Assessment of the genotoxicity of Cu and Zn in raw and anaerobically digested slurry with the Vicia faba micronucleus test

Abstract

Genotoxicity of Cu and Zn was assessed by use of the micronucleus (MN) test on Vicia faba roots. Plants were exposed to various leachates of rawand anaerobically digested pig slurry, with maximum total concentrations of 200MCu and 600MZn. The results indicated stabilisation of the organic matter during anaerobic digestion of the slurry and bioconversion of some phytotoxic organic compounds (e.g. phenols or p-cresol), but did not showa relationship between Cu and Zn concentrations and MN frequency. Exposure of Vicia plants to binary inorganic solutions of Cu and Zn (CuSO4/ZnSO4, 1:3) showed a significant micronucleus induction at concentrations of 40M Cu and 120M Zn and higher. When MN frequency was plotted against dissolved Cu (<0.45m), applied as slurry or as CuSO4, a single curve was obtained. At concentrations lower than 10M, modulation of the genotoxic effect of Cu was found. At concentrations up to 150M,MNinduction increased significantly, while phytotoxic symptoms appeared at higher concentrations.