Delhiites Wake Up to ‘Very Poor’ Category Air Quality Level After Witnessing ‘Cleanest October’ Since 2015

New Delhi: On Monday (November 1) morning, residents of the national capital woke up to overall air quality of ‘very poor’ category, as the Centre-run System of Air Quality and Weather Forecasting and Research (SAFAR) recorded Air Quality Index (AQI) of 302. The weather forecasting agency has further predicted that the air quality will “improve to the upper end of poor” due to the expected change in wind direction to westerly/south-westerly reducing transport of emissions from stubble burning. “Isolated rainfall is likely in the upwind region that would improve air quality,” it added. As per SAFAR, the share of crop residue burning emissions in PM2.5 is about 8 per cent.

The air quality level slipped in New Delhi after witnessing the cleanest October air this year since the Central Pollution Control Board (CPCB) started measuring the city’s AQI or air quality index in 2015. Earlier on Sunday, the India Meteorological Department (IMD) predicted that the air quality in the national capital is likely to be in the lower end of the Very Poor category on November 1-2.

“The air quality is likely to remain in the lower end of Very Poor category till November 4 and then deteriorate on November 5-6 significantly. PM2.5 to be the predominant pollutant,” IMD said. As per government agencies, an AQI within the range of 0-5 is regarded as ‘good’, 51-100 is ‘satisfactory’, 101-200 is ‘moderate’, 201-300 is ‘poor’ and 301-400 is ‘very poor’ and 401-500 is considered ‘severe’.

Record-breaking rainfall gave Delhi its cleanest October and best air quality

According to the latest data provided by the CPCB, an extended monsoon season and record-breaking rainfall in October gave Delhi its best air quality in the month in four years. This is also the first time in four years that Delhi did not see a single “very poor” or “severe” air quality day in October which generally records a sharp rise in pollution levels due to unfavorable meteorological conditions and stubble burning in the northwest region of the capital.

However, the capital recorded a “good” air day in October this year, also a first in four years. An AQI between zero 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”

Delhi gauged 122.5 mm of rainfall in October, the highest in the month since 236.2 mm of precipitation recorded in 1956, according to the India Meteorological Department. Stubble burning and its share in Delhi’s PM2.5 pollution also remained low due to bountiful rain. According to data from the Indian Agricultural Research Institute, Punjab has recorded 10,374 farm fires this season since September 15 as compared to 29,712 stubble burning incidents in the corresponding period last year.

The city recorded an average air quality index of 173 in October this year, the lowest in the month in four years. October saw an average AQI of 265 in 2020; 234 in 2019 and 264 in 2018.

The CPCB data showed the city witnessed three “satisfactory” air quality days in October this year as compared to zero in 2020, four in 2019, and nil in 2018. The capital also saw 19 “moderate” air quality days as against six such days each in 2020, 2019 and 2018. Eight “poor” air quality days this month was the lowest in October since 2018.

(With agency inputs)

source https://www.india.com/news/delhi/delhiites-wake-up-to-very-poor-category-air-quality-level-after-witnessing-cleanest-october-since-2015-5078579/