NEW DELHI: 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, Mandir Marg, Pusa, 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, Sirifort, 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 Organization (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.
In addition to enhancing the checks, the Delhi Police held an inter-state coordination meeting with its counterparts in Haryana and Uttar Pradesh to discuss strategies for managing the flow of vehicles into the national capital, an officer said.
“For strict enforcement of the restrictions, we will install joint pickets at key border areas. These pickets will monitor and restrict the entry of vehicles not meeting the required norms,” the officer said.
Ten police pickets will be installed at every district. These checkpoints will be responsible for imposing fines on BS-III petrol and BS-IV diesel vehicles for plying in the city, another officer said.
GRAP Stage IV was invoked in Delhi for the first time this season in November due to consistently high pollution levels.
The Supreme Court allowed the Commission for Air Quality Management (CAQM) to relax the curbs in the first week of December after the city’s air quality improved.
Unfavorable meteorological conditions, combined with vehicle emissions, paddy-straw burning, firecrackers and other local pollution sources lead to hazardous air quality levels in Delhi-NCR during winters.
According to doctors, breathing Delhi’s polluted air is equivalent to smoking approximately 10 cigarettes a day.
Prolonged exposure to high pollution levels can exacerbate respiratory issues such as asthma, bronchitis and chronic obstructive pulmonary disease (COPD) and significantly increase the risk of cardiovascular diseases, they say.
