New Delhi, 1 Nov

A thick layer of haze blanketed Delhi, with the national capital's AQI plunging to 362 on Friday as people defied a citywide ban on firecrackers during Diwali celebrations. Delhi also recorded its most polluted Diwali in three years.

On Diwali on Thursday, the city's 24-hour average Air Quality Index (AQI) was recorded at 330, compared to 218 in 2023 and 312 in 2022, according to Central Pollution Control Board (CPCB) data. The national capital's AQI was recorded in the 'very poor' category with a reading of 362 at 9 am on Friday.

Most monitoring stations in Delhi showed similar pollution levels, with 37 out of 39 reporting air quality in the 'very poor' category.

According to the Sameer app that provides hourly updates of the national AQI published by the CPCB, the AQI in Alipur was recorded at 355, Anand Vihar at 396, Ashok Vihar at 389, Aaya Nagar 351, Bawana at 396, Burari at 394 and Mathura Road at 371. At IGI Airport, the AQI was at 371, Dwarka at 376, Jahangirpuri at 390, Mundka at 375, Patparganj at 365, Rohini at 390, Sonia Vihar at 396, and Wazirpur at 390.

An AQI between zero and 50 is considered 'good', 51 and 100 'satisfactory', 101 and 200 'moderate', 201 and 300 'poor', 301 and 400 'very poor', 401 and 450 'severe' and above 450 'severe plus'.

The concentration of PM2.5 -- fine particles which easily penetrate the respiratory system and pose serious health risks, especially for children, the elderly and those with pre-existing respiratory conditions -- also exceeded the safe limit.

At 6 am on Friday, the PM2.5 concentration in Delhi was recorded at 207.8 micrograms per cubic metre. The safe limit for PM2.5 is 60 micrograms per cubic metre.

In an effort to combat the spike in pollution during and after Diwali, the Delhi government had enforced a comprehensive ban on firecrackers for the fifth consecutive year, prohibiting their manufacture, storage, sale and use.

The city government had also set up 377 enforcement teams and spread awareness through local associations to ensure compliance with the ban. Police teams were deployed to monitor neighbourhoods, with officials warning that legal action would be taken against violators.

Despite these efforts, there was large-scale flouting of the restrictions in neighbourhoods across Delhi. Reports indicated widespread defiance across east and west Delhi, with firecrackers lighting up the sky in areas such as Jaunapur, Punjabi Bagh, Burari and East of Kailash.

Last year, a decrease in stubble burning incidents in neighbouring states and favourable meteorological conditions, including rain, prevented the national capital from turning into a gas chamber after Diwali.

On Friday, the national capital's minimum temperature was recorded 2.3 notches above normal at 18.4 degrees Celsius. The wind speed was around 10 kilometres per hour, according to the weather office.

Higher wind speeds help disperse pollutants, improving the air quality. At 8:30 am, the humidity level was at 70 per cent on Friday. The weather office has forecast clear skies during the day.