According to the data of the Central Pollution Control Board (CPCB), Delhi’s air quality (Air Quality Index AQI) was the worst this time during November in the last seven years. There was ‘severe’ pollution in the national capital for 11 days, and the air quality was not ‘good’ for a single day.
Experts have attributed this to the extension of the period with the highest incidence of stubble burning by about a week due to the prolonged monsoon season. The 30-day average for the capital’s Air Quality Index (AQI) was 376. According to CPCB, this index was 328 in 2020, 312 in 2019, 335 in 2018, 361 in 2017, 374 in 2016 and 358 in 2015.
AQI between zero and 50 is ‘good’, 51 to 100 ‘satisfactory’, 101 to 200 ‘moderate’, 201 to 300 ‘poor’, 301 to 400 ‘very poor’ and 401 to 400 Between 500 is considered ‘severe’. The air quality in Delhi remained in the ‘severe’ category for 11 days in November this year, the highest in the month since the CPCB started air quality data in 2015. The index was recorded in the ‘severe’ category for seven days in the first fortnight of the month.
Gufran Baig, founder-project director of air quality forecasting agency SAFAR, said the extreme pollution events (a period with a sharp rise in Diwali and stubble burning incidents) shifted to November this year due to the delayed withdrawal of monsoon. “This is the main reason why the air quality in November this year was poor as compared to the last few years,” he said. Delhi witnessed 11 ‘severe’ air quality days in November this year, the highest in the month since the CPCB maintained air quality data in 2015. Seven ‘severe’ air quality days were recorded in the month.
There was a direct effect of increasing the incidents of the bursting of crackers and setting fire to the fields on Diwali. The share of stubble burning in Delhi’s PM2.5 pollution was 41 per cent on November 6 and 48 per cent on November 7. The city saw nine ‘severe’ air quality days last year, seven in 2019, five in 2018, seven in 2017, 10 in 2016 and six in 2015. The data also showed that the capital did not record a single “good”. This month there were “satisfactory” or “moderate” air quality days, while there were two “poor” and 17 “very poor” air quality days.