[Method quantitative assessment of the danger of chemical carcinogen exposure]

A formula of quantitative estimation of the degree of blastomogenic activity of chemical substances is suggested, in which blastomogenic activity of the substance (C) is directly proportional to a total number of the names of tumor involved organs in experimental animals (T), a relative frequency of carcinogenesis 100 (See Article), and is inversely proportional to the logarythm of an effective carcinogen dosage mg/Kg/lg ED50), a latent perioe of tumor development (l) in days, a total number of the names of tumor involved organs in control animals (T). (See Article), wheren-the number of experimental tumor-bearing animals, n1 -- the number of control animals with tumors, N -- the number of experimental animals surviving the first tumor appearance, N1 -- the number of control animals surviving the first tumor appearance. Numerical values are given for four classes of the blastomogenic activity of chemical compounds according to "C" criterion. The first class -- extremely high greater than 0.5, II class -- high 0.499 -- 0.1, III class -- moderately high 0.099 -- 0,05, IV class -- low less than 0.05.