Top 10 Most Polluted Cities in the World Based on AQI⁺ (US) [Updated 2025]

Top 10 Most Polluted Cities in the World based on AQI⁺ (US) 2025: Air pollution is the contamination of the atmosphere, which originates from both natural sources, such as wildfires and volcanoes, and also from human activities like vehicle emissions, industrial processes, and energy production. While natural events contribute to air pollution, but not as much human activity because there activity is currently the primary cause. 

Air pollution signifies threats to human health, leading to respiratory and cardiovascular diseases. Furthermore, it damages the environment by reducing visibility, contributing to acid rain, and worsening climate change.

According to IQAir data released on October 13, Baghdad, Iraq, currently ranks as the most polluted city in the world, with an AQI⁺ (US) exceeding 2330.

In this article, we will explore the top 10 most Polluted Cities in the World based on AQI⁺ (US).

Top 10 Most Polluted Cities in the World based on AQI⁺ (US) [Updated 2025]

On October 13, 2025, Live AQI has been recorded, and here is the list of the Top 10 Most Polluted Cities in the World:

Source: IQAir Quality Index

Note: Live AQI has been recorded as of October 13, 2025 (Monday) – 12:35 IST PM – on IQAir Air Quality Rankings

Which are the Most Polluted Cities in the World?

Baghdad of Iran is the Most Polluted City in the World based on AQI⁺ (US), as per the Live AQI, which was recorded on October 13, 2025 (Monday) – 12:35 IST PM – on IQAir Air Quality Rankings. 

PM2.5 particles are floating particulate matter in the air measuring 2.5 micrometres in diameter or less. PM2.5 is so small that it can be absorbed into the bloodstream upon inhalation. 

For this reason, it is typically the pollutant posing the greatest health threat.

PM2.5 concentration is currently 156.4 times the World Health Organisation annual PM2.5 guideline value, and the Main pollutant is PM2.5 is about 782 µg/m³ in Baghhdad.

How many Indian Cities fall in the category of the Most Polluted Cities in the World?

Currently, as per the Live AQI, which was recorded on October 13, 2025 (Monday) – 12:35 IST PM – on IQAir Air Quality Rankings, three Indian cities fall in the category of the Most Polluted Cities in the World, which are:

1. Kolkata

2. Delhi

3. Mumbai

These three cities mainly fall in the category of the Most Polluted Cities in the World due to the largest number of migrations toward these cities for jobs, to settle down in the most advanced cities, and there is maximum industrialisation in these cities and also due to traffic. 

Conclusion

Air Pollution, which is a serious global concern regarding the health and environmental crisis in 2025, & cities like Baghdad, Lahore, Tashkent & Kolkata are the Most Polluted Cities in the World. Increasing AQI⁺ levels highlight the urgent need for restrictions on emissions, proper sustainable planning and use of clean technologies to safeguard public health and combat climate change effectively.