a quick, relatively nontechnical evaluation of the risk potential of situations that have not received detailed analysis. For operational reasons, procedures for determining whether an activity meets exposure standards are desirable because they are relatively easy to formulate and to implement, and they can serve as guides in situations requiring quick decisions based on scarce information by nontechnical decision-makers. The military already uses exposure standards of various kinds a great deal to ensure safety of ongoing operations and to guide decision-making about the special, more-intensive exposures that might occur in emergencies, some deployments, and combat. Different kinds of standards are appropriate for different settings. Broadly, it is appropriate to allow for different durations of exposure, because a level tolerable for a short time without ill effect might not be so for ongoing exposure. It is also useful to allow for standards that admit some degree of toxic response but protect against incapacitation or irreversible injury for use in guiding actions in emergencies or when important risk trade-off decisions must be made quickly, such as in combat. By analogy with occupational standards in the civilian arena, military standards for emergencies and cumulative exposures (such as radiation exposure) are useful. The military's operational exposure standards are intended to allow for ongoing exposure of indefinite duration during the conduct of ''normal" operations without ill effect, where "normal" means having to do with usual ongoing duties and activities, including military occupational activities. One could imagine a special set of operational
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--> exposure standards with assumptions appropriate to limited-term deployments or deployment-specific activities, but in practice the military's usual operational exposure limits fulfill the intent of this kind of standard. The Short-Term Chemical Exposure Guidelines for Deployed Military Personnel (ACHPPM 1999) are aimed at defining higher exposure levels that can be tolerated in a deployment situation with low likelihood of marked response. They use some military-specific exposure factors but do not make any special consideration for the effect of stress or other deployment-specific factors that might modify sensitivity to agents. They are also aimed at specifying relatively safe levels. The scheme for reporting risk-assessment results proposed by Rodricks (1999; abstracted in Appendix A) suggests an approach to defining standards that acknowledges that in some situations one must bear adverse effects from exposures to accomplish some other end. This approach is seen most clearly in the Emergency Exposure Guidance Levels (NRC 1986, 1993b, 1998), which estimate air concentrations of substances that might produce reversible effects but do not impair ability to respond to an emergency for a period of an hour. Other standards that provide for different levels of tolerance of some toxic effects for various lengths of exposure could be imagined and could prove useful in particular settings. A caveat raised before is worth repeating here: standards tend to be set on the most obvious end points, but one must beware of overlooking subtle effects from low-level exposures that might accumulate with repeated episodes of exposure or might manifest themselves long after exposure, even though the exposure causes no detectable immediate harm and might be classified as "safe" with respect to the end point on which short-term limits are based. A recent GAO report was critical of existing DOD procedures and doctrine on this question (GAO 1998). Contingency Plans The generalized planning aimed at improving capabilities can be supplemented by contingency plans aimed at specific classes of deployments. These would provide insights into what might be expected in deployments in specific world regions under specific conditions and for specific purposes. They serve as templates, complete with bodies of analysis, ready to be consulted in the eventuality that particular deployments come to be considered, and into which the up-to-date, region-specific information can be plugged. This addresses the problem that complex analyses are difficult to carry out quickly and thoroughly, so the degree to which they can be prepared ahead of time increases preparedness.
