According to a study published in the journal JAMA Neurology, researchers led by the University of California-San Francisco and the San Francisco VA Medical Centre revealed that 2 years of exposure to trichloroethylene can increase the risk of Parkinsons disease by 70%.

Trichloroethylene (TCE) is a liquid chemical that can be found for decades in the air, water, and soil. TCE has been used for about 100 years in industrial and commercial applications as a surgical anesthetic until it was prohibited in 1977. However, at present, it is mostly used to degrease industrial metal components.

In the study, researchers compared the diagnosis of Parkinson’s in approximately 160,000 Navy and Marine veterans in the US. The findings of the study showed that 430 veterans were diagnosed with Parkinsons. The researchers also observed that the veterans who were exposed to the chemical were at 70% higher risk in comparison to those who were not exposed.

Furthermore, it was also observed that the exposed veterans exhibited a greater frequency of prodromal Parkinsons disease, i.e., symptoms that were indicative of Parkinsons but did not meet the diagnostic criteria for the condition.

According to the lead author of the study, Dr. Samuel M. Goldman of the UCSF Division of Occupational, Environmental, and Climate Medicine, the civilian population is also in danger of TCE exposure, as between 9% and 34% of US water sources contain quantifiable levels of the toxin. 

(Source: https://medicalxpress.com/news/2023-05-chemical-exposure-parkinson.html )