Delhi's air quality index (AQI) remained in "poor" category early Monday. While, the city's overall AQI stood at 201 in the morning, it was slightly lower than that recoded Sunday evening. The air quality had worsened at 4 pm on Sunday when the AQI was at 232.

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.

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Delhi had recorded its first bad air day in over three months on October 5. A spell of rain thereafter suppressed farm fires and kept the air clean. On October 10, Delhi breathed the cleanest air (AQI 41) since August 31, 2020.

With declining air quality, the Commission for Air Quality Management (CAQM) asked agencies to strictly implement measures under Stage I of the Graded Response Action Plan (GRAP).

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Activities under GRAP

Under Stage 1 (poor air quality), the CAQM has recommended restrictions on construction and demolition activities at sites having plot size equal to or more than 500 square metre that are not registered on the "web portal" of the respective states for remote monitoring of air pollution levels.

Authorities are also required to ensure proper implementation of guidelines for dust mitigation, management of construction and demolition waste and use of anti-smog guns at construction sites.

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Periodic mechanised sweeping of roads and water sprinkling must also be ensured as per the guidelines. Heavy fines will also be imposed for violation of the curbs on open burning of biomass and municipal solid waste.

The authorities are required to strictly enforce PUC (pollution under check) norms for vehicles and maintain a strict vigil to ensure that there are no burning incidents at landfills and dumpsites.