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--> Training The effectiveness of efforts to design procedures and equipment to further the cause of risk prevention depends on the proper and efficient actions of the troops, and training can advance this end. Because a large number of reservists are often deployed, they should be included in such training. Review In any complex program in which there are many activities that must interact productively to reach the motivating goals, the military should conduct regular reviews of how well its risk-assessment process is working and how its goals are being fulfilled. It is all too easy to carry out the activities on a list of tasks without ever really bringing the results to bear in the way that motivated the efforts in the first place. Specific Deployment Activities The second major phase of the framework (Figure 5) addresses the use of these risk-assessment activities in actual, specific deployments. The key activities in this phase are to implement plans made in anticipation of deployment (ongoing strategic baseline preparations), update them with information specific to the deployment situation at hand, note the advent of threatening exposures when they actually occur, and activate the appropriate parts of the response plans accordingly. This phase must also include vigilance for exposures that, despite all the planning, were unanticipated. Finally, it must include collection and archiving of samples for future analysis. Four subphases of activities associated with specific deployments are (1) deployment-specific planning, (2) activities upon arrival, (3) activities during deployment, and (4) deployment-termination activities. Deployment-Specific Planning Once a specific deployment is anticipated, but before it actually occurs, there is an opportunity to apply information specific to the location, mission, and current conditions, and to update and render specific the more generalized contingency plans that might have been developed in the first phase. The kinds of information that can be applied include current meteorological conditions and forecasts for the immediate future, updates on the locations of hazardous materials, and current assessments of the capa-
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--> bilities and inclinations of any adversaries that might be met. The ongoing strategic baseline analyses divided inventories of threats into those related to deployment per se, those specific to mission types, and those specific to places. The advantage of such a classification is that, when faced with a particular deployment, a situation-specific catalog of hazards can be created by taking all of the first list and adding those from the second and third lists that are appropriate to the particular mission and location. This situation-specific information can then be integrated into the earlier anticipatory analyses as part of the process of mission analysis and planning. Biological specimens and health-status determinations are helpful tools in monitoring troops' exposures and health, and it is important to establish baseline levels among troops slated for deployment. Baseline information could be obtained by conducting annual health evaluations on reserve and active-duty personnel. Considerations for use of biological markers are discussed in much more detail in a paper commissioned for this project by the NRC (Lippmann 1999, abstracted in Appendix A). Lippmann argues that environmental and biological samples are a good deal less expensive to collect and archive than they are to analyze, and immediate analysis necessarily focuses on agents recognized at the time of collection as being of interest. It is therefore wise to archive most samples and to analyze them only once a specific hypothesis is formed that requires deeper investigation and specific analytical methods. Activities Upon Arrival The arrival of the deployed force might provide the first opportunity to collect on-the-ground intelligence. This should include obtaining local samples of soil, air, and water. Some of these should be archived to serve as baseline measures for future reference, but a subset should be analyzed to provide information on the extent and identity of local environmental pollution. Appropriate detection and meteorological instrumentation can be set up to provide the basis for feeding information into exposure models. Activities during Deployment This subphase also comprises the main part of the second phase of the risk-assessment framework. During the course of deployment, the key issue is detection of potential exposures and recognition of when situations and contexts occur for which useful prior analysis has been conducted. In the ongoing strategic baseline planning, hypothetical scenarios and schemes for the unfolding of possible threats, the consequences of each threat realized, and the likelihood that hazardous situations would be encountered.
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--> Presumably, plans were formulated for appropriate responses to a range of various eventualities. During an actual deployment, the task is to discern which of the sets of contingent events imagined beforehand are actually transpiring and need a response. This is not merely the detection of agents of concern in the environment, it is the larger question of recognizing the determinants of the changing probabilities that various hazards will be encountered and will pose threats, and modifying actions accordingly. Detection of Exposures The detection of imminent exposures is an important aspect of during-deployment activity. (See NRC [1999a] for a discussion of detection methodology and capabilities.) The issue here is how such information can be used. A hierarchy of exposure information could be obtained. First is qualitative detection, which might be provided by a monitoring device that sounds an alarm when a concentration above a certain cutoff is detected. Such detection could trigger actions to employ protective equipment or to take evasive action, but it does not allow such actions to be modulated by the magnitude of the exposure. In many situations, this might not be a significant handicap, because the critical issue is the fact that exposure occurs at all. Next in the hierarchy is the measurement of a concentration (either instantaneously or averaged over some moderate interval). This kind of detection allows different actions depending on whether the concentration is high or low. There is no time component, however, so no allowance for the eventual duration of