Environmental degradation is costing Indian economy nearly Rs 3.75 lakh crores annually, which is equivalent to 5.7 per cent of country's gross domestic product (GDP), according to a fresh report by the World Bank.

The World Bank report, released on Wednesday, air pollution in India's urban areas is claiming as many as 1.09 lakh lives of adults, and another 7,513 lives of children below five years per year.

While outdoor air pollution accounts for 29 per cent of deaths, indoor air pollution and cropland degradation are responsible for 23 per cent and 19 per cent, respectively. Water supply & sanitation for 14 per cent, while pasture and forest degradation for 11 per cent and 4 per cent, respectively.

The national level study focused on PM10 (Particulate Matter up to 10 micrometers in size) from burning of fossil fuels. PM10 has serious health consequences amounting nearly 3 per cent of the country's GDP along with costs because of lack of access to clean water supply, sanitation & hygiene.

In rural parts of the country, indoor air pollution is mainly caused by burning of wood.

Muthukumara Mani, environmental economist at the World Bank, said that small steps could help improve the situation and save lives. Commenting on the findings, he suggested, "For example, washing coal is a simple process - not too expensive - which can also help in not only improving the efficiency of coal, but also save a lot of lives."

Commissioned by the Central government, the study claims that around a quarter of child mortality cases in the country are due to environmental degradation and lack of access to clean water and sanitation.