Air pollution in India is a serious environmental issue.[1] Of the 30 most polluted cities in the world, 21 were in India in 2019.[2][3] As per a study based on 2016 data, at least 140 million people in India breathe air that is 10 times or more over the WHO safe limit[4] and 13 of the world's 20 cities with the highest annual levels of air pollution are in India.[5] The main contributors to India's particulate air pollution include industrial and vehicular emissions, construction dust and debris, dependence on thermal power for electricity, waste burning, and use of wood and dung by low-income and rural households for cooking and heating.[6] 51% of India's air pollution is caused by industrial pollution, 27% by vehicles, 17% by crop burning and 5% by other sources.[7][better source needed] Air pollution contributes to the premature deaths of 2 million Indians every year. Emissions come from vehicles and industry, whereas in rural areas, much of the pollution stems from biomass burning for cooking and keeping warm. In autumn and spring months, large scale crop residue burning in agriculture fields – a cheaper alternative to mechanical tilling – is a major source of smoke, smog and particulate pollution.[8][9][10] India has a low per capita emissions of greenhouse gases but the country as a whole is the third largest greenhouse gas producer after China and the United States.[11] A 2013 study on non-smokers has found that Indians have 30% weaker lung function than Europeans.[12]
In 2015, Government of India, together with IIT Kanpur launched the National Air Quality Index.[14] In 2019, India launched 'The National Clean Air Programme' with tentative national target of 20%-30% reduction in PM2.5 and PM10 concentrations by 2024, considering 2017 as the base year for comparison. It will be rolled out in 102 cities that are considered to have air quality worse than the National Ambient Air Quality Standards.[15] There are other initiatives such as a 1,600-kilometre-long and 5-kilometre-wide The Great Green Wall of Aravalli green ecological corridor along Aravalli range from Gujarat to Delhi which will also connect to Shivalik hill range with planting of 1.35 billion (135 crore) new native trees over 10 years to combat the pollution.[7] In December 2019, IIT Bombay, in partnership with the McKelvey School of Engineering of Washington University in St. Louis, launched the Aerosol and Air Quality Research Facility to study air pollution in India.[16] According to a Lancet study, nearly 1.67 million deaths and an estimated loss of US$28.8 billion worth of output were India's prices for worsening air pollution in 2019.[17]