Nearly 44 per cent Indian cities face chronic air pollution, indicating a structural problem driven by persistent emission sources rather than short-term episodes, an analysis by the Centre for Research on Energy and Clean Air (CREA) has found.

However, only 4 per cent of these cities are covered under the National Clean Air Programme (NCAP), the report said.

Using satellite data, CREA assessed PM2.5 levels in 4,041 Indian cities.

"Out of 4,041, at least 1,787 cities exceeded the national annual PM2.5 standard every year across five recent years (2019-2024), excluding the COVID-affected year of 2020. This means nearly 44 per cent of Indian cities face chronic air pollution, indicating a structural problem driven by persistent emission sources rather than short-term episodes," the report said.

The PM2.5 assessment for 2025 ranks Byrnihat (Assam), Delhi, and Ghaziabad (Uttar Pradesh) as India's top three most polluted cities with annual concentrations of 100 µg/m³, 96 µg/m³, and 93 µg/m³, respectively.

Noida is the fourth on the list, followed by Gurugram, Greater Noida, Bhiwadi, Hajipur, Muzaffarnagar, and Hapur.

"Yet, India's flagship NCAP covers only a fraction of this burden. Just 130 cities were included under NCAP, and only 67 overlap with the 1,787 persistently non-attainment cities. As a result, NCAP currently addresses only 4 per cent of India's chronically polluted cities, leaving the vast majority outside targeted clean air action," it added.

Non-attainment cities are urban areas identified by the Central Pollution Control Board (CPCB) that consistently fail to meet the National Ambient Air Quality Standards (NAAQS) over several years.