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Fixed‐effect‐level toxicity equivalents—a suitable parameter for assessing ethoxyresorufin‐ O ‐deethylase induction potency in complex environmental samples
Author(s) -
Brack Werner,
Segner Helmut,
Möder Monika,
Schüürmann Gerrit
Publication year - 2000
Publication title -
environmental toxicology and chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.1
H-Index - 171
eISSN - 1552-8618
pISSN - 0730-7268
DOI - 10.1002/etc.5620191015
Subject(s) - bioassay , ec50 , toxicity , chemistry , potency , environmental chemistry , fractionation , acute toxicity , ecotoxicology , enzyme , pharmacology , toxicology , biochemistry , chromatography , biology , in vitro , ecology , organic chemistry
Abstract Within the scope of bioassay‐directed identification of dioxin‐like toxicants in complex environmental samples, EC50‐based and fixed‐effect‐level‐based 2,3,7,8‐tetrachlorodibenzo‐ p ‐dioxin (TCDD) toxicity equivalents (TEQs) were compared to assess 7‐ethoxyresorufin‐ O ‐deethylase (EROD) inducing potency of sediment fractions using the rainbow trout liver cell line RTL‐W1 as bioassay system. Toxicity equivalents on the basis of fixed effect levels are suggested in order to minimize interpretation problems due to the superposition of enzyme‐inducing and enzyme‐inhibiting effects. Bioassay‐directed fractionation of a contaminated sediment extract in the industrial region of Bitterfeld (Germany) based on fixed‐effect‐level TEQs indicated high dioxin‐like activity in the lipophilic sediment fractions containing the prototypic arylhydrocarbon receptor (AhR) agonists polychlorinated biphenyls (PCBs) and polycyclic aromatic hydrocarbons (PAHs). However, only a small part of the EROD induction could be attributed to the PCBs and PAHs that were analyzed. Significant EROD induction occurred also with some of the more polar fractions.