Delhi’s air quality plunged once again into alarming territory on Tuesday evening, marking a troubling return to conditions that pose significant health risks for residents. After a brief period of marginal improvement, pollution levels surged across the national capital, with nearly half of the city’s monitoring stations recording air quality in the ‘severe’ category. The spike underscores the persistent nature of the pollution crisis that engulfs Delhi every winter, driven by a complex mix of local emissions, meteorological factors, and regional pollution transport.

According to the Central Pollution Control Board (CPCB), Delhi’s overall Air Quality Index (AQI) shot up to 390 by 9 pm on Tuesday, a significant jump from 304 on Monday and 279 on Sunday. These numbers reflect a rapid and widespread deterioration in air quality within just 48 hours. Out of the city’s 39 official monitoring stations, 19 recorded AQI readings above 400—levels classified as ‘severe’ and known to cause acute respiratory distress even in healthy individuals.

Localities that reported the worst pollution readings included Anand Vihar, Ashok Vihar, Mundka, Bawana, Burari Crossing, Punjabi Bagh, Vivek Vihar, Rohini, Sonia Vihar, and several others. Some of these areas have become chronic pollution hotspots, often recording some of the highest particulate matter concentrations in the capital.

One of the most concerning readings came from Chandni Chowk, which registered an AQI of 471—dangerously close to the upper limit of the AQI scale. Nehru Nagar (446), Vivek Vihar (437), Okhla Phase 2 (431), and Wazirpur (433) were among the other stations recording exceptionally high pollution levels, indicating that the deterioration was not localized but spread across both residential and industrial zones.

The Air Quality Early Warning System for Delhi has offered little relief in terms of expectations. According to its forecast, the city’s air quality is likely to remain in the “very poor” category until at least December 5. Moreover, no improvement is expected even in the subsequent six days. This extended forecast highlights the grim reality that atmospheric conditions—such as low wind speeds, temperature inversion, and high moisture content—are likely to trap pollutants near ground level, preventing dispersion.

Officials attributed the spike largely to a combination of meteorological stagnation and emissions from local sources. Transport pollution emerged once again as the largest contributor to Delhi’s overall particulate load. According to figures quoted by news agency PTI, vehicle emissions accounted for 18.4% of Delhi’s pollution on Tuesday, making it the dominant local source. This was followed by emissions from peripheral industries, which contributed around 9.2%.

Neighbouring regions, too, played a significant role in the pollution levels recorded in Delhi. Noida contributed 8.2%, Baghpat 6.2%, Ghaziabad 4.6%, Panipat 3.3%, and Gurugram 2.9%. These transboundary emissions—including dust, industrial smoke, and vehicular pollutants—often merge with Delhi’s local emissions, creating a dense layer of smog over the National Capital Region.

The sectors contributing to air pollution are expected to remain largely unchanged over the next 24 hours. Transport emissions, for instance, are projected to contribute around 15.6% to the city’s overall pollution load on Wednesday. Factors such as holiday-season travel, construction activities, and peak winter fuel use only add to the burden.

The CPCB’s air quality classification system provides a sobering context to the current situation: while AQI levels between 0–50 are considered “good,” 51–100 “satisfactory,” 101–200 “moderate,” and 201–300 “poor,” the 301–400 range is labelled “very poor,” signalling serious discomfort. Any reading above 400 is marked as “severe”—a level at which even healthy individuals can experience respiratory distress, and those with existing conditions may face serious exacerbations.

Medical experts routinely warn that exposure to severe air quality conditions can cause immediate and long-term health effects, including irritation in the eyes and throat, reduced lung function, aggravated asthma, and increased risks of heart attack and stroke. Children, older adults, and those with chronic heart or lung diseases are particularly vulnerable during such pollution spikes.

Delhi’s recurrent pollution crisis has become an annual reminder of the urgent need for structural reforms and coordinated action. While authorities have implemented measures such as construction bans, dust control protocols, and traffic restrictions during previous severe pollution episodes, the persistence of hazardous air quality suggests that these measures alone may be insufficient. Long-term solutions—such as sustainable urban transport systems, industrial emission controls, and regional collaboration on agricultural residue management—are crucial for meaningful improvement.

For now, however, residents have little choice but to endure yet another prolonged bout of toxic air. With forecasts indicating no immediate respite, Delhiites are likely to face extended days of hazardous pollution, limiting outdoor activities and further straining the city’s healthcare infrastructure. As winter intensifies, the challenge of restoring breathable air becomes ever more daunting, reinforcing the urgency for decisive, sustained action to combat the capital’s long-standing air quality crisis.