Delhi's AQI sees unexpected sharp drop, lowest reading in three years for October

Delhi’s air quality saw a surprising improvement on Friday, with the Air Quality Index (AQI) dropping from 373 on Thursday — the city’s worst October level in three years — to 218. The 155-point improvement came without significant rainfall, leaving experts uncertain about the exact cause, TOI reported.

Delhi environment minister Manjinder Singh Sirsa attributed the improvement to the deployment of over 1,200 enforcement teams, 390 anti-smog guns, 280 sprinklers, and 3,000 km of daily mechanical road sweeping. “Our entire government machinery, including MCD, DDA, NDMC and DSIDC, has been working in complete coordination. As a result, Delhi's AQI stands at 218, compared to 357 on the same day last year. This reflects that science-driven action and enforcement are delivering measurable results,” Sirsa said after chairing a review meeting, according to TOI.

Experts cite possible dispersion, stubble impact
Meteorological officials said humidity levels were lower on Friday, helping pollutants disperse. “Winds were almost calm on Friday but light winds of 5-7 kmph prevailed for a few hours. Unlike Thursday, humidity levels were less. Moisture traps pollutants while a reduction in humidity levels aids dispersion,” a Met official told TOI.

Sunil Dahiya, founder and lead analyst at think tank EnviroCatalysts, said, “Slightly better dispersion and changed wind direction can explain a little drop in pollution levels. Contribution from stubble burning might have also come down compared to Thursday. However, such a high and sudden drop without rain is a bit complex to understand. We will need more research to fully explain the fluctuations in air quality over the past few days,” TOI reported.

Most monitoring stations report ‘poor’ or ‘moderate’ air
According to Central Pollution Control Board data cited by TOI, only Wazirpur remained in the ‘very poor’ category on Friday, while all other monitoring stations reported ‘poor’ or ‘moderate’ air quality. Burari Crossing saw its AQI drop from 399 (‘very poor’) to 183 (‘moderate’), and Anand Vihar improved from 410 (‘severe’) to 249 (‘poor’) within 24 hours.

Monitoring and enforcement intensified
Sirsa said 443 teams are monitoring open waste burning, while 378 and 578 teams are checking dust and vehicular pollution, respectively. “Delhi's 40 automatic air monitoring stations are tamper-proof and fully automatic. Data cannot be altered by anyone. Monitoring is done by DPCC, CPCB and IMD, and results are simultaneously published on multiple platforms,” Sirsa told TOI.

The Air Quality Early Warning System for Delhi had earlier predicted that AQI would remain ‘very poor’ till November 3. It now expects air quality to stay in the ‘very poor’ range over the next few days, TOI reported.

Residents, however, continue to express frustration over the city’s recurring pollution crisis, describing the smog-filled skyline as a sign of Delhi’s deteriorating air quality and resilience, TOI added.

(With inputs from TOI)