4 years into clean air programme, pollution levels rising in cities

Four years after the launch of the National Clean Air Programme (NCAP) and an expenditure of Rs 6,897 crore, data shows that less polluted cities like Bengaluru, Mumbai and Chennai are seeing an increase in pollutants while the worst ones marginally improved their air quality.

The Centre launched the NCAP in January 2019 to take up mitigation measures in 102 polluted cities, classified as 'non-attainment cities' as the levels of particulate matter (PM) 2.5 and PM10 breached the ceiling set by the National Ambient Air Quality Standards (NAAQS).

The permissible levels of PM2.5 and PM10 as per NAAQS are 40 micrograms/cubic metre and 60 micrograms/cubic metre, respectively. Though these are highly diluted standards compared with those set by the World Health Organisation, experts considered the programme to be a good start as the government pushed cities to meet the national standards by 2024.

NCAP Tracker, a joint project by Climate Trends and Respirer Living Sciences, picked 10 cities each from the top and bottom of the list of polluted cities to compare their performance with the latest (2022) annual average data. The exercise revealed a gradual worsening of air quality in cities that were at the bottom of the list. The number of non-attainment cities went up to 132 from 102.

In Mumbai, the annual average of PM10 rose from 82 micrograms/cubic metre in 2019 to 120. Bengaluru (74 to 75), Nashik (68 to 74), Chennai (55 to 65) and Pune (87 to 92) also saw gradual worsening. Rajahmundry and Hubballi were two exceptions by reducing PM10 levels by a few micrograms, though they remained above the annual average.

PM2.5 levels were also increasing in these cities, inching closer to NAAQS ceiling or breaching it. Bengaluru's count increased from 32 micrograms/cubic metre in 2019 to 36 while Mumbai crossed the safety standards (34 to 49).

The study noted that the higher numbers were also due to better monitoring. "In 2019, there were just nine continuous air quality monitoring stations in Mumbai, which improved to 20 operational (stations) in 2022. Clearly, a wider network of data allowed for an improved understanding of pollution trends in Mumbai," it said.

Bengaluru has seven continuous monitoring stations and 13 manual stations. Authorities are planning to set up additional stations which will give a real picture of the city's air quality.

There was marginal improvement among the most polluted cities. Ghaziabad, the worst performer in 2019, saw a decline in PM2.5 from 117 micrograms/cubic metre to 91/cubic metre in 2022. The trend was observed in Noida (114 to 80), Delhi (108 to 100), Varanasi (91 to 58), Jodhpur (82 to 69) and others.

PM10 levels also dipped slightly in Ghaziabad (243 in 2019 to 218 in 2022), Delhi (217 to 213) and Noida (217 to 212).

Aarti Khosla, Director of Climate Trends, said, "While the Central Pollution Control Board has already issued stricter reduction targets for non-attainment cities, we are just a year away from 2024, the original target for NCAP. Many cities are still far from reaching their targets and may be unable to do so without aggressive plans and stringent measures."

Ronak Sutaria, Founder and CEO of Respirer Living Sciences, said the deterioration in air quality of lesser polluted cities was a concern. He said the most polluted cities were seeing marginal improvement due to implementation of action plan while the lesser polluted ones were getting worse due to less vigilance.