In which cities across the world is the health burden from urban air pollution particularly high?
A city's health burden from urban outdoor air pollution depends on levels of pollutants in that city as well as on the number of people who breathe the pollution.
A disproportionate health burden from urban outdoor air pollution is observed in middle-income countries. The large and rapid increase in the number of motor vehicles, especially those with older engines and using poorer quality fuels, as well as the increase in power generation from coal and other dirty fuels, has put the populations of these emerging economies at some of the greatest health risks from polluted air.
In many of these rapidly growing economies, regulations and policies have yet to be put in place or be implemented more rigorously to help curb emissions and maintain a healthy and clean air. As these regions continue to grow and expand, so does the need for action to clean the air and protect population health.
Health concerns are not limited to the most polluted cities: substantial health effects are seen even in the relative cleaner cities of Australia, Europe, New Zealand or North America, where PM levels are typically 3-10 times lower than in the most polluted cities. The lower the level of air pollution in a city, the more protected is the health of its population.