Carcinogenicity of Dioxins in Experimental Animals and Humans:Evaluations by the IARC Monographs (〔日本環境変異原学会第27回大会〕シンポジウム) -- (ダイオキシンの生体影響)
スポンサーリンク
概要
- 論文の詳細を見る
Of the 75 possible mono- and polychlorinated dioxins, only one has been well studied for carcinogenicity in experimental animals. The nonchlorinated parent compound, dibenzo-para-dioxin, has been thoroughly tested in both rats and mice, and is not carcinogenic in those species. The most toxic member of the polychlorinated dibenzo-para-dioxin (PCDD) family, 2,3,7,8-tetrachlorodibenzo-para-dioxin (TCDD) , has been extensively studied for carcinogenic activity in rodents and has been shown to be a nongenotoxic tumor promoter and carcinogen for multiple epithelial tissues in mice and rats, and also to induce mesenchymal tumors in mice. The tumor spectrum seen depends on the genetic back-,1 ground of the test animals and varies greatly from one species to another and from one inbred strain to another within a species. Because of its prolonged biological half-1ife (7.1 years in humans) and the equilibrium between serum levels and concentrations in body fat, accurate measurements of current serum levels of TCDD in workers can be extrapolat-ed backwards in time to the levels that occurred soon after industrial and civil accidents that involved human exposure to large quantities of TCDD. Individuals can thus be accurately stratified into low, medium and high levels of exposure. Studies of four cohorts of workers involved in chlorophenoxy herbicide manufacture, three of which involved accidents that released large quantities of TCDD, have been most informative regarding cancer risk. All have shown a small but consistent dose-dependent increase in risk for all cancers combined. TCDD has been classified by the IARC Monographs as carcinogenic to humans (Group 1) . On the basis of current data, all other PCDDS are not classifiable as to carcinogenicity to humans (Group 3) .
- 日本環境変異原学会の論文
- 1999-07-12