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WHO tightens guidelines for air quality

WHO has recently released the new Air Quality Guidelines. New scientific evidence has led to lowering of the air quality guideline level for annual nitrogen dioxide (NO2) by 75% to 10μg/m3. Levels of fine particulate matter (PM2.5) have been halved to 5 μg/m3 and levels for particulate matter (PM10) have been adjusted to 15 μg/m3. For the first time WHO includes a peak season level for ozone, which is set to 60 μg/m3. More than 15 years of research have been conducted since the old guidelines. Scientific knowledge has improved with more precise methods in measurements, modelling and exposure assessment methods.

Source:  WHO press release, 22 September 2021

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