Delhi’s air quality has deteriorated sharply over recent days, pushing the region into an alarming pollution crisis. On Sunday, the average Air Quality Index (AQI) surged to 441 at 4 pm, marking the season’s worst and placing the city deep into the ‘severe’ category. By evening, the AQI climbed past 450, entering the ‘severe plus’ zone, prompting the Commission for Air Quality Management (CAQM) to enforce the fourth stage of the Graded Response Action Plan (GRAP) starting 8 am Monday.
This critical escalation in pollution has had significant impacts on schools. Chief Minister Atishi announced that all schools would transition to online classes, except for students in Class 10 and Class 12, who would continue in-person learning. The move aims to protect younger students from exposure to toxic air as Delhi battles one of its worst pollution episodes.
GRAP-IV measures are triggered when AQI crosses 450, signifying ’emergency’ levels. This stage includes strict restrictions on vehicular movement to help control emissions. For instance, non-emergency trucks and certain diesel-operated vehicles have been barred from entering Delhi. Additionally, construction and demolition activities related to public infrastructure projects, such as roads and bridges, are no longer exempt from these restrictions.
The Central Pollution Control Board (CPCB) reported that Delhi’s AQI rose throughout Sunday, from 421 in the morning to 452 by 6 pm, peaking at 468 by 10 pm. This marked the fourth day in November when the AQI hit the ‘severe’ level. The last comparable spike was recorded on November 13, when the AQI briefly touched 454. According to CPCB, Sunday’s reading of 441 was the second-highest this year, trailing only the January 14 high of 447.
Anumita Roychowdhury, executive director of the Centre for Science and Environment (CSE), attributed the severe air quality to a combination of winter inversion and accumulated local and regional pollutants. “Urgent measures are needed to prevent further pollution loading from primary sources,” she stressed.
A significant contributor to the worsening air quality has been stubble burning, which accounted for 25.2% of Delhi’s PM2.5 levels on Saturday, as reported by the Decision Support System. Unfortunately, no immediate relief is expected. According to the Indian Meteorological Department (IMD) and the Indian Institute of Tropical Meteorology (IITM), Delhi’s AQI is likely to remain in the higher end of the ‘severe’ to ‘severe plus’ category due to dense fog, stagnant winds, and unfavorable weather conditions.
The latest GRAP-IV measures supplement existing Stage 1 to 3 actions already in place, including construction bans implemented on November 15. The decision to extend the ban to public infrastructure projects marks a significant step in reducing further emissions.
The CAQM has also advised state governments in Delhi and the National Capital Region (NCR) to consider additional emergency steps. These include implementing work-from-home policies for public, municipal, and private offices, and restricting non-essential commercial activities. The central government may also decide on allowing work-from-home arrangements for its employees. The commission’s order also suggested that state governments might explore vehicle restrictions, such as an odd-even rule based on registration numbers.
On Sunday, Delhi experienced persistent smog, exacerbated by winds under 6 km/h that failed to disperse pollutants. The lowest visibility was recorded at 300 meters at Safdarjung at 7 am, while Palam reported 150 meters at 11 pm. Despite a faint sun during the day, visibility remained low, with a peak of 900 meters at Palam at 5:30 pm. The day also saw a temperature dip, with a maximum of 27.2 degrees Celsius, one degree below normal, and a minimum of 15.9 degrees Celsius, four degrees above average.
The IMD has issued an orange alert, warning of very dense fog for Sunday night and Monday morning, signaling continued air quality challenges ahead.
