Air pollution levels have deteriorated across several Indian cities following Diwali, with Delhi recording an alarming Air Quality Index (AQI) of 743, the highest among 10 major cities covered in the latest readings. Lucknow followed with an AQI of 493, while Indore and Pune recorded 449 and 412, respectively, according to data available on AQI.in on Monday, November 9.
The readings placed six cities, including Delhi, Lucknow, Indore, Pune, Noida and Rajkot, in the hazardous category. Meanwhile, Mumbai, Chennai, Ahmedabad and Dehradun reported comparatively lower pollution levels, although their air quality remained unhealthy.
The elevated concentrations of fine particulate matter (PM2.5) and inhalable particulate matter (PM10) across these cities point to the widespread deterioration in air quality following the festival. The pollution spike has also highlighted how the impact of Diwali celebrations extends beyond Delhi-NCR, affecting several urban centres across the country.
Six cities report hazardous air quality
Delhi topped the list with an AQI of 743. Its PM2.5 concentration stood at 447 micrograms per cubic metre (µg/m³), while PM10 was recorded at 593 µg/m³.
Lucknow was the second most polluted city among those listed, with an AQI of 493. The Uttar Pradesh capital recorded a PM2.5 concentration of 322 µg/m³ and PM10 levels of 388 µg/m³.
Indore reported an AQI of 449, with PM2.5 and PM10 concentrations standing at 298 µg/m³ and 358 µg/m³, respectively. Pune followed with an AQI of 412, while its PM2.5 and PM10 readings stood at 271 µg/m³ and 328 µg/m³.
The situation was also concerning in Noida and Rajkot. Noida recorded an AQI of 373, with PM2.5 at 261 µg/m³ and PM10 at 358 µg/m³. Rajkot reported an AQI of 358, while its PM2.5 and PM10 concentrations stood at 238 µg/m³ and 284 µg/m³, respectively.
Mumbai, Chennai and Ahmedabad record comparatively lower AQI
Among the other cities covered in the readings, Chennai recorded an AQI of 188, with PM2.5 at 109 µg/m³ and PM10 at 132 µg/m³.
Ahmedabad reported an AQI of 179. Its PM2.5 concentration stood at 95 µg/m³, while PM10 was recorded at 114 µg/m³.
Mumbai's AQI stood at 156, with PM2.5 and PM10 concentrations of 67 µg/m³ and 81 µg/m³, respectively. Dehradun recorded a marginally lower AQI of 155, with PM2.5 at 80 µg/m³ and PM10 at 121 µg/m³.
Although these four cities recorded lower readings than Delhi, Lucknow, Indore and Pune, AQI.in continued to classify their air quality as unhealthy.
Delhi-NCR pollution worsens despite restrictions
The deterioration in air quality comes despite restrictions imposed under the Graded Response Action Plan (GRAP) across Delhi-NCR. The Commission for Air Quality Management (CAQM) had invoked Stage III measures on November 6 amid forecasts of worsening pollution.
The restrictions include curbs on construction and demolition activities, tighter measures to control vehicular emissions and provisions for hybrid classes for younger schoolchildren.
Firecracker emissions have added to the existing pollution burden following Diwali celebrations. The situation has been compounded by seasonal factors, including low wind speeds and cooler conditions, which can trap pollutants close to the ground and prevent their dispersal.
Vehicle emissions, construction dust, industrial activity and crop-residue burning in neighbouring states also contribute to the region's deteriorating air quality.
Delhi's official pollution readings and the figures reported by AQI.in should, however, be viewed separately, as they reflect different monitoring and reporting systems. While AQI.in recorded a reading of 743 for the capital, the Central Pollution Control Board's (CPCB) official city-wide AQI stood at 370 on Monday morning, placing Delhi in the very poor category. Several monitoring stations across the capital nevertheless recorded readings in the severe category.
The latest readings underline the scale of India's post-Diwali air pollution problem, with hazardous conditions extending well beyond the national capital and several other major cities continuing to grapple with elevated particulate pollution.