Oxidative stress was found to be associated with short-term exposure to air pollution in a community study reported in the Journal of the American Heart Association. Although the association has been reported in limited controlled exposure studies, researchers at the Harvard Clean Air Research Center (83479801) observed that exposure to PM2.5, Black carbon (BC), and sulfate were consistently associated with biomarkers of oxidative stress in 2,035 participants to the Framingham Offspring Cohort. Levels of ozone, nitrogen oxides, ozone, PM2.5, BC, and sulfate were measured at the Boston Supersite over the 1998-2001 and the 2005-2008 periods. Several biomarkers, including blood myeloperoxidase and urinary 8‐epi‐PGF2α were measured, along demographic, lifestyle and socioeconomic variables. Myeloperoxidase was associated with exposure to PM2.5 and BC over periods between 1 and 7 days. This association was stronger for people with diabetes. Sulfate and PM2.5 were associated with 8‐epi‐PGF2α . The associations support the hypothesis that oxidative stress is a mechanism for the risk of ischemic stroke, heart infarction, and other acute cardiovascular events associated with air pollution exposure.