In response to the invasion of Kuwait by Iraq in August 1990, the United States led a coalition of 34 countries, including Australia, Canada, Denmark, France, and the United Kingdom, in a buildup of forces in the Persian Gulf called Operation Desert Shield. This multinational effort was followed by Operation Desert Storm, which began in January 1991 with an air offensive and a 4-day ground war. The war was over by the end of February, and a ceasefire was signed in April 1991. Over the course of the buildup and war, almost 700,000 U.S. troops were deployed to the Persian Gulf region, although by June 1991 only about 50,000 U.S. troops remained in the area. Although brief with relatively few injuries and deaths among the coalition forces, the legacy of the war has been a large contingent of veterans who suffer from a number of health problems that have persisted for more than 25 years.
Prior to and during the Gulf War, the service members who were deployed to the theater of conflict were exposed to many hazardous agents and situations, both known and unknown, many of which were unique to that conflict. Because Iraq had been known to use chemical and possibly biological agents against its own people and others, many service members received mandatory vaccines to prevent anthrax and botulism. Pyridostigmine bromide (PB) was first used as a prophylaxis against potential nerve agent exposure. Previous conflicts had not included exposures to depleted uranium in munitions. Other known exposures ranged from oil-well fire smoke, to dust and excessive heat, to pesticides. While some of these exposures were documented, many were not; the exposures experienced by service members were numerous and highly variable.
During and after the Gulf War, veterans began reporting a variety of health problems, particularly a constellation of symptoms that have been termed Gulf War illness. These symptoms continue to plague as many as one-third of the veterans who were deployed to the Persian Gulf region. Furthermore, these symptoms are seen in veterans from several of the countries that formed the coalition forces. Numerous researchers have studied the variety of health outcomes presented by Gulf War veterans and attempted to identify possible exposures that may have caused or contributed to those outcomes.
This section provides background for the numerous Institute of Medicine (IOM) committees that have attempted to determine what health effects may be expected from the myriad exposures that Gulf War veterans received during their deployments. In particular, it focuses on the environment of the Persian Gulf and the many natural and anthropogenic exposures that the Gulf War veterans, primarily U.S. service members, may have experienced. Some exposures were unique to the Gulf War such as the numerous oil-well fires and their smoke, the release of the nerve agents sarin and cyclosarin, and the use of PB as a prophylaxis for the nerve agents. Other exposures, such as vaccinations against anthrax and botulinum, while uncommon, have been used in other wars, including the recent conflicts in Iraq and Afghanistan. A discussion of the possible health effects of Gulf War service, however, involves many complex issues, some of which are explored below. These issues include exposure to multiple biologic and chemical agents, multiple exposures to those agents, a dearth of environmental sampling data collected during or modeled after deployment, and individual variability factors.
Deployment and Demographics
The buildup for the Gulf War was extremely rapid. Within 5 days after Iraq invaded Kuwait in August 1990, Operation Desert Shield began with U.S. troops moving into the Persian Gulf region. In less than 2 months, more than 150,000 U.S. service members, including nearly 50,000 reservists, were in the region, and in October 1990, another 60,000 troops had arrived in the region followed by an additional 135,000 reservists and National Guard members in November. Of the 697,000 U.S. troops deployed in the Gulf War, the peak number there at any one time was about 560,000. The 1990–1991 Gulf War reflected many changes from previous wars, particularly in the demographic composition of military personnel. Military personnel were, overall, older than those who had participated in previous wars with a mean age of 28 years. Compared with any prior force in U.S. history, those deployed to the Persian Gulf region were also more ethnically diverse; 70% of the troops were non-Hispanic/white; 23% were black, and 5% were Hispanic (Joseph, 1997). They also were comprised of more women (almost 7%), parents, and activated members of the Reserves and National Guard (about 17% or 106,000) who were temporarily uprooted from their civilian lives (VA, 2011).
Combat is widely acknowledged to be one of the most intense experiences that a person can have and may include many threatening situations such as killing or attempting to kill an enemy; being shot at by others; exposure to dead and wounded comrades, enemy combatants, and civilians; and being injured. Although the Gulf War was relatively short and involved few deaths and casualties, there were numerous opportunities for exposure to potentially harmful situations during deployment. These situations included being in the vicinity of Scud missile explosions, contact with prisoners of war, direct combat duty, coming under small-arms fire, having artillery close by (Kang et al., 2000; Unwin et al., 1999), and fear of terrorist or chemical attacks. Many surveys have been conducted to assess Gulf War veterans’ combat experiences and exposures, and in nearly all of them, veterans have reported exposure to a wide variety of threatening or harmful situations during their deployments.
