NEW DELHI: Seasonal average of winter pollution in Delhi-NCR in 2020-2021 was higher than in the previous year but the severity and duration of smog episodes was lower, a new analysis by environment think tank Centre for Science and Environment (CSE) said on Wednesday.
For the purposes of implementation of the Graded Response Action Plan (GRAP), winter in the region is officially demarcated as the period from October 15 to February 1, the CSE said.
This winter, there were 23 days when the city-wide average of PM2.5 concentration was in the ‘severe’ or ‘worse’ AQI category — down from 25 such days in the winter of 2019-2020 and 33 in 2018-19, the analysis said.
“Technically, a smog episode is defined for the purpose of implementing emergency action under GRAP, when levels of PM2.5 remain in the ‘severe’ category for three consecutive days,” it said.
It also said that Ghaziabad was the most polluted among the four neighbouring towns of Delhi and in the national capital city, north…