Phototoxic effect of polycyclic aromatic compounds on human fibroblast cultures

: The phototoxic effects of polycyclic aromatic hydrocarbons (PAH) benzo(a)pyrene, benzo(a)anthrazene, indeno(1,2,3-cd)pyrene, fluoranthene and perylene, and their relation to the known carcinogenicity of these compounds was examined with human fibroblastic cultures. Using different light filters it could be demonstrated that phototoxic effects on the cell cultures only occur with wave lengths shorter than 400 nm, that is in the longwave UV-region. With wave lengths longer than 400 nm, that is in the visible region of light, no cytotoxic effects could be detected. Irradiated with long-wave UV, the highly cancerogenic compounds benzo(a)pyrene, and indeno(1,2,3-cd)pyrene proved to be highly cytotoxic, the moderately cancerogenic benzo(a)anthrazene turned out to be distintly cytotoxic, fluoranthene supposed to be not cancerogenic, proved to be only slightly cytotoxic. Perylene that is considered not cancerogenic either, reacted completely indifferent. These results are completely compatible with those obtained earlier with ciliata (unicellular protozoa). They confirm the assumption that the so-called ciliata test (Tetrahymena pyriformis) can be used as a practicable test system to ascertain the carcinogenicity of PAH.