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Report on the Environment

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Air provides the oxygen and carbon dioxide needed to sustain human, animal, and plant life on Earth, and the composition of trace gases in the atmosphere plays an important role for the climate. Air pollution can adversely affect these critical functions of the atmosphere in many ways. High levels of air pollution, whether indoors or outdoors, can harm human health by triggering asthma attacks, aggravating allergies, and contributing to or potentially causing various diseases. Certain types of outdoor air pollution can impair visibility and damage other valued resources, such as forests, lakes and streams, and building surfaces. On a global scale, air pollution released worldwide can eventually change the atmosphere’s composition with important consequences, including depletion of the Earth’s ozone layer and climate change.

An important component of EPA’s mission is to protect and improve air quality in order to avoid or mitigate the consequences of air pollution’s harmful effects. State and tribal air pollution control agencies help fulfill this mission by implementing many of the air pollution control requirements that EPA sets at the federal level. Other federal partners, the academic community, industry and trade associations, and non-governmental organizations all conduct important research that contributes to the current understanding of regional, national, and global air quality issues.

Efforts to maintain good air quality are complicated by population increase, energy consumption, motor vehicle use, and other factors that can lessen air quality. Outdoor air is polluted by emissions from a broad array of industrial and mobile sources, as well as everyday activities like dry cleaning, painting, and refueling vehicles. Emissions from natural sources, such as wildfires, also contribute to outdoor air pollution. Similarly, indoor air quality is affected not only by these outdoor sources, but also by sources found within buildings, such as home heating devices, tobacco smoke, consumer products, and building materials.

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