Quantifying the Effect of Long-Term Exposure to Pollution on Cardiovascular Health

Air pollution has long been associated with cardiovascular disease, but many scientists have believed that harm occurs only at concentrations greater than the U.S. Environmental Protection Agency (EPA) recommendations. These researchers examined Medicare data in 2000–2016 on 63 million individuals to evaluate how fine particulate matter (particles with an aerodynamic diameter of ≤2.5 microns; PM_2.5), nitrous dioxide (NO₂), and ozone might affect hospitalizations for pneumonia and three cardiovascular endpoints (ischemic stroke, myocardial infarction, and atrial fibrillation).

Mean yearly levels of the three pollutants were below EPA accepted standards. Long-term exposure to higher levels of PM_2.5 was associated with all outcomes. The stronge…