Summary

This is the final report of the Committee on Battlefield Radiation Exposure Criteria, produced under the auspices of the Medical Follow-up Agency of the Institute of Medicine, National Academy of Sciences. In it, the committee addresses technical and ethical aspects of military radiation protection and safety policies applicable in instances of the potential exposure of military personnel to radiation doses that are less than those that cause acute effects but that are associated with a long-term risk of subsequent cancers. At the request of the Surgeon General of the U.S. Army, the project's sponsor, the committee focused its interim report (IOM, 1997) on the scientific merit of proposed North Atlantic Treaty Organization (NATO) guidelines for this category of military operations. This final report summarizes the general technical points of the interim report and expands the committee's discussion of the ethical considerations, education, training, and the decisionmaking process involved in initiating appropriate actions when military personnel may be at risk of exposure to radiation doses up to 700 millisievert (mSv). The committee also includes consideration of the evaluation of the long-term health effects of radiation.

In this summary, the committee presents a synopsis of its recommendations in Table S-1; it then proceeds to layout the study's history and a brief outline of material in the interim report. The committee divides the rest of this Summary into three parts. The first section reprints the list of recommendations from the interim report. For discussion of those points, refer to Chapter 5 of the full report. Next, the committee highlights the concepts of justification for imposing risk on others; procedures for optimizing the risk situation to protect soldiers while also meeting military objectives; policies for recording, maintaining, and using dose information regarding individual soldiers; and programs that may be used to identify potential adverse health effects that become apparent long after the exposure. This summary concludes with the five recommendations that the committee presents in the report's final chapter.



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--> Summary This is the final report of the Committee on Battlefield Radiation Exposure Criteria, produced under the auspices of the Medical Follow-up Agency of the Institute of Medicine, National Academy of Sciences. In it, the committee addresses technical and ethical aspects of military radiation protection and safety policies applicable in instances of the potential exposure of military personnel to radiation doses that are less than those that cause acute effects but that are associated with a long-term risk of subsequent cancers. At the request of the Surgeon General of the U.S. Army, the project's sponsor, the committee focused its interim report (IOM, 1997) on the scientific merit of proposed North Atlantic Treaty Organization (NATO) guidelines for this category of military operations. This final report summarizes the general technical points of the interim report and expands the committee's discussion of the ethical considerations, education, training, and the decisionmaking process involved in initiating appropriate actions when military personnel may be at risk of exposure to radiation doses up to 700 millisievert (mSv). The committee also includes consideration of the evaluation of the long-term health effects of radiation. In this summary, the committee presents a synopsis of its recommendations in Table S-1; it then proceeds to layout the study's history and a brief outline of material in the interim report. The committee divides the rest of this Summary into three parts. The first section reprints the list of recommendations from the interim report. For discussion of those points, refer to Chapter 5 of the full report. Next, the committee highlights the concepts of justification for imposing risk on others; procedures for optimizing the risk situation to protect soldiers while also meeting military objectives; policies for recording, maintaining, and using dose information regarding individual soldiers; and programs that may be used to identify potential adverse health effects that become apparent long after the exposure. This summary concludes with the five recommendations that the committee presents in the report's final chapter.

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--> TABLE S-1. Report Recommendations 1. Balancing future and present harm When making decisions, commanders should consider long-term health effects that any action may have on their troops. 2. Philosophy of radiation protection The U.S. Department of Defense (DoD) should develop and clearly express an underlying philosophy for radiation protection, including justification and optimization. 3. Communicating risk Military personnel should receive appropriate training in both radiation effects and protection in a way that neither inappropriately minimizes effects nor creates unwarranted fear. 4. Radiation dosimetry, records, and reporting Troops expected to be in radiation areas should have individual dosimeters. DoD should also maintain exposure records, with strong privacy assurances, and make these available to the exposed individuals. 5. Follow-up Given the tests that are currently available and their limitations, monitoring programs for cancer (whether spontaneous or radiogenic) should be limited to those testing and monitoring programs included in guidelines for the general population. Historical Perspective and Rationale During the Cold War era, NATO and the U.S. Army instituted policies involving radiation dose limits and control measures to be used in the event of global nuclear war. The U.S. Army also has in place a radiation safety and protection program—comparable to civilian occupational protection programs-for personnel involved in routine duties involving possible radiation exposure. In the post-Cold War setting, however, military scenarios involving radiation exposure rarely reflect global nuclear war but more often consider limited nuclear exchanges, terrorist actions with improvised nuclear devices, conventional explosives employed as a means of disseminating radioactive materials, or nuclear power plant accidents. Military operations involving such situations are not covered by either the guidelines designed for nuclear war or the programs in effect for occupational duties. Supreme Headquarters, Allied Powers Europe (SHAPE), recognized a need to plan for potential radiation exposure of military forces in Europe that might occur during the peacekeeping mission in Bosnia. In response, SHAPE staff, with U.S. Army participation, developed the Allied Command Europe (ACE) Directive Number 80-63, ''ACE Policy for Defensive Measures against Low Level Radiological Hazards during Military Operations" (NATO, 1996).

