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30. Vilnius, Lithuania -

Average PM2.5 Concentration: 9.1

As Lithuania's capital, Vilnius boasts relatively low levels of industrial activity compared to larger European capitals. Its historic charm blends with modern urban planning that favors green spaces and clean public transit, contributing to its favorable air quality.

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29. Tokyo, Japan -

Average PM2.5 Concentration: 9.0

Rapid urbanization and industrialization resulted in many environmental issues over the last century. And while pollution may have decreased when compared to those more heavily industrialized times, there are still many traces of pollution from factories.

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28. Ankara, Turkey -

Average PM2.5 Concentration: 9.0

Despite being a major political and administrative hub, Ankara has maintained moderate pollution levels. The city has taken steps to curb emissions, but air quality still fluctuates due to vehicular traffic and energy production.

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27. Buenos Aires, Argentina -

Average PM2.5 Concentration: 8.9

As one of South America’s largest cities, Buenos Aires has long grappled with pollution from vehicles and industry. However, ongoing initiatives to improve public transportation and green spaces have helped reduce airborne pollutants.

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26. Brussels, Belgium -

Average PM2.5 Concentration: 8.9

Brussels has made strides in reducing car traffic and encouraging cycling and public transport. While it’s an administrative powerhouse, efforts to tackle urban pollution have made the air cleaner than in many other European capitals.

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25. George Town, Cayman Islands -

Average PM2.5 Concentration: 8.5

George Town benefits from its island geography and ocean breezes that help disperse pollutants. Although cruise ships and vehicles contribute to emissions, the overall air quality remains quite high.

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24. Paris, France -

Average PM2.5 Concentration: 8.3

Paris has historically faced challenges with smog and vehicle emissions. Recent policies encouraging cycling and restricting cars in central areas have led to measurable improvements in air quality.

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23. Madrid, Spain -

Average PM2.5 Concentration: 8.1

Even at low levels, the Spanish capital's air pollution causes significant health effects. Poor air quality can aggravate or cause respiratory problems, such as asthma.

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22. London, England -

Average PM2.5 Concentration: 7.8

London is regularly found to have some of the highest air pollution levels in the country. The main pollutants are generated from urban transport and the heating of homes.

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21. Luxembourg, Luxembourg -

Average PM2.5 Concentration: 7.7

This small, affluent capital emphasizes sustainability. With free public transportation and a strong environmental focus, Luxembourg maintains low pollution levels despite being a major financial center.

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20. Washington D.C., USA -

Average PM2.5 Concentration: 7.6

Nearly half of Washington's air pollution originates from cars, trucks, trains, and planes.

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19. Lisbon, Portugal -

Average PM2.5 Concentration: 7.4

The Portuguese capital's current PM2.5 concentration is above the recommended number.

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18. Bern, Switzerland -

Average PM2.5 Concentration: 7.2

Bern’s commitment to green energy and its well-preserved natural surroundings help keep air pollution low. The Swiss capital is known for its clean streets, efficient transit, and strong environmental regulations.

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17. Copenhagen, Denmark -

Average PM2.5 Concentration: 7.1

Considered one of the most sustainable cities in the world, the Danish capital nonetheless has some problems with air pollution. This is particularly prevalent on the access roads and in the capital's inner city.

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16. Oslo, Norway -

Average PM2.5 Concentration: 6.9

A fairly sustainable city, the largest sources of air pollution in Oslo today are road traffic and heating.

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15. Dublin, Ireland -

Average PM2.5 Concentration: 6.6

One of the main causes of Dublin's air pollution levels are fumes and emissions coming from vehicles.

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14. Vaduz, Liechtenstein -

Concentrazione media di PM2,5: 6.5

L'attuale concentrazione di PM2,5 a Vaduz è superiore al limite raccomandato dall'OMS.

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13. Ottawa, Canada -

Average PM2.5 Concentration: 6.0

Similar to many other cities, one of the main causes of air pollution in Ottawa are vehicular fumes and emissions.

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12. Port of Spain, Trinidad and Tobago -

Average PM2.5 Concentration: 6.0

Just at the limit of WHO's recommendation, Port of Spain has fairly good air quality.

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11. Helsinki, Finland -

Average PM2.5 Concentration: 5.5

Thanks to protective initiatives in play, as well as meteorological and geographical factors, air pollution is much reduced in the Finnish capital.

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10. Stockholm, Sweden -

Average PM2.5 Concentration: 5.3

Known for being a 'green' city, nonetheless, most of the polluted air in Stockholm is generated by vehicle use.

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9. Brasília, Brazil -

Average PM2.5 Concentration: 5.2

Built with modern planning in mind, Brasília’s layout limits congestion. The city enjoys cleaner air than many other major Brazilian cities, thanks in part to green spaces and less industrial activity.

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8. Tallinn, Estonia -

Average PM2.5 Concentration: 4.3

This Baltic city has relatively good air quality and low pollution levels. Perfect for a city stroll!

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7. Wellington, New Zealand -

Average PM2.5 Concentration: 4.3

Wellington's coastal winds and low population density help keep its air remarkably clean. The city benefits from strong environmental protections and a culture that values sustainability.

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6. Canberra, Australia -

Average PM2.5 Concentration: 3.9

At number six is the Australian capital of Canberra! However, during summer, the city can see a rise in air pollution from nearby bushfires.

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5. Reykjavík, Iceland -

Average PM2.5 Concentration: 3.8

Coming in a respectable third place, Reykjavík is the only European capital to break the top five.

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4. Bridgetown, Barbados -

Average PM2.5 Concentration: 3.1

Bridgetown enjoys ocean winds and limited industrialization, keeping its air fresh. While traffic and tourism bring some pollution, the overall environment remains one of the cleanest in the Caribbean.

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3. Papeete, French Polynesia -

Average PM2.5 Concentration: 2.8

Papeete's remote location and small population contribute to its clean air. Surrounded by natural beauty, the capital experiences minimal industrial pollution, offering some of the Pacific’s freshest air.

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2. San Juan, Puerto Rico -

Average PM2.5 Concentration: 2.6

The capital in the Caribbean with the best air quality goes to San Juan!

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1. Nassau, Bahamas -

Average PM2.5 Concentration: 2.3

Nassau benefits from its island setting and the dispersing effects of sea breezes. Though tourism and cruise activity add to local emissions, its air quality remains impressively high year-round.

Sources: (IQAir) (Visual Capitalist)  

See also: The safest countries to avoid natural disasters

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