Air pollution can trigger painful rheumatoid arthritis flares

New research from Seoul links air pollution to rheumatoid arthritis flare-ups, including higher swelling, pain, and disease activity. The study tracked 1,070 patients across 12,583 outpatient visits from 2021 to 2024. Higher pollution readings corresponded to greater disease activity and a higher chance of a flare, with fine particulate matter (PM2.5) emerging as the strongest signal among six pollutants measured. The association was most pronounced when elevated PM2.5 levels persisted for more than two weeks. The study, from Seoul National University Hospital, matched visits to monthly pollutant levels and used daily comparisons that control for fixed differences such as genetics and location.