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--> The ACE Directive (NATO, 1996) provides general policy for the conduct of operations in the presence of radiation. It seeks to avoid unnecessary radiation exposure whenever possible and to minimize doses when exposure is unavoidable. The Directive touches on planning, coordination, security, dosimetry, recordkeeping, training, equipment, expertise, and commander responsibilities. It includes a chart (excerpted here from the Directive as Table S-2 and as Table 4-1 in Chapter 4 of this report) that defines radiation exposure state categories and outlines actions to be taken when personnel receive (or are at risk of receiving) specified levels of radiation dose. The operational exposure guidance presented in the Directive was the focus of the committee's interim report. Radiation Physics, Radiation Biology, and Radiation Safety and Protection The first few chapters of this report include basic information about (I) radiation physics and radiation biology, (2) accepted standards of U.S. and international civilian and emergency radiation protection and safety practices, and (3) current U.S. Army radiation program practices. Next, the committee discusses the U.S. Army's approach to addressing issues relating to situations in which troops may be at risk of receiving radiation doses up to as much as 700 mSv in light of standard civilian practices, including the consideration of risk assessment, communication, training, education, commander decisionmaking, reporting, and follow-up. Taken together, these considerations form the building blocks of an ethically based approach to the planning, implementation, and follow-up of operations involving potential radiation exposure. Recommendations from the Interim Report* The committee recommends that the U.S. Army: Underlying Philosophy Provide soldiers the same level of radiation protection as civilians working in similar environments. Develop and state an explicit radiation protection philosophy that defines missions as falling under the framework of either a practice or an intervention. *   An Evaluation of Radiation Exposure Guidance for Military Operations: Interim Report. J.C. Johnson and S. Thaul (eds.). Washington, D.C.: National Academy Press, 1997.

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--> TABLE S-2. Draft (August 2, 1996) Operational Exposure Guidance for Low Level Radiation Total Cumulative Dose (cGy)a Radiation Exposure State Category Stateb Actions [<0.5 mGy] <0.05 cGy 0 No risk   None [0.5-5 mGy] 0.05-0.5 cGy 1A Normal risk   Record individual dose readings Initiate periodic monitoring [5-50 mGy] 0.5-5 cGy 1B Minimal risk   Record individual dose readings and continue monitoring Initiate rad survey Prioritize tasks Establish dose control measures as part of operations [50-100 mGy] 5-10 cGy 1C Limited risk   Record individual dose readings Continue monitoring and update survey Continue dose control measures Execute priority tasks onlyc [100-250 mGy] 10-25 cGyd 1 Increased risk   Record individual dose readings Continue monitoring and update survey Continue dose control measures Execute critical tasks onlyd [250-700 mGy] 25-70 cGye 1 E Significant risk   Record individual dose readings Continue monitoring and update survey Continue dose control measures Execute critical tasks only

