Air Pollution Exposure and Risk for PD, Dyskinesia: New Data

TOPLINE:

Increased exposure to nitrogen dioxide (NO2) and particulate matter with a diameter of ≤ 2.5 µm (PM2.5) is associated with an increased risk for Parkinson’s disease (PD) and dyskinesia, a new study showed. Increased exposure to PM2.5 is also linked to a higher risk for akinetic rigid PD.

METHODOLOGY:

• Researchers conducted a population-based case-control study using data from the Rochester Epidemiology Project.
• The study included 346 patients with PD (median age, 72 years; 62% men; 95% White) and 4813 matched control individuals.
• Mean annual exposures to PM2.5 and NO2 within a square kilometer area of participants’ residences were estimated from 1998 to 2019 and from 2000 to 2014, respectively.
• The primary outcome was PD risk; secondary outcomes were assessed only among patients with PD and included all-cause mortality and the risk for tremor-predominant vs akinetic rigid PD and dyskinesia.

TAKEAWAY:

• Increased exposure to PM2.5 was associated with a 14% higher risk for PD among those with the highest exposure vs those at the lowest exposure (odds ratio [OR], 1.14; 95% CI, 1.11-1.18).
• Increased exposure to NO2 was associated with a 13% higher risk for PD among those with the highest exposure vs those with the lowest exposure (OR, 1.13; 95% CI, 1.07-1.19).
• Increased exposure to PM2.5 was linked to a 36% higher risk for the akinetic rigid subtype of PD (OR per 1-µg/m³ increase in exposure, 1.36; 95% CI, 1.02-1.80).
• Exposure to PM2.5 was not associated with all-cause mortality, but in patients with PD, each 1-µg/m³ increase in exposure to PM2.5 was associated with a 42% higher risk for dyskinesia (hazard ratio [HR], 1.42; 95% CI, 1.17-1.73), after accounting for patient demographics and the Rural Urban Commuting Area classification.

IN PRACTICE:

“Importantly, in 2024, the US Environmental Protection Agency reduced the annual PM2.5 standard from 12 μg/m³ to 9 μg/m³ due to growing evidence of negative health effects at levels below the previously set standard. 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 — a level previously advocated for by the American Lung Association and other health organizations,” the authors wrote.

SOURCE:

This study was led by Brittany Krzyzanowski, PhD, Barrow Neurological Institute, Phoenix. It was published online on September 16 in JAMA Network Open.

LIMITATIONS:

The study’s geographic range was limited to parts of Minnesota, Wisconsin, and Iowa, which may have affected the generalizability of the findings. The population was predominantly White, which limited the applicability to more diverse populations. The study did not have information on occupational history or activity space. The distribution of PM2.5 exposure among patients with PD was relatively small, and adjustments for some important clinical factors related to dyskinesia (such as body weight, disease severity, and levodopa treatment) could not be made. The relevant exposure window may have extended beyond 10 years prior to symptom onset, which was the window used in the study. However, PM2.5 estimates were only available from 1998 onward, possibly missing earlier relevant exposure data.

DISCLOSURES:

The funding source was not disclosed. One author disclosed receiving support from the National Institute on Aging, the National Institute of Neurological Disorders and Stroke, the Parkinson’s Disease Foundation, Acadia Pharmaceuticals, and the Michael J. Fox Foundation, outside the submitted work.

This article was created using several editorial tools, including AI, as part of the process. Human editors reviewed this content before publication.