With water in short supply in many areas of Australia, attention is turning to the use of recycled water for both indirect potable and non-potable uses.
Traditional chemical measurements alone are an insufficient basis for environmental risk assessments where trace contaminants are involved, particularly for complex mixtures such as wastewater. In this project, we developed an 'ecotoxicity toolbox' to characterise water quality through the wastewater treatment process. The toolbox assesses a range of toxic responses, including in vitro endpoints for whole-cell toxicity (MicroLumo bioassay), DNA damage (umuC bioassay), herbicide effects (Max-I-PAM assay) and estrogenic and androgenic endocrine disruption (E-SCREEN and AR-CALUX respectively); as well as in situ effects using mosquitofish (Gambusia holbrooki) as the sentinel species.
This study has demonstrated the usefulness of combining multiple lines of evidence such as chemical analysis, in vitro assays, and in situ monitoring in the assessment of water quality. Biomarkers of exposure (in vitro) and effect (in vivo) are complementary, and together provide information with a greater level ofecological relevance than chemical measurements alone. The toolbox developed in this project shows promise for application to water recycling initiatives with arange of end-uses and allows a better understanding of the water quality issues involved.