Delhi-NCR's air quality neared the emergency threshold on Thursday, prompting an immediate ban on non-essential construction work and the closure of primary schools in the capital

These measures constitute the final stage of the Centre's air pollution control plan and should ideally be activated at least three days prior to the Air Quality Index surpassing the 450 mark in the capital, as outlined in a policy document prepared by the Commission for Air Quality Management (CAQM)

The Delhi government has also announced the closure of all primary schools for two days in an effort to safeguard young children from health-threatening pollution

Delhi's AQI skyrocketed from 351 at 10 am on Thursday to 471 at 9 am on Friday

The city's 24-hour average AQI, recorded at 4 pm each day, was 392 on Thursday, 364 on Wednesday, 359 on Tuesday, 347 on Monday, 325 on Sunday, 304 on Saturday, and 261 on Friday

The Congress voiced concern over rising air pollution in the country and called for a total revamp of the Air Pollution Act and air quality standards to make them stringent and effective

Congress general secretary Jairam Ramesh said The Air Pollution (Control and Prevention) Act came into being in 1981. Thereafter, ambient air quality standards were announced in April 1994 and later revised in October 1998, he noted

The AQI from 0 to 100 is considered good, while from 100 to 200 it is moderate, from 200 to 300 it is poor, and from 300 to 400 it is said to be very poor and from 400 to 500 or above it is considered as severe

AQI at multiple locations in Noida also plunged to the 'severe' category with Sector 62, Sector 1 and Sector 116 recording 483, 413 and 415 respectively