New Delhi: Ground-level ozone emerged as one of Delhi’s most widespread air pollution challenges this May, with nearly half of the city’s air quality monitoring stations recording violations of national standards and several locations experiencing sustained exposure throughout the month.
Ozone Hotspots Identified Across Delhi
According to an analysis by the Centre for Research on Energy and Clean Air (CREA), 24 of the city’s 45 monitoring stations recorded at least one exceedance of standards for ozone. The analysis identified five major ozone hotspots across the city. The highest concentration was recorded at Pusa (IITM), where the maximum eight-hour ozone average touched 292 micrograms per cubic meter, nearly three times the national standard of 100 micrograms per cubic meter. This was followed by NSUT Jaffarpur (229 micrograms per cubic meter), Commonwealth Sports Complex (208 micrograms per cubic meter), Delhi University North Campus (207 micrograms per cubic meter), and Chandni Chowk (178 micrograms per cubic meter).
Persistent Ozone Exposure
Pusa recorded ozone exceedances on 25 days during May, the highest in Delhi. Several other locations also witnessed persistent ozone exposure. The findings are notable because the affected stations span institutional, residential, and urban-background areas, suggesting that ozone pollution is not restricted to traffic-heavy corridors or industrial clusters.
Unlike particulate matter, ozone is not emitted directly from any source. “Delhi’s ozone hotspots reflect the science of how ozone forms: it is not directly emitted, but produced in the atmosphere when sunlight drives reactions between nitrogen oxides and volatile organic compounds, with transport and local chemistry shaping where it builds up most,” said Manoj Kumar, India analyst at CREA.
Year-Round Concern
The findings add to growing evidence that ozone is becoming a year-round concern in Delhi. Earlier analysis of Central Pollution Control Board data showed ozone emerging as the lead pollutant in the daily air quality index on 16 of the 28 days this February, eight days in March, and two days in January. In contrast, ozone was the lead pollutant on nine days in February 2025 and did not emerge as the dominant pollutant in February 2023.
Regulatory Attention
The increasing prominence of ozone has prompted greater regulatory attention. Last December, the Union environment ministry informed the National Green Tribunal that it would constitute an expert panel to study ground-level ozone pollution, mitigation strategies, and associated health impacts.
You Can Also Check: Gold Rate in Delhi | Silver Rate in Delhi | Bank Holidays in Delhi | Public Holidays in Delhi | Delhi AQI | Weather in Delhi | Petrol Price in Delhi | Diesel Price in Delhi | CNG Price in Delhi | LPG Price in Delhi
About the Author: Kushagra Dixit writes on environmental issues, wildlife conservation, climate change, agriculture, human rights, and scientific research. His investigative coverage encompasses river contamination with emphasis on the Yamuna, air pollution, urban waste, and their collective effects on public wellbeing.
