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.

Total estrogenic activity and nonylphenol concentration in the Donggang River, Taiwan

“…The estradiol equivalency factor (EEF) is the quotient of the EC 50 (E2)/EC 50 (NP) value and conventionally is set to 1 for E2. Reported EEF values for NP cover a very wide range from 7.2 × 10 −7 to American river Snyder et al (2001) EEQ 17β-estradiol equivalent quotient, LOD limit of detection 7.0 × 10 −3 (Murk et al 2002;Gomes et al 2003;Petrovic et al 2004;Pojana et al 2004) and in this study the EEF value for NP was 2.85 × 10 −5 (Fig. 3), close to the reported mean value of 2.0 × 10 −5 (Pojana et al 2004).…”

“…Recently, most estrogenic activities measured in aquatic environments have focused on the influent and effluent of sewage treatment plants (STP; Desbrow et al 1998;Leusch et al 2006;Jin et al 2008;Sun et al 2008), discharge of industrial water (Snyder et al 2001;Holbrook et al 2002;Murk et al 2002), and receiving water in urban areas (Fenet et al 2003;Cargouët et al 2004). Comparatively, the data concerned with estrogenic activities in receiving water affected by agricultural operation have been limited, especially discharge from concentrated animal feeding operations (CAFOs).…”

Endocrine disrupting compounds and other emerging contaminants in the environment: A survey on new monitoring strategies and occurrence data

“…Analysing steroid sex hormones in STP influents Murk et al [65] explained 70% of the ER-CALUX activity. However, in the effluent samples the explained fraction decreased to 20%, which coincides with a lower contribution of hormones and possible formation of bioactive metabolites.…”

Integrated procedure for determination of endocrine-disrupting activity in surface waters and sediments by use of the biological technique recombinant yeast assay and chemical analysis by LC?ESI-MS

“…Several publications compare the advantages and drawbacks of the different bioassays used [14,25,26,27,28,29,30,31,32,33,34]. Although in-vivo assays are widely used, they are unsuitable for large-scale screening and their utility is further limited by their relatively poor sensitivity, higher cost, and time-consuming nature compared with in-vitro assays [28].…”