City with the least air pollution
Who
Captain Cook, Kailua Kona
What
2.5 microgram(s) per cubic metre
Where
United States ()
When
2019

According to the IQAir 2019 World Air Quality Report, covering 4,680 cities globally, the two least polluted cities in the world are Captain Cook and Kailua Kona, both in Hawaii, USA, with an average PM2.5 level of just 1.9 µg/m³ in 2019. PM2.5s are very small particles such as soot, dust and ash, prolonged exposure to which can cause cancer, lung and heart conditions.