Air pollution exposure increases risk for Parkinson's disease

Higher exposure to air pollution increases the risk for Parkinson’s disease (PD), according to a study published online Sept. 16 in JAMA Network Open.

Brittany Krzyzanowski, Ph.D., from the Barrow Neurological Institute in Phoenix, and colleagues assessed whether air pollution is associated with an increased risk for PD and clinical characteristics of PD. The analysis included data from 346 patients with PD and 4,813 matched controls participating in the Rochester Epidemiology Project (1998 to 2015).

The researchers found that greater exposure to particulate matter with a diameter of <2.5 μm (PM_2.5) was associated with increased PD risk, and this risk was greatest for populations within metropolitan cores (odds ratio [OR], 1.23) for the top quintile of PM_2.5 exposure versus the bottom quintile.

An increased risk for PD was also seen with greater nitrogen dioxide (NO₂) exposure, when comparing the top quintile to the bottom quintile (OR, 1.13). Exposure to air pollution was associated with an increased risk for akinetic rigid presentation (OR per each 1-μg/m³ increase in PM_2.5, 1.36).

Among individuals with PD only, higher PM_2.5 exposure was associated with a greater risk for developing dyskinesia (hazard ratio [HR] per 1-μg/m³ increase in PM_2.5, 1.42), as was increased NO₂ exposure (HR per 1-μg/m³ increase in NO₂, 1.13).

“Importantly, in 2024, the U.S. Environmental Protection Agency reduced the annual PM_2.5 standard from 12 μg/m³ to 9 μg/m³ due to growing evidence of negative health effects at levels below the previously set standard,” the authors write. “Our study not only supports the findings that led to this change, but suggests that the upper limit should be lowered to 8 μg/m³.”

One author disclosed ties to the pharmaceutical industry.

More information:
Brittany Krzyzanowski et al, Air Pollution and Parkinson Disease in a Population-Based Study, JAMA Network Open (2024). DOI: 10.1001/jamanetworkopen.2024.33602