National clear air policy shows mixed results; Delhi remains pollution hotspot

FIve years after the telephone exchange regime launched the subject strip broadcast Programme (NCAP), air pollution levels remain high across India. In 2024, 92% of stations exceeded national annual standards for PM10 across 96 NCAP cities, and about 61% exceeded annual standards for PM2.5 across 95 NCAP cities, a report titled “Assessment of Changes in Air Quality in Indian Cities Since the Launch of the NCAP” has said.The report, however, found that for PM 2.5 the stations not meeting annual standards, declined by about 33% between 2017 and 2024, with steady year-on-year improvements observed.Most importantly, among the top 25 most polluted stations for PM2.5 in 2024, all were located in Delhi except for one highlighting once again the magnitude of air pollution in Delhi.NCAP, which was launched in 2019 initially targeted a 20%–30% reduction in PM10 and PM2.5 concentrations by 2024 in 102 cities.Based on directions from the National Green Tribunal (NGT), 20 additional cities were later added to the list.In 2020, two more cities were included, bringing the total to 124. In September 2022, the target was revised to reduce PM10 levels by up to 40% or meet national standards by 2025- 26 across 130 nonattainment cities.Non-attainment cities are urban areas that consistently fail to meet the National Ambient Air Quality Standards (NAAQS) for key pollutants like PM2.5 and PM10 over five years.Also Read: Noida files FIRs for dumping untreated waste into drainThe report by the US based Health Effects Institute has found that for PM 10, more than 90% of stations exceeded the annual National Ambient Air Quality Standards (NAAQS) every year from 2017–2024.In contrast, for PM 2.5 the stations above NAAQS declined by about 33% over the same period, with steady year-on-year improvements observed. Although PM2.5 is not included in the revised NCAP target, some progress has been made with respect to PM2.5 in terms of NAAQS compliance, the report said.In many locations, concentrations have either begun to decline or show signs of stabilisation. Delhi-NCR continues to dominate the list of most polluted locations, reinforcing persistent regional hotspots, it has added.The authors used multiple analytic approaches to detect trends, accounting for data completeness, seasonality, and meteorological influences. The analysis uses realtime data from government-run continuous ambient air quality monitoring stations (CAAQMS) spanning 2017–2024 , with 2017 as the NCAP baseline year.The monitoring infrastructure has expanded rapidly since NCAP was launched in 2019.The number of PM2.5 monitoring stations grew by 344%—from 78 across 38 cities in 2017 to 346 in 101 cities by 2024. The number of PM10 monitoring stations rose 462%, from 61 in 33 cities to 343 in 102 cities. However, coverage remains uneven with some large cities having many stations and rural areas are still largely unmonitored. Even with 75% data availability, gaps of more than 2 months, and in some cases up to 3 months, can occur, potentially omitting an entire season, the report has identified.Overall, for PM10 levels, 66.5% of the 209 stations analyzed showed decreases, while 33.5% showed increases. For PM2.5 levels, 67.7% of the 211 stations analysed showed decreases, and 32.2% showed increases, the report has found.The Delhi National Capital Region (NCR) cluster dominates the list of the most polluted stations for both metrics, underscoring persistent regional hotspots.In 2024, the most polluted station in the country was Jahangirpuri in Delhi, which recorded an annual average PM10 level of 276.1 µg/m³. All of the top 20 most polluted stations were located in Delhi-NCR with 95% (19 stations) situated within Delhi, the report flagged.Other highly polluted locations included stations in Patna-Muradpur (203.7 µg/m³), Samanpura (197.4 µg/m³), DRM Office Danapur (162.8 µg/m³), and Rajbansi Nagar (155.2 µg/m³). A high PM10 level was also reported from the Central Academy for SFS in Byrnihat, Meghalaya (162.7 µg/m³).Only about 8.2% of the stations (23 out of 281) reported annual averages below 60 µg/m³. The lowest PM10 concentration was observed at Mahatma Basaveswar Colony in Kalaburagi, with an annual average of 38.6 µg/m³.“While there is a declining trend, it is difficult to attribute the improvements solely to NCAP, as several overlapping policy measures including Bharat Stage-VI fuel norms and expansion of access to LPG for cooking have occurred over a similar time frame. Furthermore, funding timelines have varied across cities, complicating the attribution of changes specifically to NCAP,” the report concluded.HT has sought MoEFCC response to findings of the report and the copy will be updated whenever it is received.