The World Health Organization (WHO) reports that a record number of over 6000 cities in 117 countries are now monitoring air quality, but the populations living in them are still breathing unhealthy levels of fine particulate matter and nitrogen dioxide (NO2), with people in low and middle-income countries suffering the highest exposures. Overall, almost the entire global population breathes air that exceeds WHO air quality limits, and potentially threatens their health.
The 2022 update of the WHO’s air quality database introduces, for the first time, ground measurements of annual mean concentrations of NO2, a common urban pollutant and precursor of particulate matter and ozone. It also includes measurements of particulate matter with diameters equal or smaller than 10 μm (PM10) or 2.5 μm (PM2.5). Both groups of pollutants originate mainly from human activities related to fossil fuel combustion.
The new air quality database is the most extensive yet in its coverage of air pollution exposure on the ground. An additional 2,000 cities or human settlements are now recording ground monitoring data for particulate matter PM10 and/or PM2.5 compared to the last update. This marks an almost six-fold rise in reporting since the database was launched in 2011.
Source: WHO, 4 April 2022