Far-Less Studied Natural Estrogens as Ignored Emerging Contaminants in Surface Water: Insights from Their Occurrence in the Pearl River, South China

Abstract

Compared to the well-studied major natural estrogens [i.e., estrone (E1), 17β-estradiol (E2), and estriol (E3)], little information is currently available for far-less studied natural estrogens such as 2-hydroxyestrone (2OHE1), 4-hydroxyestrone (4OHE1), 16α-hydroxyestrone (16α-OHE1), 2-hydroxyestradiol (2OHE2), 4-hydroxyestradiol (4OHE2), 17-epiestriol (17epiE3), 16-epiestriol (16epiE3), and 16-ketoestradiol (16ketoE2) in surface water. In this study, seven natural estrogens (E1, 2OHE1, 16α-OHE1, E2, 4OHE1, 2OHE2, and 17epiE3) were found in the water of the Pearl River, with detection frequencies of 96%, 80%, 60%, 40%, 28%, 12%, and 12%, respectively. The mean concentrations of the detected natural estrogens decreased in the following order: 2OHE1 (12.0 ng/L) > 16α-OHE1 (8.3 ng/L) > E1 (5.2 ng/L) > 4OHE1 (2.6 ng/L) > E2 (2.3 ng/L) > 2OHE2 (1.1 ng/L) > 17epiE3 (0.5 ng/L). In addition, the estrogen equivalence (EEQ) contribution ratios of the far-less studied natural estrogens ranged from 0% to 94%, of which EEQ ratios of 37.5% of the sampling sites exceeded 50%. What’s more, if only the three major natural estrogens are considered, the number of sample sites at high risk will be reduced from 13 to 1. This work clearly shows that the current water safety assessments, which are only based on well-known major estrogens, need to be re-examined and updated with care.

Activity measurement of arylsulfatase and β‐glucuronidase in activated sludge: HPLC‐based versus classical spectrophotometric method

“…EDCs mainly include natural estrogens/androgens, phytoestrogens, mycoestrogens, synthetic estrogens/androgens, progestins, and industrial chemicals (Huang et al, 2018; Luo et al, 2020; Tang et al, 2020; Wang, Liu, Zhang, et al, 2020). Among these, natural estrogens (NEs) are one of the most important EDCs due to their high estrogenic potencies as well as their high occurrence (Liu et al, 2009a; Liu, Lu, Yin, & Dang, 2015; Tang, Liu, Wan, et al, 2021). Human and animal excretions via urine and feces are the main sources to their occurrence in the natural environment, thus improving removal performance of wastewater treatment plant (WWTP) on NEs are the most effective way to protect our natural environment (Ben et al, 2017; Liu et al, 2009b; Raman et al, 2004; Tang et al, 2022; Zhang et al, 2014).…”