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Author: Khirstyn-Lien

Journal of Epidemiology
Date: January 18, 2026

Abstract

Parkinson’s disease (PD) is a progressive neurodegenerative disorder influenced by both genetic and environmental factors. Recent epidemiological studies have explored a potential association between residential proximity to golf courses and increased PD risk, hypothesizing pesticide exposure as a contributing mechanism. This article synthesizes current peer-reviewed research, including large case-control studies, to evaluate the strength of this association, underlying biological plausibility, and limitations of existing evidence. Findings suggest a statistically significant correlation between proximity to golf courses and PD incidence, particularly in regions with vulnerable groundwater systems. However, causation remains unproven, necessitating further investigation into environmental toxicology and exposure pathways.

Introduction

Parkinson’s disease is characterized by the degeneration of dopaminergic neurons in the substantia nigra, leading to motor and non-motor impairments. While approximately 10–15% of PD cases are attributed to genetic causes, the majority are considered sporadic, with environmental exposures playing a substantial role. Among these, pesticide exposure has emerged as a key risk factor.

Golf courses, which require intensive chemical maintenance including herbicides, insecticides, and fungicides, have recently come under scrutiny as potential environmental sources of neurotoxic exposure. This review examines whether living near golf courses is associated with increased PD risk and explores the mechanisms that may explain this relationship.

Methods Overview of Key Study

A landmark case-control study published in JAMA Network Open (2025) analyzed data from the Rochester Epidemiology Project spanning 1991–2015. JAMA Network Open study on golf courses and Parkinson’s disease risk

• Participants: 419 individuals diagnosed with PD and over 5,000 matched controls
• Exposure variables:
  • Distance from residential address to nearest golf course
  • Municipal water service areas containing golf courses
  • Groundwater vulnerability and well depth
• Outcome: Incident Parkinson’s disease diagnosis

The study incorporated geospatial mapping and environmental data to estimate exposure risk.

Results

1. Proximity and Risk Gradient

Individuals living within one mile of a golf course were found to have a 126% increased risk (2.26× higher odds) of developing PD compared to those living more than six miles away. Risk decreased progressively with distance, with approximately a 9% reduction in risk per mile. (Parkinson’s Foundation)

2. Water Contamination as a Key Pathway

The association was strongest in populations whose drinking water systems included golf courses. Residents in such areas had:

• ~96% higher risk compared to those without golf course exposure in their water system
• Elevated risk when groundwater was classified as highly permeable or vulnerable to contamination (Parkinson’s Foundation)

These findings suggest that pesticide leaching into groundwater may be a primary exposure route.

3. Environmental Toxicology Evidence

Pesticides commonly used on golf courses such as paraquat and rotenone have been shown in laboratory studies to:

• Induce oxidative stress
• Disrupt mitochondrial function
• Cause selective death of dopaminergic neurons

These mechanisms closely mirror the pathophysiology observed in Parkinson’s disease. (JAMA Network)

Discussion

Biological Plausibility

The link between pesticide exposure and PD is supported by decades of agricultural and occupational studies. Golf courses, although recreational environments, use similar or overlapping chemical compounds at high frequencies. Chronic low-dose exposure via inhalation, dermal contact, or contaminated water may contribute to cumulative neurotoxicity.

Strength of Evidence

The reviewed study demonstrates:

• Strong statistical association
• Dose-response relationship (distance gradient)
• Environmental pathway consistency (groundwater contamination)

However, it remains observational in nature and cannot establish causality.

Limitations

• Lack of direct measurement of pesticide levels in individuals
• Potential confounding variables (e.g., socioeconomic status, urban planning factors)
• Regional specificity (Minnesota/Wisconsin populations) limiting generalizability
• Absence of longitudinal exposure tracking

Public Health Implications

These findings highlight the importance of environmental regulation and monitoring, particularly in:

• Water safety near pesticide-intensive areas
• Urban planning around recreational land use
• Public awareness of environmental risk factors for neurodegenerative diseases

Conclusion

Emerging research suggests a significant association between living near golf courses and increased risk of Parkinson’s disease, likely mediated by pesticide exposure through groundwater contamination. While causation has not been definitively established, the consistency of epidemiological patterns and biological plausibility warrants further investigation. Future studies should focus on direct exposure measurements, longitudinal designs, and broader geographic populations to better understand this potential environmental risk factor.

References

1. Krzyzanowski B, et al. Proximity to Golf Courses and Risk of Parkinson Disease. JAMA Network Open. 2025. (PubMed)
2. Parkinson’s Foundation. Golf Course Pesticides, Drinking Water & Parkinson’s Risk. 2025. (Parkinson’s Foundation)
3. Neurology Advisor summary of groundwater contamination and PD risk. 2025. (paaci.org)