This article does a couple of things that seem strange. The title’s “first ever” claim is a bit odd since the WHO has been basing their recommendations on globa

This article does a couple of things that seem strange. The title’s “first ever” claim is a bit odd since the WHO has been basing their recommendations on global studies for decades. The WHO page already says “WHO data show that almost all of the global population (99%) breathe air that exceeds WHO guideline limits and contains high levels of pollutants, with low- and middle-income countries suffering from the highest exposures.” https://www.who.int/health-topics/air-pollution#tab=tab_1 https://www.who.int/health-topics/air-pollution#tab=tab_1 Another strange bit is the quote “the WHO’s recommended safe limit of 15 μg/m³.” The WHO’s 2005 “ideal” recommendation was 10 for average annual exposure, and the recommendation in their 2021 is for 5 μg/m³. I’m not sure where the 15 came from, but the WHO has proposed 4 levels of “interim” targets for cities & counties to aim for, starting at 35 and dropping to 5. For anyone who cares about air quality, I’d totally recommend reading the WHO’s material, there is a shorter executive summary [1], a much longer full report describing methodology [2] and a web site full of resources [3]. [1] https://apps.who.int/iris/bitstream/handle/10665/345334/9789240034433-eng.pdf https://apps.who.int/iris/bitstream/handle/10665/345334/9789... [2] https://apps.who.int/iris/bitstream/handle/10665/345329/9789240034228-eng.pdf https://apps.who.int/iris/bitstream/handle/10665/345329/9789... [3] https://www.who.int/health-topics/air-pollution https://www.who.int/health-topics/air-pollution