April 11, 1997
CRS Report for Congress
Received through the CRS Web
Gulf War Veterans' Illnesses
C. Stephen Redhead
Analyst in Biomedical Sciences
Science Policy Research Division
In 1990 and 1991, approximately 697,000 U.S. troops were deployed in the Persian
Gulf during Operations Desert Shield and Desert Storm. The United States suffered
relatively few casualties during the brief air and ground war against Iraq. Since returning
home, however, many veterans have developed illnesses that appear to be related to their
military service in the Gulf. Researchers caution that it may be impossible to identify the
causes of these illnesses because of the absence of baseline data on the health of military
personnel and the lack of reliable exposure data. This report provides concise answers
to a series of questions concerning Gulf War veterans' illnesses, based on currently
available scientific information.
Although the war against Iraq lasted only six weeks, U.S. troops experienced an
usually stressful environment and were exposed to numerous known and potential health
risks in addition to limited combat. These included temperature extremes, blowing dust
and sand, smoke from oil well fires, petroleum fuels and their combustion products,
pyridostigmine bromide to protect against nerve gas, anthrax and botulism vaccines,
depleted uranium used in artillery shells, pesticides, chemical warfare agents, and pervasive
psychological and physiological stress.
Many Gulf War veterans developed debilitating illnesses soon after returning to the
United States. Commonly reported symptoms included fatigue, muscle and joint pain,
memory loss, and severe headaches. Although a majority of ill veterans have been
diagnosed with a recognized disease, a significant number of veterans remain undiagnosed.
The array of symptoms reported by Gulf War veterans is popularly known as "Gulf War
Syndrome," which suggests the existence of a new disease or syndrome related to military
service in the Gulf. However, several expert panels have found no evidence of a new or
unique Gulf War–related disease. Sick veterans appear to be suffering from multiple
illnesses with overlapping symptoms and causes that are likely to be connected to their
Gulf War service.
Congressional Research Service ˜ The Library of Congress
The Departments of Defense (DOD) and Veterans' Affairs (VA) have taken several
steps to address Gulf War veterans' illnesses, including establishing medical programs to
identify and treat sick veterans, providing disability compensation to veterans with
undiagnosed illnesses, and conducting research on the prevalence, nature, and possible
causes of their illnesses. In June 1996, the DOD reversed its position on chemical
exposure by announcing that as many as 20,000 troops may have been exposed to nerve
gas when a battalion of engineers blew up the Khamisiyah ammunition depot in southern
Iraq in early March 1991. Until last summer, the DOD had maintained that there was no
compelling evidence of exposure to or detection of chemical warfare (CW) agents. On
April 9, amid growing tension and charges of a cover-up, the Central Intelligence Agency
(CIA) released a report showing that the agency had solid intelligence in 1986 that
thousands of chemical weapons had been stored at Khamisiyah. However, the CIA failed
to include the depot on a list of suspected CW sites provided to the Pentagon before the
war. The CIA warned the Army of the possible presence of chemical weapons at
Khamisiyah just days before the depot was blown up, but the information was not relayed
to the engineers who carried out the detonations.
What Types of Symptoms Have Gulf War Veterans Presented?
In August 1992, the VA established a Persian Gulf Health Registry to provide clinical
evaluations and treatment for military veterans who served in the Gulf. In June 1994, the
DOD established a similar program, the Comprehensive Clinical Evaluation Program
(CCEP), for Gulf War veterans still on active duty. As of October 1996, approximately
62,000 veterans had been examined in the VA Registry, and more than 34,000 active duty
personnel had requested examinations in the CCEP. Roughly 10% of participants had no
detectable symptoms, and many others reported minor complaints. The symptoms most
frequently reported by participants in both programs include fatigue, headache, muscle and
joint pains, and memory loss. The majority of Registry and CCEP participants have been
diagnosed, but approximately 18% of CCEP participants and 20% of Registry participants
are undiagnosed and listed as having "ill-defined symptoms and signs."
How Many Gulf War Veterans Are Ill?
