All but one of the world’s top 20 most polluted cities last year were in Asia, a new study shows. The majority of these cities – 13 – are in the world’s most populous country, India, where booming economic growth is fired largely by coal and where hundreds of millions live in traffic-clogged and congested megacities .

India saw a seven per cent decline in PM2.5 levels in 2024, but six of the world's ten most polluted cities were still in the country, according to the IQAir 2024 World Air Quality Report. India's annual PM2.