Association Between Long‐Term Exposure to Air Pollution and Parkinson's Disease: Administrative Cohort of Older Adults in South Korea
Jongmin Oh, Jisun Myung, Dong‐Wook Lee, Changwoo Han, Yun‐Chul Hong, Soontae Kim, Yoon‐Hee Kang, Hyun‐Joo Bae, Youn‐Hee LimAbstract
Background
Evidence regarding the association between long‐term exposure to ambient air pollution and Parkinson's disease (PD) remains inconsistent, particularly among older adults in Asian populations.
Objective
We aimed to examine the association between long‐term exposure to ambient air pollutants and incident PD in a nationwide administrative cohort of older adults in South Korea.
Methods
We analyzed 5.3 million adults aged ≥65 years from the Korean National Health Insurance Database (2010–2019). Incident PD was ascertained using nationwide insurance claims data, requiring hospitalization or repeated outpatient diagnoses. District‐level annual concentrations of fine particulate matter (PM 2.5 ), nitrogen dioxide (NO 2 ), and ozone (O 3 ) were estimated using the Community Multiscale Air Quality model. Time‐varying Cox proportional hazards models were used to estimate hazard ratios (HRs) per interquartile range (IQR) increase in a 1‐year moving‐average exposure, adjusting for individual‐ and district‐level covariates.
Results
During follow‐up, 143,557 PD cases were identified. In fully adjusted models, each IQR increase in PM 2.5 (4.3 μg/m 3 ) and O 3 (7.3 ppb) was associated with a modestly increased PD incidence (PM 2.5 : HR = 1.018, 95% CI: 1.008–1.028; O 3 : HR = 1.019, 95% CI: 1.006–1.033). However, NO 2 showed an inverse association after full adjustment. Effect modification by demographic or clinical characteristics was not statistically significant.
Conclusions
Long‐term exposure to PM 2.5 and O 3 was associated with a small but statistically significant increase in PD incidence among older adults in Korea. These findings are consistent with a possible association between air pollution and the etiology of neurodegenerative diseases, although effect sizes were modest and should be interpreted with caution. © 2026 The Author(s). Movement Disorders published by Wiley Periodicals LLC on behalf of International Parkinson and Movement Disorder Society.