Combat troops were crowded into warehouses and tents upon arrival in the gulf region and then often moved to isolated desert locations. Most troops lived in tents and slept on cots lined up side by side, affording virtually no privacy or quiet. Sanitation was often primitive, with strains on latrines and communal washing facilities. Hot showers were infrequent, the interval between laundering uniforms was sometimes long, and desert flies were a constant nuisance, as were scorpions and snakes. Military personnel worked long hours and had narrowly restricted outlets for relaxation. Troops were ordered not to fraternize with local people, and alcoholic drinks were prohibited in deference to religious beliefs in the host countries. A mild traveler’s type of diarrhea affected more than half of the troops in some units. Fresh fruits and vegetables from neighboring countries were identified as the cause and were removed from the diet. Thereafter, the diet consisted mostly of packaged foods and bottled water.
For the first 2 months of troop deployment (August and September 1990) the weather was extremely hot, with air temperatures as high as 115°F and sand temperatures reaching 150°F. Except for coastal regions, the relative humidity was less than 40%. Troops had to drink large quantities of water to prevent dehydration. Although the summers were hot and dry, temperatures in winter were low, with windchill temperatures at night dropping to well below freezing. Wind and blowing sand made protection of skin and eyes imperative. Goggles and sunglasses helped somewhat, but visibility was often poor.
Deployment to a war zone and combat exposure can result in psychological as well as physical stressors for service members. Rapid mobilization exerted substantial pressure on those who were deployed, disrupting lives and separating families. Uncertainty about the duration of deployment was a continuing concern for U.S. troops during the Gulf War, particularly during the early phases of the buildup. This conflict, unlike the earlier Vietnam War, mobilized large numbers of reserve and National Guard units. For these troops, there was the added uncertainly about whether their jobs would be available when they returned to civilian life (VA, 2011). Although this conflict had better mechanisms for and access to communication with family in the United States, deployment could add to the stress of maintaining family relationships, particularly for reserve and National Guard personnel who may not have deployed with a familiar or cohesive unit.
The veterans also experienced other psychological stressors typically associated with combat and deployment such as uncertainty about the presence of chemical and biological agents, seeing dead or wounded combatants and civilians, and fear of attack by opposition forces. Women and men who deployed to the Gulf War theater in 1990–1991 experienced many of the same exposures and stressors. Although women were not allowed to serve in combat specialties, they were deployed in combat-support roles as administrators, air-traffic controllers, logisticians, ammunition technicians, engineering-equipment mechanics, ordnance specialists, communicators, radio operators, drivers, law-enforcement specialists, aviators, and guards. Still others served on hospital, supply, oiler, and ammunition ships or served as public affairs officers and chaplains (DoD, 2004). Female military personnel were more likely to experience sexual harassment and assault than male personnel (Wolfe et al., 1998). In one survey of deployment experiences, although men and women reported similar exposure to most stressors, women reported more exposure to interpersonal stressors, such as incidents of sexual harassment, and less postdeployment social support. Men reported more mission-related stressors, such as combat experiences (Vogt et al., 2005). The effects of these psychologic stressors are discussed in more depth in Gulf War and Health, Volume 6 (IOM, 2008b).
Environmental and Chemical Exposures
During their deployment to the Persian Gulf, service members had a variety of environmental exposures related to their deployment such as solvents, fumes from kerosene heaters, vaccines, and environmental exposures that resulted from the conflict itself, such as the depleted uranium (DU) used in munitions, excessive heat, and oil-well fire smoke. Some of the exposures were constant such as dust, heat, and pesticides, while other exposures were intermittent or infrequent such as PB or DU.
Oil-Well Fire Smoke
The most visually dramatic environmental event of the Gulf War was the smoke from more than 750 oil-well fires in Kuwait. Smoke plumes from individual fires rose and combined to form giant plumes that could be seen for hundreds of kilometers. As noted in earlier Gulf War and Health volumes, it has been difficult to correlate veterans’ self-reports of exposure to the smoke with dispersion models based on troop location information (IOM, 2006b). Health outcomes associated with exposure to the smoke from the Kuwaiti oil well fires are discussed in Volume 3 of the Gulf War and Health series (IOM, 2005).
