Fine particulate pollution linked to increased rheumatoid arthritis activity and flares

In a prospective cohort of 1,070 rheumatoid arthritis patients at Seoul National University Hospital, investigators recorded disease activity across 12,583 outpatient visits between 2021 and 2024. Monthly concentrations of six common pollutants were matched to each visit, with statistical controls for demographics, serology, medication, socioeconomic status and weather. Fine particulate matter (PM2.5) emerged as the primary factor linked to increased disease activity and flare risk, particularly after more than two weeks of high exposure.

The authors propose that inhaled particles may trigger oxidative stress and inflammatory pathways that exacerbate arthritis. While further research is needed to confirm whether improving air quality reduces disease severity, the findings highlight air pollution as a potential modifiable risk factor for patients and policymakers.