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--> a Dose is uniform to the entire body due to whole-body irradiation. This table does not consider the intake of radioactive material. This is assumed because of the employment of effective respiratory protection and other measures. All doses should be kept as low as reasonably achievable (ALARA). This will reduce the risk to the individual soldier and will retain maximum operational flexibility for future employment of exposed soldiers. The use of the measurement millisievert (mSv) is preferred in all cases. However, due to the fact that normally the military has only the capability to measure centigray (cGy), as long as the ability to obtain measurements in millisievert is not possible, ACE forces will use centigray. For whole-body gamma irradiation, 1 cGy is equal to 10 mSv. b Risk is of long-term health consequences, primarily induction of fatal cancer starting 2 years postexposure. Total lifetime risk is assumed to be 4 to 7 percent per 100 cGy (1,000 mSv). This is in addition to the 20 to 25 percent incidence of fatal cancer among the general population. Additional health risks that may occur are teratogenesis and mutagenesis and their associated psychological and social consequences. It must be noted that higher radiation dose rates produce proportionally more other health risk than the same total dose given over a longer period. c Examples of priority tasks are those missions required to avert danger to persons or to prevent damage from spreading. Examples of critical tasks are those missions required to save human lives. d During peacetime this dose shall not be exceeded except to save human lives. e Radiation Exposure State (RES) category 1E covers a wide range of doses and its lower level (25 cGy = 250 mSv) is the peacetime maximum operational dose in many NATO nations. This category is normally applicable only in wartime. Intentional exposures to doses in this category (25 to 70 cGy = 250 to 700 mSv) require additional justification. SOURCE: NATO. ACE Policy for Defensive Measures against Low Level Radiological Hazards during Military Operations. ACE Directive Number 80-63. Brussels, Belgium: Supreme Allied Headquarters Europe, August 2. 1996 (with minor editorial revisions).

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--> Clearly state in the policy paragraph of the subsequent versions of the ACE Directive the definitions adopted for practices and interventions in the necessary military context. Terminology Not use the term low level to describe the radiation dose range of 50 to 700 milligray (mGy) (5 to 70 rad). Use terms other than no risk and normal risk for the risk state categories labeled RES [radiation exposure state] 0 and RES IA in the table of exposure guidance in Annex A of the ACE Directive. Avoid the term radiological hazard when describing the exposure of soldiers to radiation, unless the hazard refers to a specific detrimental effect. Prospective Risk Assessments Develop requirements for measuring, interpreting, and responding to airborne and surface contamination (particularly that containing alpha and beta emitters). Guidance should define levels of alpha and beta contamination that would trigger use of protective equipment and actions. Reconsider its absolute requirement that soldiers wear protective equipment within an exclusion zone as defined in the ACE Directive. Make a clear distinction between military intelligence threat estimates and radiation risk estimates. Develop explicit requirements to define when individual radiation monitoring is required in the field. Dosimetry Review its dosimetry capabilities and determine if they are adequate to support the use of the Operational Exposure Guidance in the ACE Directive. Increase the specificity of the dosimetry program guidelines in subsequent versions of the Directive (e.g., provide specific guidance on the capabilities of monitoring devices and equipment). Not assume, as the ACE Directive does, that internal doses will be zero because respiratory protection will be used. Review its capability to measure airborne radioactive contamination. Expand Operational Exposure Guidance to include radiation doses from both internal and external sources of radiation. These should be expressed in terms of effective dose and be consistent with the requirements of the U.S. Nuclear Regulatory Commission. Adopt the millisievert (mSv) as the standard unit of effective dose and milligray (mGy) as the unit of absorbed dose.

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--> Clearly define the time over which doses are to be accumulated for assignment of RES levels in the Operational Exposure Guidance in Annex A of the Directive. Review and revise doctrine and procedures on dosimetry to ensure that individual doses are monitored and recorded for all soldiers exposed to radiation, whether from routine occupational exposure or as a consequence of uniquely military missions. Reference Levels for Operational Exposure Guidance Include radiation doses from internal sources (e.g., from inhaled airborne radioactivity) in applying reference levels in Operational Exposure Guidance. Clearly specify what actions are recommended at each reference level in the Operational Exposure Guidance. Restructure the table of Operational Exposure Guidance to account for the uncertainty of dose estimates in interventions. Develop separate Operational Exposure Guidance for managing practices (routine tasks involving radiation exposure) in the context of a military operation. Ethical Framework Justifying Placing Individuals at Risk of Harm There is a general ethical principle that one should not put individuals at risk of harm. Exceptions to this principle require justification. There are standard, not mutually exclusive, ways of looking at how to ethically justify placing some at risk for the benefit of others: consent and role-related responsibility. In many circumstances it is considered ethically justifiable to place individuals at risk of harm for the benefit of others if they consent to that imposition. To be ethically valid, the consent must be based on an adequate understanding of the nature and implications of the risk, and the person must be free to refuse. Another way of thinking about risk focuses on role responsibility. Certain roles, like soldiering, carry with them an obligation to bear risk for the benefit of others. There are both voluntary and involuntary assumptions of roles; it does not necessarily follow that because a role was not voluntarily assumed that it does not carry with it some socially acceptable and morally justifiable risk. For example, whether they enlist or are conscripted, all soldiers assume the role-related risks of military service. Justifications of consent and role responsibility do not exhaust the ethical considerations associated with the imposition of risk. Several other ethical conditions must be satisfied.

