Occurrence, spatial distribution, risk assessment, and management of environmental estrogens in surface waters of the Taihu basin

Rationale. The Taihu Basin is a critical freshwater ecosystem susceptible to contamination from various anthropogenic activities. Environmental estrogens (also known as endocrine disrupting chemicals, EDCs) are exogenous substances that can disrupt the normal functioning of endocrine systems. The contamination of water by EDCs is primarily caused by effluents from sewage treatment plants and livestock poultry farms. In this study, we assessed the spatial distribution and potential risks of environmental estrogens in surface water in the Taihu basin. Various statistical evaluations were employed to establish connections between measured concentration of heavy elements, estrogens and physicochemical parameters, to identify potential sources of these contaminants. Methodology. Water samples from 44 sampling points in five lakes in Suzhou were taken for evaluation of environmental estrogens. Gas chromatography-mass spectrometry was used for identification of concentrations of estrone (E1), estradiol (E2), ethinyl estradiol (EE2) and bisphenol A (BPA). Inductively coupled plasma-mass spectrometry was employed to identify heavy element concentrations in water samples. Results. Environmental estrogen concentrations were detected ranging from 0.001 to 209 ng L-1, with the highest attributed to BPA, whereas E1, E2 and EE2 were comparatively lower. Correlation evaluation between environmental estrogens, physicochemical parameters and heavy element contents revealed a positive correlation (P < 0.05) between the total chromium and environmental estrogen contents. Consequently, the risk entropy value of Shanghu Lake exceeded 0.5, indicating a potentially high risk of estrogenic activity. Discussion. The widespread distribution and high concentrations of BPA in freshwater raise urgent concerns, highlighting the need for frequent monitoring of environmental estrogens in surface waters throughout the year to mitigate potential risks in the future. Our results suggest that a potential estrogen risk exists in the Shanghu Lake in the Taihu basin. Potential treatment methods for endocrine disruptors have been proposed, which could provide actionable plans for stakeholders.