For the new study, researchers at the Indian Institute of Tropical Meteorology and the US National Center for Atmospheric Research created computer simulations using 2011 data and found that air pollution could kill more than 570,000 people prematurely.

Furthermore, the researchers say, the problem would likely cost the Indian economy hundreds of billions of dollars annually.

Air pollution has been a public health concern in India for years. In February, a report by Greenpeace said it surpassed China in the quantity of fine particulate matter in the air. It found there were 128 micrograms of fine particulate matter in New Delhi's air.

By comparison, Washington, DC, had 12. The World Health Organization recommends no more than 10 micrograms. The report said the Indo-Gangetic region, the north of the country, had the most pollution.

Meanwhile, newly released figures by WHO are suggesting increasing pollution is claiming 7 million lives every year around the world.

WHO Public Health Director Maria Neira says most of the deaths are being caused by simply breathing the air in polluted cities.

Neira says based on their survey of some three thousand cities around the globe, the most polluted cities are still found in China and India.