Delhi's air quality worsened to the 'severe plus' for the first time in the season as the Air Quality Index (AQI) surged to 457. Earlier, in the morning people in the national capital woke up to dense smog on Sunday morning, with air quality remaining in the ' severe' category. But, after a few hours, according to the System of Air Quality and Weather Forecasting and Research (SAFAR), the city's overall Air Quality Index (AQI) was recorded at a 'severe-plus 457, triggering grave health concerns.
According to AQI classifications, a 0-50 range is considered "good," 51-100 "satisfactory," 101-200 "moderate," 201-300 "poor," 301-400 "very poor," and 401-500 "severe/severe-plus".
Delhi second-most polluted city in India
Four cities in the country recorded the AQI in the "severe" category. Bahadurgarh in Haryana topped the list with an AQI of 445, followed by Delhi (441), Bhiwani in Haryana (415) and Bikaner in Rajasthan (404), according to the CPCB's data.
Of the 40 monitoring stations in the capital, data from 34 provided by the CPCB showed that 32 stations recorded the air quality in the "severe" category, with AQI levels of above 400.
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", 401 and 450 "severe" and above 450 "severe-plus".
GRAP restrictions in force in Delhi-NCR
With the third stage of the Graded Response Action Plan (GRAP) restrictions coming into force in Delhi-NCR from Friday, a stringent ban has been imposed on construction and demolition activities, mining-related operations have been suspended, shifting to online classes for students up to Class 5 is being considered and daily water sprinkling on major roads has been mandated.
The GRAP for Delhi-NCR is divided into four stages of air quality -- Stage 1 for "poor" air quality (AQI ranging from 201 to 300), Stage 2 for "very poor" air quality (AQI from 301 to 400), Stage 3 for "severe" air quality (AQI from 401 to 450) and Stage 4 for "severe-plus" air quality (AQI above 450).
According to the Centre's Decision Support System for Air Quality Management, vehicular emissions contributed approximately 15.8 per cent to Delhi's pollution on Sunday.
The system also reported that stubble burning was the main contributor to the capital's air pollution on Saturday, accounting for 25 per cent of the total pollution.
Meanwhile, the prominent pollutant was PM2.5, according to the CPCB. PM2.5 refers to fine particles with a diameter of 2.5 micrometres or less, about the width of a human hair. These particles are so small that they can penetrate deep into the lungs and even enter the bloodstream, posing significant health risks.
Also read: PM Modi reacts to 'The Sabarmati Report' movie, here is what he said
