Researchers have found in a new study that exposure to high levels of fine particulate air pollution (PM) was associated with increased disease activity and a higher risk of flares in patients with rheumatoid arthritis (RA). The findings suggest that environmental air pollution, like tobacco smoke, may worsen RA and should be considered a modifiable factor in disease management. Overall, air pollution exposure, especially PM 2.5 , had an association with disease activity and disease flare among individuals with RA. Additional research is needed to understand the impact of bettering air quality on reducing disease activity among those with RA. Effects of air pollution on disease activity in patients with rheumatoid arthritis.