Parkinson's disease, the most common neurodegenerative movement disorder caused by aging, can also be caused by pesticides and other neurotoxins.
A new study found strong evidence that trichloroethylene (TCE) is a risk factor for parkinsonism, a group of nervous disorders with symptoms similar to Parkinson's disease. TCE is a chemical widely used in industry that is also found in drinking water, surface water and soil due to runoff from manufacturing sites where it is used. The study was published in the October 2007 issue of Annals of Neurology (http://www.interscience.wiley.com/journal/ana), the official journal of the American Neurological Association.
Led by Don M. Gash and John T Slevin, of the University of Kentucky in Lexington, KY, researchers conducting a clinical trial of 10 Parkinson's disease patients came across a patient who described long-term exposure to TCE, which he suspected to be a risk factor in his disease. TCE has been identified as an environmental contaminant in almost 60 percent of the Superfund priority sites listed by the Environmental Protection Agency and there has been increasing concern about its long term effects. The patient noted that some of his co-workers had also developed Parkinson's disease, which led to the current study of this patient and two of his co-workers diagnosed with Parkinson's disease who underwent neurological evaluations to assess motor function. All of these individuals had at least a 25 year history of occupational exposure to TCE, which included both inhalation and exposure to it from submerging their unprotected arms and forearms in a TCE vat or touching parts that had been cleaned in it. In addition, questionnaires about experiencing signs of Parkinson's disease, such as slowness of voluntary movement, stooped posture and trouble with balance, were mailed to 134 former workers. The researchers also conducted studies in rats to determine how TCE affects the brain.