Delhi air turns toxic on Diwali eve: AQI crosses 400 in several areas, experts warn of ‘severe’ pollution

Delhi AQI

As the festival of lights nears, Delhi and its surrounding regions are once again enveloped in a toxic haze. On Sunday, October 19, air quality across the National Capital Region plummeted to hazardous levels, raising serious health concerns just a day before Diwali.

According to the Central Pollution Control Board (CPCB), Delhi’s overall Air Quality Index (AQI) was recorded at 274 at 5:30 am, falling in the “poor” category. By 7 am, several parts of the city had slipped into the “very poor” and “severe” zones. Anand Vihar was among the worst-hit areas, with AQI levels touching 426, while Vivek Vihar (349), Dwarka (327), Ashok Vihar (304), RK Puram (322), Jahangirpuri (314) and Bawana (303) also reported “very poor” readings.

Other areas, such as Lodhi Road (221), Najafgarh (212), Okhla Phase 2 (283) and Narela (266), were in the “poor” category. Across NCR, Loni in Ghaziabad recorded 341, Sector 125 Noida stood at 342, and Sector 51 Gurugram also touched 342, all categorised as “very poor”.

What’s behind the pollution spike

Experts say the spike in pollution is driven by multiple factors: vehicular emissions, stubble burning in neighbouring states, and unfavourable weather conditions. Transport contributes nearly 15.6 per cent of Delhi’s total pollution load, while calm winds and clear skies have trapped pollutants close to the surface.

“Regional meteorological conditions and local emissions are causing hazardous pollution levels at multiple locations, and these levels will likely rise further during festive celebrations,” said an expert quoted by Hindustan Times.

Forecast points to worsening air

The Indian Institute of Tropical Meteorology (IITM) has forecast that Delhi’s air quality could deteriorate further on Diwali day, reaching the upper end of the “very poor” category and possibly slipping into “severe” levels by October 21 if firecracker emissions spike.

The India Meteorological Department has predicted fog in the morning, followed by clear skies, with temperatures ranging between 19°C and 33°C, offering little relief from the smog.

Authorities step up enforcement

Authorities have stepped up enforcement after the Supreme Court’s order on October 15 allowed only “green crackers” to be burst within limited hours: from 6 to 7 am and 8 to 10 pm on October 19 and 20. The Delhi Police and Pollution Control Committee have launched patrols and surprise checks to curb the sale of non-certified crackers. Only crackers certified by NEERI and carrying valid QR codes are permitted for sale through licensed vendors.

Health experts sound alarm

Doctors have warned that exposure to such high pollution levels can aggravate asthma, heart disease, and respiratory illnesses, particularly among children and the elderly. Residents have been advised to wear N95 masks outdoors, avoid morning walks, and use air purifiers indoors.

Recurring Diwali pattern

If emissions remain unchecked, experts fear Delhi could once again turn into a “gas chamber” after Diwali night, mirroring the toxic trends of previous years. A 2024 study by the Centre for Science and Environment reported a 46 per cent surge in PM2.5 levels around Diwali, with concentrations peaking at 603 µg/m³ on Diwali night — a figure 13 per cent higher than 2022 and 2023 levels.

Satellite imagery has also detected nearly 1,000 stubble-burning incidents across northern India this season, worsening the smog over the capital. Unless strict controls are implemented and weather conditions improve, Delhi may find itself trapped in a grey haze once again.