Mutagenicity of Pulp and Paper Mill Effluent: A Comprehensive Study of Complex Mixtures

Pulp and paper mill effluents are complex mixtures of dissolved lignin and cellulose degradation products and other substances extracted during the pulping process. The toxicity of these effluents to fish has been documented (Howard and Walden, 1971; Wande, 1976; Walden and Howard, 1977). A number of investigators have shown that effluents and process streams from pulp and paper mills are mutagenic in Salmonella (Ander et al., 1977; Eriksson et al., 1979; Douglas et al., 1980) and cause chromosome damage in mammalian cells (Douglas et al., 1980). Over 300 compounds have been identified in studies on various pulp and paper mill effluents (reviewed in CPAR, 1978). Because of the extensive use of chlorine in the bleaching process, many of these compounds contain chlorine substitutions. Since first chlorination-stage liquors are consistently among the most mutagenic by-products of the pulping process, it has been suggested that chlorinated substances are responsible for a major portion of the mutagenicity found (Bjorseth et al., 1979; Nestmann et al., 1979; Nestmann et al., 1980; McKague et al., 1981; Rapson et al., 1980).