Air pollution led to 1.24 million deaths in India in 2017 and reduced the average life expectancy by 1.7 years, according to a study.
The research published in Lancet Planetary Health yesterday showed that 51.4 percent of these deaths were in people younger than 70 years.
Delhi had the worst air pollution with high levels of PM2.5, or the particulate matter 2.5 micrometres or less in diameter, followed by Uttar Pradesh, Bihar, and Haryana states in northern India.
"We estimated that 1.24 million deaths in India in 2017 could be attributed to air pollution, including 0.67 million to ambient (outdoor) particulate matter pollution and 0.48 million to household air pollution," the study said.
The major contributors to air pollution included coal burning for thermal power production, industrial emissions, construction activity, brick kilns, transport vehicles, road dust, waste burning, agricultural stubble burning, and diesel generators.
If the air pollution levels in India had been lower than the "theoretical minimum risk exposure levels" associated with health loss, the average life expectancy last year would have been higher by 1.7 years, the study found.
India has disproportionately high mortality and disease burden due to air pollution and reducing it is "dependent on rapid deployment of effective multisectoral policies throughout India that are commensurate with the magnitude of air pollution in each state", it said.
The World Health Organisation (WHO) said earlier this year that the world's 14 most polluted cities were in India.
According to the WHO's estimates, air pollution kills seven million people per year worldwide.