In a seemingly simple experiment, a scientist exposes rats to a certain pesticide over several days, and the rodents start showing symptoms remarkably similar to those seen in Parkinson’s patients. But the scientific search for the causes of the disease, which affects 7 million to 10 million people worldwide, is nowhere near simple. An article in Chemical & Engineering News, the weekly newsmagazine of the American Chemical Society, dives into the potential pesticide-Parkinson’s link.