Hyderabad: Ozone pollution breached safe limits across four major Indian cities this summer, with Hyderabad logging 22 days of unsafe air, according to a study by the Centre for Science and Environment (CSE).
The data, recorded between March 1 and May 31, showed a sharp spike in surface-level ozone concentrations in Hyderabad, Kolkata, Mumbai, and Bengaluru.
In Hyderabad, ozone levels exceeded the safety threshold on 22 separate days, with a peak reading of 51 micrograms per cubic metre. Compared to last year’s data, air quality fell by 55 per cent.
Mumbai recorded 32 days above the safe mark, with the highest daily concentration touching 90 micrograms. Air quality in the city dropped 42 per cent year-on-year.
Kolkata matched Hyderabad with 22 unsafe days, registering a 45 per cent decline in ozone air quality. Bengaluru crossed the safety limit on 45 days, but saw a 29 per cent improvement over the previous summer.
Ozone at ground level forms through chemical reactions between nitrogen oxides, volatile organic compounds, and carbon monoxide, mostly emitted by vehicles, power plants, and industries.
Unchecked, this form of pollution could pose a serious public health risk, warned CSE executive director Anumita Roy Chowdhury.