Detection of Estrogenic Potency in Wastewater and Surface Water With Three in Vitro Bioassays

Abstract

A study was performed to optimize sample preparation and application of three in vitro assays for measuring estrogenic potency in environmental extracts. The three assays applied were an estrogen receptor (ER)-binding assay and two reporter gene effect assays: a yeast estrogen screen (YES) and the ER-mediated chemically activated luciferase gene expression (ER-CALUX) assay. All assays were able to detect estrogenicity, but the amounts of material needed for the assays differed greatly between the three assays (ER-binding assay >> YES > ER-CALUX). In addition, in the ER-binding assay, both agonists and antagonists give an estrogenic response, resulting in higher estradiol equivalency (EEQ) levels than both the ER-CALUX and the YES assay for the same samples. The EEQs found in wastewater treatment plants (WTPs) with the ER-CALUX assay were in the range of 4 to 440 and 0.11 to 59 pmol/L for influent and effluent, respectively. Water extracts from four large rivers had levels ranging from 0.25 to 1.72 pmol/L. Extracts from suspended matter and sludge contained estrogenic potency of 0.26 to 2.49 and 1.6 to 41 pmol EEQ/g dry weight, respectively. In WTPs, the average reduction of estrogenic potency in effluent compared to influent was 90 to 95% in municipal WTPs and about 50% in industrial WTPs. In influent, 30% of the ER-CALUX activity could not be explained by the calculated potencies based on chemical analysis of a number of known (xeno)estrogens; in effluent the unexplained fraction was 80%. These first results of analyzing estrogenic potency in WTP water and surface water in The Netherlands indicate that further studies are warranted to investigate the actual risks for aquatic systems.

Assessing the Detoxication Efficiencies of Wastewater Treatment Processes Using a Battery of Bioassays/Biomarkers

“…Endocrine disruption activity in WWTP effluents has also been frequently studied (Nasu et al 2001;Murk et al 2002;Alatriste-Mondragon et al 2003). This effect was attributed to a group of chemicals including natural products, pharmaceuticals, and industrial chemicals, which have been shown to be estrogen mimics.…”

Partitioning, bioavailability and effects of oestrogens and xeno-oestrogens in the aquatic environment

“…In trials with chemically-characterized water and particulate samples, Murk et al (2002) recently compared three of the most widely used in vitro assays in -an oestrogen receptor (ER) binding assay and two reporter gene assays (YES, the yeast oestrogen screen developed by , and ER-CALUX the ER-mediated chemical activated luciferase reporter gene expression assay). The responses with ER-CALUX and YES were more comparable with each other than with the ER binding data, probably explained by the different principles of these assays.…”

“…The same authors were also able to compare oestrogenicity of a number of other ED chemicals and to study the influence of metabolism on their activity; thus, exposure of E2 to microsomal degradation clearly reduced potency, whilst decreasing the side chain length of APEO resulted in increased oestrogenic activity (the degradation products OP and NP showing highest potency). Using the same assay, Murk et al (2002) were able to estimate the efficacies of various treatment plants in removing oestrogenic potency: for some domestic STW this was in the range 90-95%, compared with approximately 50% in an industrial treatment plant. Variable efficiencies for the removal of oestrogencity by STW, ranging from 62-97%, were indicated in a similar study by Cargouet et al (2004).…”

Monofluorinated Analogues of Polybrominated Diphenyl Ethers as Analytical Standards: Synthesis, NMR, and GC-MS Characterization and Molecular Orbital Studies

“…because of their high sensitivity for estrogenic hormones, their biological relevance by directly measuring activity via (part of) the mechanism of action, and their ability to measure the total estrogenic potency of mixtures present in a sample (1). Indeed, in real life, exposure to chemicals seldom is to a single compound but usually to mixtures of different chemicals.…”

“…water, suspended particulate matter, several animal matrixes, and sediment (1,4,5). Several studies have focused on the validation of bioassays for the detection of (mixture) effects of (xeno-)-estrogens and for the application to environmental and human samples (e.g.…”