To characterize the neurologic outcomes of individuals with suspected exposure to chlorinated solvents used in dry cleaning. 

Clusters of Parkinson’s disease (PD) have been reported in the media and academic journals, but few have been rigorously evaluated. Some clusters are tied to chlorinated solvents used in dry cleaning, including trichloroethylene (TCE). TCE contamination of soil and groundwater can enter buildings through vapor intrusion akin to radon, often undetected. Occupational TCE exposure was previously associated with a 500% increased risk of PD (Ann Neurol. 2012;71(6):776-784).

We surveyed law partners who worked between 1968 and 2001 near a site known to be contaminated by a past dry cleaner. Soil was contaminated with chlorinated and petroleum-based dry cleaning solvents from the 1950s through the mid-1990s and was remediated in 1998. We collected neurologic disease and work histories. Legal representatives of deceased or incapacitated attorneys provided survey responses on their behalf.

Of all 81 attorneys who worked from 1968-2001, 65 responses were collected (80.2% response rate). 54 responses were provided by attorneys answering for themselves (mean age 66.5 (11.6) years, 6 female) and 11 responses were provided by proxies due to death (10) or incapacitation (1). Attorneys worked an average of 18.5 (10.2) years on-site. Five respondents reported PD (7.7%), including one with both PD and diffuse Lewy body disease and one with “possible” PD. None had a first-degree relative with PD. 11 additional respondents (12.9%) without any neurologic disorders reported at least one Parkinsonian symptom. Four reported other neurologic disorders (multiple systems atrophy, trigeminal neuralgia, essential tremor, and idiopathic neuropathy).

The surveyed attorneys had a considerably high PD prevalence rate (7.7%). We are conducting a detailed clinical investigation of this group to further characterize these findings. Given the widespread use of chlorinated solvents, additional PD clusters tied to these chemicals may be identified.