In his notice, Tagore cited the 24-hour average Air Quality Index (AQI) of 461 in Delhi, categorised as "Severe Plus," marking the highest level this season.
Commission for Air Quality Management (CAQM) on Saturday invoked Stage IV of the Graded Response Action Plan (GRAP) after the Air Quality Index (AQI) neared the 'Severe Plus' mark at 450.