New Delhi, Nov. 4 -- Delhi, Ghaziabad and Noida emerged as most polluted cities in the month of October, while Dharuhera in Haryana topped the chart, according to a study by the Centre for Research on Energy and Clean Air (CREA) released on Tuesday.

The air quality in the national capital remained in the 'very poor' category over the last few days.

The national capital was ranked the sixth most polluted city in the country in October, with an average concentration of 107 µg/m³, three times higher than its September average of 36 µg/m³.

The report by CREA says that the sharp rise in pollution levels, despite stubble burning contributing less than 6 per cent of Delhi's PM2.5 levels in October, highlights the impact of...