Silent killer: More than three million dying early from air pollution
More than three million people around the world die prematurely because of air pollution, scientists have estimated.
Most of the deaths occur in Asia, where large numbers of people in countries such as India and China use highly polluting methods of heating and cooking in their homes.
In the US, traffic pollution made the biggest contribution to global death rates while in Europe, Russia and eastern Asia, agricultural sources had the greatest impact.
Outdoor air pollution includes ozone, a toxic form of oxygen, and tiny sooty particles that lodge in the lungs.
The study, published in the journal Nature, was conducted by combining a global atmospheric chemistry model with population data and health statistics.
Scientists predict that premature mortality from air pollution could double by 2050 with a death toll of 6.6 million lives per year.
The authors, led by Professor Jos Lelieveld, from the Max Planck Institute for Chemistry in Mainz, German, concluded: "Our results suggest that if the projected increase in mortality attributable to air pollution is to be avoided, intensive air quality control measures will be needed, particularly in South and East Asia.
"The poorly characterised uncertainty about the relative toxicity of various classes of particles such as sulphates, nitrates, organics, crustal materials, black carbon, and especially smoke from biomass combustion, limits unambiguous attribution of sources. Nevertheless, our study suggests that emissions from residential energy use should be considered in air pollution control strategies and, if all fine particles are equally toxic, the reduction of agricultural emissions would improve air quality."
A related paper in the journal Nature Geoscience reported that around 400 to 1,700 premature deaths per year might have been avoided in recent years as a result of large reductions in deforestation-related fires in the Brazilian Amazon.