Lahore in Pakistan jumped more than 10 places to become the city with the worst air in the world in 2022, according to an annual global survey by a Swiss maker of air purifiers. The report published on Tuesday by IQAir also said that Chad in central Africa had replaced Bangladesh as the country with the most polluted air last year.

IQAir measures air quality levels based on the concentration of lung-damaging airborne particles known as PM2.5. Its annual survey is widely cited by researchers and government organisations. Lahore’s air quality worsened to 97.4 micrograms of PM2.5 particles per cubic meter from 86.5 in 2021, making it the most polluted city globally.