Toxicologic Responses to a Complex Coal Conversion By-Product: Mammalian Cell Mutagenicity and Dermal Carcinogenicity

Abstract

The overall toxicity of complex mixtures cannot be predicted simply by adding the toxicities of known toxic compounds in the mixture. The toxicity of some of the components in the mixture is often unknown and synergisms and antagonisms, which cannot be predicted solely on the basis of the chemical composition, may occur. To better understand the chemical and biochemical interactions that modify the ultimate toxicity of mixtures, we are isolating and characterizing well-defined chemical classes of chemicals and determining the toxicity of these chemical class fractions with in vivo andin vitro bioassays. The need for this approach with coal conversion materials has recently been demonstrated by interactive effects observed in both in vitro and in vivo toxicity assays. For example, a mixture of polycyclic aromatic hydrocarbons from coal conversion materials inhibited the bacterial mutagencity of benzo[a]pyrene (Haugen and Peak, 1983) and potentiated the mutagenicity of 2-aminoanthracene (Pelroy and Peterson, 1979; Kawalek and Andrews, 1981) as measured in the Salmonella/microsome assay. In addition, tumorigenic responses to carcinogenic components of coal conversion materials were greater than those determined for the whole material (Mahlum, 1984).