We saw stubble burning during Covid, so why was air clearer, asks Justice Suryakant
Even as stubble burning dropped to a multi-year low this season, Delhi-NCR’s air quality remained locked in the ‘very poor’ to ‘severe’ categories through most of October and November, driven overwhelmingly by local emissions — particularly from vehicles. A new analysis by the CSE (Centre for Science and Environment) shows that a “toxic cocktail” of PM2.5, nitrogen dioxide (NO₂) and carbon monoxide (CO) has dominated early-winter pollution. The report, based on CPCB data, found that 22 monitoring stations breached CO limits on more than 30 of the 59 days analysed, with Dwarka Sector 8 logging the most violations (55 days), followed by Jahangirpuri and Delhi University’s North Campus (50 days each). New and expanding pollution hotspots Delhi’s pollution hotspots have expanded drastically. From 13 hotspots officially identified in 2018, many more locations now record far worse pollution than the city average. Jahangirpuri emerged as the most polluted hotspot with an annual PM2.5 average of 119 µg/m³, followed by Bawana and Wazirpur (113 µg/m³), Anand Vihar (111 µg/m³), and Mundka, Rohini and Ashok Vihar (101–103 µg/m³). New hotspots include Vivek Vihar, Alipur, Nehru Nagar, Siri Fort, Dwarka Sector 8 and Patparganj. Smaller NCR towns also saw prolonged smog episodes. Bahadurgarh recorded a 10-day continuous smog event from November 9 to 18, underscoring that Delhi-NCR increasingly functions as a single, polluted airshed. Vehicular emissions driving synchronized spikes CSE’s analysis found that PM2.5 levels rose and fell almost simultaneously with NO₂ during peak traffic hours — 7–10 am and 6–9 pm — as emissions accumulated under shallow winter boundary layers. CO breaches also rose sharply across the city. “This synchronised pattern reinforces that particulate pollution spikes are being fuelled daily by traffic-related emissions of NO₂ and CO, especially under low-dispersion conditions,” said Anumita Roychowdhury, Executive Director (Research & Advocacy), CSE. She added, “Yet, winter control efforts remain dominated by dust measures, with weak action on vehicles, industry, waste burning and solid fuels.”