Air pollution

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Air pollution

Before desulfurization filters were installed, the emissions from this power plant in New Mexico contained excessive amounts of sulfur dioxide.

Air pollution is the human introduction of chemicals, particulate matter, or biological materials that cause harm or discomfort to organisms, into the atmosphere.^[9] Stratospheric ozone depletion is believed to be caused by air pollution (chiefly from chlorofluorocarbons).

Worldwide, air pollution is responsible for large numbers of deaths and respiratory disease. Enforced air quality standards, like the Clean Air Act in the United States, have reduced the presence of some pollutants. While major stationary sources are often identified with air pollution, the greatest source of emissions is actually mobile sources, principally the automobile.^{[citation needed]} Gases such as carbon dioxide, methane, and fluorocarbons contribute to global warming, and these gases, or excess amounts of some emitted from fossil fuel burning, have recently been identified by the United States and many other countries as pollutants.^{[citation needed]}