There is more evidence that pesticide exposure increases a person's risk of developing Parkinson's disease, according to the latest U.S. Parkinson's research conducted at Duke University, Miami University, and the Udall Parkinson's Disease Research Center of Excellence. Study results showed that subjects exposed to pesticides had a 1.6 times greater risk, and those with "heavy use" (200 or more days of exposure over a lifetime) carried over double the risk of developing Parkinson's.