NEW DELHI: India's deepening pollution problem, which hit home with a vengeance after Diwali last year as Delhi and NCR woke up enveloped in smog that refused to lift for days, has a death toll second only to China's+ , and together the two nations account for over half the world's deaths from pollution.

According to the State of Global Air 2017 report, released in Boston on Tuesday, as many as 2.54 lakh deaths occurred in 2015 on account of exposure to ozone and its impact on chronic lung disease.

India+ accounts for the highest number of premature deaths due to ozone pollution, its toll 13 times higher than Bangladesh's, and 21 times higher than Pakistan's.

An interactive website on the report also highlights that 92% of the world's population lives in areas with unhealthy air+ . "We are seeing increasing air pollution problems worldwide, and this new report and website details why that air pollution is a major contributor to early death," said Dan Greenbaum, president of the Health Effects Institute HEI), the research institute that designed and carried out the study. He said, "The trends we report show that we have seen progress in some parts of the world, but serious challenges remain". 

Involving more than 2,000 researchers, the report factored in the role of an extensive set of behavioural, dietary and environmental risk factors for more than 300 diseases in 195 countries from 1990 onwards.