Implications of chemical-based effluent regulations in assessing DNA damage in fathead minnows (Pimephales promelas) when exposed to metal plating wastewater.

The application of chemical-based regulation on effluents has limitations because of their diverse chemical components, complicated interactions between contaminants, and the lack of information on the bioavailability of constituents (U.S.EPA 1991). In Korea, like in most developing countries, environmental regulations for the protection of the aquatic biota from discharges are based only on this chemical-based approach. The Permissible Wastewater Discharge Standards (PWDS) are the current legislation in Korea. The discharge limits are set for several heavy metals (e.g. Cr, Fe, Zn, Cu, Cd, Hg, As, Pb, etc.), a few organics (phenol, PCB, trichloroethylene, tetrachloroethylene, etc.) and some physicochemical parameters (pH, temperature, etc.). Among these pollutants, the trace metals are important because they might adversely affect the indigenous aquatic biota even at low levels. Genetic toxicity of trace metal has been a major concern (Barron and Adelman 1984; Ciccarelli and Wetterhahn 1985; Parrott and Sprague 1993; Beyersmann and Hartwig 1994; Hartwig et al. 1994). Metals readily bind to phosphate groups and to heterocyclic bases of the DNA and, hence not only change the stability, but also hinder the normal functioning of the DNA (Eichhom et al. 1970). The resulting consequences of metal-induced DNA damage include mutagenesis, carcinogenesis, and/or teratogenesis (Jones and Parry 1992).