A thick blanket of smog engulfed large parts of north India on Monday, a day after Diwali celebrations, with air quality deteriorating sharply across Delhi, Haryana, Punjab and western Uttar Pradesh as firecracker emissions added to the pollution burden.
Delhi recorded its highest post-Diwali air pollution level in five years, with the overall Air Quality Index (AQI) touching 371 at 10 am on Monday, placing it in the 'very poor' category.
The reading was marginally lower than Sunday's average AQI of 376, which made it the capital's most polluted Diwali in five years, according to the Central Pollution Control Board (CPCB).
Of the 51 monitoring stations in Delhi that reported data on Monday morning, 14 recorded 'severe' air quality, while 33 were in the 'very poor' category and four in the 'poor' category. Delhi Technological University (DTU) recorded the highest AQI at 439. The overall reading stood at 370 at 8 am.
According to CPCB data, Delhi's average AQI on Diwali was 376, compared with 382 in 2021, the previous highest for the festival day since then.
However, real-time readings on the AQI.in platform painted a more alarming picture, with Delhi's AQI reportedly soaring to 2,283 after Diwali celebrations on Sunday. Six other Indian cities also recorded readings above 1,000 at 9 pm, according to the platform. On Monday morning, the platform recorded Delhi's AQI at 637, categorising the air quality as 'hazardous'.
According to IQAir, the concentration of fine particulate matter (PM2.5) in Delhi stood at 170 micrograms per cubic metre, around 34 times the World Health Organisation's annual guideline value.
The national capital also recorded elevated levels of other pollutants. PM10 concentration stood at 126 micrograms per cubic metre, while ozone was recorded at 31, nitrogen dioxide at 44.6 and sulphur dioxide at 32. Carbon monoxide levels stood at 1,461.5 micrograms per cubic metre.
PM2.5, fine particulate matter that can penetrate deep into the lungs and enter the bloodstream, poses significant health risks, particularly to people with respiratory conditions, children and the elderly. IQAir's dashboard also carried an air quality alert for Delhi, based on data from 32 monitoring stations provided by 12 contributors.
Western Uttar Pradesh was among the worst-affected regions, with several cities recording 'very poor' air quality and pockets of Ghaziabad, Meerut and Saharanpur entering the 'severe' category.
Among the 24-hour average readings recorded up to 4 pm on Monday, Noida registered an AQI of 332, Ghaziabad 324, Baghpat 305 and Bulandshahr 303. Greater Noida recorded 252, Muzaffarnagar 225, Meerut 269, Shamli 275 and Hapur 202.
The deteriorating air quality also triggered health concerns in Meerut, where doctors reported an increase in patients complaining of breathing difficulties, asthma, throat infections and eye irritation following Diwali.
In Ghaziabad, the municipal corporation stepped up mechanical road sweeping, water sprinkling and dust-control measures at identified pollution hotspots, City Health Officer Mitlesh Kumar said.
The impact, however, varied across Uttar Pradesh. Bareilly recorded a comparatively lower AQI of 102, followed by Vrindavan at 110. Fatehabad registered 138, Pratapgarh 141, Jhansi 144, Mathura 169, Firozabad 176 and Agra 187.
Other major cities also reported elevated pollution levels, with Lucknow recording an AQI of 245, Kanpur 221, Prayagraj 241, Varanasi 274 and Gorakhpur 261.
Neighbouring Haryana and Punjab also witnessed a deterioration in air quality, with several cities recording 'very poor' readings.
In Haryana, Bahadurgarh recorded an AQI of 400, while Charkhi Dadri registered 389 in the 24-hour average readings reported at 4 pm. Rohtak recorded 378, Faridabad 350, Kaithal 347, Gurugram 345, Bhiwani 340, Manesar 333, Ballabhgarh 316 and Narnaul 305.
Residents in Gurugram reported breathing difficulties and eye irritation amid the deteriorating conditions.
In Punjab, Jalandhar and Mandi Gobindgarh recorded an AQI of 336 each, placing them in the 'very poor' category. Ludhiana recorded 292, Amritsar 257 and Patiala 221, all in the 'poor' category. Chandigarh, the joint capital of Punjab and Haryana, recorded an AQI of 148, placing it in the 'moderate' category.
(With inputs from PTI)