Environmental contamination by emerging pollutants in the estuarine system of São Vicente-SP and the ocean acidification effects in oyster Crassostrea brasiliana exposed to benzoylecgonine

Abstract

The intense and continuous contribution of emerging contaminants might represent a risk to non-target organisms. This could be aggravated by the decrease in the ocean's pH. The cocaine and its main human metabolite, the benzoylecgonine, become relevant for ecotoxicology studies since they have been reported in several environmental matrices, specially in aquatic ecosystems. In this panorama, the aim of this study is to identify and quantify emerging contaminants in the estuarine system of a seaside city with subnormal dwellings, as well as elucidating the metabolism, mode of action and the adverse effects caused by relevant environmental concentrations of benzoylecgonine in ocean acidification scenarios. Therefore, will be conducted assays employing biomarkers in the oyster Crassostrea brasiliana and will be evaluated the activities of the first and second phases of metabolism (EROD, DBF and GST), assessment of antioxidant system through the enzymatic activity of GPx, analyze the cytotoxicity of the compounds through the neutral red retention time assay (NRRT), oxidative stress by the lipid peroxidation and mitochondrial DNA damage. Will also be evaluated changes in the protein concentration of neurotransmitters (dopamine, serotonin and norepinephrine), in the cholinergic system (cholinesterase), in the total content of lipids, in the transport of electrons in the mitochondria (MET) and the COX activity. It is expected to identify and quantify emerging contaminants in regions where there is a higher concentration of subnormal dwellings and that the ocean acidification increase the possible damage caused by benzoylecgonine in bivalves' tissues. (AU)