Toxic effects of the combined exposure of tetrabromobisphenol A and polyethylene microplastics in native Brazilian freshwater species

Abstract

Tetrabromobisphenol A (TBBPA) and microplastics (MP) are emerging contaminants that have been detected in water bodies in Brazil and the world and have adverse effects for aquatic biota. They can coexist in the aquatic environment, and due to the MP's ability to adsorb organic pollutants such as TBBPA, the toxic effect of the co-exposure for biota has been studied. In this project, acute and chronic ecotoxicity tests will be carried out with two native invertebrates from Brazil, the oligoqueta Allonais inaequalis and the microcrustacean Ceriodaphnia silvestrii, in order to assess the potential effects that the combined exposure of TBBPA and MP (polyethylene 40 - 48 µm) can cause in species. The organisms will be grown in the laboratory and sensitivity tests will be carried out to ensure that the test results can be used. In the acute ecotoxicity test, it is proposed to analyze, in both organisms, the mobility responses, proportion of the tube filled by MP (mm²) and the release of particles from the digestive tube when in a clean environment, in addition to the effect on the swimming of C. silvestrii. The tests will be carried out in a factorial combination of concentrations of the contaminants. Considering the greater TBBPA + MP combination that did not cause an acute effect, the chronic ecotoxicity test will be carried out, in which it is intended to analyze the effect of the isolated substances and this combination on the reproduction of species and the length of the body of C.silvestrii. The results will be analyzed statistically to verify which exposures differ from the control. It is hoped to understand the combined toxic effects of two contaminants of emerging relevance to native aquatic species. (AU)