Barely any difference in PM 2.5 trends among cities covered in NCAP and those outside it: Report

New Delhi: There is barely any difference in overall PM2.5 trends between cities covered under the National Clean Air Programme (NCAP) and those outside its ambit, according to a new analysis by the Centre for Science and Environment (CSE).

The NCAP is a national-level strategy aimed at a 20 per cent to 30 per cent reduction in PM2.5 and PM10 concentration by 2024, with 2017 as the base year for comparison. PM2.5 are fine inhalable particles, with diameters that are generally 2.5 micrometers and smaller, and are the greatest risk to health.

The programme covers 132 cities that do not meet the prescribed national ambient air quality standards.

Under NCAP, city-specific action plans have been prepared which include measures for strengthening the air quality monitoring network, reducing vehicular and industrial emissions, increasing public awareness, etc.

According to available data, National Capital Region (NCR) cities dominate the list of most improved non-NCAP cities. Most change (positive or negative) is noted among north Indian cities.

"There is barely any difference in overall PM2.5 (particulate matter 2.5) trends between cities under the National Clean Air Programme (NCAP) and those outside its ambit.

"'Both groups of cities reflect similar mixed trends in air quality in different climatic zones, and this means they require a substantial reduction in particulate pollution levels to be able to meet the national ambient air quality standards," the report read.

The CSE carried out the analysis of PM2.5 levels in cities for which data is available to understand the trend in both NCAP and non-NCAP cities. It said only 43 NCAP cities have adequate PM2.5 data for the period 2019-2021 – enough to create a reasonable trend for tracking progress.

Due to the lockdown phases, nearly all cities recorded a dip in 2020 followed by a subsequent increase in 2021.

A comparison between 2019 and 2021 shows only 14 of the 43 cities have registered a 10 per cent or more reduction in their PM2.5 level, the green think-tank said.

Seven cities show negligible (less than 5 per cent) change. These include Delhi and Ghaziabad.

Sixteen cities have registered a significant increase (5 per cent or more) in their PM2.5 levels. The 2021 annual value in Khanna, Jaipur, and Udaipur increased by over 20 per cent compared to the 2019 annual value.

Punjab, Rajasthan and Maharashtra cities dominate the list of cities that have registered a significant increase in PM2.5 levels between 2019 and 2021.

There are 46 cities not covered under the NCAP but have adequate real-time data for both 2019 and 2021.

In this group, 15 cities have registered a significant worsening of annual PM2.5 levels between 2019 and 2021, the CSE said.

Ankleshwar in Gujarat with a 34 per cent increase in annual PM2.5 value is the worst performer in the pool, followed by Satna (Madhya Pradesh), Vatva (Gujarat), Bahadurgarh (Haryana), and Bhatinda (Punjab); all of which have registered an over 20 per cent increase.

Ten cities registered negligible change (less than 5 per cent) in their annual values; 21 recorded significant improvement, with a 5 per cent or more decline between 2019 and 2021.

Cities in Haryana, Madhya Pradesh and Gujarat dominate the list of non-NCAP cities that have registered a significant increase in air pollution levels between 2019 and 2020.

Palwal in southern Haryana with a 60 per cent improvement in its annual PM2.5 level is the best performer among non-NCAP cities.

Cities within NCR show improvement, while cities outside indicate worsening levels.

The CSE said there are 16 NCAP cities and 15 non-NCAP cities that registered a significant increase in their annual PM2.5 levels – with nearly identical numbers. The same goes for cities (20 NCAP and 21 non-NCAP) that registered a significant improvement in their annual PM2.5 levels.