Exposure to Solvent TCE May Increase Risk of Parkinson’s Disease: Study

Solvents found in industrial cleaning chemicals and metal degreasers could increase the risk of Parkinson’s disease by a factor of ten, according to the findings of a new study. 

Researchers from The Parkinson’s Institute found strong associations between Parkinson’s disease and exposure to tricholoethylene (TCE) and perchloroethylene (PERC). The findings of the study were published this week online by the Annals of Neurology.

PERC, also known as tetrachloroethylene, and TCE are both industrial solvents used in paint removers, metal cleaners and degreasers, spot removers and carpet cleaning solutions. They are some of the most common pollutants in groundwater, and are also found in air and soil as well.

The study looked at 99 sets of twins interviewed as part of the National Academy of Science/National Research Council World War II Veteran Twins Cohort study, which tracked twin WWII vets throughout their lives. In all of the sets of twins chosen for the study, one had developed Parkinson’s disease and the other had not. Those who had worked in close contact with PERC were 10 times as likely to be diagnosed with Parkinson’s disease than those who had not, and the veterans who were exposed to TCE faced a six-fold increase in risk.

Parkinson’s Disease is caused by the death of dopamine-producing cells and causes severe tremors, limb rigidity and other symptoms. The progressive neurodegenerative disease is eventually fatal and about 100,000 Americans are diagnosed with the condition each year, with about 1 million Americans currently suffering from the ailment.

TCE was declared a carcinogen by the U.S. Environmental Protection Agency in September. While it has been banned for some uses that brought it in direct contact with humans, like skin disinfectants and general anesthetics, it is still used on an industrial level. 

The researchers also looked at the solvents toluene, xylene and n-hexane, but found no correlation between those chemicals and Parkinson’s disease. Preliminary findings of the study were first revealed in February 2010.