The rising threat of air pollution in India’s small cities

livemint.com:

Bihar and Odisha, far away from the glitz of metros, data from the Central Pollution Control Board show. Diwali is just one sample point. In many non-metro cities, the average daily level of the PM2.5 pollutant through the year exceeds the safe zone.

(PM2.5 is fine particulate matter that can penetrate the lung barrier and enter the blood system.) An analysis of the three most populous cities in each state (these are mostly tier-2 and tier-3 cities) confirms this. Out of 54 such cities with available data, 37 have averaged PM2.5 levels above India's acceptable standard of 40 micrograms per cubic metre (μg/m³) in 2023 so far, shows an analysis by Respirer Living Sciences, a climate tech startup that tracks official air quality data. (The World Health Organization uses a stricter safe PM2.5 limit of 5 μg/m³.) While Delhi and its neighbour Gurugram were the most polluted, next on the list was Bihar's capital city Patna (89 μg/m³).

Bhagalpur in Bihar (81.4 μg/m³), Cuttack in Odisha (80 μg/m³), and Dhanbad in Jharkhand (72.1 μg/m³) also registered high average pollution levels. For 12 cities, including Ludhiana, Coimbatore, Chandigarh, Nagpur, and Amritsar, November 2023 was more polluted in terms of PM2.5 levels than November 2019, Respirer’s analysis shows. Only looking at state capitals, out of the 15 that had data for both those months, seven saw increased PM2.5 levels.