Even as farm fires remained at a multi-year low, Delhi-NCR’s winter air quality continued to choke residents, oscillating between the ‘very poor’ and ‘severe’ categories for most of October and November. A new analysis by the Centre for Science and Environment (CSE) shows that the capital’s air is now being fuelled largely by a rising “toxic cocktail” of PM2.5, nitrogen dioxide (NO2), and carbon monoxide (CO)—pollutants linked mainly to traffic and local combustion activities.
CO Levels Breach Limits at 22 Monitoring Stations
CSE found that 22 air-quality monitoring stations recorded CO levels above permissible limits on more than 30 of the 59 days assessed.
- Dwarka Sector 8 had the highest number of breaches (55 days).
- Jahangirpuri and Delhi University’s North Campus followed with 50 breach days each.
The report highlights the rapid expansion of pollution hotspots across Delhi.
Pollution Hotspots Multiply Across Capital
In 2018, Delhi officially had 13 hotspots. Today, many more areas routinely record pollution levels far higher than the city average.
Most Polluted Hotspots (Annual PM2.5 averages):
- Jahangirpuri – 119 µg/m³
- Bawana & Wazirpur – 113 µg/m³
- Anand Vihar – 111 µg/m³
- Mundka, Rohini & Ashok Vihar – 101–103 µg/m³
CSE also flagged Vivek Vihar, Alipur, Nehru Nagar, Siri Fort, Dwarka Sector 8 and Patparganj as emerging hotspots.
NCR Towns Also See Intense, Prolonged Smog
Smaller NCR regions witnessed longer smog episodes this year.
- Bahadurgarh recorded the longest continuous smog spell: 10 days (November 9–18).
The trend shows NCR increasingly behaving as one connected airshed with uniformly high pollution.
Farm Fires Low, But Local Pollution Drives Smog
The report underscores that despite low stubble-burning incidents—due in part to flood-related disruptions in Punjab and Haryana—Delhi’s early winter pollution plateaued at unhealthy levels.
Farm Fire Contribution:
- Mostly below 5%
- Rose to 5–15% on some days
- Peaked at 22% on November 12–13
CSE says the significant drop prevented extreme spikes but did not improve daily air quality, which remains dominated by local sources such as traffic, industries, waste burning and domestic fuels.
Traffic-Linked Pollutants Peaked During Rush Hours
Researchers found a strong synchronised pattern between PM2.5 and NO2:
- 7–10 am and 6–9 pm: sharp spikes during peak traffic
- NO2 showed sudden peaks;
- PM2.5 rose more gradually but stayed elevated for longer
- CO exceeded the 8-hour standard at several sites
CSE’s Anumita Roychowdhury said:
“These patterns show particulate pollution is being fuelled daily by traffic-related emissions of NO2 and CO, especially under low-dispersion winter conditions. Yet, winter control efforts remain dominated by dust measures, with weak action on vehicles, industry, waste burning and solid fuels.”
Toxic Winter Continues Despite Lower Firecrackers, Fewer Stubble Fires
Key findings for October–November:
- PM2.5 remained the primary pollutant on 34 days
- PM10 dominated on 25 days
- Ozone on 13 days
- CO on 2 days
The AQI stayed in ‘very poor’ to ‘severe’ for most of November.
While peak pollution levels were lower than in the past three winters, average pollution showed no meaningful improvement.
- PM2.5 levels were 9% lower than last year,
- but remained similar to the three-year baseline.
Between 2018 and 2020, PM2.5 levels declined—partly due to Covid lockdowns. Since 2021-22, however, levels have plateaued at elevated ranges.
In 2024, the annual average rose sharply to 104.7 µg/m³, reversing earlier gains.
What CSE Recommends
The report calls for deep structural reforms, including:
- Time-bound electrification targets
- Scrapping of old polluting vehicles
- Expanded public transport & better last-mile connectivity
- Walking and cycling infrastructure
- Parking caps & congestion taxes
- Cleaner industrial fuels
- Lower gas taxes
- Strict elimination of waste burning
- Improved segregation and remediation of legacy dumps
Current Air Quality
As of Monday, Delhi’s 3 pm AQI was 303, placing it in the ‘very poor’ category, according to the CPCB.