As mentioned previously the term “dioxins” is used for a group of closely associated chemical compounds that share certain structural and biological characteristics. Hundreds of these compounds exist and all belong to one of three families: the chlorinated dibenzo-p-dioxins (CDDs), chlorinated dibenzofurans (CDF), and certain polychlorinated biphenyls (PCBs). It is important to note that the most famous and most toxic dioxin is 2,3,7,8-tetrachlordibenzo-para-dioxin (TCDD).

 

 

 

Most cases of dioxin poisoning are the result of this dioxin (actually in the dioxin sub-family as opposed to the furan or PCB family), and usually when the term dioxin is used outside the scientific research field, it is in reference to TCDD.

 

 

 

 

There are no practical uses for dioxins (except for certain PCBs used in manufacturing) and almost all dioxins in the environment are the result of anthropogenic sources. Dioxins have always existed in extremely low levels in the natural environment do to natural incineration processes, such as forest fires and volcanoes. However, dioxin levels did not become a greater issue during and after the industrial revolution of the 1920s. Dioxin levels have been decreasing since the early seventies when federal and state regulators began getting involved; however, it still remains a primary environmental concern.

 

Dioxins are usually byproducts of incineration, chlorine bleaching of pulp, and some chemical manufacturing. Small amounts of dioxin are released in cigarette smoke. In the United States the largest source of dioxins is the burning of residential waste. [1]

 

 

 

 

 

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