Trichloroethylene exposure increase risk of Parkinson's disease: JAMA

A new study by Samuel Goldman and team showed that veterans who served at a location across the country had a 70% lower incidence of Parkinson's disease than Marines stationed at Camp Lejeune. The findings of this study were published in the Journal of American Medical Association. 

There is minimal evidence, but exposure to the solvent trichloroethylene (TCE) has been linked to an increased risk of Parkinson disease (PD). TCE is present in food, water, and the air for millions of individuals in the US and throughout the world. In order to determine if veterans who served at Marine Corps Base Camp Lejeune—where the water supply was tainted with TCE and other volatile organic compounds (VOCs)—have a higher chance of developing Parkinson's disease (PD) than soldiers who did not.

This population-based cohort study, with follow-up from January 1, 1997, to February 17, 2021, examined the risk for PD among all Marines and Navy personnel who lived at Camp Lejeune, North Carolina (contaminated water) (n = 172 128), or Camp Pendleton, California (uncontaminated water) (n = 168 361), for at least 3 months between 1975 and 1985. The International Classification of Diseases (ICD) diagnosis codes for Parkinson's disease (PD), other types of parkinsonism, and associated drugs, as well as diagnostic codes suggestive of prodromal illness, were searched for in the Veterans Health Administration and Medicare databases. An examination of the medical records verified the diagnosis of Parkinson disease. Multiple VOCs were present in the water at Camp Lejeune. TCE had the highest levels, with monthly median readings more than 70 times the allowable limit.

The main outcomes were PD risk is higher among former Camp Lejeune residents than among Camp Pendleton inhabitants. The chance of being diagnosed with prodromal PD symptoms in people without Parkinson's disease or another form of parkinsonism was evaluated both individually and collectively using likelihood ratio tests.

The key findings of this study were:

The health records of 158 122 veterans (46.4%) were accessible. 

The demographics of Camp Lejeune and Camp Pendleton were comparable. 

There were 430 veterans in total who had PD, of whom 279 were from Camp Lejeune (prevalence, 0.33%), and 151 were from Camp Pendleton (prevalence, 0.21%). 

Veterans of Camp Lejeune showed a 70% greater risk of PD in multivariable models. 

For other types of neurodegenerative parkinsonism, no additional risk was identified. 

Additionally, Camp Lejeune veterans had greater cumulative prodromal risk scores and a considerably higher chance of prodromal PD diagnoses, such as tremor, anxiety, and erectile dysfunction.

Since the 1920s, trichloroethylene has been a common environmental pollutant used all over the world. Millions have been exposed and still are.

Reference:

Rubin, R. (2023). Large Study Links Industrial Solvent in Drinking Water to Parkinson Disease Risk in Camp Lejeune Veterans. In JAMA. American Medical Association (AMA). https://doi.org/10.1001/jama.2023.6079