The Central Pollution Control Board (CPCB) has raised alarms over growing ground-level ozone pollution in India’s urban regions, with the National Capital Region (NCR) and Mumbai Metropolitan Region (MMR) being the worst affected. Unlike the protective stratospheric ozone layer, surface ozone is a harmful pollutant that affects both health and the environment.
Key Findings
- NCR recorded the highest ozone exceedances, with nearly half its monitoring stations crossing the safe eight-hour limit of 100 µg/m³.
- MMR followed, while cities like Pune, Chennai, and Bengaluru showed moderate but notable levels.
- In 2023–24, multiple stations breached the stricter one-hour standard of 180 µg/m³, particularly during summer months.
Causes and Sources
Ozone forms when nitrogen oxides (NOx) and volatile organic compounds (VOCs) from vehicles, industries, and power plants react under sunlight. Additional precursors include carbon monoxide and methane from households, agriculture, and natural sources like wildfires.
Impact on Health and Environment
Exposure to ozone can trigger coughing, chest pain, and worsen asthma. Long-term effects include chronic respiratory illness. It also damages crops, forests, and biodiversity, threatening food security.
Action Ahead
The National Green Tribunal (NGT) has taken note of the crisis, urging stricter emission controls and cleaner technologies. CPCB’s ongoing monitoring aims to identify hotspots and guide regulatory measures to safeguard public health and the environment.
