WHO Global Ambient Air Quality Database (update 2018)
Air pollution affects all regions of the world. However, populations in low-income cities are the most impacted. According to the latest air quality database, 97% of cities in low- and middle- income countries with more than 100,000 inhabitants do not meet WHO air quality guidelines. However, in high-income countries, that percentage decreases to 49%.
In the past two years, the database – now covering more than 4300 cities and settlements in 108 countries – has nearly doubled, with more and more locations measuring air pollution levels and recognizing the associated health impacts.
As air quality declines, the risk of stroke, heart disease, lung cancer, and chronic and acute respiratory diseases, including asthma, increases for the people who live in them.