A thick blanket of smog enveloped Delhi on Diwali night as firecracker emissions pushed air quality into the 'severe' category at 20 monitoring stations, with the city's overall Air Quality Index (AQI) touching 371 at 10 pm.
The haze intensified as the evening progressed, with smoke from firecrackers hanging over roads and residential neighbourhoods, reducing visibility and leaving a strong smell of burnt crackers in the air. Residents in several parts of the capital also reported breathing difficulties.
Despite restrictions on firecracker use, fireworks continued across several parts of the city on Sunday evening, with reports emerging from Pitampura, Burari, Mayur Vihar and areas of Lutyens' Delhi.
Ahead of Diwali, the Delhi government had urged residents to adhere to the Supreme Court's directions on the sale and use of green firecrackers. An order issued by the District Magistrate (East) permitted their use only on November 7 and 8, between 6 am and 7 am and 8 pm and 10 pm.
Residents reported intense firecracker bursting in Pitampura and Burari, particularly in the latter, while similar activity was reported from Mayur Vihar, Bishambardas Marg and parts of Lutyens' Delhi. The intensity had, however, eased slightly in some areas.
Of the 59 monitoring stations that recorded air quality at 10 pm, 20 registered 'severe' AQI, 33 recorded 'very poor' levels and six reported 'poor' air quality.
Sonia Vihar recorded the worst air quality, with an AQI of 463, followed by Jahangirpuri at 450. Burari, Alipur and Punjabi Bagh were among the other areas reporting high pollution levels. Sonia Vihar, Jahangirpuri, Punjabi Bagh, Burari, Okhla and Rohini remained in the 'severe' category throughout the day.
The city's AQI had stood at 371 at 7 pm, close to the threshold for the 'severe' category, as firecracker bursting gathered pace from around 5-6 pm. While much of Delhi's roads remained relatively deserted during the day, celebrations intensified after sunset, with smoke accumulating over several neighbourhoods.
Several social media users also flagged the deteriorating air quality on X, reporting a strong smell of smoke, reduced visibility and difficulty breathing.
Delhi's average AQI for the day settled at 376 in the 'very poor' category, compared with 369 on Saturday, amid a persistent layer of smog and reduced visibility.
According to the Central Pollution Control Board (CPCB), an AQI of 0-50 is classified as 'good', 51-100 as 'satisfactory', 101-200 as 'moderate', 201-300 as 'poor', 301-400 as 'very poor' and 401-500 as 'severe'.
The Air Quality Early Warning System (EWS) has forecast that Delhi's air quality is likely to deteriorate into the 'severe' category from November 9 and remain at that level for the next few days.
Unfavourable meteorological conditions, vehicular emissions, Diwali celebrations and the peak stubble-burning season in neighbouring states are expected to compound the pollution burden.
According to the EWS, a ventilation index below 6,000 square metres per second, along with average wind speeds of less than 10 kmph, is unfavourable for the effective dispersion of pollutants.
PM2.5 remained the predominant pollutant in the national capital on Sunday, with firecracker emissions adding to the particulate matter load.
The Decision Support System (DSS) for Delhi estimated that the transport sector would account for the largest share of the city's pollution on Sunday at 19 per cent. Stubble burning was projected to contribute 3.5 per cent, with its share expected to remain around 2.99 per cent on Monday.
(With inputs from PTI)