Researchers from the Parkinson’s Institute in Sunnyvale, California have discovered a possible connection between trichloroethylene (TCE) exposure and an increased risk for Parkinson’s disease. Their study entitled “Solvent Exposures and Parkinson Disease Risk in Twins” was recently published in the Annals of Neurology Journal and is the first ever study to suggest a “significant association” between TCE and Parkinson’s.
A research team led by Drs. Caroline Tanner and Samuel Goldman interviewed 99 sets of twins in which one twin had Parkinson’s and the other twin did not. The twins were asked about their lifetime hobbies and occupations using a detailed job task-specific questionnaire. The study found an increased risk for developing Parkinson’s disease that was six times higher in individuals who were regularly exposed to TCE than in persons with lower levels of TCE exposure. The study also found a link between exposure to carbon tetrachloride and perchloroethylene and a significantly increased risk for Parkinson’s disease.
TCE is a colorless liquid–sometimes dyed blue–that is commonly used as a cleaner and degreasing agent. It is found in paints, paint removers, adhesives, carpet cleaners, and dry-cleaning solutions. It was also used as a skin disinfectant, general anesthetic, and coffee decaffeinating agent until the Food and Drug Administration banned its use in 1977. The chemical does not naturally occur in the environment, but it has been found in surface water and underground water surfaces due to its manufacture, use, and disposal.
“Our study confirms that common environmental contaminants may increase the risk of developing PD [Parkinson’s disease], which has considerable public-health implications,” Dr. Goldman said. “Our findings, as well as prior case reports, suggest a lag time of up to 40 years between TCE exposure and onset of PD, providing a critical window of opportunity to potentially slow the disease process before clinical symptoms appear.”
Parkinson’s disease is a debilitating neurological disorder characterized by muscle stiffness, limb tremors, speech impairment, and slowed movement. According to the National Institute of Neurological Disorders and Stroke (NINDS), nearly a half-million Americans suffer with Parkinson’s disease, with over 50,000 new diagnoses every year.