7 May 2014: The 2014 Ambient Air Pollution in Cities Database released by the World Health Organization (WHO) shows that air quality in most cities around the globe is much higher than recommended by WHO’s Guidelines on Air Quality, with many cities showing a declining trend.

According to the database, which contains information from ambient air pollution monitoring 1600 cities, only 12% of residents in these cities enjoy air quality that conforms with WHO guidelines, whereas half of the world’s urban population suffers from air pollution that is 2.5 times higher than the thresholds beyond which there is an increased risk of respiratory disease and other health problems.

While the growing number of cities reporting air quality data – 500 more than in 2011 – reflects increasing awareness of air quality concerns, the trends for many cities that have provided data in previous years indicate that air pollution is becoming a more serious problem. Only low- and middle-income countries in Europe and the Western Pacific Region and high-income countries show moderate improvements in air quality.

Air pollution, in particular fine particulate matter, is associated with increased risk of heart disease, stroke, respiratory illnesses and various cancers. WHO’s work on air pollution includes databases and regular reports on indoor and outdoor pollution, as well as research and recommendations on effective investments for air quality improvement [WHO Press Release] [UN Press Release] [Database Summary] [Database and background documentation] [WHO Air Quality Guidelines]