Researchers do not yet know the full extent of illness among Gulf War veterans. The
VA Registry and CCEP were designed as clinical rather than research programs, and the
data cannot be generalized to the entire population of Gulf War veterans. Participants in
both the Registry and CCEP are self-selected, symptoms and exposures are self-reported,
reported exposures cannot be validated, and there is no comparable control group.
Epidemiologic studies designed to answer questions about the prevalence,
distribution, and causes of illness among Gulf War veterans are underway and will
continue for years. A recent study found a significantly higher death rate among Gulf War
veterans between May 1991 and September 1993, compared to a group of military
personnel who were not deployed in the Gulf.1 However, the excess mortality was due to
accidents, especially motor vehicle accidents, and not disease. This study indicates that
if there are excess illnesses among Gulf War veterans, they do not appear to have been life-
Kang, H.K. and Bullman, T.A. Mortality Among U.S. Veterans of the Persian Gulf War.
New England J. Medicine, v. 335, Nov. 14, 1996. p. 1498.
threatening. A second study examined military hospital records of 547,000 Gulf War
veterans who remained on active duty in the two years following the war.2 It found no
excess of unexplained hospitalization among Gulf War veterans, compared to veterans of
the same era.
Several studies of small clusters of Gulf War veterans have confirmed the presence
of a variety of sometimes debilitating symptoms. A recent study of a representative sample
of all Gulf War veterans in Iowa found a significant excess of physical and psychological
symptoms, compared to Iowa military personnel who were deployed elsewhere.3 These
symptoms were more common among Gulf War veterans who reported exposure to
various chemical agents than among those who reported no such exposure. A limitation
of all these studies is that symptoms and exposures are self-reported and therefore subject
to recall bias.4
Are Gulf War Veterans From Other Nations Reporting Similar Illnesses?
Approximately 1,200 of the 45,000 British troops deployed in the Gulf have reported
symptoms similar to those reported by U.S. Gulf War veterans. The British government
has established a clinical evaluation program and appointed an independent panel to
investigate its veterans' concerns. Smaller numbers of Canadian veterans have also
reported the same types of symptoms. However, French veterans have not complained of
Gulf War–related illnesses, despite extensive publicity about veterans' concerns in Britain
and the United States.5
Gray, G.C. et al. The Postwar Hospitalization Experience of U.S. Veterans of the Persian
Gulf War. New England J. Medicine, v. 335, Nov. 14, 1996. p. 1505.
The Iowa Persian Gulf Study Group. Self-Reported Illness and Health Status Among
Persian Gulf Veterans. J. Amer. Med. Assoc., v. 277, Jan. 15, 1997. p. 238.
Landrigan, P.J. Illness in Gulf War Veterans: Causes and Consequences (Editorial). J.
Amer. Med. Assoc., v. 277, Jan. 15, 1977. p. 259.
Darkness at Noon. Economist, Jan. 11, 1997. p. 71.
What Are the Possible Causes of Veterans' Illnesses?
The Presidential Advisory Committee (PAC) on
Gulf War Veterans' Illnesses examined exposure and,
independently, expected health effects for ten risk
factors (see box). In its December 1996 report, the
PAC concluded that the objective exposure data on
these risk factors are extremely limited. Information
on exposure is largely based on anecdotal
recollections of veterans, which makes it difficult to
establish scientifically a link between illnesses and
specific risk factors. Even in the absence of
exposure data, the PAC determined that most of the
risk factors evaluated are "unlikely to be associated
with the health problems currently reported by Gulf
Gulf War Risk Factors
Biological warfare agents
Chemical warfare agents
Smoke from oil well fires
As expected from experiences in previous wars, a significant number of veterans have
stress-related psychological conditions, such as post-traumatic stress disorder (PTSD) and
depression. Stress is also known to cause serious physical illnesses, and some Gulf War
veterans report stress-related symptoms, including fatigue, headache, sleep problems, and
loss of appetite. The PAC concluded that stress "is likely to be an important contributing
factor to the broad range of physical and psychological illnesses currently being reported
by Gulf War veterans."
