NEW DELHI: Ninety-five out of 132 polluted cities identified under a national programme on clean air have shown improvement in air quality by reducing particulate matter (PM10) concentration in 2021-22 compared to 2017, with Varanasi recording the highest 53% reduction in the level of hazardous pollutant during the period, claimed the government in its analysis, even as the green thinktank Centre for Science and Environment (CSE) has flagged limitations of such city-based approach.
The analysis found that 20 of the 95 cities, including Chennai, Madurai, Nashik and Chittur, have even conformed to the National Ambient Air Quality Standards (NAAQS) that put acceptable annual average limit of PM10 at 60 micrograms per cubic meter (µg/m3).
The analysis, done by the environment ministry, has, however, not factored in the other fine and more hazardous particulate matter, PM2. 5, for the sake of uniformity as only PM10 is monitored in all 132 cities. Under the national clean air programme (NCAP), the ministry has set targets of 20-30% reduction in particulate matter concentration by 2024 from 2017 levels across the country. Only 43 NCAP cities have adequate PM2. 5 data for the period 2019-2021.
Besides Varanasi that reported the biggest improvement, the other cities thathave shown improvement in PM10 levels during that period include Delhi, Mumbai, Kolkata, Bengaluru, Hyderabad, Noida, Ghaziabad, Lucknow, Kanpur, Agra, Pune, Nagpur and Chandigarh. The PM10 concentration in most of the cities, however, continues to be figured at much higher levels than the targets as well as the NAAQS limit despite showing improvement.
For example, in Delhi, the PM10 level reduced from 241µg/m3 in 2017 to 196 µg/m3 in 2021-22 — a reduction of 18%, but it is more than three times of the acceptable limit of 60 µg/m3. In Mumbai, the PM10 level reduced from 151µg/m3 in 2017 to 106 µg/m3 in 2021-22. In Kolkata, it reduced from 119 µg/m3 in 2017to 105 µg/m3 in 2021-22.
The CSE warned that the existing clean air action plans that draw hard boundaries around cities for the clean-up job are failing to address the major pollution sources in the larger orbit.
“The science of regional influence of pollution has begun to take shape in India. The NCAP has taken on board the principle of regional air quality management. But there is no regulatory framework to enable multi-jurisdiction management for aligned action and to establish the upwind and downwind responsibilities of state governments to improve regional air quality,” said Anumita Roychowdhury, executive director, CSE.