Cocarcinogens

Finally, it is important that further research be carried out on the identification and mechanism of action of environmental cocarcinogens and tumor promoters which can enhance the carcinogenicity of PAH. Human exposure to at least trace amounts of PAH is unavoidable. The probability of eventual tumor development may be controlled primarily by repeated exposure to cocarcinogens or promoters. 

Ring structures of representative tumorigenic, cocarcinogenic, and carcinogenic PAHs... 

Carbamate esters of zinc, zineb, and ziram are carcinogenic and teratogenic in animals, but this is attributed to the action of the carbamate esters and not to zinc (Elinder 1986). Results of studies with small mammals showed zinc to be cocarcinogenic with 4-nitroquinoline-N-oxide on oral cancer, and with N-ethyl-N-nitrosourea on brain cancer (Leonard and Gerber 1989). 

Interaction effects of arsenic with other carcinogens, cocarcinogens, promoting agents, inhibitors, and common environmental contaminants... 

Bocchetta, M., I. Di Resta, A. Powers, R. Fresco, A. Tosolini, J. R. Testa, H. I. Pass, P. Rizzo, and M. Carbone. 2000. Human mesothelial cells are unusually susceptible to simian virus 40-mediated transformation and asbestos cocarcinogenicity. Proc Natl Acad Sci USA 97(18) 10214—9. 

Van Duuren BL, Goldschmidt BM. 1976. Cocarcinogenic and tumor promoting agents in tobacco carcinogenesis. J Natl Cancer Inst 56 1237-1242. 

It is postulated from epidemiologic studies that fibrous materials are also carcinogenic or cocarcinogenic. Lung cancer and mesothelioma (cancer of the pleura) have both been linked to occupational exposure of fibrous materials. The mechanisms of induction of these, as most cancers, are thought to start as changes in the affected cells. 

Bingbam E, Falk HL Environmental carcinogens. The modifying effect of cocarcinogens on the threshold response. Arch Environ Health 19 779, 1969... 

Toxicology. Catechol is a skin, eye, and respiratory tract irritant and at high concentrations may cause convulsions it acts as a cocarcinogen in animal skin-painting studies and produces stomach mmors after oral administration in rodents. 

Van Duuren BL, Katz C, Goldschmidt BM Cocarcinogenic agents in tobacco carcinogenesis, y Natl Cancer Inst 51 703-705, 1973... 

NTl 71 Hecht, S. S., S. Carmella, H. Mori, and D. Hoffmann. A study of tobacco carcinogenesis. XX. Role of catechol as a major cocarcinogen in the weakly acidic fraction of smoke condensate. J Natl Cancer Inst 1981 66(1) 163-169. 

Another health hazard associated with exposure to UV radiation is the potential cocarcinogenic activity of UV light with the contaminant on the skin. Past studies have found that exposure to UV radiation results in a significant enhancement of the effects of chemical carcinogens such as 7,12-dimethyl benzanthracene (13) and benzo[a]pyrene (14). Even normally innocuous compounds such as anthracene, n-decane and n-tetradecane can develop tumorigenic activity in mice under irradiation with long-wavelength (>350 nm)... 

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