Estrogenicity of chemical mixtures revealed by a panel of bioassays

Abstract

Estrogenic compounds are widely released to surface waters and may cause adverse effects to sensitive aquatic species. Three hormones, estrone, 17β-estradiol and 17α-ethinylestradiol, are of particular concern as they are bioactive at very low concentrations. Current analytical methods are not all sensitive enough for monitoring these substances in water and do not cover mixture effects. Bioassays could complement chemical analysis since they detect the overall effect of complex mixtures. Here, four chemical mixtures and two hormone mixtures were prepared and tested as reference materials together with two environmental water samples by eight laboratories employing nine in vitro and in vivo bioassays covering different steps involved in the estrogenic response. The reference materials included priority substances under the European Water Framework Directive, hormones and other emerging pollutants. Each substance in the mixture was present at its proposed safety limit concentration (EQS) in the European legislation. The in vitro bioassays detected the estrogenic effect of chemical mixtures even when 17β-estradiol was not present but differences in responsiveness were observed. LiBERA was the most responsive, followed by LYES. The additive effect of the hormones was captured by ERα-CALUX, MELN, LYES and LiBERA. Particularly, all in vitro bioassays detected the estrogenic effects in environmental water samples (EEQ values in the range of 0.75–304 × EQS), although the concentrations of hormones were below the limit of quantification in analytical measurements. The present study confirms the applicability of reference materials for estrogenic effects' detection through bioassays and indicates possible methodological drawbacks of some of them that may lead to false negative/positive outcomes. The observed difference in responsiveness among bioassays – based on mixture composition - is probably due to biological differences between them, suggesting that panels of bioassays with different characteristics should be applied according to specific environmental pollution conditions.

Analysis of (Anti-)Oestrogenic and (Anti-)Androgenic Activities in Wastewater from the Lodz Sewer System

“…It should be noted, however, that the data of methods depends mainly on the matrix; that effect is very important in the real samples. According to [73] and previous studies [74][75][76][77], bioassays are promising tools for environmental moni-toring and risk assessment of chemical substances, allowing the evaluation of biological responses to a given complex sample, including possible interactions of different pollutants. Nevertheless, for example, cytotoxicity and anti-oestrogenic activity found in the sample tested might mask the oestrogenic activity of dissolved and particulate fractions of samples, leading in this case to possibly underestimated results.…”

Beyond the Black Box of Life Cycle Assessment in the Wastewater Treatment Plants: Which Help from the Bioassays?

“…Rather than focusing on a subset of known contaminants, this final strategy promotes the biological response by including both known and unknown chemicals in the mixture. Several researchers have been applied this bioanalytical approach on the wastewater [30][31][32][33][34], drinking water [35][36][37] and surface water [38].…”

Estrogenic Potency of Endocrine Disrupting Chemicals and Their Mixtures Detected in Environmental Waters and Wastewaters

“…Most of the studies of steroid hormones present in aquatic environment focus on E1, E2, E3, synthetic hormone EE2, and a few others (e.g. testosterone and progesterone) (Gómez et al, 2021;González et al, 2020;Harraka et al, 2021;Praveena et al, 2016;Thorpe et al, 2006). However, many other steroid substances were detected in the environment (Grobin et al, 2022a;Ojoghoro et al, 2021;Pironti et al, 2021).…”