 "An anti-smog gun being used to spray water droplets to curb air pollution, at Raisina Hills in New Delhi. PTI")
Delhi and its neighbouring towns are shrouded in a thick haze, with air quality becoming increasingly hazardous with each passing day.
On Thursday, Delhi residents woke to another day of ‘severe’ air quality, a day after the national capital recorded the country’s worst AQI. As dense smog settled over the NCR, visibility was reduced to almost zero in some regions.
In an effort to combat the alarming pollution, the Commission for Air Quality Management (CAQM) considered implementing Stage 3 of the Graded Response Action Plan (GRAP), a set of anti-pollution measures. Yet on Thursday, authorities opted not to proceed with it, NDTV reported.
But why did they make this choice? Here’s a closer look at the situation.
Smog blankets Delhi
On Wednesday, pollution levels in New Delhi surged sharply, with the Air Quality Index (AQI) reaching 418, marking the season’s first entry into the “severe” category.
By Thursday, the AQI continued to rise, hitting 432, as reported by the Central Pollution Control Board (CPCB). Out of 36 monitoring stations across the city, 30 recorded ‘severe’ air quality levels.
The thick smog covering the region drastically reduced visibility, causing disruptions to both flights and trains in and around the national capital.
According to NDTV, visibility at Punjab’s Amritsar and Pathankot airports dropped to zero at 5:30 am. By 7:00 am, the same was true for Uttar Pradesh’s Gorakhpur airport.
This prompted several airlines operating in and out of Delhi to issue travel advisories on social media X (formerly Twitter). Indigo advised passengers to monitor their flight status, warning of potential delays due to “winter fog.”
The worsening pollution has also led to a surge in respiratory problems among Delhi residents.
Doctors at Fortis Hospital have reported a 20-25 per cent rise in patients suffering from pollution-related ailments.
Dr Vikas Maurya, Senior Director and Head of Respiratory Medicine and Interventional Pulmonology, told ThePrint, “These are typically healthy individuals who remain fit throughout the year but develop these conditions, particularly in the winter months, when AQI levels in the city rise.”
The Commission for Air Quality Management attributed the conditions to an “unprecedented extremely dense fog,” calling it an “episodic event.” They later chose to closely monitor the situation before bringing into place Stage III of the Graded Response Action Plan (GRAP).
Also read: Winter is here: How Delhi is choking on thick smog and poor air
What is GRAP and its stages?
GRAP, or the Graded Response Action Plan, is similar to an emergency alert system, which aims to direct the government to take actions based on the severity of pollution, especially during winter months when pollution peaks.
The plan undergoes regular updates to address the worsening air quality, with the eighth iteration currently in effect, according to Down to Earth.
Initially, GRAP’s focus was primarily on PM2.5 and PM10 concentrations. However, subsequent revisions have shifted its basis to the city’s Air Quality Index (AQI) levels.
The AQI is calculated from eight pollutant concentrations: PM10, PM2.5, nitrogen dioxide, sulphur dioxide, carbon monoxide, ground-level ozone, ammonia, and lead.
The GRAP divides pollution severity into four stages based on Delhi’s AQI:
Stage I — ‘Poor’ (AQI 201-300)
Stage II — ‘Very Poor’ (AQI 301-400)
Stage III — ‘Severe’ (AQI 401-450)
Stage IV — ‘Severe+’ (AQI > 450)
Each stage includes a set of targeted actions designed to reduce pollution levels effectively.
What happens in GRAP stage 3?
The newly launched GRAP Stage 3 action plan focuses on reducing the impact of diesel vehicles, a major contributor to pollution in Delhi.
Under Stage 3, the government enforces strict restrictions on Delhi-registered diesel-operated medium goods vehicles (MGVs) that meet BS-III standards or below. However, vehicles carrying essential goods or providing essential services are exempt.
BS, or Bharat Stage, emission standards regulate the amount of pollutants that internal combustion engines release into the air.
The plan also bans inter-state buses from NCR states, unless they are electric (EV), CNG, or BS-VI diesel. Buses and tempo travellers with an All India Tourist Permit are the only exceptions.
Another significant change is the requirement for diesel generator (DG) sets to operate in dual-fuel mode or be equipped with emission control technology.
In addition, there is a complete ban on construction and demolition activities. State governments may also suspend in-person classes up to Class 5, and there is an increased focus on promoting public transportation.
Currently, Stage 2 is still in effect, which was implemented on October 22.
Why has GRAP Stage-3 not been implemented?
According to NDTV, Delhi’s Environment Minister Gopal Rai announced that the third phase of the Graded Response Action Plan (GRAP 3) will not be implemented at this time.
“There is a possibility of improvement in the pollution level from tomorrow, due to which Grap 3 is not being imposed in Delhi. Today we are again giving instructions that the rules made under Grap 2 should be followed on the ground so that Grap 3 does not have to be implemented,” Rai said.
He added that the fog layer in Delhi was caused by low wind speeds, which are expected to improve soon.
Also read: How high temperatures and strong winds helped Delhi breathe a bit easier this Diwali
“If the pollution again goes into the ‘severe’ category then the Delhi government will take all the necessary steps and will work together with the people of Delhi,” the minister said.
Citing meteorologists, Rai also noted that snowfall in the mountains has led to a temperature drop in Delhi. This has resulted in dry conditions across North India, contributing to a sharp decline in air quality over the past two days.
With input from agencies