Were the Troops Exposed to Chemical Warfare Agents?
Based on its review of all the available information, including operational and
intelligence logs, and reports from DOD and United Nations officials, the PAC concluded
that there is "overwhelming" evidence that CW agents were released during aerial
bombings of the storage depot at Khamisiyah. Low-level exposure of troops within a 50kilometer radius of the depot should therefore be presumed while efforts to collect more
precise exposure data continue. The PAC also stated that other site-specific exposures
cannot be ruled out, but it concluded that "the best evidence available indicates that
theater-wide contamination with [chemical warfare] agent fallout from the air war is highly
Presidential Advisory Committee on Gulf War Veterans' Illnesses.
Washington, U.S. Govt. Print. Off., 1996.
In May 1994, the staff of the Senate Banking Committee released a report based on
numerous first-hand accounts and other anecdotal information that provided evidence of possible
widespread exposure to chemical warfare (CW) agents. James Tuite, the report's lead investigator,
has also compiled information on aerial bombings of Iraq's chemical weapons factories and storage
sites. Using satellite weather photographs taken during the bombings, he argues that tons of nerve
gas rose in a thermal plume that drifted south over the entire theater of operations. According to
Tuite, that would explain the detections by Czech chemical weapons experts deployed in northern
Saudi Arabia at the time, and the numerous CW alarms that sounded in U.S., British, and French
Is Exposure to Chemical Agents the Cause of Veterans' Illnesses?
The PAC report concluded that it is "unlikely" that veterans' illnesses are the result
of exposure to CW agents. Those agents are extremely toxic, and exposure to small
amounts produces immediate (i.e., acute) and characteristic symptoms of poisoning.
Numerous animal and human studies indicate that long-term (i.e., chronic) neurological
effects may develop after recovery from acute poisoning. However, DOD's medical
monitoring and surveillance efforts reported no cases of acute nerve gas poisoning among
U.S. military personnel during the Gulf War.
Many ill veterans claim that they were exposed to extremely small amounts of nerve
gas, which went unrecognized at the time of exposure. The PAC concluded, however,
that the very limited available scientific evidence suggests that so-called subclinical
exposure to CW agents does not result in chronic neurophysiological or
neuropsychological health effects.
Are DOD and the VA Providing Medical Care to Ill Veterans?
The VA Registry and CCEP (see page 2) provide clinical evaluation and treatment,
free of charge, to any Gulf War veteran. Both programs use the same clinical protocol,
which includes a medical history, thorough physical examination, laboratory tests, and
standard questions regarding possible exposures. The VA refers veterans with
undiagnosed symptoms to one of four designated medical centers in Washington, DC,
Houston, TX, Los Angeles, CA, and Birmingham, AL. The DOD established a specialized
care center at Walter Reed Army Medical Center in Washington, DC, to evaluate and treat
Gulf War service members with chronic debilitating symptoms.
Veterans are particularly concerned about the impact of Gulf War military service on
reproductive health outcomes (e.g., infertility, birth defects). Whereas active duty
personnel and their family members have access to comprehensive reproductive health-care
benefits, the VA has extremely limited authority to provide such medical care and
counseling to veterans. Both the VA and DOD have implemented innovative programs
to help veterans cope with combat-related stress.
What Kind of Research is Underway?
The Departments of Defense, Veterans' Affairs, and Health and Human Services,
through the Persian Gulf Veterans' Coordinating Board, have established a comprehensive
research program. To date, more than 100 projects have been funded, including several
epidemiologic studies at the Naval Health Research Center in San Diego, CA (see footnote
2). Clinical and laboratory research priorities include the possible long-term health effects
of low-level exposure to CW agents; the long-term health effects of stress; and the
potential long-term health effects of combinations of vaccines, pyridostigmine bromide,
and other chemical agents.
units during that period.
