Study Links Gulf War Illness to Service Location

One of the ironies of the Gulf War, also known as Operation Desert Storm, is that even though the conflict ended in February, 1991 after a six-week air campaign and four-day ground war, it is unclear why veterans who served in the war are still feeling certain effects 20 years later.

Studies have estimated that Gulf War Illness (GWI)—the term commonly used for the complex of symptoms such as chronic headache, widespread pain, memory and concentration difficulties, unexplained fatigue, and digestive and other abnormalities—affects at least 25% of veterans who served in the war.

Over the last two decades, the cause of GWI has been a puzzle, but a study released today by researchers at Baylor University has concluded that it appears to be the result of several factors that differ in importance depending upon the locations where veterans served during the war.

The researchers found that GWI was most prevalent in veterans who served in forward areas of Iraq and Kuwait, where it was most strongly associated with use of pyridostigmine bromide (PB) pills, which were given to soldiers to protect them from the effects of nerve agents. For personnel who remained in support locations, GWI was significantly associated only with pesticide use during the war.

“Understanding the causes of GWI has presented a complex puzzle in the 20 years since the Gulf War,” Lea Steele, PhD, an epidemiologist at Baylor and lead author of the study, said in a statement. “Many of the nearly 700,000 US veterans who served in that war encountered different levels and combinations of potentially hazardous substances. Our study determined that wartime exposures and rates of GWI were not the same for all veterans in all areas. In earlier studies, the causes of GWI often seemed indecipherable when such differences were not taken into account.”

The study, which was published online ahead of print in Environmental Health Perspectives, found that GWI prevalence was nearly six times higher in veterans who served in Iraq or Kuwait, where all ground battles took place during the 1991 conflict, compared to veterans who remained on board ship during the war.

GWI prevalence was 3.5 times greater in the subgroup of troops in the high-risk areas that used PB pills compared to those who did not. GWI incidence was also increased for forward-deployed personnel who reported being near exploded SCUD missiles or smoke from the Kuwaiti oil fires, and pesticide use.

For veterans who remained in support areas GWI was significantly increased only in the relatively small subgroup that wore pesticide-treated uniforms and also used skin pesticides. The study found no significant link between GWI and warzone experiences associated with a high degree of psychological stress.

The study evaluated symptoms, health conditions, and deployment experiences reported by 304 veterans who served in war. It found that a large proportion of veterans who were in Iraq and Kuwait used PB pills and were also exposed to smoke from over 600 burning oil well fires that burned for much of 1991.

Previous investigations have indicated that approximately 100,000 US troops were potentially exposed to low levels of chemical nerve agents released during weapons demolition operations in Iraq after the war. They also showed that thousands of troops were likely overexposed to different types of pesticides, which were commonly misused during the 1991 Gulf War.

“Our study results strongly suggest that GWI is the residual effect of exposures encountered by military personnel who served in the 1991 Gulf War,” said Steele, research professor of biomedical studies in the Institute of Biomedical Studies at Baylor. “Although the specific biological mechanisms are not well understood, we know that a number of the 1991 Gulf War exposures of concern—PB pills, many of the pesticides, and low-level nerve agents—affect the same nerve signaling chemical, acetylcholine, which is involved in diverse processes necessary for normal brain and neurological function.”

SourcesCauses of Gulf War Illness Are Complex and Vary by Deployment Area [Baylor University]Complex Factors in the Etiology of Gulf War Illness: Wartime Exposures and Risk Factors in Veteran Subgroups [Environmental Health Perspectives]