There are  very few places in the world where you can breathe air clean enough to meet WHO standards . The focus is on a type of air pollution called PM2.5, which is smaller than 2.5 micrometers in diameter, and mostly comes from auto emission and burning of biomass and fossil fuels.  This fine particulate matter is associated with a wide range of heart and lung disorders, plus cancers. In the  study,  scientists examined pollution data from monitoring stations in 6,475 cities in 117 countries and territories.   Only 3.4% got an acceptable grade. 93 cities had PM2.5 concentrations  10 times higher  than WHO standards. Central and South Asia had 46 of the world's most polluted cities. In Africa only one of 65 cities examined met WHO air quality standards. Asia?  Only 4 of 1887 cities. Europe should be okay, right?  Nope.  Only 55 of 1588 cities achieve this. What about the USA? This report  said:  not a pretty picture. 2408 American cities climbed from 9.6 in 2020 to 10.3. While Los