In 2019, WHO estimated that 6.7 million premature deaths could be attributed to ambient and household air pollution from particulate matter (particles with a diameter less than 2.5 μm, PM2.5. Of the 4.2 million deaths attributed specifically to ambient air pollution exposures. In 2021, WHO updated its air quality guidelines with more stringent values for selected pollutants, particularly NO2 and PM2.5 – the most widely accepted indicators for health impacts. WHO data on air quality from some 6700 cities worldwide, updated in 2022, reveals that air pollution in 83% of high-income cities and 99% of low-income cities that are monitoring air quality exceeds WHO recommended levels. This guidance and tools presented in this report represent an effort to address this yawning gap between reality and aspirations for better air quality – in a stepwise approach that advances progress on Sustainable Development Goal (SDG) 11 – “Make cities and human settlements inclusive, safe, resilient and sustainable.”
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