This database was released in April 2022 (5th edition) and the years of measurement range mostly from 2010 to 2019.
The WHO air quality database 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.
The 2022 update (Fifth Version) database was released in April 2022 and hosts data on air quality for over 600 human settlements in more than 100 countries.
The data compiled in this database is used as input to derive the Sustainable Development Goal Indicator 11.6.2, Air quality in cities, for which WHO is custodial agency.
