Study Confirms Gulf War Illness Caused By Exposure to Toxic Nerve Agent

Photo Credit: Roger Ryan / Crown / Imperial War Museums / Getty Images
Photo Credit: Roger Ryan / Crown / Imperial War Museums / Getty Images

After over 30 years of not understanding the cause of Gulf War Illness, veterans of the Persian Gulf War appear to finally know why they continue to experience a wide array of chronic symptoms, including fatigue and muscle pain. According to a new study published in journal Environmental Health Perspectives, the cause was the use of sarin nerve gas in the Kuwaiti Theater of Operations.

Two American soldiers standing in the turret of an M1A1 Abrams tank
During the Gulf War, a pair of American soldiers stand in the turret of an M1A1 Abrams tank as, near the border with Iraq, oil wells burn in the distance, March 1991. (Photo Credit: Allan Tannenbaum / Getty Images)

Gulf War Illness, also known as Gulf War Syndrome, is a chronic disorder affecting a large number of veterans who served in the Persian Gulf from 1990-91. It’s characterized by a number of symptoms, with the severity differing from person to person. It’s estimated that 250,000 of the 697,000 US veterans to serve in Kuwait are suffering from the disorder, while the Royal British Legion suggests it affects 33,000 UK Gulf War veterans.

Despite the prevalence of the illness, researchers have never been able to concretely determine its cause, with many assuming it was a psychological disorder. There was also a belief it was caused by exposure to depleted uranium, but that was disproven in early 2021.

Two US Marines crouched down behind a barbed wire fence
US Marines crouch behind a barrier of barbed wire. They are training in a Saudi Arabian desert just before the onset of the Gulf War. (Photo Credit: Peter Turnley / CORBIS / VCG / Getty Images)

The study, published in the journal Environmental Health Perspectives on May 11, 2022, confirms the illness was caused by exposure to chemical warfare agents during the Gulf War – in particular, sarin, a manmade nerve gas. Odorless, clear, tasteless and colorless, sarin is difficult to detect. It was initially developed by the Germans in 1938 as a pesticide.

Prior to and after the Gulf War, Iraqi President Suddam Hussein stockpiled the nerve gas. According to the CDC, “all nerve agents cause their toxic effects by preventing the proper operation of an enzyme that acts as the body’s ‘off switch’ for glands and muscles. Without an ‘off switch,’ the glands and muscles are constantly being stimulated.”

Four soldiers with the US 82nd Airborne Division dressed in chemical warfare suits
Dressed in chemical warfare suits, gloves and M-17A1 protective masks, four soldiers from the US 82nd Airborne Division walk around their camp to acclimate their bodies to the heat of the Saudi summer during Operation Desert Shield, 1990. (Photo Credit: CORBIS / Getty Images)

The study, which was led by Dr. Robert Haley, a professor of internal medicine and the director of the Division of Epidemiology at the University of Texas, Southwestern Medical Center, came to its conclusion after studying a group of 1,016 Gulf War veterans. Of those, 508 surveyed had developed symptoms of Gulf War Illness following their service, while the other half hadn’t.

Blood and DNA samples were collected, and each veteran was asked if they’d heard nerve gas alarms during their deployment – and how often.

After thorough analysis, those conducting the study found that those veterans who were exposed to sarin were more likely to develop the illness, particularly if they had a weaker variant of the PON1 gene. PON1 plays a role in breaking down toxic agents in the body, and there are two variants of the gene: Q, which generates an enzyme that breaks down sarin, and R, which is not efficient enough to break down the nerve agent, but can destroy other chemicals.

According to SciTechDaily, everyone carries two copies of the gene, either RR, QQ or the QR genotype.

Two soldiers walking away from a damaged tank
Troops in the Persian Gulf region during the Gulf War, 1991. (Photo Credit: Colin Davey / Getty Images)

Those veterans with the QR genotype and who heard nerve agent alarms were 4.43 times more likely to develop Gulf War Illness, while those with the QQ genotype saw their chances increase by 3.75 times. Those with the RR genotype had it worst, with their chances of developing the illness increasing by 8.91 times, while those with the genotype and low-level exposure were over seven times more likely to become sick.

According to, it’s likely thousands of coalition troops – including those serving with the US Armed Forces – were likely exposed to sarin and the organic phosphate cyclosarin when they destroyed a bunker at the Khamisiyah Ammunition Storage Depot. Located in southern Iraq, the bunker was housing chemical weapons, which, when destroyed, created a plume that spread over a 25-mile radius.

The Department of Veterans Affairs estimates some 100,000 servicemen could have been exposed to low levels of the nerve agents.

Two soldiers with the 82nd Airborne Division watching a CH-47 Chinook helicopter landing
Soldiers with the 82nd Airborne Division stand atop an M-998 high-mobility multi-purpose wheeled vehicle as they watch a CH-47 Chinook helicopter prepare to touch down during Operation Desert Shield. (Photo Credit: DoD / Getty Images)

Gulf War Illness has been a source of controversy over the decades. In 1997, a Congressional investigation found the VA had little interest in finding the cause of the disorder and instead blamed its symptoms on stress and other mental health issues.

More from us: Here’s How Much US Troops Were Paid In Every War

The report by the Committee on Government Reform and Oversight went so far as to say the VA and the Department of Defense were “plagued by arrogant incuriosity and a pervasive myopia that sees a lack of evidence as proof” that Gulf War Illness didn’t exist, despite the overwhelming evidence of symptoms.

Clare Fitzgerald

Clare Fitzgerald is a Writer and Editor with eight years of experience in the online content sphere. Graduating with a Bachelor of Arts from King’s University College at Western University, her portfolio includes coverage of digital media, current affairs, history and true crime.

Among her accomplishments are being the Founder of the true crime blog, Stories of the Unsolved, which garners between 400,000 and 500,000 views annually, and a contributor for John Lordan’s Seriously Mysterious podcast. Prior to its hiatus, she also served as the Head of Content for UK YouTube publication, TenEighty Magazine.

In her spare time, Clare likes to play Pokemon GO and re-watch Heartland over and over (and over) again. She’ll also rave about her three Maltese dogs whenever she gets the chance.

Writing Portfolio
Stories of the Unsolved