Biomarkers of metal exposure: an overview of research at the CPUT

Abstract

It is well known that sublethal concentrations of metals may lead to toxic effects in plants and animals. These effects are increasingly used as tools, termed biomarkers, to indicate ecosystem health and pollutant toxicity. Several recent studies in the Faculty Applied Sciences, CPUT, focused on measuring toxic effects of metal bioaccumulation in a variety of invertebrates and aquatic plants. A number of these studies showed a reduction in the stability and viability of invertebrate membranes, as well as changes in the structure and numbers of certain cells, as a result of metal exposure. Another study also showed significantly higher antioxidant activities as a result of metal exposure. In two invertebrate groups, metals were shown to cause external structural deformities. In aquatic plants, relationships were found between metal bioaccumulation and reduced chlorophyll content, as well as between metal exposure and increased antioxidant activities. This presentation will provide an overview of results from previous and current studies, as well as the limitations of using these toxic effects as biomarkers in toxicity assessment.