exposure or the particular concentration-time profile can be made, unless the time course can be guessed from the nature of the source of exposure. A yet more sophisticated detector might be able to keep track of the changing profile of concentration over time. Even if the time-concentration profile is critical to the toxic response engendered, information about the profile becomes complete only after the exposure is completed, and so such information might be of reduced value as a basis for modifying actions to avoid risk. If such profile information is recorded and saved, however, it might be valuable for dosimetry purposes in a retrospective analysis of the impacts of the exposure on the troops who experienced it. Vigilance for Unsuspected Exposures Detectors register the presence of those agents they are designed to detect, and prior analyses of threats address the situations that were anticipated, but necessarily exclude possible unexpected exposures. Detecting these in the short run is a challenge, because detection methods would have to be general enough to register whatever agents appear, yet not so
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--> general as to react to ubiquitous innocuous compounds. Archived samples might be able to establish previously unsuspected exposures in retrospect. The issues involved in detecting unsuspected exposures, as well as other topics related to preparedness for health protection during deployment, are discussed in a report of the National Science and Technology Council (NSTC 1998). Sampling, Archiving, and Record Keeping It is important to take samples over the course of a deployment to document exposures. For practical reasons, the program of sample collection must be tailored to the force size, the nature and duration of the mission, and the type of activities the troops will be called upon to perform. Certain military occupational specialties with known high potential for exposures to particular hazards could be targeted for special attention in personal biological sampling and health surveillance. As noted, it is probably wisest to archive most of these samples until specific questions arise that require their analysis. It should be borne in mind that the surveillance methods have strengths and limitations, and appropriate, validated techniques are not always available. The considerations to be kept in mind when using biological markers are reviewed in a paper commissioned for this project (Lippmann 1999, abstracted in Appendix A). Samples are needed of (1) environmental samples to document initial levels and changes in concentrations over time; (2) information on unit activities and positions over time, so that these can be correlated with mapping of concentrations of agents; and (3) archives of the information gathered by monitors and detectors. Given that all of this information is of value chiefly in retrospect, the motivation to keep records and properly archive materials might be limited. It would appear wise to consider a moderate demand for such activity, but to act to ensure that that modest task is indeed carried out in a context of enormous pressure and demands for successful completion of the military mission. Medical surveillance and record keeping are discussed more fully in a companion report (IOM 1999). Deployment-Termination Activities DOD should consider the effectiveness and feasibility of collecting biological samples after deployment for comparison with baseline samples. Challenges in compliance are to be expected, given the troops' personal priorities upon returning home, so sufficiently rigorous enforcement of collection would be needed.
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--> Post-Deployment Activities The third and final phase of the overall risk-assessment framework (Figure 6) is the post-deployment phase. This includes the ongoing targeted medical surveillance of deployed veterans to identify late-appearing effects and analyze possible associations of exposure with later health experiences. These activities are discussed in more detail in IOM (1999). The focus here is on the gathering of information that can be fed back to ongoing research on the health and safety risks of deployment. Enough information must be taken and carefully archived to facilitate reconstruction and tracking of troops' exposures over the course of deployment. The degree to which such exposure reconstruction can occur at the level of individuals or at the level of units depends on the amount of detail available in the records. Among the techniques that can be employed are to assess current exposures to groups that may be similarly exposed or exposed to agents with similar properties, to employ modeling of emissions and environmental fate to reconstruct environmental concentration estimates, and to estimate variation in exposure among individual troops through records of tasks and occupations they experienced during deployment together with estimates of typical exposure while conducting those activities. Exposure assessment approaches are discussed further in a companion report (NRC 1999a). In a sense, all post-deployment activity is deployment-specific in that it focuses on examining the history and progress of veterans of particular actions. In another sense, however, it is not specific, in that it should be part of a program of following each person through his or her military career and beyond, maintaining job and exposure histories to track all of the factors that are thought likely to be relevant to health protection and the discovery of hazards. Each person will have been involved in a range of activities, and each person's health experience should be examined in the light of that whole history, integrated over specific episodes, including specific deployments. The issues involved with medical surveillance and record-keeping are further discussed in a companion report (IOM 1999). It seems that possible environmental correlates of disease always bring out alarm-raisers and debunkers, whose public statements can raise public awareness of controversy about the analysis and interpretation of human experience. In view of the objectives of this framework to foster confidence in DOD's reputation as being diligent and responsible in its investigation of the potential causes of health complaints, DOD will have to think carefully about how it will conduct its own surveillance and retrospective analyses and how it will report on these matters to deployed veterans and to the public. Several particular aspects of post-deployment activities are listed below.
