Groundwater Age Linked to Parkinson’s Disease Risk

A new study suggests a potential link between the age of drinking water and the risk of developing Parkinson’s disease. Researchers found that individuals whose drinking water comes from newer groundwater sources may have a higher risk compared to those who consume water from older sources.

The Connection Between Groundwater and Parkinson’s

Preliminary findings, presented at the American Academy of Neurology’s 78th Annual Meeting in April 2026, indicate that the age and source of groundwater could be an environmental risk factor for Parkinson’s disease. The study, conducted by researchers at Atria Research Institute and Barrow Neurological Institute, analyzed data from over 1.2 million individuals, including 12,370 people with Parkinson’s disease.

What is Groundwater Age?

Groundwater is water held underground in layers of porous rock, silt, or sand known as aquifers. The age of groundwater refers to how long the water has been underground. Newer groundwater, recharged by precipitation within the last 70 to 75 years, has been exposed to more potential pollutants. Older groundwater, often dating back over 12,000 years from the ice age, has typically been better shielded from surface contamination due to its depth and natural filtration processes. Newsweek reports on this distinction.

Key Findings of the Study

• Individuals who sourced their drinking water from carbonate aquifers had a 24% higher risk of Parkinson’s disease compared to those from other aquifer types.
• The risk increased to 62% higher when compared to those whose water came from glacial aquifers.
• Newer groundwater, from carbonate systems within the past 75 years, was associated with an 11% higher risk of Parkinson’s disease compared to groundwater older than 12,000 years.

“One way to examine our exposure to modern pollution is through our drinking water,” said study author Brittany Krzyzanowski, PhD, of Atria Research Institute. EurekAlert details this quote.

Aquifer Types and Contamination Risk

The study focused on two primary aquifer types:

• Carbonate Aquifers: These are the most common in the United States, often containing groundwater more vulnerable to surface contamination due to rapid water flow. They are prevalent in the Midwest, South, and Florida.
• Glacial Aquifers: Formed during the ice age, these aquifers are composed of sand and gravel, promoting natural filtration and slower groundwater movement. They are primarily found in the Upper Midwest and Northeast.

Important Considerations

Researchers emphasize that the study demonstrates an association, not causation. It does not prove that newer groundwater causes Parkinson’s disease. The study also acknowledges a limitation: it assumed individuals within a three-mile radius of a sampling site shared the same aquifer characteristics and groundwater age. EurekAlert highlights this limitation.

What Does This Mean for You?

Individuals can typically find out where their drinking water comes from by contacting their local water utility or, for private wells, through state or county groundwater resources. While more research is needed, understanding the source and age of your drinking water may be a step towards assessing potential environmental risks to neurological health.

Key Takeaways

• Groundwater age may be linked to Parkinson’s disease risk.
• Newer groundwater, particularly from carbonate aquifers, appears to carry a higher risk.
• The study highlights the importance of considering environmental factors in neurological health.
• Further research is needed to establish a causal relationship.

Learn more about Parkinson’s disease at the American Academy of Neurology.