Air quality deteriorates in north India post-Diwali; Delhi records highest AQI since 2021

New Delhi: A thick layer of smog hung over parts of north India on Monday, a day after Diwali celebrations during which crackers were burst beyond permitted hours, pushing air quality to alarmingly high levels.

Delhi, Haryana, Punjab and Western Uttar Pradesh's Air Quality Index (AQI) levels were well above 350, falling into the 'very poor' range.

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On Sunday, Delhi recorded its most polluted Diwali in five years, with the average AQI at 376. The next morning, the AQI dropped marginally to 371, according to the CPCB.

The overall AQI stood at 371 on Monday till 10 am, the highest for a post-Diwali day since 2021. Of the 51 monitoring stations that recorded data, 14 were in the 'severe' category, four in the 'poor' category and the remaining 33 in the 'very poor' category. Delhi Technological University (DTU) recorded the worst reading of 439. Earlier in the morning, the overall AQI was 370 at 8 am.

According to CPCB data, Delhi's AQI was 376 on Diwali, the highest recorded on the festival day since 2021, when it was 382.

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However, according to real-time readings on AQI.in, Delhi's air quality climbed to 2,283 after Diwali. Six other Indian cities also recorded AQI levels above 1,000 at 9 pm on Sunday, according to the platform.

On Monday morning, AQI.in recorded Delhi's air quality at 637, classifying it as 'hazardous'.

According to IQAir, the concentration of PM2.5 stood at 170 micrograms per cubic metre, around 34 times the World Health Organisation's annual guideline value.

The high AQI also pushed up PM 10 and PM2.5 levels in the national capital.

The concentration of PM10 was 126 micrograms per cubic metre, while ozone levels stood at 31, nitrogen dioxide at 44.6 and sulphur dioxide at 32. Carbon monoxide concentration was recorded at 1,461.5 micrograms per cubic metre.

PM2.5, fine particulate matter capable of penetrating deep into the lungs and entering the bloodstream, is among the major pollutants of concern due to its adverse health effects.

IQAir's dashboard also showed a prominent air quality alert for Delhi, with data from 32 monitoring stations provided by 12 contributors.

In Uttar Pradesh, the western region bore the brunt of post-Diwali air pollution, with several cities and localities recording 'very poor' air quality and some pockets in Ghaziabad, Meerut and Saharanpur reporting AQI levels in the 'severe' category, according to official and local data.

Among the 24-hour average readings from November 8 to 4 pm on Monday, Noida recorded an AQI of 332, Greater Noida 252, Ghaziabad 324, Baghpat 305, Bulandshahr 303, Muzaffarnagar 225, Meerut 269, Shamli 275 and Hapur 202.

In Meerut, doctors reported an increase in patients complaining of breathing difficulties, asthma, throat infections and eye irritation after Diwali.

In Ghaziabad, the municipal corporation intensified mechanical road sweeping, water sprinkling and dust-control operations at identified pollution hotspots, City Health Officer Mitlesh Kumar said.

The post-Diwali pollution levels were not uniform across the state.

Among the places covered in the 24-hour readings, Bareilly recorded a comparatively lower AQI of 102 and Vrindavan 110. Fatehabad registered 138, Pratapgarh 141, Jhansi 144, Mathura 169, Firozabad 176 and Agra 187.

Other major cities also recorded poor air quality, with Lucknow at 245, Kanpur at 221, Prayagraj at 241, Varanasi at 274 and Gorakhpur at 261.

In neighbouring Punjab and Haryana, the air quality was in the 'very poor' category on Monday.

According to the 24-hour average AQI, which is reported at 4 pm every day, Bahadurgarh in Haryana recorded 400, while Charkhi Dadri was at 389.

The CPCB's data further showed that Gurugram's AQI was 345, Rohtak 378, Manesar 333, Faridabad 350, Ballabhgarh 316, Bhiwani 340, Kaithal 347, while Narnaul recorded an AQI of 305.

The air pollution was so severe that many residents complained of breathing difficulty.

Gurugram resident Praveen Bhardwaj said that when he stepped out of his home on Monday morning, he began to experience eye irritation and difficulty breathing.

"I used to go for a walk in the park every morning. But now, due to the pollution, I'm afraid to even step outside. Many people are even having to give up their morning walks for the sake of their health", he said.

Ashok Yadav, a resident of Sector-14, said pollution has become a cause for concern even for those who head out for morning walks.

"Instead of merely issuing directives, the government and the administration should take concrete, on-the-ground measures to control pollution so that people can get relief," he added.

In Punjab, the 24-hour AQI reading in Jalandhar and Mandi Gobindgarh was 336, in the 'very poor' category, while Ludhiana (292), Amritsar (257) and Patiala (221) were all in the 'poor' category. Chandigarh, the common capital of Haryana and Punjab, recorded an AQI of 148 in the 'moderate' category.