Fuels, Combustion Products, and Propellants
There were additional potential sources of exposure to petroleum-based combustion products. Kerosene, diesel, and leaded gasoline were used in unvented tent heaters, cooking stoves, and portable generators. Exposures to tent-heater emissions were not specifically documented, but a simulation study was conducted after the war to determine exposure (Cheng et al., 2001). Petroleum products, including diesel fuels, were also used to suppress sand and dust, and petroleum fuels were used to aid in the burning of waste and trash in open air burn pits. Combustion products may contain many hazardous agents such as polyaromatic hydrocarbons, dioxins, furans, and methane. Health outcomes associated with exposure to the combustion products from the Gulf War region are discussed in Volume 3 of the Gulf War and Health series (IOM, 2005).
Pesticide exposures were widespread among troops in the Persian Gulf region, including flea collars worn by the troops, to combat the region’s ubiquitous insect and rodent populations. Although guidelines for the use of the pesticides were strict, there were many reports of misuse. The pesticides used included methyl carbamates (e.g., proxpur, carbaryl), organophosphates (e.g., chlorpyrifos, diazinon, malathion), pyrethroids, lindane, chlorinated hydrocarbons, and the insect repellant DEET (N,N-diethyl-3-metatoluamide). The use of those pesticides is covered in several reports (for example, DoD, 2001; RAND, 2000), however, objective information regarding individual levels of pesticide exposure is generally not available, and reports by individual veterans as to their use of and possible exposure to pesticides are subject to considerable recall bias. Health outcomes associated with exposure to the insecticides used in the Gulf War are discussed in Volume 2 of the Gulf War and Health series (IOM, 2003).
Solvents and Other Occupational Exposures
Many exposures could have been related to particular occupational activities in the Gulf War. The majority of occupational chemical exposures appear to have been related to repair and maintenance
activities, including battery repair (corrosive liquids), cleaning and degreasing (solvents, including chlorinated hydrocarbons), sandblasting (abrasive particles), vehicle repair (carbon monoxide and organic solvents), weapon repair (lead particles), and welding and cutting (chromates, nitrogen dioxide, and heated metal fumes). In addition, troops painted vehicles and other equipment used in the gulf with a chemical-agent-resistant coating either before being shipped to the gulf or at ports in Saudi Arabia. Working conditions in the field were not ideal, and recommended occupational-hygiene standards might not have been followed at all times. Health outcomes associated with exposure to the solvents used in the Gulf War are discussed in Volume 2 of the Gulf War and Health series (IOM, 2003).
Exposure of U.S. personnel to DU occurred as the result of friendly-fire incidents, cleanup operations, and accidents (including fires). Other personnel might have inhaled DU dust through contact with DU-contaminated tanks or munitions. Assessment of DU exposure, especially high exposure, is considered to be more accurate than assessment of exposure to most other agents because of the availability of biologic monitoring information. Health outcomes associated with exposure to the DU used in the Gulf War are discussed in Volume 1 of the Gulf War and Health series (IOM, 2000) and in Updated Literature Review of Depleted Uranium (IOM, 2008a).
Threat of Chemical and Biologic Warfare
When U.S. troops arrived in the Persian Gulf region, they had no way of knowing whether they would be exposed to biologic and chemical weapons. Iraq previously had used such weapons in fighting Iran and in attacks on the Kurdish minority in Iraq. Military leaders feared that the use of such weapons in the gulf could result in the deaths of tens of thousands of U.S. troops. Prophylactic measures were instituted to help address this uncertainty.
