As pollution in the national capital worsened on Sunday, the Centre's air quality body ordered authorities in the Delhi-NCR region to prohibit non-essential construction activities under stage III of the Graded Response Action Plan (GRAP).
Delhi's 24-hour average air quality index (AQI) stood at 407 at 4 pm.
On Sunday, the GRAP implementation subcommittee convened to discuss the regional air quality scenario as well as forecasts for meteorological conditions and the Delhi air quality index.
It was discovered that the air quality had deteriorated considerably in the previous 24 hours. In order to prevent further deterioration, the subcommittee resolved that all activities envisioned under GRAP stage III be executed with immediate effect in the NCR, in addition to all actions envisaged under stages I and II, it said in an order.
After November 4, when the AQI was 447, Delhi's pollution level entered the severe' category.
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An AQI of 201 to 300 is termed 'poor,' 301 to 400'very poor,' and 401 to 500 'severe.'
On November 14, the Commission for Air Quality Management (CAQM) directed authorities to revoke curbs imposed in the Delhi-NCR under stage III of GRAP, including a ban on non-essential construction activities.
India Meteorological Department (IMD) scientist Vijay Soni told news agency ANI that the city's AQI was over 400 but that it hoped to improve by the evening.
On Sunday, the AQI in Anand Vihar surpassed 500, while the quality index in Kashmiri Gate fell to 379.
The city's air quality stayed in the 'very poor' category for the fifth consecutive day until Saturday, before deteriorating to the 'severe' category on Sunday.