The DOD plans to spend about $27 million on Gulf War–related health research in
FY1997. In October 1994, the VA established three Environmental Hazard Centers in
Portland, OR, East Orange, NJ, and Boston, MA, to support interdisciplinary
collaborations between VA and academic scientists. A fourth center was launched recently
at the VA medical center in Louisville, KY, to focus on the impact of environmental
hazards on reproduction and development.
Are Veterans Receiving Disability Compensation?
In 1994, Congress enacted legislation allowing the VA to pay compensation benefits
to veterans for Gulf War–related disabilities caused by undiagnosed illnesses.8 Under
regulations issued in February 1995 (38 CFR 3.317), a veteran can be compensated only
for undiagnosed illnesses that manifest themselves during Gulf War service or arise within
two years of departing from the Gulf. Veterans must provide objective evidence of
chronic illness and be at least 10% disabled. However, as of January 1997, the VA had
denied 9688 (93.5%) of the 10,357 undiagnosed illness claims that had been reviewed.
Approximately 55% of the denied claims were rejected because the illness did not manifest
itself until after the two-year presumptive period.
Acting on a recommendation from VA Secretary Brown, President Clinton last month
extended the presumptive period by eight years, until December 31, 2001. The VA plans
to re-evaluate the claims that were denied on the basis of a two-year presumptive period
to determine if they now qualify for compensation under the extended period. Many Gulf
War veterans have received compensation for diagnosable service-connected illnesses and
injuries that accompanied their undiagnosed illness claims. As of January 1997,
approximately 27,000 Gulf War veterans had been awarded disability compensation for
diagnosed conditions such as hypertension, hearing loss, or knee disorders.
The health concerns of Gulf War veterans have been compared to those of Vietnam
veterans, who for years have voiced concern about the long-term health impact of
exposure to the defoliant Agent Orange. But there is a crucial difference between
environmental exposures in the two conflicts. Researchers studying Vietnam veterans
have been able to estimate Agent Orange exposure by measuring dioxin levels in tissue
samples. In the case of the Gulf War, none of the chemicals to which U.S. troops were
exposed appears to remain in the body for any appreciable length of time. Therefore,
researchers cannot measure exposure directly and must instead rely on self-reported
exposure information and exposure estimates from unit-level troop location data. These
types of data are subject to so much bias and error that they are of limited use in
epidemiologic studies. Because of the lack of reliable exposure data, many of the health
concerns of Gulf War veterans are unlikely to be resolved. The lack of baseline medical
data on the troops prior to deployment further adds to the difficulties that researchers face.
Persian Gulf War Veterans' Benefits Act, P.L. 103-446, Nov. 2, 1994. This legislation was
unprecedented because in the past the VA had always required that compensation be based on
clearly diagnosed diseases (e.g., cancer).
Research into the causes of Gulf War veterans illnesses has also been hindered by the
DOD's failure to investigate thoroughly possible exposures of U.S. troops to CW agents.
The PAC criticized DOD's investigations to date as being "superficial and unlikely to
provide credible answers to veterans' and the public's questions." The delay in releasing
evidence of site-specific, low-level CW exposures has adversely affected decisions about
research priorities and funding. Since last summer's disclosures about Khamisiyah, the
DOD has revised substantially its investigatory and research programs related to CW
exposure. While many veterans have illnesses likely to be connected to their service in the
Gulf, current scientific evidence does not support a causal link to any of the environmental
risk factors that have been investigated. Some individuals would have become ill during
the past six years whether or not they served in the Gulf. Others are suffering from
illnesses related to the extremely stressful conditions in the theater. Continued analysis of
Registry and CCEP data may reveal clusters of disease linked to specific exposures that
warrant further investigation.9
The VA recently announced the results of a preliminary analysis of 81 registry participants
who were involved in blowing up the Khamisiyah depot or were in the immediate area during the
detonations. These troops did not report an unusual amount of chronic illness compared to all
registry participants, with one exception. About 28% of the 81 Khamisiyah veterans reported
muscle and joint pains, compared to 17% of registry participants as a whole.