Cancer/carcinogens dioxin

Cancer has been at center stage from the opening curtain of the Agent Orange controversy. In animal tests, dioxin is a very potent carcinogen, and it s known that dioxin is present in the environment. 

IARC. 1997. International Agency for Research on Cancer. IARC Monographs on the Evaluation of Carcinogenic Risks to Humans Polychorinated Dibenzo-para-dioxins and Polychlorinated Dibenzofiirans (vol. 69). Summary Statements. http //www.iarc.lf/t)ublications/vol69.htm. May 8, 1997. 

NCI/NTP. 1979a. Bioassay of 2,7-dichlorodibenzo-p-dioxin (DCDD) for possible carcinogenicity. Bethesda MD US. Department of Health, Education, and Welfare, Public Health Service, National Cancer Institutes/National Toxicology Program. (NIH) DHEW Publication no. 79-1378. 

IARC, Monograph on the Evaluation of Carcinogenic Risk of Chemicals in Man, Vol. 15, Some Fumigants, the Herbicides 2,4-D and 2,4,5-T, Chlorinated Dibenzo-dioxins and Miscellaneous Industrial Chemicals, International Agency for Research on Cancer, Lyon, France, 1974. 

There is a very broad range of toxic effects of dioxins. Many of the congeners can induce toxic responses at very low dose. The most sensitive effects are immunosuppression, developmental and reproductive toxicity, as well as neurological behavioral effects. Carcinogenic effects are induced at higher exposure. TCDD was considered a complete carcinogen by the International Agency for Research on Cancer, IARC [115]. 

Dioxin is a common name for dibenzo-l,4-dioxane, which is 1,4-dioxane fused with two benzene rings. The name dioxin is often used incorrectly in the news media for 2,3,7,8-tetrachlorodibenzodioxin (TCDD), a toxic contaminant in the synthesis of the herbicide called 2,4,5-T or Agent Orange. Surprisingly, TCDD has been in the environment for many millions of years because it is also formed in forest fires. Most dioxins are toxic and carcinogenic (cause cancer) because they associate with DNA and cause a misreading of the genetic code. 

Buser HR (1991), in IARC Scientific Publication No. 108. Environmental Carcinogens Methods of Analysis and Exposure Measurement, Vol. 11 Polychlorinated Dioxins and Diben-zofurans". Review of methods of analysis for polychlorinated dibenzodioxins and dibenzofu-rans , p.105-146, Eds. Rappe C, Buser HR, Dodet B, O Neill IK International Agency for Research on Cancer, Lyon... 

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