Conflicting AQI readings ignite air quality concerns in Delhi as smog shrouds stations with PM 2.5 at 500

New Delhi : Confusion arose among residents of the national Capital on Monday as conflicting Air Quality Index (AQI) readings were reported.

While the Central Pollution Control Board (CPCB) indicated a severity level below 500 PM 2.5, Apple's Breezometer recorded levels exceeding 900 at certain locations in the city, leading to discrepancies in the assessment of air quality.

A dense and noxious haze, commonly known as 'smog,' enveloped Delhi, Noida, Greater Noida, Gurugram, Faridabad and neighbouring areas on Monday morning. This occurrence followed the bursting of crackers on Diwali night, in defiance of the Supreme Court's ban on fireworks.

On Monday evening, as per CPCB, which also contains data from the DPCC, IMD, IITM stations for air quality monitoring, the Anand Vihar station was in the 'severe' category with PM 10 at 500 and PM 2.5 at 488 while the Carbon monoxide (CO) was at 117, under the 'moderate' category, at 7 pm.

At the Bawana station PM 2.5 reached 456, in the ‘severe’ category and PM 10 at 341 was in the ‘very poor’ category, while the CO reached 70, in ‘satisfactory’ levels and NO2 at 10, 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 308 under the ‘very poor' category on Monday evening.

The air quality at the Indira Gandhi International Airport T3 area was in the 'severe' category with PM 2.5 at 439 and PM 10 at 326, in the 'very poor' category while CO reached 62, under the ‘satisfactory’ category.

At ITO station, the PM 2.5 and PM 10 crossed over 500 and were recorded in the ‘severe’ plus category. The NO2 reached 89 while CO was at 82, in the ‘satisfactory’ levels.

The PM 2.5 at Jahangirpuri was recorded at 492 while PM 10 reached 420, placing both under the ‘severe’ category. The CO reached 76, in the 'satisfactory' levels and NO2 was at 10, in the 'good' category.

At North Campus Delhi University station, the PM 2.5 reached 500 and PM 10 at 416, in the ‘severe' category while the CO was at 74, in the 'satisfactory' level.

An 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'.