Golf Course Pesticides, Drinking Water & Parkinson’s Risk
Environmental factors, such as chemical exposure, likely contribute to Parkinson’s disease (PD) risk. Golf courses consume large quantities of these chemicals, including herbicides, pesticides and insecticides. A new study from researchers using the Mayo Clinic–driven Rochester Epidemiology Project shows that living near golf courses could increase the risk of Parkinson’s.
Over the last 20 years, evidence has linked certain chemicals used in agriculture to PD. Farm-workers exposed to the weed-killer paraquat or the insecticide rotenone, for instance, develop Parkinson’s at rates two- to three-times higher than people who have never handled those chemicals. In lab settings, research shows that low doses of these compounds can damage dopamine-producing neurons in the brain — the same cells that are impacted in Parkinson’s.
While golf courses are known to be heavily treated with similar chemicals, no research has directly investigated the potential relationship between PD risk and proximity to golf courses.
This new study on golf courses and chemicals covers 25 years of medical data, from 1991 to 2015, and examines residents of several counties in southeastern Minnesota — a region where there are detailed municipal records, well‐depth charts and groundwater maps. Investigators used this information to study whether people who live close to golf courses face higher Parkinson’s risk. Additionally, they explored whether nearby public water systems explain any extra risk.
Study Results
The research team identified 419 men and women whose Parkinson’s diagnosis occurred during the study window (from 1991 to 2015) and matched them with more than 5,000 people of the same age, sex, race and neighborhood who did not have Parkinson’s.
Researchers then calculated the straight-line distance from each participant’s home to the nearest golf course on the date of PD diagnosis. Those addresses were added on maps of municipal water-service areas, the locations and depths of public wells, and geological charts highlighting regions where groundwater is considered “vulnerable,” meaning the soil or bedrock allows surface chemicals to migrate quickly downward.
Overall, the analysis revealed that people who lived within one mile of a golf course were 126% (or 2.26 times) more likely to receive a Parkinson’s diagnosis than those whose homes were six or more miles away. Being farther from the fairway seemed to help; risk steadily tapered off beyond one mile, with the odds of PD diagnoses decreasing by 9% for each mile of distance from a golf course.
Distance is only part of the story. When researchers looked at households served by a public water system that contained at least one golf course, Parkinson’s risk was 96% higher in households whose water systems did not have a golf course within their boundaries, and about 50% higher than people who use private wells. Additionally, when a golf course was in an area with groundwater vulnerable to contamination, the risk of Parkinson’s was 82% higher than in less vulnerable areas with a golf course.
Taken together, the findings suggest that the pesticides and herbicides used to keep putting greens immaculate may be leaching into drinking water, increasing Parkinson’s risk for the surrounding area.
Highlights
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Using medical records from 1991 to 2015, researchers pinpointed 419 Minnesotans with a Parkinson’s diagnosis and compared them to a group of more than 5,000 neighbors who were alike in age, sex, race, and residential area with no history of PD.
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For every person in the study, researchers measured how close they lived to the nearest golf course, then overlaid addresses onto maps showing city water-service districts, well water depths and locations, and areas where groundwater is more easily polluted.
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Those living within one mile from a golf course were 2.26 times more likely to be diagnosed with PD compared to those living 6 or more miles from a course. The odds of PD diagnosis decreased by 9% for each mile of distance from a golf course.
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People living in a public-water district with one or more golf courses had almost double the odds of developing Parkinson’s compared to those without a course, and about 50% higher odds than those using private wells.
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When a course was on land more vulnerable to pesticide contamination into the community water source, the risk of Parkinson’s was 82% higher compared to regions with a golf course located on more protective geology.
What does this mean?
This study suggests a strong association between living within close proximity to a golf course with an increased risk of developing PD. Additionally, it highlights water sources surrounding golf courses as a primary means of exposure to the chemicals routinely used on golf courses.
However, this study does not prove cause and effect, and the investigators emphasize that more work is needed before drawing firm conclusions. The research lacks direct measurements of pesticide levels in the water over time, and it cannot rule out the impact of other environmental factors related to golf courses, such as higher-income neighborhoods or traffic patterns.
Still, the clear patterns drawn from this study — highest PD risk closest to golf courses, next-highest in the water systems that share ground with a course, and more risk in areas where contaminants travel easily — gives researchers more compelling evidence about how environmental risks play a role in Parkinson’s.
What do these findings mean to the people with PD right now?
The connection between golf courses and increased PD risk may help some people living with Parkinson’s better understand one cause — exposure to environmental contaminants, potentially through drinking water. However, the environmental risk factors for PD that golf courses present are potentially preventable, by individuals and regulators. People can choose not to live near golf courses, knowing that it may put them at an increased risk for developing PD. On the other hand, regulators can also acknowledge the potential risks and improve safety measures surrounding golf courses and water sources.
The prevalence of Parkinson’s is on the rise. These findings — and new, similar studies that will most likely result from this one — highlights the need to push for mitigating risk factors for PD. Studies like this one that tie environmental factors to increased risk are shaping the future of PD research by helping people trace a contributor to their diagnosis — and help identify ways to reduce risk for future generations.
Learn More
The Parkinson’s Foundation believes in empowering the Parkinson’s community through education. Learn more about PD and the topics in this article through our below resources, or by calling our free Helpline at 1-800-4PD-INFO (1-800-473-4636) for answers to your Parkinson’s questions.
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