The team, led by Don M. Gash and John T. Slevin of the U.K. College of Medicine, identified a number of industrial workers who exhibited symptoms of Parkinsonism, a group of nervous disorders with symptoms similar to Parkinson’s disease. The workers experienced long-term exposure to TCE, a degreasing agent widely used in industry that also has been found in drinking water, surface water and soil due to runoff from manufacturing sites.
The workers were identified during a clinical trial of 10 Parkinson’s disease patients when one individual expressed concern that his long-term jobsite exposure to TCE may have contributed to the disease. He noted some of his co-workers also developed Parkinson’s.
The other two individuals with Parkinson’s had at least 25 years of occupational exposure to TCE, including both inhalation and physical contact when they submerged their unprotected arms in TCE vats or touched machine parts that had been cleaned in the chemical.
In addition, 14 others with long-term exposure to TCE had marked Parkinsonism symptoms, including significant reductions in fine motor hand movements compared to age-matched controls. Other individuals showed milder symptoms of the condition when compared to the controls.
By using an animal model, researchers showed reductions in an enzyme important to energy production following TCE exposure. They also demonstrated exposure-related degenerative changes in certain dopamine neurons.
The research team acknowledges the study is not a large-scale epidemiological investigation but assert that the results demonstrate a strong potential link between chronic TCE exposure and Parkinsonism.
"It will be important to follow the progression of movement disorders … over the next decade to fully assess the long-term health risks from trichloroethylene exposure," they stated.