Workers exposed to tricholorethylene -- a chemical once commonly used to clean metal -- may be at higher risk of developing Parkinson's disease, according to a new study from the Parkinson's Institute in Sunnyvale, CA.

Researchers analyzed the job histories of 99 sets of male twins in which one twin has Parkinson's disease, and found those who had been exposed to TCE were 5.5 times more likely to have the disease, a press release from the St. Paul, MN-based American Academy of Neurology said. The twins were participants in a World War II veterans study and had worked as dry cleaners, machinists, mechanics and electricians.

The study, funded by the National Institute of Neurological Disorders and Stroke, the Valley Foundation, and the James and Sharron Clark Family Fund, is scheduled to be presented in April at AAN's annual meeting in Toronto.