Mutagenic Potentials of Anthracene and Phenanthrene Compounds during Water Disinfection with Chlorine

Aqueous anthracene/phenanthrene compound solutions were treated with chlorine under various experimental conditions. Diethyl ether extracts from the chlorinated waters were determined by gas chromatography for their product distributions, and were tested for their mutagenic effects on TA98 and TA100 strains with and without S9 mix. Aqueous chlorination not only generated mutagens from non-mutagenic compounds (anthracene, 2-methylanthracene, phenanthrene and 2-methylphenanthrene), but also enhanced the activity of mutagenic compounds (9, 10-dimethyl anthracene and 1-methylphenanthrene). The chlorination products of anthracene compounds were most mutagenic on TA98 strain with S9 mix, while these products of phenanthrene compounds were mutagenic without S9 mix. The parent compounds were shown to produce a variety of chlorination products, including chlorine-substituted, oxygenated, and hydroxylated compounds. The formation of chlorination products and mutagenic substances was dependent on the reaction pH and chlorine dose. The significance of these findings for water chlorination systems is discussed.