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Toxic Air Pollutants

Note: EPA no longer updates this information, but it may be useful as a reference or resource.

Toxic air pollutants, also known as hazardous air pollutants, are those pollutants that are known or suspected to cause cancer or other serious health effects, such as reproductive effects or birth defects, or adverse environmental effects. Domestically, EPA is working with state, local, and tribal governments to reduce air toxics releases of 188 pollutants to the environment.


Mercury is a naturally occurring element that is present throughout the environment. Mercury in air can travel long distances, even across oceans, before getting deposited in soil or water. As a result, people and animals in areas with no local mercury releases may have elevated mercury levels. Elemental mercury is relatively insoluable, deposits on land and water slowly, and therefore can readily traverse the globe.


Persistent Organic Pollutants (POPs)

Persistent Organic Pollutants are highly stable organic compounds used as pesticides or in industry. They persist in the environment, accumulate in the fatty tissues of most living organisms, and are toxic to humans and wildlife. They are prone to long-range transboundary atmospheric transport and deposition.

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