Genotoxicity Biomarkers in Fish Erythrocytes and Water Quality Parameters

Ecotoxicological approaches in water quality assessment have become important tools in environmental studies. The analysis of biomarkers in biological organisms collected in situ or exposed to water samples under laboratory conditions provides information on the effects of substances (heavy metals, pesticides, polycyclic aromatic hydrocarbons, and other emerging contaminants). The genotoxicity evaluation carried out, among others, by the micronucleus test in fish erythrocytes, provides information on the potential DNA damage caused by the exposure to a single or a complex mixture of pollutants. Moreover, the combined analysis of genotoxic endpoints to water physicochemical parameters provides more realistic data on the pollution scenario. In Brazil, a number of studies have evidenced the poor water quality of the Sinos River basin – an important water resource located in the Southern region. A case study of this basin is presented in this chapter, where water physicochemical analysis and the micronucleus test in fish erythrocytes were performed. Some water parameters were found above the limits established by the Brazilian legislation. In contrast, no genotoxic effect was evidenced in the fish Cyprinus carpio exposed for 72 h to water samples collected at seven sampling sites distributed along the basin. Nonetheless, the continuous assessment through ecotoxicological approaches is invaluable to environmental diagnosis.