Delhi air cleaner this year than pre-lockdown 2019
NEW DELHI: This year has fared better than 2019 as far as the capital’s air quality is concerned. AQI was between 201 and 500 (poor category or worse) on 164 days in 2021, compared to 183 days in 2019. Till December 27, there were 197 days when AQI was in good, satisfactory and moderate categories, i.e., between 0 and 200. The year 2020 had seen 139 days with AQI in the 201-500 range, but it was cleaner mainly on account of the lockdown. Central Pollution Control Board (CPCB) data shows the number of days with AQI between 201 and 500 have reduced over the years and those with AQI of 0-200 have gone up. Anumita Roychowdhury, executive director, research and advocacy, Centre for Science and Environment, said, “It is already evident from CPCB data that the long-term PM2.5 curve has bent in Delhi. Also, the days in ‘satisfactory’ and ‘poor’ categories are increasing annually. Despite this improvement, the annual average concentration of PM2.5 still requires substantial reduction — close to 60% — to meet the clean air standards. Only round-the-year sustained action on sources can reduce the overall base pollution in Delhi-NCR and prevent ‘severe’ episodes during winter.” VK Soni, head, environment and research centre, India Meteorological Department, said, a season-wise analysis should be done of the past five years to draw a pattern. “The air quality deteriorated in November and December as fewer number of rain days were observed.” Dipankar Saha, former head of CPCB’s air laboratory, said, “Our air quality is mostly dependent on meteorological factors like wind speed and humidity. They are the driving force behind dilution and disposal of pollutants. This year, extended rain has reduced the number of bad days.” He added, “Disturbances in the south-east and west made the air quality poor in December this year. It is necessary to cut down emissions from all sectors to improve air quality.” According to the Air Quality Early Warning System for Delhi, the air quality of the capital is likely to remain in the ‘poor’ category for the remaining days of the month.
