In light of the acute and worsening air quality conditions in the National Capital Region (NCR), the Sub-Committee of the Commission for Air Quality Management (CAQM) invoked Stage IV of the Graded Response Action Plan (GRAP) with immediate effect on Monday night.
This decision followed the breach of the critical Air Quality Index (AQI) threshold of 400 in Delhi, where readings escalated from 399 at 9 PM to 401 at 10 PM.
The CAQM Sub-Committee convened an emergency session to assess the rapid and sustained deterioration in air quality, which was primarily attributable to highly unfavorable meteorological factors, including a steep decline in wind activity and a drop in the atmospheric mixing layer height.
Such conditions exacerbate pollutant entrapment, impeding their dispersion and contributing to sustained elevated AQI levels.
In its formal order issued on December 16, RK Agrawal, Director of the Sub-Committee on GRAP, stated, “In pursuance of the Supreme Court’s directives, the Sub-Committee hereby invokes Stage-IV of the Schedule under the GRAP, as comprehensively revised and issued on December 13, 2024, with immediate effect. The actions under Stage-IV shall be over and above the actions under Stages III, II, and I, already in force.” This invocation reflects a compliance-driven escalation, adhering to the Supreme Court’s stipulated guidelines, which mandate Stage-III restrictions when the AQI breaches 350 and necessitate the implementation of Stage-IV measures once the AQI surpasses 400.
The reimposition of GRAP Stage-III measures earlier was predicated on the persistent failure of pollutant dispersion, further aggravated by stagnant meteorological conditions. By Monday evening, the Sub-Committee underscored that the AQI had reached a critical inflection point, hovering near 400 before crossing the threshold, prompting the immediate invocation of Stage IV actions.
The GRAP framework, comprehensively revised on December 13, constitutes a tiered emergency response system tailored to address incremental severities of air pollution. Administered by the CAQM, the plan delineates specific interventions to mitigate particulate matter concentration and associated atmospheric pollutants during peak pollution episodes.
The escalation to Stage IV underscores the dire air quality crisis that Delhi and the broader NCR are facing. AQI levels persistently remain within the ‘severe’ and ‘very poor’ categories, posing significant epidemiological risks, particularly for vulnerable demographics such as children, the elderly, and individuals with preexisting pulmonary or cardiovascular conditions. The prolonged exposure to such high levels of particulate matter and other pollutants necessitates immediate public health precautions and robust mitigation strategies.
Authorities have advised residents to minimize outdoor activities, utilize protective masks, and adhere to prescribed health guidelines. The enforcement of Stage IV measures highlights both the urgency of the pollution crisis and the pressing need for multi-stakeholder cooperation to implement sustainable, long-term solutions to Delhi’s recurrent air quality degradation.
