India's 10 most polluted cities in October all in NCR

NEW DELHI: All the top 10 most polluted cities of India were from Delhi-National Capital Region in Oct, according to an analysis by Centre for Research on Energy and Clean Air (CREA). Delhi was the most polluted city in the country in Oct with an average PM2.5 concentration of 111 micrograms per cubic metre, followed by Ghaziabad at 110 and Muzaffarnagar at 103. CREA monitored 263 cities in the country, whose pollution data on continuous ambient air quality monitoring stations was available for 80% of the year's days.

According to the analysis, Ghaziabad, Muzaffarnagar, Hapur, Noida, Meerut, Charkhi Dadri, Greater Noida, Gurgaon and Bahadurgarh, all NCR cities, were identified as the second to tenth most polluted cities in India . "This alarming ranking persists despite the implementation of the Graded Response Action Plan , which has been in effect since Oct 15," said CREA.

"With the exception of Delhi, all other megacities such as Chennai, Mumbai, Kolkata and Bengaluru managed to maintain PM2.5 values below the national standard in Oct," said CREA.

CREA added that for the first time this year, Uttar Pradesh dominated the list of India's top 10 most polluted cities, with six cities in the state making the list, followed by three from Haryana. All these 10 cities recorded PM2.5 levels way higher than the daily national ambient air quality standard of 60 micrograms per cubic metre and WHO's daily safe guideline of 15 micrograms per cubic metre.

Manoj Kumar, analyst, CREA, said, "According to the Decision Support System for Air Quality Management in Delhi, transboundary sources contributed 60-70% to Delhi's average PM2.5 pollutants in October while less than 10% originated from harvest stubble burning. The elevated PM2.5 concentrations reveal the impact of year-round pollution sources such as transport, industries, and power plants, emphasising the need for comprehensive, long-term strategies."

Apart from occupying the first rank in the list of dirtiest cities in the country, Delhi recorded the highest pollution levels in this Oct compared with Oct of the past four years. The monthly average PM2.5 level in Oct this year was 111 micrograms per cubic metre as against 104 in 2023, 105 in 2022, 75 in 2021 and 133 in 2020. Besides, this year's Oct average was 2.5 times higher than Sept 43 micrograms per cubic metre.

In Oct 2024, pollution was in the 'very poor' category on 14 days (121-250 micrograms per cubic metre), 'poor' level on four days (91-120 micrograms per cubic metre), and 'moderate' level for eight days (61-90 micrograms per cubic metre). The national acceptable standard of 60 micrograms per cubic metre was recorded on just five days.