Risk of Neurologic Disorder Rises for People Who Live Near Golf Courses

People who lived near a golf course had higher risk of developing Parkinson’s disease, a case-control study suggested.

After adjusting for patient demographics and neighborhood
characteristics, living within 1 mile of a golf course was associated
with more than double the odds of developing Parkinson’s disease
compared with living more than 6 miles away (adjusted OR 2.26, 95% CI
1.09-4.70), found researchers led by Brittany Krzyzanowski, PhD, of the
Barrow Neurological Institute in Phoenix.

Living
in a water service area with a golf course also showed higher odds of
Parkinson’s compared with other water service areas (adjusted OR 1.96,
95% CI 1.20-3.23) or having a private well (adjusted OR 1.49, 95% CI
1.05-2.13), Krzyzanowski and colleagues reported in JAMA Network Open.

Living in water service areas with a golf course in vulnerable
groundwater regions — regions with coarse textured soils, shallow
bedrock, or karst geology — also correlated with risk of developing
Parkinson’s (adjusted OR 1.82, 95% CI 1.09-3.03).

“Our study found that both distance from a golf course and karst
topography were independently associated with risk of Parkinson’s
disease,” Krzyzanowski told MedPage Today.

“Karst topography describes a region with limestone bedrock that
slowly dissolves over time, creating underground voids that allow water
from the surface to move more rapidly through it,” she added. “This
means that pesticides applied to grass or crops can more readily move
into the groundwater supply after a rain.”

The
findings suggest that people living near golf courses should be aware
of possible risks and take steps to minimize exposure. “Get in touch
with the golf course and ask what days and times they spray,”
Krzyzanowski suggested. “During spray times, try to stay indoors. You
can also consider using a carbon water filter to reduce the risk of
contamination from drinking water.”

Parkinson’s disease has been tied to environmental contaminants, including industrial solvents like trichloroethylene in drinking water and pesticides like simazine, atrazine, and lindane.
Pesticides known to be associated with the development of Parkinson’s
disease have been used to treat golf courses for years, Krzyzanowski and
colleagues pointed out.

“Pesticides such as paraquat and rotenone have been shown to induce
Parkinson-like neurodegeneration in the substantia nigra, primarily
through mechanisms involving oxidative stress, mitochondrial
dysfunction, and dopaminergic neuron apoptosis,” they wrote.

Despite the biological plausibility, very few studies have explored
the relationship between pesticide exposure from golf courses and
Parkinson’s, they noted.

Krzyzanowski
and colleagues studied people with incident Parkinson’s disease and
matched controls who were part of the Rochester Epidemiology Project
(REP) from 1991 to 2015.

They identified incident Parkinson’s disease in Olmsted County,
Minnesota, by ICD codes. Controls, also from the 27-county REP study
region in Minnesota and Wisconsin, were matched on age and sex with
Parkinson’s cases.

The researchers used Esriopens in a new tab or window
software to identify 139 golf courses in the REP study area in 2013 and
collected data about 224 water service areas from the U.S. Geological
Survey. They adjusted findings for age, sex, race and ethnicity, year of
index, median household income, and urban or rural location.

All Parkinson’s cases had an Olmsted County address at the time of
symptom onset, but address histories showed cases with previous
addresses in 22 of the 27 REP counties. The median number of addresses
recorded in medical records was one, and the median time lived at an
address was 18.5 years.

The
study sample included 419 incident Parkinson’s cases (median age was
73, and 61.3% were male) and 5,113 controls (median age was 72, and
59.5% were male).

The odds of incident Parkinson’s disease decreased by 9% (adjusted OR
0.91, 95% CI 0.85-0.98) for every 1-mile increase in distance from a
golf course, up to 18 miles.

After adjusting for proximity to a golf course, people in vulnerable
water service areas had twice the odds for Parkinson’s compared with
people in non-vulnerable water service areas (adjusted OR 1.99, 95% CI
1.30-3.04, P=0.001).

The analysis assumed most golf courses in the study existed for many
years before 2013, the researchers acknowledged. Pesticides used on golf
courses decades ago may not be the same as ones used today. Unknown
confounding factors may have influenced results, and address history
data were limited.

“Our study complements, and expands on, the limited research on golf
courses and Parkinson’s disease, but more research is needed to fully
understand the risks,” Krzyzanowski said. “Our next step is to replicate
this study nationwide in a dataset of more than 22 million Medicare
beneficiaries and approximately 16,000 golf courses.”