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--> There must be an analysis that supports, if not demonstrates, that no more risk than is necessary to achieve the goal is being imposed or placed on the individual. This is the optimization principle of radiation protection, implemented by ALARA—as low as reasonably achievable—procedures. In addition, the ethical duty to minimize risk includes taking steps to minimize the likelihood that the risk will materialize into harm. In this context, the duty includes the responsibility for appropriate follow-up of exposed and potentially exposed individuals. Dosimetry, recordkeeping, and medical monitoring all support postexposure efforts to minimize harm. There is the duty to treat with respect the persons being placed at risk. This includes disclosure of the risk to the person both before and after the exposure and maintenance of the privacy of the person who has been put at risk of harm, enabling the individual to have control over access to information about his or her exposure and the uses that others might make of this information. One could provide remedy or compensation for the simple assumption of risk or limit the provision of a remedy only to circumstances when the risk materializes into harm. Finally, there is the set of considerations having to do with justice. Who is to be exposed? Are any of the individuals or groups particularly vulnerable, particularly open to exploitation, or particularly burdened by preexisting harms or risks? How should one weigh deaths or injuries that will occur in the present against deaths or illness that will occur in the future? Does it matter morally if, in choosing the nonradiation threat, the harm would befall only a small number of identifiable soldiers, while, if the choice were radiation exposure, it cannot be known at the time who among those exposed will subsequently suffer the harm'? A few features of the military context further increase the ethical burden on both commanders and the government with respect to soldiers. Commanders have much more authority over soldiers than civilian employers have over their employees. Members of the military are obligated to follow all lawful orders, even those that put them at risk of death or disability. Medical and related records (including radiation exposure information) are vital to ensuring that ethical consideration of possible radiation injury has been taken into account in addressing the military objective. Training, Recordkeeping, and Reporting Throughout the report, the committee discusses the topics of training, recordkeeping, and reporting in sequence. In a good radiation protection program all three must be intricately interwoven. Training should impart some basic understanding of radiation, communicate the risk, help the soldier to understand the ramifications of risk perception, and then place that knowledge in a context whereby the risks associated with radiation exposure can be compared with other radiation- and non-radiation-related risks. These comparisons should be tested both by experts in risk communication and with groups of laypeople to ensure that the

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--> information is understandable and not misleading. The soldier then can draw upon this foundation to (1) protect himself or herself and others during an exposure situation, (2) know which pieces of information are important to obtain and record, (3) act to notify whomever should know about exposures or effects, and (4) use his or her own dose report to help guide his or her own future occupational, avocational, and health care activities. In addition, through training, the military attempts to teach commanders how to decide when it is appropriate to put subordinates at risk (justification) and how to do so to minimize short- and long-term harm while also achieving the military mission (optimization). Therefore, training content includes conveying the value of information (e.g., records are important and notification of personnel is important) and the lesson that recordkeeping and notification procedures are valuable only if the soldier knows (through training) what to measure and how to do so, what to record, and what to do with that information once it is recorded. The common thread is communication. Accurate and appropriate information must be maintained so that it is available to be given to the right people at the right time. Furthermore, this communication must be exercised within an ethical framework in which the government seeks to meet its military objectives, protect the health of military personnel, and take responsibility for the health consequences of its decisions. Information is vital to sustaining protection. When existing technology allows detection of radiation exposures, advance notice of potential radiation exposures is the goal. When feasible, radiation levels should be monitored in settings of suspected exposure. The levels of radiation that may involve short- or long-term risks need to be predetermined. Chains of command should be prepared to disseminate radiation warnings quickly and efficiently. If possible, soldiers should be equipped with devices that detect levels of radiation in the operational field in cases in which significant radiation exposure is expected. They should be fully knowledgeable of the operation of these devices and interpretation of the readings displayed by these devices. Since the U.S. military is also the employer of the soldier, the military has an independent obligation to the volunteer to minimize the risks as much as reasonably possible. This can be done in a number of ways, including planning, the use of protective equipment, and the exploration of less risky alternatives. In addition to the requirement that the U.S. Department of Defense (DoD) maintain radiation exposure data on all its potentially exposed personnel, the committee strongly recommends that each military member so exposed be provided annually, and on termination of military service, a written document specifying the magnitude of each exposure (if possible) and the location(s) of such exposure(s) during service. A copy of this information can then be made available to the U.S. Department of Veterans Affairs for future determination of disability connected to service in the military and follow-up medical care if required. If possible, the exposure data notification document should include both a listing of the agents to which the person was exposed (e.g., radiation, chemicals, biological exposures, conventional injuries, and stressful situations) and a