Troops were given blister packs of 21 tablets of PB to protect against agents of chemical warfare, specifically nerve gas; the recommended dosage was one 30-mg tablet every 8 hours. They were to take PB on the orders of a commanding officer when a chemical-warfare attack was believed to be imminent. Chemical sensors and alarms were distributed throughout the region to warn of such attacks. The alarms were extremely sensitive and could be triggered by many substances, including some organic solvents, vehicle exhaust fumes, and insecticides. Alarms sounded often and troops responded by donning the confining protective gear and ingesting PB as an antidote to nerve gas. In addition to the alarms, there were widespread reports of dead sheep, goats, and camels, which troops were taught could be indication of the use of chemical or biologic weapons. The sounding of the alarms, the reports of dead animals, and rumors that other units had been hit by chemical warfare agents caused them to be concerned that they would be or had been exposed to such agents. Fricker et al. (2000) estimated that at least half of the deployed troops took PB pills at some time during their deployments. Health outcomes associated with exposure to PB are discussed in Volume 1 of the Gulf War and Health series (IOM, 2000).
Despite the small numbers of U.S. personnel injured or killed during combat in the Gulf War, the troops, as in any war, faced the fear of death, injury, or capture by the enemy. After the war, there was the potential for other exposures, including U.S. demolition of a munitions storage complex at Khamisiyah, Iraq, which—unbeknownst to demolition troops at the time—contained stores of sarin and cyclosarin. The potential exposures to sarin and cyclosarin from the Khamisiyah incident have been the subject of several modeling and health outcome studies. Depending on the dispersion model used to estimate the sarin and cyclosarin plume and troop unit locations, the number of Gulf War veterans who may have been exposed to the nerve agents ranged from an initial estimate of 10,000 troops within 25 km of Khamisiyah in a 1997 model, to more than 100,000 troops using a 2000 model. However, more than 35,000 troops originally considered to have been exposed and notified that they may have been within the plume were subsequently considered to have been unexposed and 37,000 troops were newly identified as being in the hazard area (IOM, 2006b), adding to the confusion of how many troops were actually exposed to nerve agents and at what levels. As stated in Volume 4, “No medical reports by the US Army Medical Corps at the time of the release were consistent with signs and symptoms of acute exposure to sarin” (IOM, 2006b, p. 28). Health outcomes associated with exposure to sarin and cyclosarin are discussed in Volume 1 of the Gulf War and Health series (IOM, 2000) and in Gulf War and Health: Updated Literature Review of Sarin (IOM, 2004).
U.S. Gulf War troops received standard vaccinations before military deployment, such as cholera, meningitis, rabies, tetanus, and typhoid. In addition, about 150,000 troops received anthrax vaccine and about 8,000 troops received botulinum toxoid vaccine. As noted in Volume 1, “Medical records from the Gulf War contain little or no information about who received these vaccines, how frequently the vaccines were administered, or the timing of vaccinations relative to other putative exposures.” Health outcomes associated with the vaccines given to U.S. troops in the Gulf War are discussed in Volume 1 of the Gulf War and Health series (IOM, 2000).
Although Operation Desert Storm was relatively short, Operation Desert Shield, the buildup of troops and equipment in the Persian Gulf region, and the aftermath of the war went on for many months. Even before the war was over, U.S. and coalition troops began complaining of a constellation of symptoms such as headaches, muscle aches, sleep disturbances, and fatigue. The mix of symptoms and the variability of their severity made it difficult to associate the health problems with a specific cause or exposure prior to or during the service member’s deployment. Upon their return to the United States, many veterans reported their complaints to the Department of Defense (DoD) and the Department of Veterans Affairs (VA). Initial studies indicated that similar symptoms were being experienced by service members from the coalition forces as well. Some veterans began calling their symptoms “Gulf War illness” or “Gulf War syndrome,” and it has become the signature health legacy of the war. Given the numerous symptoms and the multiple exposures, DoD and VA were slow to react to the influx of sick veterans. The persistence of the symptoms and their impact on the veterans’ quality of life prompted veterans and veteran service organizations to seek the assistance of Congress in getting treatment and compensation.
Of the many specific health outcomes that have (or have not) been associated with deployment to the Persian Gulf region, one of the most common adverse effects experienced by Gulf War veterans compared with their nondeployed counterparts is poor general health that results in decreased functioning and quality of life. Virtually all surveys of Gulf War veterans, whether taken shortly after the war or years later, indicate that Gulf War veterans, particularly those with Gulf War illness or PTSD, frequently experience decreased physical and mental functioning and reduced quality of life (Hoptof et al., 2003a; Proctor et al., 2001a; Toomey et al., 2007; Voelker et al., 2002) and that these issues have persisted long after the war (Li et al., 2011a; Sim et al., 2015). Poor health status can have long-term ramifications such as emotional and behavioral problems, which in turn can often lead to social and economic challenges including substance abuse. Assessing the psychosocial problems of Gulf War veterans using latent indicators such as unemployment, family instability, and homelessness may be as important as addressing their health problems (Rao et al., 2009; Robertson, 2008; Walker et al., 2007).
