A U.S. study of more than 1.2 million people near 1,279 groundwater sites found that younger groundwater, especially from carbonate aquifers, is linked to higher Parkinson’s disease risk, while older groundwater may be protective in carbonate aquifers; results show association, not causation, and rely on approximations of exposure.
A large US study linked Parkinson’s disease risk to where and how people get their drinking water. People drinking from carbonate aquifers had a 24% higher PD risk than those using other aquifers and a 62% higher risk than those drinking from glacial aquifers. Newer groundwater (past 75 years) in carbonate systems was tied to about 11% higher risk than older water. The study analyzed 12,370 people with PD and over 1.2 million without, all within 3 miles of groundwater sampling across 21 major US aquifers, and noted limitations like assuming uniform aquifer characteristics within radius. Carbonate aquifers are common in the Midwest, South, and Florida, while glacial aquifers are more in the Upper Midwest and Northeast. The findings suggest groundwater age and source may influence long-term neurological health, warranting further research.