Positive Association Seen for Ambient Trichloroethylene, Parkinson Disease Risk

TUESDAY, Oct. 7, 2025 (HealthDay News) -- Ambient trichloroethylene (TCE) is associated with an increased risk for Parkinson disease (PD), according to a study published online Oct. 1 in Neurology.Brittany Krzyzanowski, Ph.D., from the Barrow Neurological Institute in Phoenix, and colleagues conducted a population-based, case-control study to examine the association between incident PD in U.S. Medicare beneficiaries aged 67 years and older in 2016 to 2018 and their residential exposure to ambient TCE in 2002. The relative risk was estimated, adjusting for age, sex, race, smoking, health care utilization, rural-urban commuting area, and fine particulate matter.A total of 221,789 incident PD cases and 1,132,765 matched controls were identified. The researchers found a dose-dependent positive association between ambient TCE concentrations and risk for PD, with a relative risk of 1.10 for beneficiaries exposed to the top versus the lowest decile of TCE levels (0.14 to 8.66 versus 0.005 to 0.01 μg/m3). In the rust belt region of the United States and in several smaller areas, high levels of ambient TCE were observed. In the area surrounding two of the three highest ambient TCE-emitting facilities, greater PD risk was suggested, one of which demonstrated a marked decreasing gradient of risk as the distance from the facility increased."While the increased risk was modest, the sheer number of people exposed to TCE in the environment means the potential public health impact could be substantial," Krzyzanowski said in a statement. "This underscores the need for stronger regulations and more monitoring of industrial pollutants."Abstract/Full TextEditorial (subscription or payment may be required).Sign up for our weekly HealthDay newsletter