Air pollution, stroke, and anxiety

The effects of air pollution on the lungs and heart are now widely appreciated, with expanding evidence for an important role in cardiac disease.1 The Global Burden of Disease Study identified fine particulate matter (PM_2.5) in outdoor air and household air pollution from use of solid fuels as the ninth and fourth leading risk factors, respectively, for disease worldwide,2 and the World Health Organization attributes one in every eight deaths to air pollution.3 The effects of air pollution are not limited to cardiopulmonary diseases. Recent evidence suggests a role in diverse outcomes, including diabetes,4 low birth weight, and preterm birth.5 This research stems from improved understanding of the role of air pollution in initiating systemic inflammation, a response that may affect multiple organ systems. Two linked studies (doi:10.1136/bmj.h1295, doi:10.1136/bmj.h1111) add to growing evidence that air pollution is an important risk factor for an increasing number of common diseases.6 7

In the first of the two papers, Shah and colleagues6 systematically reviewed and meta-analysed …