Delhi’s air quality took a turn for the worse again as the 24 hour average AQI plunged into the ‘severe plus’ category on Thursday, breaching the 450-mark at 4 PM, according to the Central Pollution Control Board data.
The AQI readings in some areas recorded AQI as high as 470. At least 32 of the 35 monitoring stations in the national capital recorded air quality in the severe plus category with dangerously high levels of PM2.5, the primary pollutant.
The PM2.5 particles, which measure 2.5 micrometers or less in diameter, are extremely dangerous as they can penetrate deep into the lungs when inhaled, posing significant health risks.
Delhi remains under Stage 4 of the Graded Response Action Plan (GRAP), which includes stringent measures such as a complete ban on construction activities and the entry of non-essential polluting trucks into the national capital. Stage 4 was reimposed on December 16 night after Delhi’s air quality witnessed significant pollution spike.
The Indian Meteorological Department (IMD) has issued a yellow alert for Friday, December 20, warning very dense fog in the city. “The maximum temperature on Thursday was recorded at 23 degrees Celsius, slightly above the season’s normal, while the minimum temperature was five degrees Celsius, three notches below normal,” the department said.
The city’s 24-hour average AQI on Tuesday was 433 at 4 PM against 379 on Monday. Meanwhile, the city and the adjoining areas like Noida, Gurugram, and Ghaziabad woke up to a layer of dense fog with the AQI between very poor to severe-plus category. The AQI at 6 AM on Thursday stood at 448, two marks short of the severe-plus level.
In Ghaziabad, the overall AQI stood at 381, while Noida and Gurugram recorded AQI of 364 and 376, respectively. The last time Delhi’s air quality was recorded in the ‘severe’ category was on November 23, with a reading of 412.
GRAP categorises air quality into four stages: Stage I (Poor, AQI 201-300), Stage II (Very Poor, AQI 301-400), Stage III (Severe, AQI 401-450), and Stage IV (Severe Plus, AQI above 450).
As per the Central Pollution Control Board (CPCB), an AQI between 0 and 50 is considered “good,” 51-100 “satisfactory,” 101-200 “moderate,” 201-300 “poor,” 301-400 “very poor,” 401-450 “severe,” and above 450 “severe plus.”
(With inputs from news agency PTI)
