Air pollution is the contamination of air by the discharge of harmful substances.
Air pollution can cause health problems including burning eyes and nose, itchy irritated throat, and breathing problems. Some chemicals found in polluted air can cause cancer, birth defects, brain and nerve damage, and long-term injury to the lungs and breathing passages in certain circumstances. Above certain concentrations and durations, certain air pollutants are extremely dangerous and can cause severe injury or death. Air pollution can also damage the environment and property. Trees, lakes, and animals have been harmed by air pollution.