There is growing evidence of how bad—and expensive—air pollution is in Lagos, Africa’s largest mega-city.

The city which is home to over 20 million people is infamous for congestion and snaking lines of traffic jams. But as data from a recent World Bank study show, the city’s residents are paying a very high price: the study estimates air pollution resulted in 11,200 premature deaths in 2018 alone. Children under five, who are at a higher risk of respiratory infections were the most affected, accounting for 60% of deaths in 2018.