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387 & counting: Delhi AQI surges to season high
The Air Quality Index in Delhi steadily worsened from 322 at 4pm on Friday to 361 by 4pm on Saturday, according to Central Pollution Control Board data.
Delhi’s air quality plunged to its worst level this season on Saturday evening, with the hourly average index touching 387 at 11pm and headed toward breaching the “severe” threshold, even as the commission tasked with pollution control measures did not invoke stricter emergency measures mandated by the Supreme Court.
The Air Quality Index steadily worsened from 322 at 4pm on Friday to 361 by 4pm on Saturday, according to Central Pollution Control Board data. Twenty-one of the 39 AQI monitoring stations recorded “severe” readings at the time of going to print.
The Commission for Air Quality Management (CAQM), responsible for implementing the Graded Response Action Plan across the National Capital Region, did not convene a meeting or announce enforcement of stage 3 restrictions despite the AQI crossing 350 — the threshold at which the Supreme Court ordered stricter curbs last December.
As the grey haze and the acrid smell intensified on Saturday, chief minister Rekha Gupta urged residents to carpool, use public transport more frequently and encouraged private institutions to allow work-from-home arrangements.
The plunge in air quality appeared to be predominantly from local emissions, with the decision support system (DSS) for the CAQM estimating the contribution of farm fires in upwind states of Punjab and Haryana to be 8.64%.
Experts said the worsening, when seen in the context of meteorological conditions that have remained similar to Friday, might be a sign of pollution mitigation measures falling short.
“There has been no change in any meteorological conditions, so pollution levels shooting up might indicate more detailed pollution control measures are required,” said Mahesh Palawat, vice president at Skymet, while also cautioning that “more data and detailed study of the same would be required for us to be sure.”
Palawat noted that there was a slight dip in wind speed in the morning, but winds “picked up considerably during the day and was around 13-15 kmph by evening hours — which was consistent with patterns in the last few days” when the AQI was better.
CM Gupta on Friday announced staggered winter office timings for government and municipal offices starting November 15 to reduce peak-hour traffic and curb pollution. Delhi government offices will operate from 10a.m. to 6:30 p.m. while municipal offices will work from 8:30 a.m. to 5 p.m., aiming to ease congestion during the capital’s most polluted winter months.
Gupta’s appeal for voluntary measures falls short of Stage 3 restrictions under GRAP, which mandate a ban on private BS-3 petrol and BS-4 diesel four-wheelers in Delhi, Gurugram, Faridabad, Ghaziabad and Gautam Budh Nagar.
Stage 3 also imposes blanket curbs on private construction and demolition activities, restrictions on stone crushers and mining operations, and prohibits non-essential diesel-operated medium goods vehicles and older light commercial vehicles registered outside Delhi except those carrying essential goods or providing essential services. Schools up to Class 5 in Delhi and neighbouring districts must shift to hybrid lessons under Stage 3, while governments are required to stagger timings for public offices and municipal bodies across the region.
Saturday’s deterioration marked the second time this month the AQI has crossed 350. On November 2, readings had reached 366 before a slight increase in wind speed brought levels down temporarily.
Last year, the Supreme Court directed CAQM to implement Stage 3 “severe” category measures once AQI reaches 350 or above — 50 points lower than the original 400 threshold — and stage 4 “severe plus” restrictions at 400 instead of 450.
The December 5, 2024 order in the M.C. Mehta vs Union of India case stated: “We must record here that if the Commission finds that the AQI goes above 350, as a precautionary measure, Stage-3 measures will have to be immediately implemented.”
Officials in the commission did not respond to requests for a comment on why no tightening of measures were being carried out.
At a press conference Saturday, when asked whether CAQM planned to implement Stage 3 measures as a precautionary step, Delhi Pollution Control Committee chairman Sandeep Kumar said any decision would be informed at a later stage.
“Last year, GRAP 3 had been implemented on November 13. This time, with support from all departments and the residents of Delhi, we hope to prevent reaching that stage,” Kumar said, hours before the dramatic fall in air quality.
The CAQM, however, held a meeting with officials of Punjab and Haryana and called for urgent and coordinated action by the Punjab government to curb stubble burning incidents, while appearing to praise Haryana for having shown a decline in such cases during the ongoing paddy harvest season.
The Air Quality Early Warning System projected very poor conditions would persist from Sunday through Tuesday, with the outlook for the subsequent six days also indicating very poor air quality.
