CHENNAI: An analysis done by Climate Trends has revealed that the air quality index (AQI) of Chennai has improved after 2020 but still remains in unsafe ranges during the study period between 2015 and 2025.
As per the study report, Kolkata, Chennai, Chandigarh, Visakhapatnam, and Mumbai present moderate AQI values compared to northern cities but still fail to reach consistently safe levels.
Some cities like Chennai and Mumbai show notable improvement after 2020, reflecting the impact of regulatory measures, better fuel standards, and reduced industrial activity during the pandemic years. As part of the study, Climate Trends analysed AQI data recorded in 11 Indian cities during the last decade.
Among them, Bengaluru had the lowest AQI values, remaining largely between 65 and 90. Delhi remains a severely polluted city. In Chennai, AQI ranged mostly between 80 and 140. “The data clearly shows that none of the top Indian cities can be considered safe in terms of air quality during this entire period. Although some cities show gradual improvement in recent years, AQI levels remain consistently above recommended safe thresholds,” the report said.
The findings highlighted the continued impact of traffic emissions, industrial activity, seasonal factors, and rapid urbanisation across the country. The decade-long trend reinforces the need for stronger environmental policies, sustained regulatory enforcement, cleaner energy transitions, and coordinated pollution-control initiatives to safeguard public health and advance long-term urban sustainability, the report said.