Conclusions

Environmental conditions, such as air pollution, are a major determinant of childhood asthma, but such conditions are not shared equally across the population, regions, and settings where people live, work, and spend their time. Urban areas may be affected by industrial activities and traffic-related emissions with high levels of air pollution and a lack of quality and safety features that enhance healthy living, such as urban natural spaces. Urban conditions and air quality are not only important features for national and local authorities to shape healthy cities and protect their citizens from environmental and health risks, but they also provide opportunities to mitigate inequalities in the most deprived areas where the environmental burden is highest. Actions to avoid exposure to indoor and outdoor air pollutants should be complementary at different levels – individual, local, and national levels – to take strong measures to protect children who have little or no control over the air they breathe.