Perfluorinated carboxylic acids (PFCAs) are recalcitrant global contaminants 1- 5. While the results indicate that current environmental concentrations of FTAs likely pose negligible risk to aquatic biota, additional quantification of FTAs in surface waters and assessment of their toxicity is needed before meaningful assessments of potential risks to aquatic biota are possible. These results represent the first chronic toxicity data for FTCAs and additional evidence that FTCAs are more toxic than some PFCAs. Mean number of eggs/female was not affected. Few adults emerged and no reproduction occurred at the two highest concentrations (6 µg/L). Total emergence and time to first emergence, the most sensitive endpoints, yielded EC50s of 440 and 890 µg/L. dilutus, EC50s for survival and growth at 20 d were 2,610 and 1,250 µg/L. Reproduction was significantly reduced relative to the controls, with respective median effective concentrations (EC50s) for time to first brood and mean number of offspring/female of 287 and 214 µg/L for FTuCA and 50 and 48 µg/L for FTCA. Lethal concentrations (LC50s) were 150 and >60 µg/L for FTuCA and FTCA, respectively. magna tests the FTCA was consistently more toxic than the FTuCA. The present study assessed the chronic toxicity of the 8:2 saturated fluorotelomer carboxylic acid (8:2 FTCA) to Chironomus dilutus and the 10:2 saturated and unsaturated fluorotelomer carboxylic acids (10:2 FTCA and 10:2 fluorotelomer unsaturated carboxylic acid ) to Daphnia magna in separate life-cycle tests. Recent studies have detected FTAs at low concentrations (ng/L) in precipitation and surface waters however, information regarding chronic toxicity is lacking. Saturated and unsaturated fluorotelomer carboxylic acids (fluorotelomer acids: FTAs) represent important intermediates in the degradation of fluorotelomer alcohols to perfluorinated carboxylic acids (PFCAs).
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