While conducting a clinical study on Parkinson’s disease researchers came across a participant who felt strongly that his condition was the result of exposure to tricholoraethylene (TCE). Further research involving co-workers of the original participant suggest that there is a connection.

Don M. Gash and John T. Slevin, University of Kentucky–Lexington, studied the group of co-workers who all had at least 25 years of occupational exposure to TCE, including both inhalation and exposure to it from submerging their unprotected arms and forearms in a TCE vat or by touching parts that had been cleaned in it.

There were 14 former employees who reported 3 or more parkinsonian signs and had worked close to the TCE source. They were significantly slower in fine motor hand movements than age-matched controls–up to 250% slower.

Another 13 former employees reported no signs of parkinsonism worked near the source or in areas further from the TCE vat. This group exhibited some mild features of the condition. Their fine motor movements were also significantly slower than controls, but faster than the group with symptoms.

Previous studies had only linked the drug MPTP to mitochondrial neurotoxin causing parkinsonism. Now, TCE is implicated as a risk factor for parkinsonism based on its dopaminergic neurotoxicity in animal studies.

Although this was not a large scale study the researchers feel that there is a strong link between chronic TCE exposure and parkinsonism and it is essential further study is needed for the long-term health risks.