| Very little toxicological data exists for perfluorinated organic acids (PFAs), even with the increased global detection of these compounds in air, water, and biota. PFAs are unique surfactants used in many applications. Single-species laboratory tests and multi-species microcosm studies were used to evaluate the toxicity of structurally similar PFAs to selected freshwater organisms. Eight PFAs of varying chain lengths were tested in laboratory studies on five organisms representing two trophic levels. Two PFAs were tested in separate outdoor microcosm studies on the zooplankton community and the floating macrophyte, Lemna gibba. Overall, evaluations showed that relative toxicities were influenced by carbon chain length. In general, PFAs > 7 carbons were relatively toxic to all organisms, however, perfluoropropionic acid, a three carbon PFA, was toxic only to plant species but not invertebrates. Under present environmental concentrations, there appears to be no immediate hazard to freshwater organisms, however, different sensitivities, determined here, requires further investigation of these extremely persistent compounds. |