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--> Immediate attention to the process of reintegrating troops returning from deployment into their normal military life, and reintegrating veterans into the civilian world, might help deal with some of the psychological strains that have proved to be issues in past deployments. Systematic processes for the collection and archiving of samples and data should be prepared before they are needed, and put into place promptly to receive data from new deployments. Constructing such mechanisms is really a part of ongoing strategic baseline planning, and setting up systems should not be done in an ad hoc way for each deployment case. It is important to establish a follow-up system, so the appropriate retrospective look at the deployment experience gets carried out systematically. Methods should be established to link the ongoing records of the health history of deployed veterans to the deployments that they participated in. Again, this should account for the total history of each person, rather than having records segregated by deployment. The methods should be established permanently rather than set up ad hoc for particular deployments. It is important that DOD take advantage of the data on human experiences with the hazards encountered during deployment and conduct ongoing studies. Unit activities data, archived monitoring data, and environmental and biological samples can be used to reconstruct estimates of doses, and these can be examined for association with disease patterns using epidemiological analyses. Hypotheses generated by these studies can then be examined with new tests and toxicological studies, as appropriate. The points of the above exercises in surveillance and epidemiological analysis are, first, to maintain the ongoing responsibility of the military for the health of its personnel, and second, to learn from past experiences to provide better means for health and safety protection for future deployments. This pursuit can deepen understanding of known threats by adding data from actual experiences. It can in principle help to identify unanticipated threats and call attention to their need for further analysis. All of this information should be fed back to an ongoing process of recognizing and understanding the spectrum of potential threats to the health and safety of deployed U.S. forces. Responsibilities and policy for medical surveillance are given in the 1997 Deployment Medical Surveillance Directive 6490.2. Issues surrounding systematic approaches to post-deployment health surveillance, including the question of how to capture key information to feed back to characterization of incompletely understood health risks, are further discussed in NSTC (1998) and in a companion to the present report (IOM 1999).
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--> Summary and Conclusions Two general approaches could be used to organize a program to improve health protection from hazards that may be encountered in the military environment. One is to organize the risk analysis around hazards. When hazards are recognized, they are characterized and dose-response relationships determined, leading to definition of exposure levels that are deemed acceptable. These acceptable levels are expressed as standards, and activities that might lead to exposures and control measures to limit such exposures can be assessed as to whether they lead to the standards being exceeded, or the costs and effectiveness of various control strategies can be examined and the risks and benefits weighed. This mode of analysis is most appropriate when the nature and magnitude of exposures are well established and predictable, especially when exposures are ongoing. A second approach is to organize the activities not around the hazards per se, but rather around the activities that one wants to conduct. This second broad approach is most appropriate when the activities can entail a number of different hazards, especially those that might or might not arise depending on the unknown future course of events. The activities are examined to improve understanding about the situations when hazards might manifest themselves and the likelihoods that those situations will arise. The exposures themselves are quite uncertain, and the risks of adverse outcomes are as much a product of the likelihood of the events leading to exposures as they are of the likelihood of adverse responses given that exposure occurs. A typical example of this approach is the fault-tree analysis of potential failures of a nuclear power plant, including a range of modes and amounts of releases that might follow different failure events, and the different environment fates of released materials depending on weather conditions at the unknown time of release. In such an analysis, the risk question is more about the probabilities of exposures of different numbers of people than about the health risk to a person given a certain exposure. Moreover, the whole spectrum of kinds of plant failure needs to be considered together, because adverse outcomes can arise in a number of ways. Many of the hazards faced in deployment of U.S. forces are of this latter type, with the assessment of risks depending on the analysis of the uncertain events in exposure scenarios and the contingency on the course of events. Moreover, a key objective is to undertake a systematic evaluation of the sources of potential adverse effects, not simply a scanning of activities and scenarios for potential incidents of unacceptably high exposure to known hazards, and the chief challenge in this task is imagining the circumstances, activities, and agents, perhaps in combination, that
