No nation met WHO air quality standards in 2021
Not a single country managed to meet the World Health Organization’s (WHO) air quality standard in 2021, and smog even rebounded in some regions after a COVID-related dip.
The WHO recommends that average annual readings of small and hazardous airborne particles known as PM2.5 should be no more than 5 micrograms per cubic metre after changing its guidelines last year, saying that even low concentrations caused significant health risks. As many as 93 cities saw PM2.5 levels at 10 times the recommended level.
China fell to 22nd in the PM2.5 rankings in 2021, down from 14th place a year earlier, with average readings improving slightly over the year to 32.6 micrograms, with average PM2.5 readings of more than 100 micrograms, largely caused by sandstorms it fell to third on the list of the world’s most polluted cities after being overtaken by Bhiwadi and Ghaziabad, both in India.