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--> general statement of the potential health consequences related to those exposures. The quality of the information provided will vary depending on whether the military operation was during war or peacetime, with more detail expected during peacetime activities. With current equipment and personnel capabilities, the Army cannot fully implement the recommendations in this report. However, as the Army prepares and implements new policy it should bear in mind the recommendations as well as the broader discussion of issues in this report. Committee Recommendations The Surgeon General of the U.S. Army requested guidance on the management of military operations in which radiation effective doses might range up to 700 mSv. The committee has formulated recommendations that cover a number of areas. Some of these areas have already been addressed by the military but are included because they are important and the report would not be complete without their consideration. Balancing Future and Present Harm Current doctrine and risk evaluation by military commanders focus on acute injuries and fatalities and those factors which potentially affect the ability to achieve a military objective. The U.S. Department of Veterans Affairs deals with long-term health effects and disability. A focus on acute health effects from any cause is still largely appropriate for hostile situations, but it discounts or ignores long-term detriment and is inappropriate for less emergent situations in which the military may be asked to participate. The U.S. Army asked the committee to consider doses of less than 7(X) mSv. Although no significant acute effects are expected to result from such radiation doses, excess risks of many types of cancer and leukemia have statistically significant associations with doses in this range. Although the long-term effects of radiation are relatively well known, the long-term detriment associated with other exposures or potential exposures, such as psychological stress, are less well understood and quantified. The committee thinks that these should not be ignored. RECOMMENDATION 1: When making decisions, commanders should consider the long-term health effects that any action may have on their troops. This should become standard operating policy. In addition, the Department of Defense should attempt to quantify long-term detriment from a number of causes, including radiation, and develop training material and scenarios that address these effects.

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--> The long-term effects to be considered in operational decisions should include not only those from radiation but also those from conventional injuries, chemical and biological agents, and psychological stress. Philosophy of Radiation Protection A philosophy for dealing with any potential harm should be clearly stated, widely disseminated, ethically based, practical, and comprehensive. This will allow commanders to make informed decisions and be flexible rather than having to deal with prescribed limits when they may be inappropriate or impractical. This philosophy should be focused on minimizing the risk of harm while allowing the performance of the required military objective. There are clearly situations in which radiation exposure is justified because the risk of radiation-induced harm is less than the risks from other hazards associated with the action. A policy that completely avoids radiation exposure is inappropriate and may expose troops, and perhaps others, to larger risks of harm from other, nonradiation, causes. RECOMMENDATION 2: The U.S. Department of Defense should develop and clearly express an underlying philosophy for radiation protection. A.   The committee suggests application and adaptation of the system recommended by the International Commission on Radio logical Protection. This system includes practices as well as interventions. These are required to be initially justified (more benefit than risk) and then optimized (minimization of dose) in the context of the situation. B.   The committee recommends that in peacetime or nonemergent situations soldiers should be accorded the same level of protection accorded civilians. Those soldiers who may be exposed to radiation dose levels similar to those to which civilian radiation workers are exposed should have the same level of training as civilian radiation workers and should be subject to occupational dose limits. C.   In settings in which an intervention is required and specific numerical dose limits are neither applicable nor practical, the committee recommends that commanders justify the mission (there is more benefit than risk), examine competing risks, and optimize

