Ecological Effects of an Anionic C12-15 Ae-3s Alkylethoxysulfate Surfactant in Outdoor Stream Mesocosms

Abstract

The ecological assessment of a C12-15 AE-3S linear alkylethoxysulfate (AES) anionic surfactant to invertebrates, fish, periphyton, and an aquatic macrophyte was conducted in a 30-d outdoor stream mesocosm study with five replicated concentrations and controls. Alkylethoxysulfate structural integrity and exposure concentrations were maintained during the 30-d treatment period, with average measured concentrations of 0.7, 1.27, 2.2, 4.31, and 10.18 mg/L. No effects were observed on the aquatic macrophyte Myriophyllum aquaticum at the highest concentration tested. A sevenfold increase in periphyton biomass at 10.18 mg/L was observed relative to controls primarily because of increases in density of the filamentous alga Mougeotia sp. Densities of the invertebrates Annelida (Stylaria), Amphipoda, Copepoda, Trichoptera (Hydropsychidae), Cladocera, and Diptera (Chironomidae) significantly decreased in streams treated with AES at 10.18 mg/L. Densities of drifting invertebrates were not observed to be affected at any concentration tested. Reproduction of Pimephales promelas significantly decreased at 1.27 mg/L and growth of juvenile Lepomis macrochirus was significantly affected at 4.31 mg/L. Multivariate cluster analysis and nonmetric multidimensional scaling ordination showed distinct structural effects on the invertebrate communities in the streams treated with AES at 10.18 mg/ L compared to the control and streams treated at < 10.18 mg/L through the 30-d treatment. Convergence of the communities treated at 10.18 mg/L toward control communities in the ordination suggests recovery in these communities after termination of surfactant treatment. The results from this study support an ecosystem value of > 2.0 mg/L, and indicate that the conservative Dutch risk assessment for AESs has at least a fivefold margin of safety.

Environmental Safety of the Use of Major Surfactant Classes in North America

“…The second study tested C 12–15 EO 3 S linear AES in a 30-d outdoor stream mesocosm which contained invertebrates, fish, periphyton, and an aquatic macrophyte. The results from this study support an ecosystem value of >2.0 mg/L for C 12–15 EO 3 S ( Lizotte et al, 2002 ). These mesocosm studies incorporate both direct and indirect effects.…”

“…The relationship of the HC 5 to mesocosm studies provided evidence to determine whether an additional AF was needed to derive the final PNEC ( Solomon et al, 2008 ). The normalized HC 5 was 0.073 mg/L, whereas the mesocosm value based on the study of Lizotte et al (2002) was 1.5 mg/L. The non-normalized NOEC from the Belanger et al (1995b) study was also greater than the HC5.…”

“… 1 HERA (2004) , 2 Maki (1979) , 3 Lizotte et al (2002) , 4 Versteeg et al (1997) , 5 Dyer et al (2000) , 6 Belanger et al (1995a) , 7 The Procter & Gamble Company (2000) . * In the sixth column, the toxicity values are reported as normalized to a single average environmentally relevant AES structure (i.e., C 13.5 EO 3 S) based on the Dyer et al (2000) QSAR.…”

“… 1 HERA (2004) , 2 Maki (1979) , 3 Lizotte et al (2002) , 4 Versteeg et al (1997) , 5 Dyer et al (2000) , 6 Belanger et al (1995a) , 7 The Procter & Gamble Company (2000) . …”

Effects of Pollution on Freshwater Aquatic Organisms

“…Outdoor stream mesocosm studies on the ecological effects of anionic C 12-15 AE-3s linear alkylethoxysulfate showed various organism responses including increased density of filamentous algae and decreased density of several aquatic macroinvertebrates (Lizotte et al, 2002). Similar mixed-organism studies with acute lethal toxicity levels of chlorophenol, haloalkane, quinine, and substituted nitrobenzene indicated various organism responses including tolerance levels to haloalkanes for daphnia and carp were higher than that of the green algae chlorella, and that toxicity of naphthoquinone compounds to chlorella and carp was higher than that of anthraquinone (Yen et al, 2002).…”