Now, as he battles Parkinson’s disease, he’s dropped to under 150 pounds. They allege the popular weedkiller led to their Parkinson’s disease, a condition that destroys motor functions. Over the years, the company has maintained that there is no connection between paraquat and Parkinson’s disease. The EPA’s decision concluded that “the weight of evidence was insufficient” to link paraquat to Parkinson’s disease. Platt said he wants programs to better support farmworkers, as well as to provide therapy for those with Parkinson’s disease.