Pollution levels in Delhi and its surrounding areas dipped marginally overnight due to a relatively better wind speed, though the concentration of poisonous PM2.5 was still more than 80 times the healthy limit prescribed by the World Health Organization.
A thick toxic haze lingers over the city for the fifth consecutive day on Saturday, with doctors expressing concerns that air pollution is causing an increase in respiratory and eye problems among children and the elderly.
The concentration of PM2.5, fine particulate matter capable of penetrating deep into the respiratory system and triggering health problems, exceeded the government-prescribed safe limit of 60 micrograms per cubic metre by seven to eight times at multiple locations throughout Delhi-NCR.
It was 80 to 100 times the healthy limit (5 micrograms per cubic metre) set by the World Health Organization (WHO).
The air quality in Delhi-NCR declined over the past week due to a gradual drop in temperatures, calm winds that trap pollution, and a surge in post-harvest paddy straw burning across Punjab and Haryana.
Data from the Central Pollution Control Board (CPCB) shows that Delhi's Air Quality Index (AQI) increased by more than 200 points between October 27 and November 3, culminating in a descent into the "severe plus" category (above 450) on Friday.
However, the AQI marginally improved from 468 at 4 pm on Friday to 413 at 6 am on Saturday.
Friday's 24-hour average AQI (468) was the worst since the previous high of 471 recorded on November 12, 2021.
Delhi's air quality ranks among the worst in the world's capital cities.
A report by the Energy Policy Institute at the University of Chicago (EPIC) in August said that air pollution is shortening lives by almost 12 years in Delhi.
The hazardous pollution levels compelled many to forgo their morning walks, sports, and other outdoor activities.
Parents are a worried lot as health experts say children breathe faster, taking in more pollutants.
Unfavourable meteorological conditions, combined with emissions from vehicles, paddy straw burning, firecrackers, and other local pollution sources, contribute to hazardous air quality levels in Delhi-NCR during the winter every year.
According to an analysis conducted by the Delhi Pollution Control Committee (DPCC), the capital experiences peak pollution from November 1 to November 15 when the number of stubble-burning incidents in Punjab and Haryana increases.
Smoke from stubble burning accounted for 35 per cent of the PM2.5 pollution in Delhi on Friday, rising from 25 per cent on Thursday, according to a numerical model-based system developed by the Pune-based Indian Institute of Tropical Meteorology.
Officials at the Commission for Air Quality Management, a central government panel that formulates strategies to combat pollution in Delhi-NCR, expect pollution levels to further decline due to comparatively better meteorological conditions and curbs imposed on certain polluting activities, including non-essential construction work, starting Thursday.
On Friday, the commission deferred the implementation of stricter measures under the air pollution control plan, called the Graded Response Action Plan, citing a declining trend in the AQI in the region.
A day earlier, the pollution control body had ordered a ban on non-essential construction work and specific categories of polluting vehicles.
