On average, 7.2 per cent of all daily deaths in 10 of the largest and most polluted cities in India, including Delhi, Bengaluru and Mumbai, were linked to PM2.5 levels higher than World Health Organization (WHO) guidelines for safe exposure, according to a study published in The Lancet Planetary Health journal.

Delhi was found to have the largest fraction of daily and yearly deaths attributable to PM2.5 air pollution, caused by particles sized 2.5 micrometres or less in diameter. Researchers said that daily exposure to PM2.5 pollution in Indian cities is linked with a higher risk of death, and locally created pollution could be possibly causing these deaths.