New Delhi: Ahead of Diwali, Delhi’s air quality deteriorated to ‘poor’ category and is expected to worsen further after the festival. The Air Quality Index (AQI) data on Friday showed major pollutant PM 2.5 and PM 10 are at 247 and 243 respectively, at Lodhi Road. Both fall in ‘poor’ category.

An AQI between 0 and 50 is considered ‘good’, 51 and 100 ‘satisfactory’, 101 and 200 ‘moderate’, 201 and 300 ‘poor’, 301 and 400 ‘very poor’, and 401 and 500 ‘severe’. Yesterday, AQI in the neighbouring towns of Baghpat, Bhiwadi, Ghaziabad, Greater Noida, Gurgaon, and Noida was 314, 312, 346, 327, 310 and 328 respectively.

“The overall air quality of Delhi is in the “very poor” category. The decrease in wind speed has started to negatively influence Delhi’s air quality by drastically decreasing ventilation coefficients and thereby effecting dispersion. The fire count in northern India has reduced slightly but is still moderate at 700. However, winds in the boundary layer, where biomass intrusion takes place, are not quite favourable to influence Delhi”s air quality significantly for the next two days”, news agency PTI quoted the ministry of Earth Sciences’ air quality forecast and research service, SAFAR as saying.

Furthermore, it added that the calm surface winds will continue for the next two days, following which, the AQI could oscillate between high and middle range of the ‘very poor’ category.

Meanwhile, construction activities in national capital and satellite towns of Gurugram, Faridabud, Noida, Greater Noida, Ghaziabad, Sonepat and Bahadurgarh will be banned between 6 pm and 6 am from October 26 to October 30 to curb pollution in Delhi-NCR.

(With inputs from agencies)