Earth 2

Air Pollution is addition of harmful substances to the atmosphere resulting in damage to the environment, human health, and quality of life. One of many forms of pollution, air pollution occurs inside homes, schools, and offices; in cities; across continents; and even globally. Air pollution makes people sick, it causes breathing problems and promotes cancer, and it harms plants, animals, and the ecosystems in which they live. Some air pollutants return to earth in the …

…a factory or a car, and the rapid multiplication of sources. Smog in American cities is expected to increase again as the number of cars and miles driven continues to rise. Meanwhile, developing countries are building up their own industries, and their citizens are buying cars as soon as they can afford them. Ominous changes continue in the global atmosphere. New efforts to control air pollution will be necessary as long as these trends continue.