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--> the mission (identify ways to minimize dose without jeopardizing the mission). Examples of these settings include emergent or lifesaving actions, actions to prevent exposure of large populations, and hostile situations. Communicating Risk Training and risk communication are extremely important not only so the troops can adequately achieve their objective but also so they can understand the risks and protect themselves. RECOMMENDATION 3: Military personnel should receive appropriate training in both radiation effects and protection. Their training will need to vary on the basis of the particular level of potential exposure and upon the task at hand. Training may range from task-specific operational briefings to full courses, depending upon the situation. Well-crafted, realistic scenarios should be incorporated into training at all levels. Potential long-term health consequences from radiation exposure should be included in the discussion of risks. The training should put radiation effects in perspective in language that the troops can understand but not in a way that inappropriately minimizes the effects or creates unwarranted fear. When long-term risks of harm from sources other than radiation are largely unknown, this should be stated. Regardless of current NATO policy, DoD should avoid using the terms low risk or no risk in training and briefings when radiation levels clearly carry a measurable cancer risk. Radiation Dosimetry, Records, and Reporting For risk management during and after a mission, it is important to estimate or quantify current and past exposures. This is optimally done through the use of radiation detection devices, environmental sampling, personnel dosimeters, bioassays, and, possibly, whole-body counting. Even in certain hostile situations when all of these may not be possible, estimates of exposure conditions and dose can still be made. Such information should be available to military personnel during active duty and after discharge.

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--> RECOMMENDATION 4: A program of measurement, recording, maintenance, and use of dosimetry and exposure information is essential. A.   Troops expected to be in areas where there is a risk of radiation exposure should have individual dosimeters. B.   Systematic individual radiation dose records—for external and internal doses—should be maintained and should follow the soldier from one operational unit to another should be kept. C.   A system that includes the capability to field monitor, and estimate or measure and then record internal doses needs to be developed. When appropriate, organ-absorbed doses should be recorded in addition to the effective dose. D.   The U.S. Department of Defense should also maintain exposure records in a confidential manner that contains strong privacy assurances. Records should be kept in a secure form and should be available to the individual. E.   Annually and upon deactivation or discharge, potentially exposed military personnel should be given a written record of their radiation exposures with estimated doses (annual and cumulative), even if they are zero. This should be separate from any administratively required occupational recording and notification. There should also be an explanation of the implications of these radiation exposures for future health outcomes. Even if an operation is classified, there is still a need to provide such information. Follow-Up The exposure of troops to agents and situations that may have long-term health effects raises the issue of whether there is any appropriate medical monitoring (screening) that will detect such effects before they are evident clinically and that may positively affect disease progression or outcome. The primary effect in the cumulative radiation dose range that the committee considers in this report is an excess risk of certain types of cancer and leukemia. Unfortunately, at this time only a few screening tests are clearly effective; these tests are used

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--> to detect breast, cervical, and colon cancers. Physician-directed individual diagnostic testing may be useful in selected situations, particularly when the radiation absorbed doses are extremely high. It should be noted that cancer currently occurs in about 40 percent of the U.S. population (NCI, 1994). For doses in the highest dose range addressed in this report (500-700 mSv), the increased risk of cancer attributable to the radiation dose is about 1/10 the normal baseline cancer incidence rate for unexposed individuals. Although this is a low percentage, a large number of troops exposed at these doses could result in a large number of excess cancers. RECOMMENDATION 5: Given the tests that are currently available and their limitations, testing and monitoring programs for cancer (whether spontaneous or radiogenic) should be limited to those testing and monitoring programs included in guidelines for the general population. Specific periodic screening or medical monitoring of radiation exposed populations is not warranted solely on the basis of the radiation exposure in the dose range considered in this report. If effective tests for other cancer types do become available, screening may be useful on the basis of the normal cancer incidence in the general population. For persons who have received cumulative effective doses in excess of 50 mSv, the establishment of well-designed and dynamic registries may be helpful in addressing future health-related issues on an individual or population basis.