Explained | Where do Indian cities stand on toxic air?

What are the limits for particulate matter? Has the National Clean Air Campaign made a difference?

January 15, 2023 03:10 am | Updated January 21, 2023 06:37 pm IST

A bird flies over a metro line engulfed in smog in Gurugram on January 13, 2023.

A bird flies over a metro line engulfed in smog in Gurugram on January 13, 2023. | Photo Credit: AP

The story so far: Four years since the Centre launched the National Clean Air Campaign (NCAP), analysts found that progress has been slow and pollution only incrementally reduced in most cities.

What is the NCAP?

Following years of evidence that many Indian cities were among the most polluted in the world, the government launched the NCAP that committed funds as well as set targets for 131 of India’s most polluted cities on January 10, 2019. The 131 cities are called non-attainment cities, as they did not meet the national ambient air quality standards (NAAQS) for the period of 2011-15 under the National Air Quality Monitoring Programme (NAMP).

What are the target levels?

The country’s current, annual average prescribed limits for the two main classes of particulate matter (PM2.5 and PM10) are 40 micrograms/per cubic metre (ug/m3) and 60 micrograms/per cubic metre. The NCAP initially set a target of reducing key air pollutants PM10 and PM2.5 by 20-30% in 2024, taking the pollution levels in 2017 as the base year to improve upon. In September 2022, however, the Centre moved the goalposts and set a new target of a 40% reduction in particulate matter concentration, but by 2026. To meet these targets, approximately ₹6,897.06 crore has been disbursed to the cities by the government. For administering funds, the Central Pollution Control Board (CPCB), which coordinates the programme, looks at a city’s PM10 levels — the relatively larger, coarser particles. However, PM2.5, the smaller, more dangerous particles, aren’t monitored as robustly in all cities, mostly due to the lack of equipment. Cities were required to quantify improvement starting from 2020-21, which requires 15% and more reduction in the annual average PM10 concentration and a concurrent increase in “good air” days to at least 200. Anything fewer will be considered ‘low’ and the funding, provided by the Centre via the Environment Ministry, consequently reduced.

How effective has the NCAP been?

An analysis of the four-year performance of the NCAP by the Centre for Research on Energy and Clean Air (CREA), found that only 38 of the 131 cities that were given annual pollution reduction targets under agreements signed between State Pollution Control Boards (SPCBs), Urban Local Bodies (ULBs) and the Centre managed to meet the targets for FY21-22. The CREA noted that 37 cities have completed the source apportionment studies (which list out and quantify the major sources of pollution in a city). However, most of these reports weren’t available in the public domain and no city action plan had been updated with information from these studies, as they were supposed to be under the NCAP programme. The CREA estimates that India will need to install more than 300 manual air quality monitoring stations per year to reach the NCAP goal of 1,500 monitoring stations by 2024. Only 180 stations have been installed over the last four years.

Has NCAP managed to reduce pollution?

The NCAP Tracker, a joint project by two organisations active in air pollution-policy, Climate Trends and Respirer Living Sciences, have been monitoring progress in achieving the 2024 clean air targets set under the NCAP. Among these cities, the national capital of Delhi ranked the most polluted in 2022, with an annual average PM2.5 concentration of 99.71 ug/m3. But Delhi’s PM2.5 levels have improved by over 7% compared to 2019. Most cities in the top 10 most polluted list of 2022 were from the Indo-Gangetic Plain. All three of Bihar’s non-attainment cities, Patna, Muzaffarpur and Gaya, now feature in the top 10 most polluted cities on the basis of PM2.5 levels. Nine of the 10 cities, which were the most polluted in 2019, have reduced their PM2.5 and PM10 concentrations though the levels in these cities remain much higher than CPCB’s annual average safe limits for PM2.5 and PM10. In September 2022, the Centre for Science and Environment reported that based on PM2.5 levels, only 14 of 43 (NCAP) cities registered a 10% or more reduction in their PM2.5 level between 2019 and 2021. Only 43 cities were considered as only they had adequate data to scientifically establish a long-term trend. On the other hand, out of 46 non-NCAP cities with adequate data, 21 recorded significant improvement in their annual PM2.5 value with 5% or more decline between 2019 and 2021. There were 16 NCAP cities and 15 non-NCAP cities that registered a significant increase in their annual PM2.5 levels — with near identical numbers. This suggested that non-NCAP and NCAP cities were as likely to be polluted, with the NCAP regime having limited effectiveness.

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