Dioxin sampling letter, Oct 26, 2001

NYC 9/11 Public Portal Document

The following excerpts can be found at htip•//cf~ub1 eta Gov/ncea/cfm/dioxin cfm' ActType=default. .epa.gov/ncea/cfm/dioxin.cfm?ActTvpe=defpult.

Dioxin Frequently Asked Questions

GI. What are dioxins? "Dioxins" refers to a group of chemical compounds that share certain similar chemical structures and biological characteristics. Several hundred of these toxic compounds exist andare members of three closely related families: the chlorinated dibenzo-p-dioxins (CDDs),chlorinated dibenzofurans (CDFs) and certain polychlorinated biphenyls (PCBs). Sometimes the term dioxin is also used to refer to the most well-studied and one of the most toxicdioxins, 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD). CDDs and CDFs are not createdintentionally, but are produced inadvertently by a number of human activities. CDDs andCDFs are also produced by natural processes. PCBs are man-made, but are no longer produced in the U.S.

Dioxins are released into the air from combustion processes such as commercial or municipal waste incineration and from burning fuels (like wood, coal or oil). Dioxins can also be formed when household trash is burned and during forest fires. Chlorine bleaching of pulp and paper, certain types of chemical manufacturing and processing, and other industrial processes all can create small quantities of dioxins. Cigarette smoke also contains smallamounts of dioxins.

Why are people concerned about dioxins? Scientists and health experts are concerned about dioxins because studies have shown that exposure to them may cause a number of adverse health effects. Because dioxins exist throughout the environment, almost every living creature including humans has been exposed to dioxins. The health effects associated with dioxins depend on a variety of factors including: the level of exposure, when someone was exposed, and how long and how often. Because dioxins are so widespread, we all have some level of dioxins in our bodies.

The most noted health effect in people exposed to large amounts of dioxin is chloracne. Chloracne is a severe skin disease with acne-like lesions that occur mainly on the face andupper body. Other effects of exposure to large amounts of dioxin include skin rashes, skin discoloration, excessive body hair, and possibly mild liver damage.

One of the main health effects of concern for dioxins is cancer in adults. Several studies suggest that workers who were exposed to high levels of dioxins at their workplace over many years have an increased risk of cancer. Animal studies have also shown an increased risk of cancer from long term exposure to dioxins.

Finally, although not seen in human studies, based on data from animal studies there is also some concern that exposure to low levels of dioxins over long periods (or high level exposures at sensitive times) might result in reproductive or developmental effects. These could include weakened immune responses and behavior changes in offspring.

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