A day after being enforced, Stage 4 restrictions under the Graded Response Action Plan (GRAP) were revoked on Thursday in Delhi-NCR as pollution levels showed a slight improvement, according to an official statement.
The Commission for Air Quality Management (CAQM) had invoked Stage 4 restrictions on Wednesday following a sharp rise in pollution levels. The Air Quality Index (AQI) had climbed to 396, nearing the “Severe” category, due to calm winds, low temperatures, and foggy conditions that trapped pollutants in the air.
Air quality improves
Several parts of Delhi experienced light rainfall on Thursday morning, leading to an improvement in the city’s air quality from the ‘severe’ to the ‘poor’ category. However, cold weather conditions persisted, with dense fog blanketing the city.
GRAP Stage 4 restrictions
Measures under Stage 4 of the Graded Response Action Plan (GRAP), aimed at addressing “Severe Plus” air quality (AQI above 450), included a ban on all non-essential construction activities, restrictions on non-essential diesel trucks, and a prohibition on Delhi-registered BS-IV and older diesel vehicles, except those providing essential services.
Schools were also required to shift to hybrid mode for most classes, excluding grades 10 and 12. With a slight improvement in meteorological conditions, Stage 4 restrictions have been revoked, although measures under Stage 3 remain active to prevent a resurgence in pollution levels.
GRAP, a regulatory framework implemented during winter to tackle air pollution in Delhi-NCR, categorises air quality into four stages: Stage 1 (Poor, AQI 201-300), Stage 2 (Very Poor, AQI 301-400), Stage 3 (Severe, AQI 401-450), and Stage 4 (Severe Plus, AQI above 450).
The worsening air quality is a result of a combination of factors, including vehicular emissions, stubble burning, firecrackers, and adverse weather conditions.
Although Stage 4 restrictions have been lifted, the air quality remains precarious. Authorities continue to monitor the situation closely, with measures under Stage 3 still active to curb further deterioration. Residents are advised to minimise outdoor activities, use air purifiers, and follow government advisories to stay safe.