Even as pollution levels marginally decreased overnight due to a relatively better wind speed, a thick toxic haze lingered over Delhi and the NCR region for the fifth consecutive day on Saturday.
According to the Central Pollution Control Board, the Air Quality Index in several parts of the city witnessed a decrease but still remained in the 'severe' category, ranging from 401 to 500.
The concentration of poisonous PM2.5 was still more than 80 times higher than the healthy limit prescribed by the World Health Organisation.
The Municipal Corporation of Delhi has constituted 517 surveillance teams comprising 1,119 officers to keep a check on open burning, illegal construction and demolition waste dumping and dust on roads under its winter action plan, an official statement on Friday said.