Delhi reported the highest annual PM10 levels in FY 2024–25, while Byrnihat topped March 2025 pollution rankings; several cities improved air quality, but most still exceeded national and global pollution standards.
08 Apr 2025 | 1197 Views | By Sarthak Mahajan
Delhi recorded the highest annual average PM10 concentration among cities covered under the National Clean Air Programme (NCAP) for the financial year 2024–25, according to an analysis of official air quality data. The national capital reported a PM10 level of 206 µg/m³, followed closely by Byrnihat in Meghalaya at 200 ...
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Delhi recorded the highest annual average PM10 concentration among cities covered under the National Clean Air Programme (NCAP) for the financial year 2024–25, according to an analysis of official air quality data. The national capital reported a PM10 level of 206 µg/m³, followed closely by Byrnihat in Meghalaya at 200 µg/m³ and Patna at 180 µg/m³. These levels are more than three times higher than the National Ambient Air Quality Standard (NAAQS) of 60 µg/m³.
The NCAP tracks air quality trends in 130 cities across India. However, 28 of these cities still lack Continuous Ambient Air Quality Monitoring Stations (CAAQMS), limiting the scope of reliable data collection. The latest assessment is based on data from 102 cities where CAAQMS were operational between April 1, 2024, and March 31, 2025.
When compared to the NCAP’s baseline year of 2017–18, 23 cities recorded an increase in PM10 levels, while two cities showed no change. The remaining 77 cities registered improvements of varying degrees. Eighteen cities recorded a 1–10% reduction in PM10 levels, 15 cities saw a 10–20% decrease, 12 cities showed a 20–30% drop, and 11 cities reported reductions in the range of 30–40%. Twenty-one cities showed improvements of more than 40%.
Uttar Pradesh accounted for 10 cities that saw over 40% reductions in PM10 levels, followed by two cities each in Uttarakhand and Punjab. Other states that reported significant improvements included Tamil Nadu, Jharkhand, Jammu & Kashmir, Rajasthan, Nagaland, Maharashtra, and West Bengal, with one city each.
On the other hand, Odisha and Maharashtra each had five cities where PM10 levels increased compared to the baseline year. Assam had four such cities, Madhya Pradesh had three, while Bihar, West Bengal, and Chhattisgarh had two each. One city each from Chandigarh and Andhra Pradesh also recorded an increase.
Among individual cities, Bareilly (Uttar Pradesh) showed the greatest improvement, with a 78% reduction in PM10 levels. Jalgaon (Maharashtra) recorded the largest increase at 57%. Delhi, despite topping the PM10 list, reported a 15% reduction compared to 2017–18.
Due to the lack of CAAQMS data during the baseline year, the current analysis has relied on data from the National Air Quality Monitoring Programme (NAMP). This inconsistency in datasets could lead to differences in how progress or deterioration is reported. A recent report by the Comptroller and Auditor General (CAG) also flagged non-compliance with station siting guidelines in Delhi, raising concerns about the accuracy of the data.
Manoj Kumar, an analyst at the Centre for Research on Energy and Clean Air (CREA), noted that while some cities have made progress, the majority still exceed the national standards. He added that with just one year left for NCAP to meet its targets, 91 out of the 102 monitored cities continue to breach annual PM10 limits. He also cautioned against averaging data from CAAQMS and NAMP, as the two systems differ in methodology and frequency. He suggested that air quality trends should be assessed separately for each network to avoid misleading interpretations.
In March 2025, Byrnihat recorded the highest monthly average PM2.5 level in the country at 160 µg/m³. Other cities with high PM2.5 concentrations included Hajipur, Talcher, Patna, Chandigarh, Guwahati, Barrackpore, Muzaffarpur, and Howrah.
Among the 240 cities with over 80% CAAQMS data coverage, 209 recorded PM2.5 levels below the Indian daily standard of 60 µg/m³. However, only six cities met the more stringent World Health Organization (WHO) daily guideline of 15 µg/m³.
Among NCAP cities, 14 out of 98 exceeded the national daily PM2.5 standard, while all 98 crossed the WHO threshold. In non-NCAP cities, 136 of the 142 cities crossed the WHO limit, and 17 surpassed India’s national daily limit.
Bihar had the highest number of cities — seven out of 24 — exceeding the national daily PM2.5 standard in March, followed by Odisha with five out of 13 cities and Assam with three out of six.
Tirupur (Tamil Nadu) recorded the lowest PM2.5 level in March at 11 µg/m³. Other cities with lower pollution levels included Agartala, Maihar, Vrindavan, Aizawl, Tirunelveli, Bareilly, Surat, Palkalaiperur, and Damoh.
Kumar concluded that although more cities met the national air quality standards in March, India’s benchmarks remain significantly less strict than global standards. He emphasized the need for continued air quality improvement efforts throughout the year to safeguard public health.