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(284) Perfluorooctanoic acid and perfluorooctane sulfonic acid II; surfactant toxicity towards aquatic plants. Boudreau, Timothy1, Hanson, Mark1, Janutka, Richard1, Solomon, Keith 1, Sibley, Paul1, Muir, Derek2, Mabury, Scott3, 1 2 3 ABSTRACT- Perfluorinated surfactants are anthropogenic compounds found as trace amounts in many environmental compartments far from production centres. This, along with the highly persistent nature of these compounds, presents a concern for the long-term availablility in ecosystems. Outdoor mesocosms dosed with 0.3, 1, 30 and 100 mg/L of perfluorooctanoic acid (PFOA) and 0.3, 3, 10 and 30 mg/L perfluorooctane sulfonic acid (PFOS) were used to evaluate the phytotoxicity on selected aquatic macrophytes. The relative sensitivity of the floating macrophyte Lemna gibba and the rooted macrophytes Myriophyllum sibiricum and M. spicatum was compared for both surfactants in 35-day studies. These plants showed clear, acute toxicity at the highest dose of PFOA and PFOS. PFOS - included in the manufacturing process of ScotchgardTM - was the most toxic to all organisms. The most sensitive plant was L. gibba. NOEC values for L. gibba exposed up to 35-days to PFOA and PFOS were 20 ppm and 0.3 ppm, respectively. Overall, the risk these surfactants pose to aquatic macrophytes at current environmental concentrations is minimal. Key words: perfluorinated surfactant, macrophyte, toxicity, ScotchgardTM |
