
A few days before World Health Day, which is celebrated on 7 April each year, the WHO presented its updated air quality database, which revealed the shocking fact that 99% of the world's population breathes polluted air. That is, it exceeds the air quality limits set by the WHO and threatens their health.
Going into more detail, it emerges that in 17% of cities in rich countries, air quality is below WHO guidelines for the presence of Pm2.5 or PM10. But the situation is no better in low- and middle-income countries, where air quality meets WHO recommended thresholds in less than 1% of cities.