Most AQI monitoring stations in 'red zone' as Delhi celebrates Diwali with fireworks

With people across the national capital celebrating Diwali with fireworks on Monday night, Delhi's air quality deteriorated, with most of the monitoring stations marked in the 'red zone'.

The Supreme Court court had allowed the bursting of green firecrackers between 8 pm and 10 pm on the festival day, but the celebrations continued well past the allotted time.

Thirty-six out of 38 monitoring stations recorded pollution levels in the 'red zone', indicating 'very poor' to 'severe' air quality across Delhi.

At 10 pm, the city's overall air quality index (AQI) was 'very poor' at 344, with four stations reporting 'severe' air quality (above 400).

According to the SAMEER app developed by the Central Pollution Control Board (CPCB), the four stations were Dwarka (417), Ashok Vihar (404), Wazirpur (423) and Anand Vihar (404).

Delhi's 24-hour average air quality index (AQI), which is reported at 4 pm every day, remained in the 'very poor' category at 345, higher than the 326 recorded on Sunday, according to official data.

In the afternoon, 31 out of 38 stations recorded 'very poor' air quality, while three stations fell under the 'severe' zone, data showed.

The air quality is expected to slip into the 'severe' category more widely on Tuesday and Wednesday.

The CPCB categorises AQI between 0 and 50 as 'good', 51 and 100 'satisfactory', 101 and 200 'moderate', 201 and 300 'poor', 301 and 400 'very poor', and 401 and 500 'severe.'

Transport emissions contributed 15.6 per cent to Delhi's air pollution on Monday, while other factors, including industries, accounted for 23.3 per cent, data from the Decision Support System (DSS) showed.

On Sunday, the Commission for Air Quality Management (CAQM) invoked Stage II of the Graded Response Action Plan (GRAP) across Delhi-NCR.

The move followed a review of the sub-committee on GRAP on Saturday and forecasts by the India Meteorological Department (IMD) and the Indian Institute of Tropical Meteorology (IITM).

On October 15, the Supreme Court allowed the sale and bursting of green firecrackers in Delhi-NCR between 6 am and 7 pm and again from 8 pm to 10 pm on Diwali eve and the day of the festival.