PM16 Molecular Indicators for Ecological Exposure
Exhibit Hall
8:00 AM - Monday
(PM270) Effects of Alkylphenol Surfactants on the Estrogenic Activity of Selected Aquatic Pesticides.
Thrippleton, K.1, Irwin, M.A.1, Xie, L.1, Siemering, G.2, Schlenk, D.1, 1 University of California, Riverside, Riverside, CA, US2 San Francisco Estuary Institute, Oakland, CA, US
ABSTRACT- Alkylphenol ethoxylates (APEs) are primary active ingredients in many non-ionic surfactants. APEs and their metabolites, alkylphenols, share structural similarity with estrogen and have been reported to have weak estrogen-like activity. An in vivo model using juvenile rainbow trout (Oncorhynchus mykiss) was employed to monitor the estrogenic activity of selected aquatic pesticides and the effects of nonylphenol-containing surfactants on the estrogenic effects of these pesticides. This was determined using plasma vitellogenin (Vtg) as a biomarker utilizing a Biosense rainbow trout vitellogenin sandwich ELISA kit. Pesticides tested included 2,4D (Weedar 64®), Diquat (Reward®), Glyphosate (Rodeo®), and Triclopyr (Garlon 3A®). Surfactants used included R-11® and Target Propreader Activator® (TPA). Results determined that the highest environmental-related concentration of 2,4D and 2,4D mixed with TPA were able to induce elevated levels of Vtg in O. mykiss. Dose-response tests were then performed using 2,4D and 2,4D mixed with the two surfactants. Results showed dose-related responses in all samples. Surfactant mixture effects for these samples were also determined. Results showed a greater than additive effect in the 2,4D mixture with TPA, while the 2,4D mixture with R-11 showed a less than additive effect compared to the individual responses of 2,4D, R-11, and TPA. In summary, APE-containing surfactants both enhanced and reduced the estrogenic activity of aquatic pesticides, depending upon the dose and the surfactant involved.
Key words: nonylphenol, alkylphenol, estrogen, vitellogenin