New Indian Express - Delhi
Toxic start to winter: Delhi-NCR's pre-Diwali PM2.5 touches three-year high, says CSE
Delhi-NCR's early-winter air pollution has worsened this year, with the average PM2.5 concentration in the week preceding Diwali touching a three-year high, while vehicular emissions and regional pollution inflow continued to drive the toxic air, according to a new analysis by the Centre for Science and Environment (CSE).
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The analysis released on Wednesday said the average PM2.5 concentration during the week before Diwali stood at 236 micrograms per cubic metre, marking a 97 per cent increase from 120 micrograms per cubic metre in 2025 and a 32 per cent rise from 179 micrograms per cubic metre in 2024.
It said pollution levels were generally higher in the pre-winter period this year than in 2025, except for a brief decline in late September due to rainfall.
CSE said the findings highlighted the failure of year-round pollution control measures, with Diwali firecrackers aggravating an already deteriorating situation rather than being the sole cause of the pollution crisis.
"Baseline pollution is higher than in previous years," said Anumita Roychowdhury, executive director of research and advocacy at CSE, adding that inadequate emission control across major pollution sources had contributed to the worsening air quality.
The analysis, based on air quality data from the Central Pollution Control Board (CPCB), pollution-source contribution estimates from the Indian Institute of Tropical Meteorology (IITM), crop fire data and traffic analytics from Tom Tom (the geological and mapping technology company that aggregates GPS data), said vehicular transport remained the largest contributor among Delhi's local pollution sources.
Pioneer - New Delhi
City’s pre-Diwali PM2.5 at 3-year high: CSE
Delhi’s average PM2.5 concentration in the week preceding Diwali touched a three-year high of 236 micrograms per cubic metre, nearly double the level recorded last year. Vehicular emissions, pollution drifting from neighbouring NCR districts and persistent traffic congestion are emerging as major drivers of the capital’s worsening air quality, according to a new analysis by the Centre for Science and Environment (CSE) released on Wednesday.
The findings point to a deterioration in Delhi-NCR’s baseline air quality even before Diwali firecrackers and seasonal stubble burning added to the pollution burden. The analysis found that average PM2.5 levels during the pre-Diwali week were 97 per cent higher than the 120 micrograms per cubic metre recorded in 2025 and 32 per cent above the 179 micrograms per cubic metre registered in 2024.
The report also questioned the effectiveness of emergency traffic restrictions imposed under the Graded Response Action Plan (GRAP), stating that the curbs failed to improve weekday congestion significantly. It found that evening traffic continued to expose residents to elevated levels of nitrogen dioxide (NO2), a pollutant largely associated with vehicular emissions, with concentrations remaining high until midnight.
Drawing on air quality data from the Central Pollution Control Board (CPCB), pollution-source estimates from the Indian Institute of Tropical Meteorology (IITM), crop-fire data from the Indian Agricultural Research Institute and traffic analytics from TomTom, the analysis attributed the deterioration to inadequate year-round emission control.
“Baseline pollution is higher than in previous years,” said Anumita Roychowdhury, executive director of research and advocacy at CSE, arguing that firecrackers and farm fires had aggravated an already polluted atmosphere rather than being the sole cause of the crisis. An analysis of IITM’s Decision Support System data for November 1-8 found that pollution transported from neighbouring NCR districts accounted for 54.43 per cent of Delhi’s PM2.5 burden, while local sources contributed 33.06 per cent and stubble burning accounted for 14.29 per cent.
Among Delhi’s local emission sources, vehicular transport was the largest contributor at 52 per cent, followed by residential activities at 13 per cent and peripheral industries at 11 per cent. Construction contributed seven per cent, while energy use and waste burning accounted for five per cent each. Road dust and other sources contributed four per cent each.
