December 15, 2025Thousands of U.S. farmers have Parkinson’s. They blame a deadly pesticide.

Paul Friday remembers when his hand started flopping in the cold weather – the first sign nerve cells in his brain were dying. He was eventually diagnosed with Parkinson’s, a brain disease that gets worse over time. His limbs got stiffer. He struggled to walk. He couldn’t keep living on his family farm. Shortly afterward, Friday came to believe that decades of spraying a pesticide called paraquat at his peach orchard in southwestern Michigan may be the culprit. The pesticide, a weed killer, is extremely toxic. With evidence of its harms stacking up, it’s already been banned in dozens of countries all over the world, including the United Kingdom and China, where it’s made. Yet last year, its manufacturer Syngenta, a subsidiary of a company owned by the Chinese government, continued selling paraquat in the United States and other nations that haven’t banned it.