Carcinogenicity of 2,3,4,7,8-pentachlorodibenzofuran and 1,2,3,4,7,8-hexachlorodibenzofuran in rats.

In order to examine the carcinogenicity of 2,3,4,7,8-pentachlorodibenzofuran and 1,2,3,4,7,8-hexachlorodibenzofuran, these two chemicals were subcutaneously administered to Wistar strain male rats at the dose of 80 micrograms, 40 micrograms or 4 micrograms per rat. At sacrifice in two years after the start of the experiment, tumors were observed in the subcutaneous tissue and the liver. Although the number of the rats used is small, the tumor occurrence showed some tendency to relate with the dose of the chemicals given.