WHO Ambient Air Quality Database, v6.0

The World Health Organization (WHO) Ambient Air Quality database is one of the most comprehensive dataset at the level of various cities of the globe. It compiles data on ground measurements of annual mean concentrations of nitrogen dioxide (NO2), particulate matter of a diameter equal or smaller than 10 μm (PM10) or equal or smaller than 2.5 μm (PM2.5) which aim at representing an average for the city or town as a whole, rather than for individual stations. Both groups of pollutants originate mainly from human activities related to fossil fuel combustion.