Pant by numbers: the cities with the most dangerous air – listed | Cities | The Guardian
▻https://www.theguardian.com/cities/datablog/2017/feb/13/most-polluted-cities-world-listed-region?CMP=twt_a-environment_b-gdneco
Billions of people in cities around the world are exposed to dangerous air, but pollution levels vary widely – and the fast-growing cities of Asia and Africa are the worst affected.
We’ve broken down data from the World Health Organization on ultra-fine particles of less than 2.5 microns (PM2.5s) region by region. Paris’s air may have almost twice as many PM2.5s as WHO recommended levels (18 micrograms per cubic metre compared with 10µg/m³) – but Delhi’s air contains 122µg/m³, while Zabol, Iran, is the worst at 217µg/m³.