The air quality in Mundka, Nehru Nagar, Rohini and Wazirpur was recorded in the 'severe' category.
Delhi's air quality remained in the very poor category on December 7 even as Supreme Court-appointed Environment Pollution Control Authority expressed concern over hired private diesel vehicles being used by the state and central governments officials in the Delhi-NCR.
EPCA, in its meeting, also said they are seriously considering banning industrial, construction and demolition activities at major pollution hotspots in Delhi-NCR when air quality levels reach 'severe' category.
The comments came as Delhi's air quality remained in very poor category and recorded an overall air quality index of 346 with four areas in the city recording 'severe' air quality due to unfavourable weather conditions like low wind speed.
The air quality in Mundka, Nehru Nagar, Rohini and Wazirpur was recorded in the 'severe' category. It was 'very poor' in 24 areas and 'poor' in four areas of the national capital, the Central Pollution Control Board (CPCB) said.
EPCA member Sunita Narain said around 25,000 hired private vehicles which are of nature of taxis are being used by them and the EPCA will be writing to the central and state governments to ask what action they would be taking to resolve the situation.
The EPCA expressed concern over private vehicles being used as taxis by the state and central governments officials in the Delhi-NCR and said one of the solutions proposed was that government officials should only be allowed to hire CNG and petrol cars.
"The EPCA will write to central as well as to the Delhi government that it has come to their notice that they are using private diesel cars for commuting within Delhi and NCR as this is nature of taxis and as the Supreme Court order very clearly says all taxis have to be on dual fuel of petrol and CNG," Narain said.
"This would be in contravention of the court order so please let us know in case this is happening and if so what action you would be taking to remedy the situation," she said.
The decision was taken at an EPCA meeting chaired by its chairperson Bhure Lal. The meeting saw participation from various transport authorities.
In May 2016, the Supreme Court had ordered a gradual phase-out of diesel taxis from Delhi-NCR and said that they can operate until the expiry of their permits.
New licences should not be given for diesel taxis in the national capital and those with all-India tourist permits may operate till their permits expire, the Supreme Court had said in 2016.
The EPCA also said that they are contemplating banning industrial, construction and demolition activities at major pollution hotspots in Delhi-NCR when air quality levels reach 'severe' category.
The Central Pollution Control Board-led task force on November 22 recommended to the EPCA that industrial, construction and demolition activities should be banned in major hotspot areas when air quality levels reach 'severe' category.
In a meeting on Friday with various oil and gas companies, such as Adani gas, Haryana City Gas, IGL and GAIL, EPCA chairperson Bhure Lal lashed out at them asking the reason for not being able to switch to cleaner sources of energy for their operations.
"We are seriously considering a proposal from the CPCB to shut down industries in the area where the pollution reaches severe," EPCA member Sunita Narain said, adding, "The authority will write to industries asking for a breakup of their pricing of piped natural gas and what are the terms on which they supply it to the consumers."
The representatives of the firms contended that switching to electricity or gas is proving to be expensive in comparison to coal. Narain said, "We will keep pushing for switching to gas as there is no other option. We will also push the government to reduce VAT to make it cheaper by 20 per cent for industries."
On December 4, the CPCB-led taskforce identified 21 areas vulnerable to high pollution in Delhi-NCR and directed the respective municipal corporations to take "focussed actions" to mitigate the affects.
It has also asked the authorities to carry out inspection at Loni Bhopura in Ghaziabad, from where repeated complaints of violations of environmental norms have been received, according to the minutes of a meeting of the taskforce held in Delhi.
The taskforce has identified 15 pollution hotspots in Delhi. They are -- Anand Vihar, Bawana, CRRI Mathura Road, DTU, Dr Karni Singh Shooting Range, Dwarka-Sector 8, Jahangirpuri, Mundaka, NSIT Dwarka, Narela, Okhla Phase-2, R K Puram, Rohini, Shadipur, Wazirpur.
In NCR areas outside Delhi, six hotspots have been identified. They are -- Sector-16A in Faridabad, Vikas Sadan in Gurgaon, Vasundhara in Ghaziabad, Knowledge Park-III in Greater Noida, Sector-125 in Noida and RIICO Industrial Area-III in Bhiwadi.
Lal said last week, the EPCA sealed 140 units that were dealing in tar oil, rubber oil and synthetic engine oil, but another issue is that the sealed units shift to different parts of the city and continue their operations.
The EPCA chairperson also said that he would inspect burning of industrial waste in Mundka and penalise the entities responsible for it.
Delhi has been battling alarming levels of pollution for nearly two months with the air quality hovering between "very poor" and "severe", and slipping into "poor" on better days.The overall PM2.5 (fine particulate matter in the air with a diameter of less than 2.5 micrometre) level was recorded at 210 and the PM10 level at 396, it said.