In 1998, in response to the growing concerns of Gulf War veterans, Congress passed two laws: P.L. 105-277, the Persian Gulf War Veterans Act, and P.L. 105-368, the Veterans Programs Enhancement Act. The goals of those laws were to attempt to identify what health outcomes might be expected from the environmental agents to which veterans had been exposed during their deployments, and called on VA to treat those health outcomes. The laws did not mention the presence of a “Gulf War illness,” nor did they require that VA or any other organization determine the cause of the symptoms that veterans were experiencing.
Those laws directed the secretary of veterans affairs to enter into a contract with the National Academy of Sciences (NAS) to review and evaluate the scientific and medical literature regarding associations between illness and exposure to toxic agents, environmental or wartime hazards, or preventive medicines or vaccines associated with Gulf War service and to consider the NAS conclusions when making decisions about compensation. The study was assigned to the IOM, which is now part of the National Academies of Sciences, Engineering, and Medicine.
The Persian Gulf War legislation directs the IOM to study diverse biologic, chemical, and physical agents. Exposures to many of the Gulf War agents have been extensively studied and characterized, primarily in occupational settings (for example, exposure to pesticides, solvents, and fuels), but exposures to others have not been as well studied and characterized in human populations (for example, exposure to nerve agents and oil-well fire smoke).
The Veterans Programs Enhancement Act of 1998 (P.L. 105-368) established the federal Research Advisory Committee on Gulf War Veterans’ Illnesses (RAC). The RAC, which includes researchers who are studying the health of these veterans, clinicians who have treated them, and members of the general public (including veterans), has published several reports on the scientific literature on Gulf War veterans. The most recent report, published in 2014, also includes recommendations for future research efforts on illnesses affecting Gulf War veterans (RAC, 2014).
Institute of Medicine Reports
The IOM has prepared numerous studies on the health of Gulf War veterans. As a result of the 1998 legislation, the IOM has conducted more than 10 Gulf War and Health and related studies to look at the veterans’ exposures identified in the legislation and the health effects that might be associated with those exposures. Given the large number of agents to study, the IOM divided the task into several reports:
- Gulf War and Health, Volume 1: Depleted Uranium, Pyridostigmine Bromide, Sarin, Vaccines (IOM, 2000)
- Gulf War and Health, Volume 2: Insecticides and Solvents (IOM, 2003)
- Gulf War and Health: Updated Literature Review of Sarin (IOM, 2004)
- Gulf War and Health, Volume 3: Fuels, Combustion Products, and Propellants (IOM, 2005)
- Amyotrophic Lateral Sclerosis in Veterans: Review of the Scientific Literature (IOM, 2006a)
- Gulf War and Health, Volume 4: Health Effects of Serving in the Gulf War (IOM, 2006b)
- Gulf War and Health, Volume 5: Infectious Diseases (IOM, 2007)
- Gulf War and Health, Volume 6: Physiologic, Psychologic, and Psychosocial Effects of Deployment-Related Stress (IOM, 2008b)
- Gulf War and Health, Volume 7: Long-Term Consequences of Traumatic Brain Injury (IOM, 2009)
- Gulf War and Health, Volume 8: Update of Health Effects of Serving in the Gulf War (IOM, 2010)
- Gulf War and Health, Volume 9: Long-Term Effects of Blast Exposures (IOM, 2014b)
As part of the Gulf War and Health series, the IOM also prepared the reports Gulf War and Health: Updated Literature Review of Sarin (IOM, 2004), Updated Literature Review of Depleted Uranium (IOM, 2008a), and Treatment for Chronic Multisymptom Illness (IOM, 2013).
