Mike Tidd, 65, is a fourth-generation plumber from Georgia who spent his early years making 12 to 14 repair calls per day to various homes.

But that changed after the Gulf War, when he served as a Seabee in the US Navy, working on construction projects in Kuwait and Saudi Arabia. He claims that his ability to do his job has steadily deteriorated since then, and that he can now only handle four calls per week.

Tidd suffers from Gulf War syndrome, also known as Gulf War illness, a collection of symptoms that many veterans who served in the conflict in the early 1990s experience.

Tidd’s symptoms include short-term memory loss, chronic fatigue, difficulty recalling words, sleep disturbance, and tremors. The last symptom directly affects his ability to work.

According to a 2020 Department of Defense report, Gulf War syndrome is estimated to affect between 175,000 and 250,000 of the nearly 700,000 troops from the United States, the United Kingdom, and other allied countries who served in the Gulf War conflict from 1990 to 1991.

Thirty years after the Gulf War conflict, a new genetic study has discovered a link between a specific gene and the likelihood of symptom severity when sarin gas exposure is considered. According to experts, it is a step toward better understanding an illness that has long been referred to as a mystery.

Veterans with a weak variant of a gene that normally allows the body to break down sarin gas were found to be more vulnerable to the gas when exposed, according to the study, which was partially funded by the US government. During the Gulf War, Sarin was frequently released as a result of bombings of chemical weapon storage facilities in Iraq.

Dr. Robert Haley, the study’s lead researcher at the University of Texas, Southwestern, stated that experts investigated which veterans reported hearing “chemical alarms,” audible alarms used to alert servicemembers to the presence of chemical weapons, during the Gulf War. Those service members were most likely exposed to sarin gas.

Tidd, who served in the Navy Reserves in a unit activated for Operation Desert Storm, took part in the study with other veterans who experienced Gulf War Syndrome symptoms as well as those who did not.

Anthony Hardie, 54, served in the United States Army during the Gulf War and first developed respiratory symptoms of Gulf War syndrome while still in the Gulf. Among other things, he’s had chronic fatigue, irritable bowel syndrome, and chronic widespread pain during and after his service.

Hardie claims that when he first sought treatment for his symptoms after returning to the United States at Fort Bragg, his symptoms, like those of many other Gulf War veterans, were dismissed and largely ignored by medical providers.

His background has led to years of advocacy for Gulf War veterans, including congressional testimony, and his current position as national chair and director of Veterans for Common Sense.

Gulf War veterans tried to bring attention to their symptoms, but were often met with skepticism, in part because the illness lacked a formal medical explanation. According to Gulf War veterans and legal advocates, a lack of verified causation has also made it difficult to get Veteran Affairs to cover claims for illness and disability.

According to a 2017 report from the Government Accountability Office, claims filed for Gulf War Illness medical issues from 2010 to 2015 were only approved 17 percent of the time, significantly lower than the 57 percent that is typical for other medical issues.

Travis Martin, director of the Kentucky Center for Veterans Studies at Eastern Kentucky University and an Iraq War veteran, told USA TODAY that efforts are ongoing to ensure that symptoms experienced by veterans are taken seriously rather than being attributed to psychological disorders.

Tidd has taken part in a slew of blood and neurological studies since developing symptoms and returning from service. While new treatments that come as a result of the study may not help his neurological problems, Tidd said he wanted to work with Haley to potentially help other veterans.