Poster 184 – Click on poster below to view presentation from author.
Co-Authors: Ana Gabriela Itokazu, David Blersch
Recently, it has been found that Perfluorosulfonic acids (PFSAs) are toxic substances and potentially harmful to humans and the environment. These compounds are very persistent and do not easily degrade in the environment. Furthermore, they are known to be carcinogenic and are endocrine disruptors in higher animals. Further evidence has shown the potential for bioaccumulation or transmission through food webs in aquatic systems, but the exact potential for bioaccumulation of mixtures of these compounds is unknown. The purpose of this study was to test the toxicity and bioconcentration of a mixture of three substances on the green algae Scenedesmus obliquus. In exposure uptake studies in flask culture in the laboratory, a PFSAs mixture bioconcentration test at 0.01 mg/L concentration resulted in all three PFSAs found in measurable concentrations adhered to the outer cell biomass, and in substantially lower concentrations inside the cells. Also, the PFSAs concentration in the cell and biomass increased at 0.1mg/L exposure exconcentration. With the number determined for these uptake concentraitons, bioconcentration factors were calculated to be 2.79 mL/g, 0 mL/g, and 0.23 mL/g for PFOS, PFBS and PFHxS, respectively, at the 0.01 mg/L PFSAs exposure concentration; and 2.63 mL/g and 1.83 mL/g PFOS and PFHxS, respectively, at the 0.1 mg/L PFSAs exposure concentration. In toxicity tests for S. obliquus, the Half Maximal Effect Concentration (EC50) for the PFSA mixture was determined to be 120.35 mg/L. Declines in the the concentrations of Chl-a, Chl-b, and total Chl demonstrate that the PFSAs mixture causes stress on algae cells after seven days of exposure. Results from these experiments demonstrate the potential for uptake and bioaccumulation of PFSAs by phytoplankton, adding to knowledge about the fate and transport of PFSAs in aquatic systems, and inform further studies on ecological transfer in food webs of these and other PFSAs.
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