The Centre for Science and Environment said on Thursday that there has been a seven-fold increase in air pollution in Delhi since October. A CSE expert told PTI that real-time readings of particulate matter at all its monitoring stations are above the "severe" mark. Delhi’s outdoor "ambient air quality", referring to outdoor air which is measured over 24 hours, is also very poor, he added. This has caused rampant infections and respiratory diseases among the city’s population.

On Wednesday, the National Green Tribunal directed the Delhi government to roll out notifications about which of the city’s areas are most polluted. The order directed the government to begin such announcements within a week. Delhi has crossed Beijing to become the world’s most polluted city, according to this year’s World Health Organisation rankings. Experts said the quality of Delhi’s air would have prompted authorities in Beijing to regulate vehicles, shut down factories and restrict outdoor activities.