New Delhi: The air quality of Delhi entered into the ‘severe plus’ category on Thursday recording an average Air Quality Index (AQI) of 451 in 24 hours. According to the Central Pollution Control Board (CPCB) data, the AQI of 451 was recorded at 4 pm. Amidst the worsening pollution in Delhi-NCR, the entire region remains under Stage IV of the Graded Response Action Plan (GRAP).

As per the pollution control board, Delhi witnessed dangerously high levels of PM2.5, the primary pollutant, with 32 of the 35 monitoring stations recording air quality in the severe plus category. Shockingly, some areas in the national capital region recorded AQI readings as high as 470.

The PM2.5 particles, measuring 2.5 micrometers or less in diameter pose significant health risks as they can penetrate deep into the lungs when inhaled.

The national capital remains under Stage IV of the Graded Response Action Plan (GRAP), which includes the most stringent anti-pollution measures.

The measures involve a complete ban on construction activities and the entry of non-essential polluting trucks into the city.

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).

The Indian Meteorological Department (IMD) has issued a yellow alert for Friday, warning of very dense fog. 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.