Camp Lejeune TCE contamination and Parkinson’s risk analyzed
Marines at that base were 70% more likely to develop the disease, study shows
The risk of Parkinson’s disease is increased among people who have been exposed to the chemical trichloroethylene (TCE), according to a new analysis of U.S. military personnel.
The study, “Risk of Parkinson Disease Among Service Members at Marine Corps Base Camp Lejeune,” was published in JAMA Neurology. It was funded by the U.S. Department of Veterans Affairs.
TCE is a chemical that has been used widely in cleaning applications, but increasing evidence suggests it has toxic effects and can increase the risk of developing cancer and other health problems. The chemical is banned in Europe, but is still allowed for use in all U.S. states except for Minnesota and New York.
Earlier this year, scientists published a report calling for a U.S. ban on the chemical, noting that building evidence has suggested people exposed to TCE are at higher risk of Parkinson’s disease.
Here, researchers examined the risk of Parkinson’s disease among people who had served in the U.S. military at Marine Corps Base Camp Lejeune in North Carolina.
From the 1950s through the late ’80s, contamination from the base led to high levels of TCE and other chemicals in the drinking water. Monthly estimates suggest TCE levels were generally more than 70 times higher than what is currently considered acceptable. This was “one of the best-documented large-scale contaminations in US history,” the researchers noted.
For comparison, the scientists also evaluated the risk of Parkinson’s among military personnel who had served at Marine Corps Base Camp Pendleton, a facility in California with no history of TCE contamination.
A large cohort
“This study is the first in our knowledge to assess the association of [Parkinson’s] and exposure to TCE-contaminated water in a large, well-powered, population-based cohort,” the scientists wrote.
The analysis included data on 84,824 people who had served at the TCE-contaminated camp between 1975 and 1985, as well as 73,298 from the non-contaminated camp. Demographics were generally comparable between the two groups: about two-thirds were white and about a quarter were Black, and more than 90% were male.
Based on insurance data collected through 2021, 430 of the veterans went on to develop Parkinson’s: 279 (0.33%) from the contaminated base and 151 (0.21%) from the other base. Statistical analyses showed that the risk of Parkinson’s was significantly increased — by roughly 70% — among veterans who had served on the contaminated base in North Carolina.
Among veterans who did not have Parkinson’s, analyses showed that those who had served on the TCE-contaminated base were significantly more likely to experience anxiety, tremor, or erectile dysfunction. These are all well-known prodromal features of Parkinson’s, the researchers noted — meaning these conditions often emerge prior to the onset of Parkinson’s itself.
“Remarkably, among veterans without [Parkinson’s], residence at Camp Lejeune was associated with a higher risk of several clinical diagnoses that are well-established prodromal features of” Parkinson’s, the researchers wrote. These data suggest that some of the patients “may be in a pre-diagnostic phase of evolving [Parkinson’s] pathology,” they added.
The researchers stressed that, based on these data alone, it’s impossible to definitively conclude that exposure to TCE was the reason for the increased risk of Parkinson’s among veterans who served at the contaminated base. But they did say this is “a highly plausible explanation” that adds to building evidence of a connection between TCE and Parkinson’s.
TCE contamination more widespread
The scientists highlighted a need for more research to identify at-risk individuals and provide them optimal care.
“It should be noted that in addition to the exposed service members studied here, hundreds of thousands of family members and civilian workers exposed to contaminated water at Camp Lejeune may also be at increased risk of [Parkinson’s], cancers, and other health consequences. Continued prospective follow-up of this population is essential,” they wrote.