Air pollution strikes especially hard on the poor living in developing nations. People (including children) living on the streets breathe air that is heavily polluted by smoke-belching diesel trucks and buses. They bear the heaviest burden on their health. While wealthier nations have the economic resources to fund air pollution controls, developing nations struggle to do so. Economic studies of the effects of air pollution control, the costs of investing in control technologies and the consequences to the poor living in developing countries are addressed in this section.