Wire reporting: (AP, via The Boston Globe)

New Delhi woke Monday to thick smog after Diwali firecrackers overnight, with air quality readings in the severe range, Al Jazeera and The Associated Press reported^1,2,3,4.

Al Jazeera said an air quality index of 400 was recorded in parts of the city, a level it described as severe¹. The AP report, carried by The Boston Globe, The Philadelphia Inquirer and CityNews Toronto, said the index exceeded 350 in several parts of the capital Monday morning and that monitoring stations logged similarly high readings as haze cut visibility^2,3,4.

Residents set off firecrackers Sunday evening despite restrictions, according to the AP account^2,3,4. India’s Supreme Court in October limited conventional firecrackers and allowed only approved “green firecrackers” in three-hour windows on Saturday and Sunday, the same report said; those products still emit particulate matter^2,3,4.

The AP said the metropolitan region of more than 30 million people often ranks among the world’s most polluted in winter, when Diwali fireworks overlap with cooler, still air and smoke from crop-residue burning in Punjab and Haryana^2,3,4. Vehicle exhaust, industry and construction dust add to the mix, and haze can linger for days when winds are weak^2,3,4.

City measures cited in the AP copy include limits on construction and diesel generators, alongside court limits on fireworks^2,3,4. Those steps have not stopped the seasonal return of severe pollution, the report said, and environmentalists have called for longer-term cuts in energy and vehicle emissions^2,3,4. Al Jazeera’s video did not address those policy details¹.