The Greenpeace report is the first of its kind in India and says the health issues are costing the government $US3.2-4.6 billion annually.

The study pegs child mortality under five at 10,000, while reporting that 625 million people have respiratory symptoms and about 170,000 suffer from chronic bronchitis.

It says 8.4 million have chest discomfort and 20.9 million have asthma attacks while 160 million have restricted activity days.

"These impacts are likely to increase significantly in the future if Indian policymakers do not act,” the report revealed.

At approximately 210 gigawatts, India has the fifth-largest electricity generation sector in the world and government plans for the next 10 years envision deepening the country’s reliance on coal.

India’s annual 210GW generation looks set to increase by an additional 160GW of electricity over the next 10 years and, according to government projections, coal's share in the Indian electricity mix will remain largely constant at around 66%.

"Hundreds of thousands of lives could be saved and millions of asthma attacks, heart attacks, hospitalisations, lost workdays and associated costs to society could be avoided with the use of cleaner fuels, stricter emission standards and the installation and use of the technologies required to achieve substantial reductions in these pollutants," the report said.

"There is a conspicuous lack of regulations for power plant stack emissions.

“Enforcement of what standards do exist is nearly non-existent."

The study collected and analysed data from 111 major power plants and is a first-of-its-kind study in the country.

The authors noted that while comprehensive studies of health impacts caused by air pollution attributable to coal power plants had been carried out in the US and parts of Europe, such data was hard to come by in India.

The Delhi and Kolkata regions were found to be the most polluted but Mumbai, western Maharashtra, eastern Andhra Pradesh and the Chandrapur-Nagpur region in Vidarbha were all affected.

The report cautioned that urgent action was needed, calling for mandated flue gas desulphurization and the introduction and tightening of emission standards for pollutants.

The Coal Kills – An Assessment of Death and Disease Caused by India’s Dirtiest Energy Source report was produced by Greenpeace India and UrbanEmissions.info, with support from Conservation Action Trust.

It was authored by Sarath K Guttikunda and Puja Jawahar.