Exposure to air pollution causes a number of health problems. Air pollutants that are inhaled have serious impacts on human health affecting the lungs and the respiratory system. Different people are affected by air pollution in different ways. Poor people, undernourished people, very young and very old, and people with preexisting respiratory disease and other health problems are more at risk. The effects of air pollution on health are very complex and the pollutants can have synergistic effects when people are exposed to a number of pollutants present in the atmosphere.