The analysis also found that severe pollution episodes continued even as farm fires’ contribution declined. Stubble burning’s share of Delhi’s PM2.5 pollution stood at 3.9 per cent during the initial GRAP Stage I restrictions, rose to 11.5 per cent on November 1, and subsequently declined to 8.6 per cent on November 2. It peaked at 16.2 per cent on November 4 before falling to around eight per cent on November 6, when Delhi’s AQI reached 382, and GRAP Stage III restrictions were invoked.
The study also flagged a shift in Delhi’s pollution hotspots. While 11 of the city’s 13 officially designated hotspots recorded lower PM2.5 concentrations between October 1 and November 8 than in the same period last year, several other locations emerged as areas of concern.
Anand Vihar recorded a 49 per cent decline, followed by Wazirpur at 41 per cent, Ashok Vihar at 40 per cent and Bawana at 22 per cent. However, Jahangirpuri remained the most polluted designated hotspot, with an average PM2.5 concentration of 163 micrograms per cubic metre.
Among emerging hotspots, Vivek Vihar recorded 144 micrograms per cubic metre, followed by Sonia Vihar at 139, ITO at 137 and Delhi Technological University at 135. On the effectiveness of traffic restrictions, CSE’s analysis found that Delhi recorded an average daily Travel Time Index (TTI) of 2.40 during November 2-6, against 2.38 on October 30, immediately before the restrictions. The evening peak index also remained virtually unchanged at 3.49 against 3.48.
Between January and April, commuters took 13 per cent longer to complete journeys than under normal weekday conditions. Evening journeys took 13 to 31 per cent longer. Nitrogen dioxide concentrations also rose by nearly one-third from November 2, even as congestion levels remained largely unchanged.
Urban Acres
Delhi Air Pollution Worsens as 22 New Hotspots Emerge
Delhi air pollution worsened on Wednesday as the city’s average Air Quality Index rose to 313, placing it in the very poor category, while 22 new pollution hotspots were identified in a report issued by the Centre for Science and Environment. The deterioration came even as temperatures fell below 15 degrees Celsius for the first time this season.
The Central Pollution Control Board recorded Delhi’s average AQI at 313, 14 points higher than Tuesday’s reading of 299, which was in the poor category. The air quality in the Delhi Technological University area was the worst among the city’s monitored locations, crossing 400 on Wednesday evening and entering the severe category.
The rise followed a brief period of improvement in Delhi’s air quality. According to the report issued by the Centre for Science and Environment, older pollution hotspots appeared to be showing some improvement, but new hotspots were developing at a faster pace. The report identified 22 locations where pollution hotspots were emerging.
Urban Acres
Delhi Air Pollution Reveals Why Local Emissions Still Defeat GRAP-3
Delhi air pollution has intensified at the beginning of the winter season even as the contribution from stubble burning has declined, according to an analysis by the Centre for Science and Environment (CSE) reported by Navbharat Times. The finding shifts attention from a familiar seasonal explanation towards the wider urban system: emissions generated within Delhi, pollution transported from other National Capital Region cities, and weather conditions that allow pollutants to accumulate over the capital.
The CSE analysis found that the average PM2.5 concentration in Delhi during the week before Diwali was 236 micrograms per cubic metre. The report described this as the highest average for the corresponding period in the past three years. The level was 97% higher than in 2025 and 32% higher than in 2024, according to the figures cited in the report.
The numbers matter because they show that a reduction in one highly visible source has not translated into cleaner air overall. Stubble burning has long occupied a central place in public discussions about Delhi’s winter pollution. However, the CSE assessment cited by the report indicates that the seasonal pollution episode cannot be understood through farm fires alone. The contribution of local emissions and pollution arriving from other parts of the NCR remains substantial.
The distinction is important for governance. A source that is geographically outside Delhi may still affect the city’s air, while sources within the capital’s boundaries may be harder to control because they are dispersed across transport, households, construction and commercial activity. This makes the problem less amenable to a single emergency measure and more dependent on coordination across jurisdictions.