“The Air Quality parameters, however, further worsened owing to a drastic reduction in the mixing layer height and continued absolute calm wind conditions over Delhi. The Sub-Committee on GRAP was accordingly maintaining a close watch on the air quality scenario in Delhi. The Sub- Committee noted that the AQI level almost touched the 400 mark i.e. was 399 at 9 pm and was recorded as 401 at 10 pm, breaching the 400 mark,” the order by the CAQM sub-committee noted.

The commission said GRAP-4 restrictions are being invoked with immediate effect and will apply over and above the actions under GRAP stages III, II and I, already in force.

The curbs under GRAP stage 4 include a ban on all construction and demolition activities, including public projects such as highways and flyovers, and on the entry of trucks carrying non-essential goods into Delhi.

Delhi’s 24-hour average air quality index, which was 379 at 4 pm, breached the 400 mark around 10 pm amid extremely calm winds and “buildup of an inversion layer adversely affecting the vertical mixing height”.

Schools in NCR region

“State govts in the NCR and the GNCTD to mandatorily conduct classes in schools for children even for higher classes i.e. from class VI to IX and XI in a “Hybrid” mode i.e. both in physical and online mode (wherever online mode is feasible) in the territorial jurisdiction of the NCT of Delhi and in the districts of Gurugram, Faridabad, Ghaziabad and Gautam Buddh Nagar,” the order from CAQM said.

The Gautam Buddh Nagar administration has asked all schools in the district to start classes from 9 am on Tuesday.

“In view of the extreme cold, as per the instructions given by the District Magistrate, Gautam Buddh Nagar, classes in all schools will start from 9 am till further orders. In this regard, all the principals are instructed to ensure strict compliance of the above instructions,” Dr Dharmveer Singh, the District Inspector of Schools (DIOS), said in an order.

Schools in Gautam Buddh Nagar have also been asked to switch to hybrid mode of teaching for students up to Class 5.

(With inputs from PTI)