WHO Ambient Air Quality Database (Update Jan 2024)

Overview

The WHO Ambient 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 (PM_2.5) 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. In order to present air quality data that represent human exposure, we used mainly urban measurements, comprising urban background, residential areas, commercial and mixed areas or rural areas and industrial areas close to urban settlements.

The database is updated regularly every 2-3 years since 2011. 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. The primary sources of data were official countries reports sent to WHO upon request, official national and subnational reports, national and subnational websites that contain measurements of PM₁₀, PM_2.5 or NO₂.

 Update 2024 (minor) – Released on 31 Jan 2024 – 6th edition (V6.1)

The Sixth version of the database (V6.1), also called Update 2024 (minor) was realized in January 2024 and currently hosts data from 7 182 human settlements in more than 120 member states.

This version does not contain new data compared to V6.0 released in May 2023 and has been further analyzed and processed to ensure quality and consistency.