Delhi air quality enters severe category as monitoring stations record data gaps
Multiple air quality monitoring stations in the capital went blank as pollution levels worsened following Diwali celebrations.
Air quality in Delhi slipped into the severe category in several areas on Monday morning, according to data from the Central Pollution Control Board (CPCB). The deterioration occurred following Diwali celebrations and coincided with dense fog and weak wind conditions, according to Urban Acres.
An analysis by The Indian Express revealed that at least 11 monitoring stations recorded data gaps on Friday, just two days before Diwali. These included stations in Vasundhara Enclave and Nangloi, which were inaugurated last month. The disruptions resulted in 22 blind spots in hourly PM2.5 tracking and 27 missing PM10 hourly readings.
Three major stations suffered complete outages across all 24 air-quality and meteorological parameters. IIT Delhi went blank for nearly two hours on Friday, while Nangloi and NSIT Dwarka both faced four-hour blackouts. The ITO station's PM10 monitor was also reported to be non-functional for 86 consecutive hours between November 1 and November 4.
On Monday, Rohini recorded the highest Air Quality Index (AQI) reading at 475, followed by 472 at IIT Delhi. Other areas reporting severe-category readings included Burari at 437, Sonia Vihar and Vivek Vihar at 432 each, and Jahangirpuri at 426. At ITO, the AQI was recorded at 406 at approximately 4:20 am.
The India Meteorological Department stated that calm or slow winds contributed to dense fog at Safdarjung, where visibility fell to 50 metres. The Commission for Air Quality Management in the National Capital Region and Adjoining Areas had previously imposed stage three emergency measures under the Graded Response Action Plan (GRAP).