Although not part of the Gulf War and Health series, the IOM has prepared other reports on Gulf War veterans. In the 1996 report Health Consequences of Service During the Persian Gulf War: Recommendations for Research and Information Systems, the IOM was asked to review how DoD and VA collected and maintained data on Gulf War veterans and how that data might be used (IOM, 1996). DoD and VA asked the IOM to assess important health issues in Gulf War veterans and design a study to address those issues in the 1999 report Gulf War Veterans: Measuring Health (IOM, 1999). In 2001, the IOM prepared the Gulf War Veterans: Treating Symptoms and Syndromes (IOM, 2001), and in 2012, it was asked by VA to establish a case definition for chronic multisymptom illness (IOM, 2014a), also known as Gulf War illness or Gulf War syndrome. Finally, the National Academies of Sciences, Engineering, and Medicine (NASEM, 2015) recently completed Consideration for Designing an Epidemiologic Study for Multiple Sclerosis and Other Neurologic Disorders in Pre and Post 9/11 Gulf War Veterans.
Beginning with Volume 1 of the Gulf War and Health series, the IOM committees developed a process for assessing the evidence for each study and reaching conclusions regarding the weight of the evidence for each exposure or environmental agent and possible health outcomes. Because each committee was composed of different experts and the exposures varied for each report, each committee made slight modifications to the assessment process. Each committee’s approach is typically discussed at some length in the methods chapter of its report.
Although the first three volumes of the Gulf War and Health series dealt with specific environmental agents, in 2005, VA requested that the IOM appoint a committee to review the medical literature and to summarize what was known about the then current status of veterans’ health. In 2006, the committee produced the report Gulf War and Health, Volume 4: Health Effects of Serving in the Gulf War that summarized the overall health effects in veterans and noted which health outcomes were more evident in veterans who had deployed to the Persian Gulf region compared with their nondeployed counterparts, irrespective of the specific exposures experienced by the deployed veterans. The Volume 8 report was an update of Volume 4, covering the literature published between 2006 and 2009 on the health effects seen in deployed and nondeployed veterans. Volume 10 is a further update of the medical literature on Gulf War veterans’ health from 2009 through 2015.
Department of Veteran Affairs’ Response
In response to each of the IOM Gulf War and Health reports, the secretary of the Department of Veterans Affairs is required to “determine whether or not a presumption of service connection is warranted for each illness, if any, covered by the [NAS] report” (P.L. 105-277). As of July 2011, VA policy (VA, 2015a) stated:
VA presumes certain chronic, unexplained symptoms existing for 6 months or more are related to Gulf War service without regard to cause. These “presumptive” illnesses must have appeared during active duty in the Southwest Asia theater of military operations or by December 31, 2016, and be at least 10 percent disabling. These illnesses include:
- Chronic fatigue syndrome, a condition of long-term and severe fatigue that is not relieved by rest and is not directly caused by other conditions.
- Fibromyalgia, a condition characterized by widespread muscle pain. Other symptoms may include insomnia, morning stiffness, headache, and memory problems.
- Functional gastrointestinal disorders, a group of conditions marked by chronic or recurrent symptoms related to any part of the gastrointestinal tract. Functional condition refers to an abnormal function of an organ, without a structural alteration in the tissues. Examples include irritable bowel syndrome (IBS), functional dyspepsia, and functional abdominal pain syndrome.
- Undiagnosed illnesses with symptoms that may include but are not limited to abnormal weight loss, fatigue, cardiovascular disease, muscle and joint pain, headache, menstrual disorders, neurological and psychological problems, skin conditions, respiratory disorders, and sleep disturbances.
Based on the previous 2006 and 2010 IOM reports, VA has established presumptions for service connection for amyotrophic lateral sclerosis for veterans who have 90 or more days of continuous active military service, for posttraumatic stress disorder if it is associated with an in-service stressful event, and for nine infectious diseases, specifically malaria, brucellosis, Campylobacter jejuni, Coxiella burnetii (Q fever), tuberculosis, nontyphoid Salmonella, Shigella, visceral leishmaniasis, and West Nile virus. None of the other health outcomes associated with exposures experienced during deployment to the 1990–1991 Gulf War, as identified in the IOM Gulf War and Health series, are presumed to have service connection at this time, although veterans may still seek to establish service connection individually for diseases and illnesses associated with their service in the Gulf War.
