STUDIES ON THE MUTAGENICITY OF MILD GASIFICATION PRODUCTS OF COAL ANDTHEIR SUBFRACTIONS BY THE SALMONELLA MICROSOMAL ASSAY/

Mild gasification of coal is a technology being developed in the Unite d States in order to upgrade lower rank coals and facilitate their use in coal-burning electric generation plants. Thirteen coal-derived mil d gasification products from different coal sources and processing con ditions have been examined for their potential biohazards. The mutagen icity of these samples was tested with the Ames Salmonella/microsomal assay. Two solvents, dimethyl sulfoxide (DMSO) and polyoxyethylenesorb itan monooleate (Tween 80), were used to dissolve samples in a manner to facilitate their interaction with the test organisms. The results s howed that 9 of the 13 samples displayed mutagenic activity in test st rains TA98 and/or TA100 with or without metabolic activation, whether dissolved in Tween 80 or DMSO. Five mutagenic and two nonmutagenic sam ples were class-fractionated into basic, acidic, nonpolar, and polar n eutral subfractions to examine their class-related mutagenic activitie s. Results of the testing of subfractions of the five mutagenic and on e nonmutagenic samples showed mutagenic activity in at least the nonpo lar neutral fraction. The subfractions of the another nonmutagenic sam ple did not display any mutagenic activity. Chemical characterization of the subfractions revealed the existence of aromatic hydrocarbons in certain subfractions, which may be responsible for the mutagenic acti vity of the coal-derived mild gasification products. (C) 1997 Academic Press