Good air quality is essential to human health. Regularly breathing in high quality air means a decreased risk of respiratory infections, allergies, cardiovascular diseases, lung diseases and lung cancer. Specifically, when air contains low concentrations of particulate matter (PM), which consists of a mixture of sulfate, ammonia, nitrates, sodium chloride, black carbon, and mineral dust, humans are less likely to suffer from the aforementioned ailments.

PM2.5 is particulate matter with a diameter of 2.5 microns or less (to put this in perspective, a typical human hair ranges between 30-100 microns in width). PM2.5 is particularly dangerous to human health, as the particles are so small that they can penetrate the lung barrier and enter into the bloodstream. As such, for optimum health it is important to avoid prolonged exposure to PM2.5. The Word Health Organisation (WHO) guidelines for acceptable  annual mean PM2.5 measurements is 10 μg/m3 or less.

We wanted to find out which countries enjoyed the best air quality, so we accessed the 2018 edition of the WHO Global Ambient Air Quality Database. (This database consolidates annual mean PM2.5 and PM₁₀ measurements for over 2600 cities and towns across the globe). We sorted the database by country and calculated the average PM2.5 scores for all the countries with the majority of their cities listed as having PM2.5 scores under 18 μg/m3. Here are the top 5 countries with the best air quality:

  • 1. Estonia

With an average PM2.5  of only 5.00, Estonia comes out tops in terms of air quality. This small European country bordering the Baltic Sea has a population of approximately 1.3 million people. Despite its small size, Estonia (nicknamed “e-Stonia”) is one of the most technologically advanced countries in the world. The country has declared Internet access a human right, and citizens can vote, pay tax, and even access their health records and school work online.

  • 2. Sweden

Close on Estonia’s heels is the world’s chocolate-loving nation, Sweden, with an average PM2.5  of 5.67. The Swiss are known for their passion for sustainability. They harness 54% of their energy from renewables and 99% of their water is recycled. With a population of 10 million, and 86% of the population living in cities, Sweden is truly an example for all cities aiming to achieve progress and innovation without compromising human health and the environment.

  • 3. Finland

Coming in 3rd with an average PM2.5  of 5.71, we can understand why the Finnish – ranked as the world’s happiest country (according to the 2018 World Happiness Report) – have something to smile about. With a population of 5.5 million, this small Scandinavian country’s landscape comprises 70% forest and is home to 188, 000 lakes. As an added bonus, it is also one of the best places to view the Northern Lights.

  • 4. Canada

In 4th place is Canada with an average PM2.5  of 6.87. This maple syrup- and ice hockey-loving country is the world’s 2nd largest country by area, and boasts the world’s largest bi-national land border (thanks to its southern border with the United States). With over 80% of Canada’s approximately 37 million inhabitants living in cities, we commend Canadians for keeping their large country’s air so squeaky clean.

  • 5. Australia

Don’t worry if icy winters and minimal sunlight aren’t your cup of tea – it’s not only the far north that can boast about clean air. With an average PM2.5  of 7.04, you can happily trade your coats and skis for surfboards and bikinis to enjoy great air quality down under. Australia has a population of approximately 25 million and is the world’s 6th largest country by total area. The Aussie’s have a strong nature-loving outdoor culture, and are passionate about keeping their air clean so that citizens and tourists can enjoy the diverse natural landscape the country has to offer.

How do these 5 exemplary countries compare with the most polluted cities in terms of air quality? Find out in our article The 10 most polluted cities in the world.

Keywords: Air quality, health, particulate matter/PM