Delhi named most polluted megacity in NCR for 2025: Report

The assessment was based on Central Pollution Control Board (CPCB)’s monitoring data available up to December 30, 2025, which was released on Tuesday.

Delhi was the most polluted megacity in India and within the National Capital Region in 2025, an analysis of PM2.5 data by the Centre for Research on Energy and Clean Air (CREA) revealed on Wednesday. The report shows that despite a slight decline in its annual average, Delhi’s air pollution levels remain dangerously high and far exceed national and international safety standards.

Within the Capital, pollution levels varied significantly but remained universally hazardous. (ANI Video Grab)

The assessment was based on Central Pollution Control Board (CPCB)’s monitoring data available up to December 30, 2025, which was released on Tuesday.

On the same day, the Centre for Science and Environment (CSE) also released its analysis on pollution in Delhi-NCR. The environmental think-tank looked at data from the Decision Support System (DSS) for the post-stubble burning period (December 1-15, 2025), stating that only about 35% of Delhi’s total PM2.5 originated from local sources within the city. The remaining 65% of pollution is attributed to NCR districts and other regions outside the city limits.

“Transport or vehicles remains the single largest contributor, accounting for nearly half -- 46% -- of Delhi’s local 2.5 load during this period. The industrial sector contributed 22 per cent to the local pollution profile. Household-level emissions accounted for 11 per cent. Other sectors, including construction, energy use, waste burning, and road dust, contributed smaller but persistent shares,” the analysis said.

Through 2025, Delhi’s annual average PM2.5 concentration stood at 96 micrograms per cubic metre (µg/m³). This is well above India’s national ambient air quality standard of 40 µg/m³ and a staggering 19.2 times higher than the World Health Organization’s annual guideline of 5 µg/m³. Among NCR cities with sufficient monitoring data, Delhi was followed by Ghaziabad (93 µg/m³) and Noida (82 µg/m³).

The CREA analysis also highlighted major gaps in regional air quality monitoring. Of 29 NCR cities, only 14 had more than 75% data coverage for PM2.5 in 2025, it said. The remaining 15 cities with insufficient data were all in Haryana, pointing to a critical lack of consistent monitoring across the region. Except for Bharatpur and Alwar in Rajasthan, every NCR city with adequate data exceeded the annual national PM2.5 standard.

Delhi also fared the worst among India’s five major megacities. Its levels were more than double those of Kolkata (45 µg/m³) and nearly triple those of Mumbai (34 µg/m³). Bengaluru showed marginal improvement at 29 µg/m³, while Chennai saw a slight deterioration to 30 µg/m³.

Within the Capital, pollution levels varied significantly but remained universally hazardous. The industrial area of Jahangirpuri was the most polluted location with an annual average of 130 µg/m³, followed by Wazirpur (124 µg/m³ and also industrial) and Bawana (123 µg/m³). Even the cleanest monitored location, NSIT Dwarka, recorded an average of 73 µg/m³ – 1.8 times the national standard.

Seasonal analysis revealed that Delhi’s PM2.5 concentrations in April, August, and December were higher in 2025 than in the previous year, indicating that severe pollution is no longer confined to the winter months.

“The NCR situation shows that elevated pollution now persists throughout the year rather than being confined to a few months. The lack of improvement highlights the limitations of short-term, reactive measures and highlights the need for sector-specific emission reduction targets that address dominant year-round sources of pollution, including significant transboundary contributions,” said Manoj Kumar, analyst at CREA.