This is a guest blog post by Meltem Kutlar Joss on a paper we recently published. Meltem is a senior scientific collaborator and project leader at the Swiss Tropical and Public Health Institute in Basel. She obtained her master’s degree in Environmental Sciences from the Swiss Federal Institute of Technology in Zurich, Switzerland and an advanced master’s degree in Public Health from the universities of Basel, Bern and Zurich. Her main work is for the Swiss literature database on health effects of ambient air pollution LUDOK. 

Ambient air quality standards differ around the world – despite common findings on health effects

Ambient air pollution is hazardous to human health. According to the World Health Organization (WHO) it is to date the single biggest environmental health risk with around 3.7 million premature deaths worldwide per year. In 1987, the WHO gathered scientific evidence on health effects of various air pollutants setting air quality guidelines for the first time. The aim was to advise governments on setting legally binding air quality standards at levels considered to be safe or of acceptable risk. In 2005, these guidelines were revised and updated and interim targets were proposed to promote steady progress towards meeting the guideline values. Despite knowledge about the benefits of clean air policies following the WHO guideline values, it is unclear if or to what extent those guidelines are followed by national or regional policy makers.

We therefore aimed at compiling national short- and long-term ambient air quality standards of the classical ambient air pollutants PM2.5 (suspended particles smaller than 2.5 µm in size), PM10 (suspended particles smaller than 10 µm), ozone (O3), nitrogen dioxide (NO2) and sulfur dioxide (SO2) and carbon monoxide (CO) in relation to the WHO guidelines.

Out of the 194 countries targeted, we were able to compile an inventory of ambient air quality standards for 170 countries of which 53 countries did not set standards for any of the pollutants. For some pollutants, only few countries are in line with the recommended WHO guideline values proposed to protect people’s health. This is particularly the case for standards regarding particulate matter (see map) and SO2. These regulatory discrepancies amplify the differences in air quality and related health effects around the globe. In view of the huge burden of disease and economic costs from ambient air pollution, air quality should become a priority on the political agenda of governments worldwide. They should get involved in a continuous process of developing clean air policies – including standard setting – and monitoring their success, so that ultimately, all may achieve the same science-based air quality standards and meet the sustainable development goals.

You can visit the LUDOK homepage with further maps and information on national air quality standards at https://www.swisstph.ch/en/projects/ludok/grenzwerte/