This is something which I had not heard of before. The hypothesis has been made that the massive rise in Parkinson’s disease in modern times may be due to contamination by Trichloroethylene, or TCE, an industrial chemical widely used in stripping paint, and industrial cleaning. According to Dr. Ray Dorsey, a neurology professor at the University of Rochester and lead author: "When Dr. Parkinson described the condition in 1817 in London, he reported six individuals with the disease," "Two hundred years later, the global burden of disease is estimated that over 6 million people have the disease worldwide. So how do you go from six to 6 million? The rates are growing far faster than aging could explain alone. It has to be environmental factors. I think TCE and air pollution are important contributors.”