If India cuts down consumption of dirty household fuels such as wood, dung, coal and kerosene that produce high levels of household air pollution with a range of health-damaging pollutants, it can save as many as 2,70,000 lives every year, according to a joint study conducted by researchers from University of California, Berkeley and the India Institute of Technology (IIT), Delhi.
There are 3,000 chemicals that have been identified in wood smoke, and if taken at a macro level, it is very similar to tobacco smoke, they warned.
"Household fuels are the single biggest source of outdoor air pollution in India," said Kirk R Smith, professor of global environmental health at UC Berkeley and director of the Collaborative Clean Air Policy Centre. "We looked at what would happen if they only cleaned up households, and we came to this counterintuitive result that the whole country would reach national air pollution standards if they did that."
Smith is co-author of a paper describing the analysis that appeared this week in the journal Proceedings of the National Academy of Sciences.
Till early 2016, nearly half of the Indian population was reliant on biomass for household fuel. In addition to generating greenhouse gases like carbon dioxide and methane, these dirty fuels kick out chemicals and other fine particulate matter that can stick in the lungs and trigger a whole host of diseases, including pneumonia, heart disease, stroke, lung cancer and chronic obstructive pulmonary disease. In 2015, India's average annual air pollution level was 55 micrograms per cubic meter (ug m-3) of fine particulate matter.
Complete mitigation of biomass as fuel — which could be achieved through widespread electrification and distribution of clean-burning propane to rural areas — would cut India's average annual air pollution to 38 ug m-3, just below the country's National Ambient Air Quality Standard of 40 ug m-3. While this is still far above the World Health Organisation (WHO) standard of 10 ug m-3, it could still have dramatic impacts on the health of the country's residents, Smith said.
"You can't have a clean environment when about half the houses in India are burning dirty fuels every day," Smith said. "India has got to do other things to fix air pollution — they've got to stop garbage burning, they've got to control the power plants, they've got to control vehicles and so forth. But they need to recognise the fact that households are very important contributors to outdoor air pollution, too."
In 2016, India instituted a national programme to distribute clean burning stoves and propane to 80 million impoverished households, or about 500 million people. The rationale behind this programme was to prevent illness due to cooking and heating smoke trapped within the home.
However, Smith hopes the study's findings will bolster support for reducing outdoor air pollution, as well. Similar programmes have been successful in China, where air pollution is now on the decline in 80 cities. "We've realised that pollution may start in the kitchen, but it doesn't stay there — it goes outside, it goes next door, it goes down the street and it becomes part of the general outdoor air pollution," Smith said.