Air quality in Delhi dips to ‘very poor’ category

The air quality in Delhi deteriorated to the “very poor” category on Thursday after remaining “poor” for the past few days. The national capital was covered in a toxic haze in the early hours of the day.

The average Air Quality Index at 3.06 pm was 377, categorised as “very poor”, according to data from the Sameer application, which provides hourly updates published by the Central Pollution Control Board.

The overall average AQI a day earlier was 279.

An index value between 0 and 50 indicates “good” air quality, between 51 and 100 indicates “satisfactory” air quality and between 101 and 200 indicates “moderate” air quality. As the index value increases further, air quality deteriorates. A value of 201 and 300 means “poor” air quality, while between 301 and 400 indicates “very poor” air.

Between 401 and 450 indicates “severe” air pollution, while anything above the 450 threshold is termed “severe plus”.

Air quality deteriorates sharply in the winter months in Delhi, which is often ranked the world’s most polluted capital. Stubble burning in Punjab and Haryana, along with the lighting of firecrackers, vehicular pollution, falling temperatures, decreased wind speeds and emissions from industries and coal-fired plants contribute to the problem.

On Thursday, the Air Quality Early Warning System for the national capital stated that the ventilation index...

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