Assessing the endocrine disrupting potentials and genotoxicity in environmental samples from Taiwanese rivers

Pei-Hsin Chou,Tsung-Ya Tsai,Kuang-Yu Chen,Yi-Po Yeh,Fung-Chi Ko,Chien-Hsun Chen

doi:10.1186/s41021-019-0140-9

Abstract

BackgroundSurface waters receive a variety of organic pollutants via wastewater discharge, and sediment represents a sink for hydrophobic contaminants. In this study, we used in vitro yeast-based reporter gene assays and a Bacillus subtilis Rec-assay to examine the occurrence of endocrine disrupting activities and genotoxic potentials in samples collected from three Taiwanese rivers. Levels of 51 polycyclic aromatic hydrocarbons (PAHs) in muscles of fish captured from same rivers were also analyzed to assess in vivo pollution of PAHs.ResultsAntagonist activities for androgen receptor and retinoid X receptor (RXR) were detected in river water extracts at environmentally relevant concentrations., and sediment extracts exhibited RXR agonist, RXR antagonist, and genotoxic potentials concurrently. Σ16 PAHs in fish muscles ranged from 44.9–242.4 ng g− 1 dry weight, representing 38 to 59% of the total 51 PAHs concentrations, and methylated PAHs of low molecular weight PAHs were often detected as well.ConclusionTaiwanese river sediment samples concomitantly exhibited RXR disrupting potentials and genotoxic activities, whereas RXR agonist and antagonist activities were simultaneously detected in several dry-season sediment extracts. PAH levels in fish muscles were categorized as minimally polluted by aromatic compounds, nonetheless, the presence of methylated PAHs in muscles samples may be of concern owing to the higher toxic potentials than their parent compounds.

Highlights

Surface waters receive a variety of organic pollutants via wastewater discharge, and sediment represents a sink for hydrophobic contaminants
The values of 17β-E2-EQ, OHT-EQ, and FLU-EQ were lower than what have been detected in other sites of Taiwanese rivers [27, 28], our results suggested the pseudopersistence of endocrine disrupting compounds (EDCs) interfering with androgen receptor (AR)/estrogen receptor (ER) signaling in river waters of Taiwan
retinoid X receptor (RXR) agonist and antagonist activities were found in dry- and wet-season sediment extracts with the detection frequencies of 32 and 36%, respectively (Fig. 3a), whereas thyroid hormone receptor (TR) disrupting activities were rarely detected in sediment extracts (Fig. 3b)

Summary

Introduction

Surface waters receive a variety of organic pollutants via wastewater discharge, and sediment represents a sink for hydrophobic contaminants. In addition to persistent organic pollutants, emerging contaminants such as endocrine disrupting compounds (EDCs) are of environmental concern. Contaminants that interact with androgen receptor (AR) and estrogen receptor (ER) represent an important category of EDCs owing to their possible interference with reproductive function. Bioanalytical tools such as the yeast estrogen/androgen screen assays, the MCF-7 cell proliferation assay, and the chemically activated luciferase expression assays using rat/ mouse cells transfected with AR/ER-regulated luciferase reporter genes have been broadly used to examine estrogenic/androgenic activities in surface water and wastewater effluents [16,17,18,19]. A battery of in vitro bioassays have been developed and used for detecting contaminants capable of binding to different receptors, such as thyroid hormone receptor (TR), glucocorticoid receptor (GR), mineralocorticoid receptor (MR), progesterone receptor (PR), retinoid X receptors (RXRs), etc. [20,21,22,23,24]

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