Air pollution has got far worse in 46 future megacities in tropical Africa, Asia and the Middle East, the study reveals. The deterioration in air quality has led to 180,000 extra deaths due to the combination of city expansion and worsening air pollution between 2005 and 2018.
Agricultural burning from the areas around the cities is one of the main causes. But the deterioration is driven mostly by new sources such as fertiliser use in nearby farms and increased transport and industry. Problems with waste burning, including the burning of plastics, are widespread too. Cities in India are also being affected by new coal power stations that are being built in the country.