Delhi India's 6th most polluted city in October; Dharuhera worst— see full list

NEW DELHI: Delhi was ranked the sixth most polluted city in India in October, trailing behind Ghaziabad and Noida, according to a new report by the Centre for Research on Energy and Clean Air (CREA).The study, based on continuous air quality monitoring data, found a sharp drop in air quality across the Indo-Gangetic Plain, particularly in the National Capital Region. Dharuhera in Haryana topped the list as the most polluted city, recording a monthly average PM2.5 level of 123 µg/m³, double the national safe limit.Delhi’s air quality also worsened significantly, with its monthly average rising to 107 µg/m³, nearly three times higher than in September.

CREA noted that while stubble burning contributed less than six per cent of Delhi’s PM2.5 levels in October, the spike points to the impact of year-round pollution sources and the limits of short-term seasonal measures like the Graded Response Action Plan.Dharuhera breached national air quality standards on 77 per cent of the days last month, logging two ‘severe’ and nine ‘very poor’ days. Other cities high on the pollution list included Rohtak, Ghaziabad, Noida, Ballabgarh, Bhiwadi, Greater Noida, Hapur, and Gurgaon, most of them part of the NCR region.

Top 10 most polluted cities

Also read: Data under fire, SC seeks report on measures to tackle pollutionAt the other end, Shillong in Meghalaya was India’s cleanest city, with an average PM2.5 concentration of 10 µg/m³. Four cities from Karnataka and three from Tamil Nadu also featured among the top 10 cleanest.Out of 249 cities analysed, 212 met India’s national air quality standards, but only six complied with the World Health Organisation’s safe limit of 15 µg/m³. The report also showed a sharp decline in the number of cities with ‘good’ air quality, dropping from 179 in September to just 68 in October.