New evidence links exposure to pesticides with Parkinson's disease.There's no known cause of Parkinson's, a neurological disorder that can affect movement and talking. A new study was conducted by scientists at Duke and Miami universities and the Udall Parkinson's Disease Research Center. Researchers found that those exposed to herbicides and insecticides had a 1.6 times higher risk of developing Parkinson's. Those with heavy exposure - 200 days over a lifetime - carried double the risk. Experts say pesticides may play a key role in combination with environment and genetics.