Delhi’s air quality plummeted to the “severe plus” category on Friday morning, a stage at which all emergency measures, including a ban on polluting trucks, commercial four-wheelers, and all types of construction, are mandated to be initiated and enforced in the National Capital Region.

These measures constitute the final stage of the Centre’s air pollution control plan and should ideally be activated at least three days prior to the Air Quality Index surpassing the 450 mark in the capital, as outlined in a policy document prepared by the Commission for Air Quality Management (CAQM).