CPCB flags rising ozone pollution in Pune and Mumbai.
Multiple monitoring stations report frequent breaches of safe limits.
Experts warn of health risks, urge urgent emission control.
Pune, 29 September 2025: Maharashtra’s two biggest cities, Pune and Mumbai, are emerging as new hotspots for dangerous ozone pollution, according to fresh data from the Central Pollution Control Board (CPCB).
The findings, submitted to the National Green Tribunal (NGT) on September 25, reveal that ozone levels in both cities frequently cross the National Ambient Air Quality Standards (NAAQS), placing them among India’s most affected urban centres after Delhi.
The CPCB analysed data from 178 monitoring stations across 10 major cities including Delhi, Bengaluru, Kolkata, Hyderabad, and Chennai. In the Pune Metropolitan Region (PMR), six out of 12 monitoring stations reported ozone exceedances, while the Mumbai Metropolitan Region (MMR) recorded violations at 22 out of 45 stations.
Both cities also experienced short-term spikes and rare night time breaches, with at least one station in each city showing levels above prescribed limits even after sunset.
Experts attribute the rise to a combination of traffic emissions, industrial activity, and chemical reactions triggered by heat and sunlight. Ground-level ozone forms when nitrogen oxides (NOx) and volatile organic compounds (VOCs) react in the atmosphere, with carbon monoxide (CO) and methane also playing a role. These pollutants come from vehicles, power plants, and natural sources like soil emissions and wildfires.
Sachin Ghude, head of the Metropolitan Air Quality and Weather Forecasting Services (MAQWS) at IITM, said ozone levels in Pune and Mumbai are exceeding safe limits on certain days mainly due to chemical reactions and heavy traffic. He cautioned that while the current levels are not yet extreme, they pose health risks and could rise further if left unchecked.
The CPCB has urged policymakers and civic authorities to take immediate steps to curb emissions and protect public health, warning that unchecked ozone pollution can lead to respiratory problems and long-term environmental damage.