Delhi’s air quality plummets to alarming levels; GRAP IV restrictions kick in-OxBig News Network

Delhi’s air quality plummeted to alarming levels on Tuesday after 24 days, with many areas witnessing a significant spike in pollution despite the strictest measures, including a ban on construction activities and the entry of trucks into the city, coming into force.

The city’s 24-hour average Air Quality Index (AQI) was recorded in the ‘severe’ category with a reading of 433 at 4 pm against 379 on Monday, according to Central Pollution Control Board (CPCB) data.

The last time Delhi’s air quality was recorded in the ‘severe’ category was on November 23, with a reading of 412.

Experts pointed to a significant drop in wind speeds as the primary cause of the sudden spike in pollution, explaining that the lower speed allowed local pollutants to concentrate in the atmosphere.

They said the AQI was expected to remain in the ‘severe’ category for the next two days.

Of Delhi’s 35 monitoring stations, 28 recorded the air quality in the ‘severe’ category, with some breaching the 450 mark that is classified as ‘severe plus’.

Monitoring stations in Mandir Marg, Jahangirpuri, Narela, Nehru Nagar, Patparganj, Punjabi Bagh, Rohini, ITO, Jawaharlal Nehru Stadium, DTU, Major Dhyan Chand National Stadium, Pusa and Shadipur recorded the AQI in the ‘severe’ category.

The AQI was in the ‘severe plus’ category in Alipur, Anand Vihar, Ashok Vihar, Bawana, Burari, CRRI Mathura Road, North Campus, Okhla Phase 2, Siri Fort, Sonia Vihar and Vivek Vihar.

During winters, the national capital enforces restrictions under the Graded Response Action Plan (GRAP), which categorises the city’s air quality in four stages — Stage I (Poor, AQI 201-300), Stage II (Very Poor, AQI 301-400), Stage III (Severe, AQI 401-450), and Stage IV (Severe Plus, AQI above 450).

The major source of Delhi’s pollution was vehicular emission, contributing 18.8 per cent of PM2.5. There was no contribution of stubble-burning to Delhi’s pollution as the season is over in Punjab and Haryana.

PM2.5 remained the primary pollutant, with levels recorded at 252 micrograms per cubic metre at 4 pm.

These fine particles pose significant health risks as they can penetrate deep into the lungs and enter the bloodstream.

The national safe standard for PM2.5 is 60 micrograms per cubic metre while the World Health Organisation (WHO) safe limit is 15 micrograms per cubic metre.

On Monday, the Centre’s air quality panel for Delhi-NCR imposed the strictest Stage IV curbs under GRAP, including a ban on the entry of polluting trucks carrying non-essential goods into Delhi and mandatory shifting of classes, except those for classes 10 and 12, to hybrid mode.

Stage IV also includes a ban on all construction and demolition activities, including public projects such as highways, flyovers, power lines and pipelines. Diesel trucks carrying non-essential items are prohibited from entering Delhi.

Public, municipal and private offices must decide on allowing only 50 per cent of staff to work in offices, with the remaining working from home. Additional measures such as closing colleges, non-essential businesses and implementing odd-even vehicle restrictions may also be considered.

In a related development, the authorities have intensified vehicle checking in and along bordering areas of the national capital.