Taking a deadly toll on us, poor air quality claims 5.5 million lives worldwide annually, with more than half of the deaths occurring in two of the world's fastest growing economies, China and India.

Power plants, industrial manufacturing, vehicle exhaust and burning coal and wood all release small particles into the air that are dangerous to a person's health.

The University of British Columbia research found that despite efforts to limit future emissions, the number of premature deaths linked to air pollution will climb over the next two decades unless more aggressive targets are set.

Researcher Michael Brauer said that air pollution is the fourth highest risk factor for death globally and by far the leading environmental risk factor for disease, adding that reducing air pollution is an incredibly efficient way to improve the health of a population.

Researchers from Canada, the United States, China and India assembled estimates of air pollution levels in China and India and calculated the impact on health. Their analysis shows that the two countries account for 55 per cent of the deaths caused by air pollution worldwide. About 1.6 million people died of air pollution in China and 1.4 million died in India in 2013.

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In China, burning coal is the biggest contributor to poor air quality. Researcher Qiao Ma, who found that outdoor air pollution from coal alone caused an estimated 366,000 deaths in China in 2013, said that the study highlights the urgent need for even more aggressive strategies to reduce emissions from coal and from other sectors.

In India, a major contributor to poor air quality is the practice of burning wood, dung and similar sources of biomass for cooking and heating. Millions of families, among the poorest in India, are regularly exposed to high levels of particulate matter in their own homes.

India needs a three-pronged mitigation approach to address industrial coal burning, open burning for agriculture, and household air pollution sources, said Chandra Venkataraman of the Indian Institute of Technology Bombay.

The study has been presented at the 2016 annual meeting of the American Association for the Advancement of Science (AAAS).