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--> might lead to health and safety concerns and thus require further investigation and analysis. The risk-assessment framework proposed in this chapter is a structured approach to gathering, organizing, and analyzing information in a way that encourages a comprehensive, integrated approach to the analysis of threats to deployed troops. As shown in Figures 1 to 6, the framework is characterized by a variety of component parts in which different types of risk-assessment activities are conducted. The organization scheme provides a rational structure for the overall risk-assessment process so that several things become clearer in the whole scheme: where each component activity falls, how each component contributes to the achievement of the ultimate goals, where each analysis takes its input information from, and where its results are used. In general, the framework can be thought of as a scheme for how DOD can organize a comprehensive and integrated program. The framework is divided into three major categories—ongoing, during deployment, and post-deployment. The ongoing strategic baseline phase covers activities that should be done to prepare for possible future deployments. The first major step is to identify all of the major threats that deployed troops could encounter. The aim is to recognize the array of threats that require further analysis and set them in the context of the activities and settings that prompt them. Several parallel examinations—based on known hazards, notable exposures, and exposures associated with activities and settings directly—should be conducted, and from the combined results of these examinations, an inventory should be created of the agents and exposures and the relative needs for more detailed risk analysis. After identifying potential hazards to deployed troops, the next step is to develop priorities for which hazards have the greatest likelihood of being encountered and pose the greatest threats to the military mission and to troop health. This task should be based on extant information, experience, and judgment to give the military a rough but rational sequence of hazards to assess. When priorities have been set, the tools of risk assessment can be applied to quantitatively characterize the hazards, exposures, and outcomes. At this stage, the projected or estimated release, of exposure given release, of health effects given exposure, of certain scenarios unfolding, and of environmental consequences are all used to develop an overall scheme to identify realistic scenarios for given events. The practice of quantitative health risk assessment is best developed for questions concerning exposure to chemical agents and radiation, but can also be applied to microbial threats. For threats from accidents of various descriptions, actuarial data are the best guide, because a large body of documented experience is available and applicable to future settings. The results of these types of analyses can then
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--> be incorporated into planning, design of doctrine and standard procedures, and training. The framework does not provide a useful way to estimate combat casualties, which must still be derived from experience, military judgment, and the analysis of war-game results. The second major phase of activities occurs when a specific deployment is anticipated. At that stage, the generalized contingency plans developed on an ongoing basis can be refined and made more specific, based on the known location, the type of mission, and current conditions. Once deployment occurs, health and environmental data should be collected, monitored, and archived, if feasible. The data could be used for real-time risk decisions and later reconstruction of exposure scenarios. An important aspect of this step is the identification of exposures and outcomes that were not previously anticipated. Post-deployment risk-assessment activities comprise the third major phase of the framework. In this phase, when troops and reserves are reintegrated back into their garrison or civilian lives, it is important to continue surveillance of veterans' health and to study any uncertain outcomes using exposure reconstruction and epidemiological analyses. Much of the information obtained during this phase can then be used to refine earlier risk analyses and to search for or study threats not previously considered. It is presumed that the various component analyses of the framework will be executed in good faith and interpreted carefully, with full awareness of the possibilities and shortcomings of the available methods. The framework concentrates on how the results of all of these activities can come together, how they can be pursued systematically to ensure that important aspects are not overlooked, and how they become useful in addressing the overall objectives of the larger enterprise. Although the degree to which current DOD activities and programs fulfill the approaches recommended here will be important in implementation of this framework, implementation would not be a simple exercise in checking off components on a list. What makes the framework relevant is not the execution of each of its elements, however competently done, but rather the systematic approach to the process of assessing threats to deployed troops and incorporating the results of each element of analysis into an integrated program that addresses the overall objectives of the troop health-protection program. Only by keeping these ends in mind and continually evaluating the collective effectiveness of the risk-analysis activities in meeting them will the individual component activities play their needed role in the overall program.
Representative terms from entire chapter: