New Delhi, Nov 13 : A dense and noxious haze, commonly known as smog, enveloped Delhi, Noida, Gurugram, and neighbouring areas on Monday morning. This occurrence followed the widespread bursting of crackers at Diwali night, in defiance of Supreme Court's ban order. The incident exacerbated the already critical air quality in the National Capital Region, intensifying the ongoing struggle against pollution. The Anand Vihar station was in the 'severe' category with PM 10 at 500 and PM 2.5 at 473 while the CO was at 131, under 'moderate' category, as per the Central Pollution Control Board (CPCB) at 10 a.m. At the Bawana station PM 2.5 reached 469, in the severe category and PM 10 at 376 was in the 'very poor' category, while the CO reached 78, in satisfactory levels and NO2 at 12, in the 'good' category. At the Dwarka sector-8 station, the PM 2.5 reached 444, in the severe category while PM 10 was at 360 under the 'very poor' category on Monday morning. The air quality at the Indira Gandhi International Airport T3 area was in the 'severe' category with PM 2.5 at 431 and PM 10 at 295, in the 'poor' category. At ITO station, the PM 2.5 crossed over 500, in the severe plus category while PM 10 was recorded at 457 in the severe category. The NO2 reached 121 in the moderate category while CO was at 92, in satisfactory levels. The PM 2.5 at Jahangirpuri was recorded at 486 while PM 10 reached 420, placing both under 'severe' category. Carbon monoxide (CO) reached 84, in 'satisfactory' levels and NO2 was at 11, in the 'good' category. At north campus Delhi University station, the PM 2.5 reached 457 and PM 10 at 405, in the 'severe' category while the CO was at 89, in a 'satisfactory' level. The AQI between zero and 50 is considered 'good'; 51 and 100 'satisfactory'; 101 and 200 'moderate'; 201 and 300 'poor'; 301 and 400 'very poor'; and 401 and 500 'severe'. /IANS