Air pollution is one of the leading causes of death around the world.  Therefore  you may be curious: “What are the least polluted cities in the world?”  Smart Air analyzed 2020 air pollution data from 540 major cities in the world to create the 2020 ranking of the “25 Least Polluted Cities in the World”. So, which cities had the cleanest air?

Rankings: 25 Most Polluted Cities in the World

1. Zurich, Switzerland

2. Hobart, Australia

3. Reykjavik, Iceland

4. Turku, Finland

5. Tallinn, Estonia

6. Trondheim, Norway

7. Tampere, Finland

8. Uppsala, Sweden

9. Launceston, Australia

10. Bergen, Norway

11. Edinburgh, Scotland

12. Funchal, Portugal

13. Oulu, Finland

14. Honolulu, US

15. Halifax, Canada

16. Calgary, Canada

17.  Glasgow, Scotland

18. Vancouver, Canada

19. Winnipeg, Canada

20. Stockholm, Sweden

21. Adelaide, Australia

22. Saint Petersburg, Russia

23. Surrey, Canada

24. Helsinki, Finland

25. Vantaa, Finland

 

Analysis

Of the 25 least polluted cities in the world with the best air quality, Nordic countries (Finland, Sweden, Norway, Iceland) dominated the rankings.  10 out of the 25 cities with the best and cleanest air were Nordic countries.  Finland topped the list with 5 cities in the top 25.   Canada also had a great showing, matching Finland by also having 5 cities ranking in the top 25 cleanest air cities.

Even though these are some of the cities with the best air quality in the world, each city experienced times during 2020 where pollution was over the WHO recommended limit.  This shows how serious air pollution is all across the world.  There is also research that even little amounts of pollution such as those typically present in these least polluted cities can have an impact on health.

Below is a pollution heat map from the WHO.  WHO research shows that over 92% of people in the world are breathing unsafe air with high air pollution levels.

How Air Pollution Was Measured to Find Least Polluted Cities in World

There are various pollutants (both particles and gases) that can be found in the air.  One of the most commonly tracked pollutants are very small, fine particles called PM_2.5.

These small pollutants are under 2.5 micrograms in width and considered to be one of the more dangerous pollutants due to their ability to enter deep into the lungs and bloodstream.  The above rankings of the least polluted cities in the world were ranked based on their 2020 average PM_2.5 pollution levels.    

Open Data

As part of Smart Air’s open data pledge, the raw  PM2.5  AQI 2020 world pollution data used for the rankings of the world’s least polluted cities are openly available to download from the link below:

Download 2020 World Major Cities Air Quality Rankings

How I Protect Myself

Smart Air is a  certified B Corp  committed to combating the myths big companies use to inflate the price of clean air.

Smart Air provides empirically backed, no-nonsense purifiers and masks, that remove the same particles as the big companies for a fraction of the cost. Only corporations benefit when clean air is a luxury.

For protection against air pollution in Jakarta and Indonesia, check out the Sqair!

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