Does ‘Good Air Quality’ Not Exist Anymore? Study Says No Indian Metro City Had Safe Air In The Last 10 Years

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decade long study of air pollution conducted across major urban cities of the country found out that none of the top ones met safe Air Quality Index (AQI) levels ever between 2015 to 2025.The report of the study prepared by Climate Trends that works as an environmental research firm analysed the long-term lingering pollution patterns across 11 major cities of the nation. According to the reports, Delhi remained India's most polluted city throughout the period of study, with an average AQI of 250 in 2016 and hovering over 180 this year.

While there were marginal dips after 2019, the national capital has always failed to approach healthier air-quality thresholds. Vehicular emissions, crop burning and industrial pollution were some of the major contributors, all compounded by the region's geographical constraints that make it more prone to fog and pollution. However, other cities such as Varanasi, Lucknow, Ahmedabad, which recorded persistently high average AQI values the first half of the 10 year long study, gradually showed some improvement in the second half. While other southern and western cities such as Mumbai, Chennai, Bengaluru and Pune recorded relatively moderate AQI levels. But still, none of them meet safe thresholds. Bengaluru posted its lowest AQI readings in the country, between 65 and 90, still being far away from the 'good' category.

AQI is recorded by and is based on the concentration of toxic particulate matter, PM2.5 or PM10 or both in the air, whichever is higher. Alongside this, geography of the city also plays a significant role in prolonging the pollution episodes, especially across the northern plains. When the cold winds sweep into the plains and minimum temperatures start to dip, the pollutants are trapped and it becomes harder for them to disperse. This also leads to increase in the AQI level.