As a thick blanket of smog continued to engulf Delhi, the Commission for Air Quality Management (CAQM) sub-committee has decided to implement Stage IV of the Graded Response Action Plan (GRAP) for Delhi-National Capital Region, that will come into effect from Monday at 8 am, owing to ‘severe’ air quality conditions which include complete halting of construction and demolition activities that generate dust and a ban on truck entry.

Additionally, the government can choose to impose Odd-Even restrictions. The Commission issued the order as Delhi’s Air Quality Index (AQI) worsened, reaching 457 at 8 pm. Due to unfavourable weather conditions and dense fog, visibility reduced to less than 50 metres in some parts of the National Capital, leading to disruptions in flights at Indira Gandhi International Airport (IGIA).

The India Meteorological Department (IMD) issued an orange alert, warning of  dense fog on Monday morning. The decision to impose GRAP Stage IV was taken by the CAQM after meeting with all stakeholders on Sunday.

According to the order, no trucks will be allowed into Delhi except for those carrying essential items or using clean fuel (LNG/CNG/BS-VI diesel/electric). Non-essential light commercial vehicles registered outside Delhi will also be prohibited, except for EVs and CNG and BS-VI diesel ones. Delhi-registered BS-IV or older diesel medium and heavy goods vehicles are banned, except for those in essential services, the Commission said in its order. The CAQM order will be applicable for the NCR.

All construction activities, including highways, roads, flyovers, power lines, pipelines and other public projects, have been suspended.The CAQM suggested online classes for the students of Classes six to nine, and Class 11. It also recommended that offices in the NCR work at 50 per cent capacity, with the rest working from home. Work-from-home options may be introduced for central government employees, CAQM said.

The Central government may take appropriate decisions on permitting work from home for employees in their offices. State governments could also decide to close colleges, limit non-essential commercial activities and implement odd-even vehicle rules, it said.

The CAQM also advised children, elderly citizens and those with respiratory cardiovascular cerebrovascular or other chronic diseases to avoid outdoor activities and stay indoors as much as possible.

The Delhi government had already imposed GRAP Stage III restrictions on November 14 to curb pollution with junior school classes going online. Inter-state buses, besides EVs/CNG/BS-VI, private BS-III petrol and BS-IV diesel vehicles have been banned in the Capital.

Dense fog engulfed the capital city in the evening, reducing the visibility. Palam airport recorded lowest visibility 500 m during 0830 to 0900 hours IST which improved thereafter becoming 600m at 0930 hours IST and it became 900m at 1230 IST. Safdarjung airport recorded lowest visibility 300m during 0700 hours to 0900 IST which improved thereafter becoming 400m at 0930 hours IST and it became 600m at 1230 IST.

 According to reports, 250 flights were delayed while three were cancelled, according to Flightradar. Over 30 trains coming to New Delhi and Anand Vihar Railway stations have been delayed given the smog conditions. According to officials, the trains are running late by two to nine hours.

The Supreme Court is scheduled to hear on Monday, a plea seeking enforcement of measures to curb air pollution in the National Capital. As per the cause list of November 18 uploaded on the Supreme Court website, a bench of Justices Abhay S Oka and Augustine George Masih is slated to hear the plea.

Indian Biogas Association has suggested enforcement of the odd-even rule for four wheelers in Delhi NCR to check air pollution and encourage people to shift to electric vehicles or those based on compressed biogas (CBG) or natural gas.

The Delhi Transport Department has impounded 2,234 overage vehicles between October 1 and November 15 as part of an ongoing drive. According to official data, the seized vehicles include 260 diesel four-wheelers that are over 10 years old, alongside 1,156 petrol two-wheelers and 818 petrol three and four-wheelers, all older than 15 years.

Bahadurgarh in Haryana topped the list most polluted cities in India with an AQI of 445, followed by Delhi 441 as compared to 417 on Saturday.Bawana recorded the highest reading at 471, followed by Ashok Vihar and Jahangirpuri, both at 466. Mundka and Wazirpur also reported AQI levels of 463, indicating widespread pollution across the city.

The dense haze, caused by a mix of local pollution and the seasonal crop burning in neighbouring states, choked the city’s skies, triggering widespread concerns over Delhi’s ongoing battle with air pollution. Meanwhile, the Delhi airport took to its official handle to inform the flyers that low-visibility procedures are currently underway. “Low-visibility procedures are in progress at the Delhi airport. All flight operations are presently normal. Passengers are to contact the airline concerned for updated information,” posted the handle on X.

Of the 35 monitoring stations, most reported ‘severe’ air quality - Indira Gandhi International Airport (445), ITO (411), Anand Vihar (457), and Siri Fort (405), among others. The AQI level remained above 400 in most areas of Delhi, including  Ashok Vihar (466), Aya Nagar (426), Dr Karni Singh Shooting Range (415), Dwarka Sector 8 (445), Dilshad Garden (448), Major Dhyan Chand Stadium (419), Mandir Marg (434), Najafgarh (402), Narela (444), Nehru Nagar (442), North Campus DU (427), NSIT Dwarka (410), Okhla Phase 2 (409), Patparganj (439), Punjabi Bagh (442), Pusa (407), RK Puram (434), Rohini (449), Shadipur (457), Sonia Vihar (440), Vivek Vihar (454), and Wazirpur (463).

According to the Centre’s Decision Support System for Air Quality Management, vehicular emissions contributed approximately 15.8 per cent to Delhi’s pollution on Sunday. The system also reported that stubble burning was the main contributor to the capital’s air pollution on Saturday, accounting for 25 per cent of the total pollution.

Noida and Gurugram recorded AQI levels of 308 and 307, respectively. Ghaziabad reached an AQI of 372, pointing to slight improvement from the prevailing conditions. Faridabad registered the lowest among the listed cities, with an AQI of 260.