Delhi's air quality remained "severe" for the second consecutive day, prompting authorities to implement stricter pollution control measures under Gra

The GRAP (Graded Response Action Plan) has 4 stages — stage I when AQI ranges between 201 and 300, stage II when AQI is 301-400, stage III when AQI is 401-450 and stage IV when AQI is 450-500.

Delhi air quality plummets to alarming levels every year in the winter. The air quality in the capital remains in the 'severe' category prompting the authorities to impose the third stage of GRAP.