The world's worst air pollution could cut the life expectancy of 480 million people in northern India by eight and a half years, according to a study by the University of Chicago.

According to the university's annual air quality living index, 1.3 billion people in India currently breathe more air than the World Health Organization (WHO) air quality guidelines. In northern India, 480 million people breathe 10 times as much air pollution as anywhere else on earth.

The worst area of air pollution in India is the capital New Delhi, where residents can live about 10 more years if the air quality meets World Health Organization (WHO) 's guidelines, and seven more years if they meet India's own national standards, the report said.

In terms of air pollution, India is closely followed by neighboring Bangladesh, Nepal and Pakistan. In Bangladesh, if the air quality meets World Health Organization (WHO) 's standard, residents can live a little more than five years, and residents of the capital Dhaka can live nearly eight years longer. Average life expectancy in Nepal and Pakistan will increase by about five years and four years, respectively.