The air quality of the capital has improved significantly after the drop in crop residue burning on Thursday.
Delhi's air quality deteriorated again to 'very poor' category on Friday after a brief respite. The overall air quality index was recorded at 315 which falls in 'very poor' category, according to the Centre-run System of Air Quality and Weather Forecasting (SAFAR).
Sixteen areas recorded 'very poor' air quality and 22 areas in Delhi recorded 'poor' air quality, according to data by the Central Pollution Control Board.
On Friday, the PM2.5 (particles in the air with a diameter of less than 2.5 micrometres) level was recorded at 139, while the PM10 (particles in the air with a diameter of less than 10 micrometres) was recorded at 210 in Delhi.
An AQI between 0 and 50 is considered 'good', 51 and 100 'satisfactory', 101 and 200 'moderate', 201 and 300 'poor', 301 and 400 'very poor', and 401 and 500 'severe'.
Delhi's air quality has showed significant improvement in the past two days after rain washed away the pollutants.
But as rain subsided, a rise in pollution level was again recorded on Friday, authorities said.
According to Indian Institute of Tropical Meteorology, fire counts observed in past 24 hours over northwest region of India were few (less than 100 counts).
"The impact of biomass burning in northwest India is not significant over Delhi," it said.
The PM2.5 concentration will improve in the next two days. "The air quality is likely to improve next two days but remain in 'poor'/'very poor' category in Delhi-NCR. The impact of biomass burning in northwest India is marginal over Delhi," it said.
SAFAR also advised people suffering from respiratory diseases to reduce prolonged or heavy exertion. They have also been asked to take more breaks and do less intense activities.
Meanwhile, the National Green Tribunal (NGT) on Thursday issued an order to all the states to adopt a multi-method approach through in situ and ex-situ management of crop burning residue. It also directed the Narendra Modi-led government at the Centre to "disburse funds well in time" so that "states can utilise it properly".
As per the directives issued by the NGT, the Chief Secretaries of Delhi, Punjab, Haryana and Uttar Pradesh held a two-hour long meeting with members of the green panel. Representatives from the Union Ministry of Environment, Forests and Climate Change, the Central Pollution Control Board and the Union Secretary Agriculture were also present at the meeting.
The Supreme Court-appointed Environment Pollution Control Authority (EPCA), recommended to the pollution watchdog CPCB on Wednesday that it should implement either the odd-even scheme or impose a complete ban on non-CNG private vehicles if the air pollution level in Delhi increases again.
In a letter to CPCB member secretary Prashant Gargava, Bhure Lal, chairman of EPCA said that all cities, which have similar emergency plans “like Paris or Beijing” include restrictions on private vehicles, adding that vehicles contribute as much as 40 per cent of the total emission load in Delhi and roughly 30 per cent in the region.
"In this situation, the only option is to look at either a complete ban on all private vehicles (without the identification of petrol or diesel), other than CNG and/or restriction on plying by number plate (odd-even)," he said.
Reacting to the recommendation by Lal, the CPCB said the additional steps, including the complete ban on non-CNG private vehicles, should be "deliberated" by the EPCA, which is a larger body.