The charge to the Volume 4 and Volume 8 committees and to the current committee is different from charges to other IOM Gulf War and Health committees in that these three committees were not asked to associate health outcomes with specific biologic, chemical, or other agents believed to have been present in the Persian Gulf region, but rather to examine health outcomes related to deployment to the gulf region as a whole. The specific charge to the current committee, as requested by VA, is to
comprehensively review, evaluate, and summarize the available scientific and medical literature regarding health effects in the 1990–1991 Gulf War veterans. The committee will pay particular attention to neurological disorders (e.g., Parkinson’s disease, multiple sclerosis, amyotrophic lateral sclerosis, and migraines), cancer (especially brain cancer and lung cancer), and chronic multisymptom illness. The proposed study will update earlier IOM reviews on Gulf War and Health, and this volume (Volume 10)
will update the literature since the publication of the 2006 (Volume 4) and 2010 (Volume 8) Gulf War and Health reports. The committee will also provide recommendations for future research efforts on Gulf War veterans.
The committee was not asked to and did not attempt to determine the cause of or treatment for Gulf War illness. The committee also did not concern itself with any policy issues, such as potential costs of compensation or policies regarding compensation, nor did it evaluate VA practices.
The committee began its task by holding two public sessions. At those sessions, the committee heard from representatives of VA and from Gulf War veterans about their health outcomes that have persisted for the past 25 years, particularly the symptoms associated with Gulf War illness. The committee also heard presentations from representatives of the RAC, who discussed that committee’s findings and recommendations and from several researchers who have been studying Gulf War illness. Those sessions helped the committee to put its efforts in context and to clarify an approach to its task.
In addition to the public sessions, the committee conducted extensive searches of the epidemiologic literature published since 2009 (the date of the last literature search for Volume 8) using the same search strategy as that used for Volume 4 and Volume 8. In an effort to be comprehensive, literature searches were also conducted to look for animal models of Gulf War illness or toxicologic (animal) studies where the animals were exposed to a mixture of agents that attempted to simulate those experienced by Gulf War veterans during deployment. Details of the literature search strategy and criteria for selection of relevant studies are discussed in Chapter 2, “Considerations in Identifying and Evaluating the Literature.”
Each of these literature review committees recognized that its members needed to have an appreciation of the Gulf War experience, including the magnitudes of possible exposures for all the armed forces that served in the gulf, including those deployed to the region after the war ended. Therefore, in addition to reviewing studies on U.S. troops, this and prior committees reviewed studies of Gulf War veterans from Australia, Canada, Denmark, France, Kuwait, and the United Kingdom, where available.
To be comprehensive in its approach to the epidemiologic literature, the committee defined its body of evidence to include studies reviewed in Volume 8 (which also assessed those studies cited in Volume 4) and any new studies identified in the literature search or submitted to the committee. Once the committee had considered the studies cited in Volume 8 and evaluated the new studies identified from the updated literature, it also considered whether there were other studies that provided useful background information or otherwise informed the committee’s deliberations. The committee reviewed the entire body of relevant literature using a weight-of-the-evidence approach and determined the strength of the association between being deployed to the Gulf War and a specific health condition. Throughout this process, many tangential but relevant and informative studies were identified, such as those using neuroimaging techniques or genetic markers to assess aspects of Gulf War illness; they are briefly discussed in each relevant section as “Other Related Studies.”
Chapter 2 provides the committee’s methods for choosing and evaluating the epidemiologic and other studies that are reviewed in later chapters and its weight of the evidence approach. Chapter 3 describes the major epidemiologic studies that have been conducted on Gulf War veterans and provides information about the numerous studies that have been derived from them; the chapter includes a summary table
that lists all the original Gulf War veteran cohort studies and their derivative studies. In Chapter 4, the committee considers the many health conditions that have been examined in deployed and nondeployed Gulf War veterans. For each health condition, the committee provides a summary of the literature that was described in Volumes 4 and 8 and any new relevant literature, and comes to a conclusion as to the strength of the association between deployment to the Gulf War and a health condition. Animal toxicity studies that have attempted to look at the etiology, mechanisms, and health outcomes associated with Gulf War exposures are presented in Chapter 5. Finally, in Chapter 6 the committee summarizes its findings with regard to the health of Gulf War veterans and makes recommendations for future research efforts to help diagnose and treat their many health conditions. Chapter 7 contains all the references cited in the previous chapters. Brief biographical sketches of the committee members are provided in the Appendix.
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