GRAP-III reimposed as Delhi air turns ‘severe’ again, AQI breaches 400

As toxic smog once again enveloped the national capital, authorities on December 13 reimposed Stage III of the Graded Response Action Plan (GRAP-III) across Delhi-NCR with immediate effect after air quality slipped back into the ‘severe’ category.

The Commission for Air Quality Management (CAQM) ordered the renewed curbs after the Air Quality Index (AQI) crossed 400, signalling a sharp deterioration following a short-lived improvement earlier in the week.

Officials said the decision was taken amid a sustained decline in air quality and rising pollutant concentrations, exacerbated by unfavourable meteorological conditions. In a statement, the CAQM said all measures prescribed under GRAP-III have been enforced to prevent further worsening of pollution levels.

Under the restrictions, non-essential construction and demolition activities — including earthwork, piling, open trenching, welding, painting, plastering and flooring — have been halted. Operations of ready-mix concrete plants, stone crushers, brick kilns and mining activities have also been suspended. The transportation of construction materials such as cement, sand and fly ash on unpaved roads has been barred.

Vehicular curbs include a ban on BS-III petrol and BS-IV diesel four-wheelers, non-essential diesel-powered medium goods vehicles, and inter-state diesel buses that do not comply with CNG, electric or BS-VI norms. Industries using unapproved fuels have been ordered to shut down.

However, essential infrastructure and public service projects — including metro, railway, airport, highway, defence, healthcare and sanitation works — have been exempted, subject to strict dust-control and waste-management measures. Construction linked to critical projects has been permitted with safeguards, while persons with disabilities have been exempted from vehicle restrictions. Authorities have also encouraged the use of public transport and allowed hybrid or online classes up to Class 5.

Smog chokes city, hotspots turn hazardous

The impact of the deteriorating air quality was visible early Saturday morning as dense smog mixed with shallow fog blanketed large parts of the city, sharply reducing visibility. Low-visibility procedures were activated at the Indira Gandhi International Airport, though flight operations remained normal.

Pollution hotspots bore the brunt, with 18 locations recording AQI levels above 400, indicating hazardous conditions. Wazirpur emerged as the most polluted area with an AQI of 443, followed by Jahangirpuri (439), Vivek Vihar (437), Rohini and Anand Vihar (434 each), Ashok Vihar (431), and Sonia Vihar and DTU (427 each).

Other areas in the severe category included Narela (425), Bawana (424), Nehru Nagar (421), Patparganj (419), ITO (417), Punjabi Bagh (416), Mundka (415), Burari Crossing (413), Chandni Chowk (412) and Delhi University’s North Campus (401).

Roller-coaster AQI trend

Delhi had endured ‘very poor’ air quality for nine consecutive days before witnessing marginal improvement earlier in the week. The average AQI dipped to 282 on December 9 and 259 on December 10, before worsening again to 307 on December 11 and 349 on Friday. By Saturday, pollution levels breached the 400 mark, pushing the city back into the severe zone.

NCR mirrors Delhi’s crisis

The grim picture extended across the National Capital Region. Ghaziabad and Noida recorded AQI levels of 422 each, firmly in the severe category. Gurugram reported an AQI of 295, while Faridabad stood at 208, both in the ‘poor’ category.

Weather traps pollutants

Experts attributed the sudden spike to low wind speeds, high moisture levels and falling temperatures, which prevented pollutants from dispersing. According to the India Meteorological Department (IMD), visibility in New Delhi dropped to around 500 metres.

While no dense fog alert has been issued for Delhi-NCR, an orange alert for very dense fog remains in place for eastern Uttar Pradesh. Parts of Punjab, including Amritsar, reported near-zero visibility in pockets. Weather officials warned that dense fog is likely to persist over the next two days across parts of Uttar Pradesh, Haryana, Punjab and Delhi-NCR, with visibility in some areas expected to fall below 50 metres.

Despite the pollution spike, winter chill has remained subdued this December. The minimum temperature hovered around 11°C on Saturday morning, while the maximum was expected to remain near 22°C, both above normal due to the absence of active western disturbances that typically help disperse pollutants.

Authorities have urged residents to limit outdoor exposure, use public transport where possible and take necessary precautions as hazardous air quality continues to grip Delhi and large swathes of the NCR.