According to the Central Pollution Control Board (CPCB) reading, with the city’s average Air Quality Index (AQI) touching 304, a clear deterioration from the AQI of 270 (in “poor” zone), Delhiites suffered the first “very poor” air day of the season on Wednesday (16th October 2019).
As satellite pictures showed the region under a haze of pollution, most of the 37 air quality monitoring stations in Delhi recorded AQI in the ‘very poor’ category. It is predicted that Delhi’s air quality may worsen further from the 4 th week of October.
However, the Delhi government said the foul air and bad quality was largely because of crop burning in the geographical region of Punjab and Haryana. The Centre-run System of Air Quality and Weather Forecasting and research (SAFAR) said, Delhi’s air quality was likely to remain unchanged or deteriorate marginally over the next two days. The dip in the air quality was attributed to slow winds that were preventing pollutants from dispersing.
Of the stations that monitor air quality in NCR, 2 were in the ‘severe’ zone on October 16; Dwarka Sector-8 recorded the worst air quality on the day at 463 (severe). Most cities around Delhi recorded the ‘very poor’ AQs and the air quality got worst like Ghaziabad had the worst AQI of 339, followed by Noida (326) and greater Noida (314). The air quality of Faridabad (300) and Gurugram (287) were slightly better off with AQIs still in poor range.
The following table shows
- Air quality
- Very Poor
After Dwarka being most polluted, second most polluted was Siri Fort 424 and third most polluted was Bawana 355, AnandVihar 335, Wazirpur 326 and Mathura Road 310. SAFAR bulletin stated that surface winds continue to be slow and variable with predominant direction from southeast. Hence, there is a change in local weather conditions rather than external intrusion.
Stubble burning activity in Haryana, Punjab and nearby border regions had increased over the last 48 hours, with a few new fires also observed over western UP. However, SAFAR model estimates the biomass contribution to Delhi AQI at just 5% and the wind directions are not favourable for the direct plume transport to Delhi.
According to SAFAR, the temperature will start to cool and anti-cyclone is expected to strengthen by mid-fourth week and associated clear skies, and sinking motion will make the atmosphere stable with calm surface winds. Both will lead to stagnant weather conditions, which favour fine particulate matter formation and accumulation of pollutants.
Air crisis could deepen if any additional internal like firecrackers or external emissions (stubble burning) enter the air. SAFAR said it may lead to rapid accumulation and trigger high pollution levels. This bad air quality crisis can be avoided if local emissions are controlled.
Delhi government contradicted the assertion that present pollution levels are due to local emissions and this was likely to become city’s political issue.
Delhiites need to Gear Up
With winter months coming in, risk of smog and haze has increased and with Diwali around the corner, more chances of pollution are there. The sudden spike in pollution is a result of smoke coming from outside, possibly the Punjab crop fires, otherwise the air quality of Delhi has been good or moderate for the last seven to eight months.