What are Dioxins and Furans?

"Dioxins and furans" refer to a group of chemical compounds that share certain similar chemical structures and biological characteristics. Dioxins and furans are an unwanted byproduct of combustion, both from natural sources like forest fires and from man-made sources like power plants, backyard burn barrels and industrial processes.

According to the EPA, dioxins and furans released into the air during combustion can be carried long distances before settling to the earth's surface. As a result, they are found almost everywhere at low levels. Dioxins and furans are produced by both natural and man-made processes and have therefore existed for centuries. The term "current background" is used to refer to the levels of dioxins and furans in the environment today.

Dioxins and furans falling to land from air emissions tend to bind tightly to vegetation and soil. When dioxins and furans are released into water, they tend to settle into sediments where they can become trapped and stationary, or be ingested by fish and other aquatic organisms. Dioxins and furans trapped in sediment can be further transported during activities that dislodge sediment, such as flooding or dredging.

In the United States, the primary way people are exposed to dioxins and furans is through eating meat and dairy products. The animals we eat are exposed to background levels of dioxins and furans in the soil, on vegetation and in some commercial animal feeds. Eating meat or dairy products exposes us to these low levels of dioxins and furans. Over time, we accumulate dioxins and furans in the fatty tissues of our own bodies.