Raging stubble fires in neighbouring States, fall in the temperature and wind speed pushed the national Capital’s air quality in the “severe” zone on Tuesday with the Government’s air quality monitor, SAFAR, forecasting that pollution levels in Delhi-NCR are expected to enter the “severe plus” or “emergency” category on Wednesday.
Meteorologists said Delhi recorded a minimum temperature of 11.7 degrees Celsius, the season’s lowest so far on, Tuesday morning. It is two notches below normal for this time of the year. “A dip in wind speed and temperature makes the air cold and dense,” leading to accumulation of pollutants in the air, said Kuldeep Srivastava, head of the India Meteorological Department’s regional weather forecasting centre.
According to the Central Pollution Control Bureau (CPCB), Delhi’s overall air quality index (AQI) was 425 at 4 pm on Tuesday. It was 360 at 4 pm on Monday.
The levels of PM 2.5 — tiny particulate matter less than 2.5 microns in diametre that can enter deep into the lungs and even the bloodstream — shot up to 292 micrograms per cubic metre, around five times the safe limit of 0-60 micrograms per cubic metre.
The levels of PM10 increased to 436 micrograms per cubic metre, more than four times the safe limit of 100 micrograms per cubic metre.
Most of the 37 air quality monitoring stations in Delhi recorded air quality in the severe category. The spike in pollution came on a day when the Delhi Government lifted restrictions under its odd-even vehicle rationing scheme in view of the the 550th birth anniversary of Sikhism founder Guru Nanak Dev.
Bawana was the most-polluted area in the city with an AQI of 458, followed by Wazirpur (454), Rohini (454), Dwarka Sector-8 (453) and Anand Vihar (450).
Faridabad (406), Gurugram (402), Ghaziabad (453), Greater Noida (436), and Noida (440) also choked on extremely polluted air.
An AQI between 201 and 300 is considered ‘poor’, 301-400 ‘very poor’ and 401-500 ‘severe’. An AQI above 500 falls in the ‘severe plus’ category.
The SAFAR said the share of stubble burning accounted for 25 per cent of Delhi’s pollution on Tuesday, up from 18 per cent on Monday.
“No sudden recovery is expected at least for the next two days and the AQI is likely to deteriorate further towards severe-plus category by tomorrow. The condition may slightly improve by November 15,” it said in a report.
