New Delhi: Even with farm fires at multi-year lows, Delhi-NCR’s winter air remains dangerously polluted. For most of October and November, air quality levels oscillated between ‘very poor’ and ‘severe’, driven largely by a “toxic cocktail” of PM2.5, nitrogen dioxide (NO2) and carbon monoxide (CO), primarily emitted from vehicles and other local sources.
According to a new analysis by the Centre for Science and Environment (CSE), at least 22 air-quality monitoring stations in Delhi recorded CO levels above permissible limits on more than 30 of the 59 days assessed. Dwarka Sector 8 logged the highest number of breaches at 55 days, followed by Jahangirpuri and Delhi University’s North Campus at 50 days each.
The report also highlights a troubling rise in pollution hotspots. In 2018, only 13 locations were officially designated as hotspots. Now, several areas consistently record pollution levels far above the city average. Jahangirpuri emerged as Delhi’s most polluted hotspot, with an annual PM2.5 average of 119 µg/m³, followed by Bawana and Wazirpur (113 µg/m³), Anand Vihar (111 µg/m³), and Mundka, Rohini, and Ashok Vihar (101–103 µg/m³). New hotspots flagged by CSE include Vivek Vihar, Alipur, Nehru Nagar, Siri Fort, Dwarka Sector 8, and Patparganj.
Smaller towns in the NCR also recorded prolonged smog events. Bahadurgarh experienced the longest continuous episode, lasting 10 days from November 9 to 18, indicating the region increasingly behaves as a single airshed with uniformly high pollution levels.
CSE’s assessment finds that early winter pollution has plateaued at unhealthy levels, driven mainly by local emissions, even as stubble burning has declined significantly. The analysis, based on CPCB data, shows that PM2.5 levels rose and fell almost in tandem with NO2 during peak traffic hours (7–10 am and 6–9 pm), while CO frequently breached the eight-hour standard across several locations.
“This synchronised pattern reinforces that particulate pollution spikes are being fuelled daily by traffic-related emissions of NO2 and CO, especially under low-dispersion conditions,” said Anumita Roychowdhury, Executive Director (Research and Advocacy), CSE. She added, “Yet, winter control efforts remain dominated by dust measures, with weak action on vehicles, industry, waste burning and solid fuels.”
Stubble burning in Punjab and Haryana was subdued this year, partly due to floods disrupting the crop cycle. For most of early winter, farm fires contributed less than 5 per cent to Delhi’s pollution, rising to 5–15 per cent on some days, and peaking at 22 per cent on November 12–13. While this decline prevented extreme spikes, it had little effect on daily air quality. PM2.5 remained the dominant pollutant on 34 days, followed by PM10 on 25 days, ozone on 13 days, and CO on two days.
Despite reduced firecracker use and limited farm-fire impact, average pollution levels showed almost no improvement compared to past winters. PM2.5 levels for October–November were about 9 per cent lower than last year, but compared to the three-year baseline, no meaningful progress was observed. Between 2018 and 2020, PM2.5 levels had steadily declined, partly due to the pandemic, but since 2021–22, annual averages have plateaued. In 2024, the annual average surged to 104.7 µg/m³, reversing earlier gains.
The report recommends deep structural measures to curb emissions across sectors, including time-bound electrification targets, scrapping older vehicles, expanding public transport and last-mile connectivity, and improving walking and cycling infrastructure. It also calls for parking caps, congestion taxes, cleaner industrial fuels, lower gas taxes, elimination of waste burning, better waste segregation, and remediation of legacy dumps.
On Monday, Delhi’s AQI at 3 pm stood at 303, placing it in the ‘very poor’ category, according to the CPCB air quality bulletin.
With PTI inputs