New Delhi: Delhi’s air quality deteriorated sharply on Sunday morning, as the city grappled with another surge in pollution levels and dense fog that disrupted air travel. According to data released by the Central Pollution Control Board (CPCB), the city’s Air Quality Index (AQI) stood at 298 at 8 am, edging close to the upper limit of the ‘poor’ category. This represents a significant rise from the 24-hour average of 267 recorded at 4 pm on Saturday, highlighting the continuing struggle of the national capital with air pollution in the winter months.

The worsening conditions come amid forecasts by the India Meteorological Department (IMD), which had issued a yellow alert on Sunday, warning of moderate to dense fog in the early hours. While much of Delhi itself did not experience extreme visibility issues, certain northern regions saw visibility drop below 100 metres, affecting both road and air transport.

At the Indira Gandhi International Airport, flight operations were significantly impacted by the combination of poor weather conditions and disruptions at connecting airports across northern India. According to flight tracking service FlightRadar24, at least 170 flights experienced delays on Sunday morning alone. Airport authorities explained that flight schedules are adjusted not only based on weather conditions in Delhi but also considering visibility and operational constraints at destination and source airports, contributing to the widespread delays.

Experts pointed out that a temporary improvement in Delhi’s air quality had occurred on Friday due to strong surface winds, prompting the Commission for Air Quality Management (CAQM) to lift Stage III restrictions under the Graded Response Action Plan (GRAP) across the National Capital Region (NCR) that evening. However, the calm was short-lived, and pollution levels began climbing again on Saturday, compounded by cold and stable atmospheric conditions that trap pollutants close to the ground.

Forecasts from the Air Quality Early Warning System (AQEWS) indicate that Delhi’s air quality is likely to worsen further. “The air quality is likely to be in the very poor category from Sunday to Tuesday. The outlook for the subsequent six days is that the air quality is likely to remain in the very poor category,” the AQEWS bulletin stated.

The CPCB classifies air quality into categories to reflect the potential health impact on residents. An AQI between 101 and 200 is considered “moderate,” 201 to 300 is “poor,” 301 to 400 is “very poor,” and beyond 400 is classified as “severe.” For regulatory purposes under GRAP, Stage III measures are triggered if AQI levels are forecasted to exceed 400, while Stage IV measures are implemented if levels reach or cross 450. Although Delhi’s current AQI remains in the upper ‘poor’ range, authorities continue to monitor the situation closely, as winter conditions and stagnant air can quickly push levels into the “very poor” or “severe” categories.

Meteorological conditions have also played a role in the declining air quality. Cold northwesterly winds, which are typical in northern India during the winter months, have contributed to a further dip in the minimum temperature. On Sunday, the minimum temperature in Delhi was recorded at 7.4°C, 0.5°C below the seasonal average, while Saturday had seen a minimum of 8.1°C. The maximum temperature on Saturday was 17.3°C, and forecasts suggest that temperatures on Sunday will range between 17°C and 19°C, maintaining the cool conditions typical of early January.

Dense fog, coupled with poor air quality, poses multiple challenges for public health and transport. Health experts advise residents, particularly children, the elderly, and individuals with respiratory conditions, to limit outdoor activities during periods of poor air quality. The combination of smog and fog also reduces visibility on roads and runways, increasing the risk of accidents and causing travel delays, as witnessed at the Delhi airport.

In addition to weather-related factors, anthropogenic activities continue to exacerbate the pollution situation. Vehicular emissions, construction dust, industrial activity, and the burning of biomass or waste in neighboring regions all contribute to the accumulation of particulate matter in the air. During winter, temperature inversions often trap these pollutants close to the ground, preventing their dispersion and leading to spikes in AQI.

Authorities have urged residents to follow preventive measures under Stage I and Stage II of the Graded Response Action Plan. These include reducing non-essential outdoor activities, limiting vehicle use, avoiding open burning of waste, and following public health advisories regarding the use of masks or air purifiers. Construction and demolition activities, which were previously restricted under Stage III measures, cannot resume without explicit approval from the Commission for Air Quality Management.

The impact of air pollution on human health can be severe, even in the short term. Exposure to high levels of particulate matter (PM2.5 and PM10) is associated with respiratory illnesses, aggravated asthma, cardiovascular issues, and eye irritation. Long-term exposure increases the risk of chronic respiratory diseases and other systemic health complications. Public health officials have emphasized the importance of adhering to safety protocols and remaining informed about daily AQI levels.

As Delhi continues to contend with the seasonal surge in pollution and dense fog, authorities are closely monitoring weather patterns, pollutant concentrations, and public health indicators. Residents are advised to stay updated through official channels and take precautions to minimize exposure, particularly during early mornings and late evenings when pollution levels tend to peak.

In summary, Delhi woke up to a hazardous combination of near-300 AQI readings and dense fog on Sunday, which disrupted air travel and raised concerns for public health. While meteorological factors and strong surface winds temporarily improve conditions at times, winter stagnation, combined with human activities, continues to make pollution a persistent challenge for the national capital. With forecasts indicating that very poor air quality is likely to continue over the coming days, citizens, authorities, and public health experts are all on alert, emphasizing preventive measures, close monitoring, and timely interventions to mitigate the impact of Delhi’s persistent winter smog crisis.