NEW DELHI: Delhi's air quality worsened to the 'severe plus' category on Monday with the city recording an AQI of 484.
Tighter pollution control measures, including a ban on truck entry and suspension of construction at public projects, came into force in the morning.
The dense toxic smog caused visibility to drop sharply in the morning.
According to officials, visibility at Safdarjung airport was 150 metres.
Delhi's Air Quality Index (AQI) stood at 484, the worst this season, at 8 am, according to the Central Pollution Control Board (CPCB).
The AQI was 441 at 4 pm on Sunday and rose to 457 by 7 pm due to unfavourable weather conditions.
With the AQI crossing 450, the Commission for Air Quality Management in the National Capital Region and Adjoining Areas ordered the implementation of Graded Response Action Plan (GRAP) Stage-IV restrictions in Delhi-NCR.
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 order said.
All construction activities, including highways, roads, flyovers, power lines, pipelines and other public projects, have been suspended.
The CAQM recommended that offices in the National Capital Region (NCR) work at 50 per cent capacity, with the rest working from home.
The Delhi government asked all schools to discontinue physical classes for all students, except those in classes 10 and 12, from Monday.
An AQI of 400 or higher is deemed 'severe' and it can have an adverse effect on both healthy individuals and people who already have medical conditions.
First implemented in 2017, the GRAP is a set of anti-air pollution measures followed in the capital and its vicinity according to the severity of the situation.
It classifies the air quality in the Delhi-NCR under four different stages: Stage 1 - 'poor' (AQI 201-300), Stage 2 - 'very poor' (AQI 301-400), Stage 3 - 'severe' (AQI 401-450) and Stage 4 - 'severe plus' (AQI above 450).
Delhi recorded a minimum temperature of 16.2 degrees Celsius, 3.9 degrees above normal.
The maximum temperature is expected to settle at 27 degrees Celsius, according to the India Meteorological Department (IMD).
The weather department has predicted very dense fog during the day.
Delhi Chief Minister Atishi announced on Sunday that physical classes shall be discontinued for all students, apart from classes 10 and 12. The announcement came shortly after the implementation of GRAP-4 in Delhi-NCR from Monday.
In a post on X, CM Atishi wrote, "With the imposition of GRAP-4 from tmrw, physical classes shall be discontinued for all students, apart from Class 10 and 12. All schools will hold online classes, until further orders".
Delhi Environment Minister Gopal Rai will hold a meeting with the Heads of Departments of all concerned departments on Monday for the effective implementation of the GRAP IV, his office said in a statement on Sunday.
"Keeping in view the prevailing trend of deteriorating air quality of NCR, and in an effort to prevent further deterioration of air quality in the region, the Sub-Committee today has taken the call to invoke all actions as envisaged under Stage-IV of GRAP - 'Severe+' Air Quality (Delhi's AQI > 450), w.e.f. 08:00 AM of 18.11.2024 (tomorrow) in the entire NCR," the CAQM said in a statement.
This is in addition to the preventive/ restrictive actions mentioned under Stage I, Stage II and Stage III of GRAP already in force.
The Stage-IV response encompasses an 8-point action plan designed to mitigate the pollution crisis. Key measures include banning the entry of non-essential truck traffic into Delhi, except for trucks carrying essential commodities or providing essential services.
LNG/CNG/electric and BS-VI diesel trucks will still be permitted. Light commercial vehicles (LCVs) registered outside Delhi will also be restricted from entering, except those powered by electric, CNG, or BS-VI diesel engines. Delhi-registered BS-IV and below diesel-operated medium and heavy goods vehicles will be prohibited from operating, except for those carrying essential services.
The Sub-Committee has also extended the ban on construction and demolition activities to include public infrastructure projects like highways, roads, flyovers, and power transmission lines.
State governments and the Government of Delhi (GNCTD) have been advised to consider shifting physical classes for students in grades VI-IX and XI to online mode and to limit office attendance to 50%, with the rest working from home. A similar work-from-home arrangement may be considered for central government employees.
Additionally, state governments have been urged to consider emergency measures such as closing colleges and non-essential commercial activities and implementing an odd-even vehicle policy to reduce pollution. The CAQM has called on citizens to cooperate with these measures and stay indoors as much as possible, especially vulnerable groups such as children, the elderly, and those with respiratory or cardiovascular conditions.
The CAQM emphasized that it is closely monitoring the air quality and will review the situation regularly to assess further action.
(With inputs from PTI and ANI)
