Atmospheric science: The death toll from air-pollution sources

Estimates of worldwide deaths associated with exposure to fine particles in atmospheric pollution provide some surprising results. The findings will guide future research and act as a wake-up call for policymakers. See Letter p.367 Premature mortality can be linked to a wide range of causes including the effect of outdoor air pollutants such as ozone and fine particulate matter on human health. This paper investigates the link between premature mortality and seven sources of atmospheric pollutants in urban and rural environments. Jos Lelieveld et al. find that outdoor air pollution, mostly by fine particulate matter, leads to around three million premature deaths per year worldwide. Emissions from residential energy use such as heating and cooking, prevalent in India and China, have the largest effect on premature mortality globally. In large areas of the United States and a few other countries, emissions from traffic and power generation are important, whereas in the eastern USA, Europe, Russia and East Asia agricultural emissions make the largest relative contribution to fine particulate matter, with the overall health effect depending on assumptions regarding particle toxicity.