Gas May Have Harmed Troops,
By IAN URBINA
Published: May 17, 2007
WASHINGTON, May 16 — Scientists working with the
Defense Department have found evidence that a
low-level exposure to sarin nerve gas — the kind
experienced by more than 100,000 American troops in
the Persian Gulf war of 1991 — could have caused
lasting brain deficits in former service members.
Though the results are preliminary, the study is
notable for being financed by the federal government
and for being the first to make use of a detailed
analysis of sarin exposure performed by the
Pentagon, based on wind patterns and plume size.
The report, to be published in the June issue of the
journal NeuroToxicology, found apparent changes in
the brain’s connective tissue — its so-called white
matter — in soldiers exposed to the gas. The extent
of the brain changes — less white matter and
slightly larger brain cavities — corresponded to the
extent of exposure, the study found.
Previous studies had suggested that exposure
affected the brain in some neural regions, but the
evidence was not convincing to many scientists. The
new report is likely to revive the long-debated
question of why so many troops returned from that
war with unexplained physical problems. Many in the
scientific community have questioned whether the
so-called gulf war illnesses have a physiological
basis, and far more research will have to be done
before it is known whether those illnesses can be
traced to exposure to sarin. The long-term effects
of sarin on the brain are still not well understood.
But several lawmakers who were briefed on the study
say the Department of Veterans Affairs is now
obligated to provide increased neurological care to
veterans who may have been exposed.
In March 1991, a few days after the end of the gulf
war, American soldiers exploded two large caches of
ammunition and missiles in Khamisiyah, Iraq. Some of
the missiles contained the dangerous nerve gases
sarin and cyclosarin. Based on wind patterns and the
size of the plume, the Department of Defense has
estimated that more than 100,000 American troops may
have been exposed to at least small amounts of the
When the roughly 700,000 deployed troops returned
home, about one in seven began experiencing a
mysterious set of ailments, often called gulf war
illnesses, with problems including persistent
fatigue, chronic headaches, joint pain and nausea.
Those symptoms persist today for more than 150,000
of them, according to the Department of Veterans
Affairs, more than the number of troops exposed to
Advocates for veterans have argued for more than a
decade and a half that a link exists between many of
these symptoms and the exposure that occurred in
Khamisiyah, but evidence has been limited.
The study, financed by the Department of Veterans
Affairs and the federal Centers for Disease Control
and Prevention, is the first to use Pentagon data on
potential exposure levels faced by the troops and
magnetic resonance imaging to scan the brains of
military personnel in the exposure zone. It found
signs of brain changes that could be due to
exposure, showing that troops who had been exposed
at higher levels had about 5 percent less white
matter than those who had little exposure.
White matter volume varies by individual, but
studies have shown that significant shrinkage in
adulthood can be a sign of damage.
The study was led by Roberta F. White, chairman of
the department of environmental health at the Boston
University School of Public Health. Dr. White and
other researchers studied 26 gulf war veterans, half
of whom were exposed to the gases, according to a
Defense Department modeling of the likely chemical
makeup and location of the plume. The researchers
found that troops with greater potential exposure
had less white matter.
In a companion study, the researchers also tested
140 troops believed to have experienced differing
degrees of exposure to the chemical agents to check
their fine motor coordination and found a direct
relation between performance level and the level of
potential exposure. Individuals who were potentially
more exposed to the gases had a deterioration in
fine motor skills, performing such tests at a level
similar to people 20 years older.
Dr. White says this study and the results of
research from other studies provide “converging
evidence that some gulf war veterans experienced
nervous system damage as a result of service, and
this is an important development in explaining gulf
Phil Budahn, a spokesman for the Department of
Veterans Affairs, said the research required further
“It’s important to note that its authors describe
the study as inconclusive,” Mr. Budahn said, adding,
“It was based upon a small number of participants,
who were not randomly chosen.”
Dr. White said she did not describe her study as
inconclusive, though she said it would be accurate
to call it preliminary.
Lea Steele, a Kansas State University epidemiologist
and the scientific director of the veterans
department’s advisory committee on gulf war
illnesses, said she thought the study was extremely
important. Dr. Steele said that gulf war illnesses
had been described by their symptoms, but that until
now scientists had struggled to find physiological
conditions that corresponded with those symptoms.
But the new research, Dr. Steele said, used
previously nonexistent brain scanning technology to,
essentially, “look into the brain to evaluate the
difficult-to-characterize problems affecting gulf
Thus, she said, it is “the first to demonstrate
objective indicators of pathology in association
with possible low-level sarin-cyclosarin exposures.”
Dr. Daniel J. Clauw, professor of medicine and
director of the Chronic Pain and Fatigue Research
Center at the University of Michigan, said that
while the study indicated that the veterans had not
imagined their illnesses, more research was needed.
“Future studies need to compare the results of brain
scans of gulf war veterans with individuals with
chronic pain and other symptoms who were not
deployed to the gulf war before concluding that any
changes are due to wartime exposures,” Dr. Clauw
For more than five years after the explosions at
Khamisiyah, the Pentagon denied that any American
military personnel had been exposed to nerve gas.
Confronted by new evidence in 1996 and 1997, it
acknowledged that up to 100,000 troops might have
been in the path of the plume and exposed to
low-level doses that produced no immediate effect.
In 2002, it released a report saying the exposures
had been too low to have caused a long-term adverse
effect on health.
Now, the government is straining to handle the
health and rehabilitation needs of soldiers
returning from the current wars in Iraq and
Afghanistan, and lawmakers say they are concerned
that veterans facilities will soon need to provide
brain scans and treatment to soldiers from the 1991
war who learn of the new research.
On May 2, after learning about the research,
Senators Patty Murray, Democrat of Washington, and
Christopher S. Bond, Republican of Missouri, wrote
the Defense and Veterans Affairs Departments, asking
about their plans for outreach and expanded benefits
for exposed troops.
The new research, the senators wrote, finally
provides “comfort to the thousands of gulf war
veterans who have fought for answers and now know
that there is a ‘significant association’ between
gulf war illnesses and nerve agent exposure in
Khamisiyah, Iraq, in 1991.”
The Pentagon has not decided whether to inform
veterans about the possibility of a link between
exposure and brain damage.
Dr. Michael E. Kilpatrick, deputy director of the
Force Health Protection and Readiness Initiative at
the Defense Department, said that while Dr. White’s
study represented an important finding, he did not
believe that his department would send letters to
potentially exposed veterans alerting them of it.
The impact of the study was limited, Dr. Kilpatrick
said, because it did not establish a direct causal
connection between sarin exposure and gulf war
illnesses, and it depended on Defense Department
data that was at best an estimate and at worst a
guesstimate of exposure levels by troops.
“But I’m sure we will be talking with members of
Congress about it in deciding how to go forward,”
said Dr. Kilpatrick, who has handled much of the
department’s work on Khamisiyah and troop health
In 2005, the Pentagon notified about 100,000 gulf
war veterans who had been exposed that a study
showed a link between brain cancer and gas exposure.
Ms. Murray said the Pentagon needed to send similar
letters about the new research, expressing concern
that many veterans might not know that something
might be wrong with them.