Striving for clean air: Air pollution and public health in South Asia

Nine out of the world’s 10 cities with the worst air pollution are in South Asia. Concentrations of fine particulate matter (PM 2.5) in some of the region’s most densely populated and poor areas are up to 20 times higher than what WHO considers healthy (5 µg/mᶾ).  It causes an estimated 2 million premature deaths in the region each year and incurs significant economic costs. Controlling air pollution is difficult without a better understanding of the activities that emit particulate matter. Air pollution travels long distances in South Asia and gets trapped in large “airsheds” that are shaped by climatology and geography. This report identifies six major airsheds in the region, analyzes four scenarios to reduce air pollution with varying degrees of policy implementation and cooperation among countries, and offers a roadmap for airshed-wide air quality management.