Paraquat, a weed killer (herbicide) used in both commercial agriculture and common groundskeeping, has recently been linked to an increased risk of Parkinson’s disease in people who have been routinely exposed to Paraquat. A study by the University of Guelph found that 'low-level exposure to the pesticides [Paraquat and Maneb] disrupts cells in a way that mimics the effects of mutations known to cause Parkinson’s disease.'