Delhi consistently ranks among the top 3 most polluted cities in the world. As of October 25, 2025, it is the most polluted city in the world, with air quality edging from unhealthy to very unhealthy, reporting levels above 186. The condition worsens every year beginning from Diwali, lasting through winter. Vehicular emissions and industrial pollutants, every year, pollutants from Diwali firecrackers and stubble burning make the city dangerous. Despite interventions by the authority, like the Graded Response Action Plan, residents, especially elders, suffer from respiratory problems

Beijing ranks second in the IQAir list with an AQI of 180, indicating “unhealthy” air. The primary reasons are the same vehicular emissions, industrial pollutants and seasonal inversions that trap pollutants in the air. In 2024, the annual average PM2.5 concentration in Beijing was 30.9 micrograms per cubic meter, which is more than 6 times that of the WHO guidelines of 5 micrograms per cubic meter.

Kolkata’s air quality is also routinely poor. Its AQI in October was recorded at 179. The sheer volume of old vehicles, industrial emissions combine with humid conditions to worsen air quality. Post Diwali, Kolkata has also reported an increase in the average AQI.

Lahore is also consistently among the top-most polluted cities list. According to IQAir, Lahore’s AQI is 176, closing in on 180. A persistent smoke engulfs the sky every winter. Vehicular emission, industrial pollutants, crop residue and seasonal inversion contributes to the haze. The authorities have launched anti-smog gun operations in mid-October 2025 to attempt to clear the air.

Dhaka also has unhealthy air quality and remains among the top 10 most polluted cities globally, with an AQI recorded at 157. The city’s average PM2.5 concentration throughout 2024 was 70 µg/m³, which is 14 times the WHO annual guideline of 5 µg/m³.

The Central Asian city of Tashkent has long been facing severe problems with air pollution. As of October 25, 2025, Tashkent’s AQI is recorded as 148. Citizens and experts point to the emissions from coal- and fuel oil-fired power plants, as well as air pollution from automobile transportation and the shrinking of green spaces due to the city’s continuous construction, as the primary reasons behind the consistently deteriorating air quality.

On October 25, 2025, Hanoi is experiencing high levels of air pollution. Based on IQAir’s global data, Hanoi is at sixth place with a recorded AQI of 142. Traffic congestion, industrial activity, and seasonal weather patterns contribute to high PM2.5 levels. Residents have reported reduced visibility and increased respiratory irritation,

Wuhan’s AQI is 122 and is fluctuating in the “unhealthy for sensitive groups” to “unhealthy” range. The city’s heavy manufacturing base and vehicle emissions are major pollution sources. The reasons are similar across almost every city.

Dubai ranks ninth with an AQI of 112. The city’s pollution stems largely from dust storms, vehicular emissions, and construction activities associated with rapid urban expansion. Despite high environmental standards and modern infrastructure, the desert climate poses ongoing challenges in controlling airborne particulate matter.

Baghdad’s AQI is 110, and it is shifting from moderate to unhealthy for sensitive people. Industrialisation, rapid urbanisation, and frequent dust storms are the major reasons for poor air quality. Baghdad, on October 14, recorded an AQI value of 183 and was the most polluted city on Earth.

NOTE – This article was originally published in WION and can be viewed here