Delhi air quality turns 'severe' at AQI 483 ahead of Diwali; several areas cross 400

New Delhi: Delhi's air quality deteriorated sharply on Sunday morning, with the overall Air Quality Index (AQI) reaching 483 at 8.10 am, placing the national capital in the 'severe' category. Several monitoring stations across the city also recorded pollution levels above 400, according to the Central Pollution Control Board (CPCB).

The deterioration comes amid heightened pollution concerns ahead of Diwali, with the Commission for Air Quality Management (CAQM) invoking Stage III of the Graded Response Action Plan (GRAP) across Delhi-NCR on Friday.

CPCB data showed that Punjabi Bagh recorded an AQI of 449, while RK Puram registered 448. Bawana recorded 446, followed by IIT Delhi and Rohini at 445 each. Chandni Chowk and Patparganj reported AQI readings of 420 and 421, respectively, while Alipur recorded 413.

Anand Vihar registered an AQI of 328, while Narela recorded 395, placing both areas in the 'very poor' category.

Pollution levels around prominent landmarks also remained high. India Gate recorded an AQI of 398, while the area around Akshardham Temple registered 336, with both falling under the 'very poor' category.

Several parts of the national capital woke up to a thick blanket of haze on Sunday, with reduced visibility adding to concerns over the worsening air quality as winter sets in.

The overall AQI of 483 marked a sharp deterioration from Saturday morning, when the city recorded an AQI of 364 at 8 am, placing it in the 'very poor' category.

According to CPCB standards, an AQI of 0-50 is classified as 'good', 51-100 as 'satisfactory', 101-200 as 'moderate', 201-300 as 'poor', 301-400 as 'very poor' and 401-500 as 'severe'.

GRAP restrictions tightened across Delhi-NCR

The CAQM's activation of Stage III of GRAP brought additional pollution-control measures into force across Delhi and adjoining areas of Haryana, Uttar Pradesh and Rajasthan. The measures operate alongside the restrictions already imposed under the earlier stages of the emergency action plan.

GRAP is a four-stage pollution-control framework implemented by the CAQM in coordination with the CPCB and state governments. The restrictions become progressively stricter as air quality deteriorates, with the aim of controlling pollution before it reaches critical levels.

Stage I is implemented when AQI falls in the 201-300 range, classified as 'poor'. The measures primarily focus on controlling road dust, enforcing pollution standards and preventing open waste burning.

Stage II applies when AQI reaches 301-400, categorised as 'very poor'. It includes intensified dust-control measures, higher parking fees and staggered office timings.

Stage III, applicable in the 401-450 AQI range, classified as 'severe', introduces stricter restrictions on vehicles and construction activities. It also provides for hybrid learning arrangements for primary school students.

Stage IV, the most stringent level, is triggered when AQI exceeds 450 and enters the 'severe plus' category. It includes restrictions on heavy goods vehicles and additional emergency measures to curb vehicular and industrial emissions.

Under the Stage III restrictions, BS-III petrol and BS-IV diesel four-wheelers are prohibited from operating across Delhi and designated districts of the NCR.

Restrictions have also been tightened on older light and medium goods vehicles, along with diesel commercial vehicles registered outside Delhi entering the national capital.

Construction activities that generate significant dust have been suspended. These include major excavation work, earthwork, demolition and road construction. Essential projects allowed to continue must comply with strict dust-control measures.

Stone crushers and mining operations, which contribute to dust pollution, are also subject to shutdowns or operational restrictions.