The air quality in Delhi - NCR was back to "severe - plus" or "emergency" category on Monday - - for the second time in past six days - - even as the Delhi government urged the National Green Tribunal (NGT) to allow exemptions for women drivers and two - wheelers for "this year" in implementation of the odd - even traffic restriction scheme.
The toxicity in the air rose to "severe - plus" category on a day schools in the national capital reopened after remaining closed since Thursday due to "severe" air pollution levels.
The weather monitoring agencies, on the other hand, warned on Monday of further rise in the toxicity levels.
Monday also saw Haryana Chief Minister Manoharlal Khattar and his Delhi counterpart Arvind Kejriwal trading barbs over the proposed meeting on the raging issue of stubble burning and finally agreed to meet in Chandigarh on Wednesday.
The Delhi government, which had on Saturday decided to halt the odd - even traffic restriction scheme, which was scheduled to be implemented from November 13 to 17, moved the country's top green tribunal on Monday with a review petition.
"We have filed a review petition demanding exemptions for women drivers and two - wheelers for this year only, " Delhi government counsel Tarunvir Singh Khehar told the media here.
On Saturday, the National Green Tribunal (NGT) gave the go - ahead to the odd - even scheme but disapproved the exemptions given during the previous two rounds of odd - even scheme in January and April 2016.
The Delhi government had on Saturday said it would approach the green court again on Monday, requesting the exemptions and, subject to the NGT decision, it would "consider implementing it again".
Stating it did not have enough public transport as of now to accommodate the extra commuters - - over 30 lakh during the odd - even if two - wheelers were not exempted - - the Delhi government said the process of procuring new buses was going on.
According to it, about 3, 500 new buses were being procured to ply in the national capital.
The Delhi government counsel said that from next year, with better preparation, it would be in a position to implement the odd - even scheme without any exemption.
The Tribunal would hear the matter on Tuesday, NGT Chairperson Justice Swatanter Kumar said.
The Delhi government on Monday also decided to work out a Standard Operating Procedure (SOP) with state - owned helicopter service company Pawan Hans for aerial sprinkling of water over the city to contain pollution.
The average Air Quality Index (AQI) in the national capital on Monday at 8. 00 p. m was 449, with PM2. 5 at 447 units.
For the entire Delhi - NCR, the average was 440 units, with PM2. 5 at 438 units.
The safe limit for PM2. 5 - - particles in the air with a diameter less than 2. 5mm - - is 25 microgrammes per cubic meters as per international standards, though it is 60 units according to Indian standards.
Ghaziabad was the most polluted city in the entire NCR with an AQI of 500 and PM2. 5 at an astounding 816 units at 4. 00 p. m - - over 32 times the safe limit.
The System of Air Quality and Weather Forecasting And Research (SAFAR) initiative of the government said Delhi "may see increase in pollution levels" due to meteorological factors but the real picture would be clear after Tuesday.
The Met office has forecast rain on November 15.
The Supreme Court - appointed Environment Pollution Control Authority (EPCA) said Delhi's air had "reversed" to "severe - plus" or "emergency" category after some signs of improvement on Friday and Saturday.
The "emergency" or "severe - plus" situation requires PM2. 5 to remain above 300 units or PM10 to be above 500 units for 48 hours.
According to the CPCB, Delhi air had been polluted beyond the specified limits for over 50 hours by 3. 00 p. m. on Monday.
The "emergency situation" was last witnessed from Thursday to Saturday morning.
However, the pollutant levels fell below the red line for an hour on Saturday noon.
In response to the Delhi government's charge that Haryana was not responsive to its requests for a meeting to discuss the smog situation and stubble burning, Khattar on Monday landed in Delhi and said he was in Delhi and ready to have a meeting with Kejriwal.
Khattar also shared on his Twitter handle a letter he had written to Kejriwal on November 10 in which he had expressed his willingness to meet the Delhi Chief Minister, and also blamed Kejriwal for his "inability to rise above short - term electoral interests".
After arriving in Delhi, Khattar told reporters: "I am in Delhi, where is the meeting?"
Kejriwal replied through a tweet: "Khattarji called.
He is in Delhi till tomorrow.
Says he is very busy and can't meet me in Delhi.
He has asked me to come to Chandigarh on Wednesday.
I look forward to meeting him in Chandigarh on Wednesday. "