Air pollution is a critical concern for both human health and ecosystems and has become a high-priority environmental issue. Concentrations of air pollutants, such as particulate matter (PM), ozone, and toxic chemicals (mercury, persistent organic pollutants, and lead), are contributing to increased rates of asthma, lung and cardiovascular disease, and cancer. The World Health Organization estimates that in 2004, slightly less than one million disability-adjusted life years were lost due to outdoor air pollution.

Policy interventions, such as the Clean Air Act in the United States and the Clean Air Directive in Europe, have helped, but in other parts of the world (Asia in particular), air pollution is becoming an increasingly severe problem due to rapid industrial and urban growth. MORE 

This post originally appeared on State of the Planet, the Earth Institute's blog.

Air quality matters for human health, and many of the world’s urban areas suffer from high levels of contamination. One of the worst pollutants is PM_2.5., which are microscopic particles less than 2.5 microns in diameter that lodge deep in the lungs, potentially leading to respiratory and cardiovascular disease in exposed populations. According to World Health Organization research on the environmental burden of disease, outdoor air pollution causes close to one million premature deaths worldwide each year, with particulate matter as one of the leading contributors. Fine particulates originate in large part from fossil fuels combustion and from agricultural and forest fires. MORE