The World's Most Polluted Cities

According to the IQAir World Air Quality Report not one country in the whole world managed to meet the World Health Organization’s (WHO) PM2.5 annual air quality guidelines in 2021. In 2021 the five most polluted countries were: Bangladesh, Chad Pakistan, Tajikistan and India.

IQAir's annual air quality report is based on an analysis of air pollution data collected from air monitoring stations in 6,475 cities around the globe.6,253 cities (out of the total 6,475 cities covered in the report) failed to meet WHO's PM2.5 guideline. 93 of those cities actually had PM2.5 concentrations exceeding 10 times the WHO guideline.

You can explore for yourself the annual PM2.5 concentration in all the cities covered in the report on IQAir's Interactive Map of 2021 PM2.5 Concentrations by City. On this mapped visualization air monitoring stations around the world are colored to show their annual concentration of fine particulate matter (PM2.5). The cities colored blue on the map are those that managed to meet the WHO guidelines. The cities colored dark purple exceeded the guidelines by at least 10 times. If you click on a marker on the map you can view that city's actual PM2.5 measurement for 2021 and (where available) also view its annual measurements for 2017, 2018, 2019 and 2020.

In 2021 Los Angeles was the most air polluted city in the United States (although the city did actually manage to decrease its PM2.5 pollution by 6 percent compared to 2020). The report covers 2,408 cities in the United States. Generally air quality worsened in American cities during 2021. On average American cities saw an increase of 0.7 µg/m3 in PM2.5 concentrations compared to 2021.

If you want to know the air quality in your city today then you can refer to IQAir's real-time Live Air Quality Map. This map visualizes the latest air quality measurements from thousands of air monitoring stations located around the world. The map also includes an air quality layer which predicts the current air quality based on the latest measurements and wind forecasts.