Biosciences, College of Life and Environmental Sciences, University of Exeter, Exeter, EX4 4QD, UK; College of Medicine and Health, St Luke's Campus, Heavitree Road, Exeter, EX1 2LU.
Institute of Environment, Health and Societies, Brunel University London, Uxbridge, Middlesex, UB8 3PH, UK.
Aquat Toxicol. 2022 Aug;249:106229. doi: 10.1016/j.aquatox.2022.106229. Epub 2022 Jun 17.
Experimental exposures aimed at assessing the risks posed by estrogens in waste-water treatment work (WwTW) effluents to fish populations have rarely considered whether populations differ in their sensitivity to estrogenic compounds. This is despite evidence that selection at genes involved in the estrogen response has occurred in wild populations, and evidence that genotype can influence estrogen-response. In this study we compare the effects of a two-year exposure to a low measured concentration (1.3 ng/L) of ethinylestradiol (EE2) on the sexual development of roach (Rutilus rutilus) whose parental generation was sampled from two river stretches heavily contaminated with WwTW effluent and from two without any known WwTW effluent contamination. Exposure to EE2 significantly reduced the proportion of genetic males and induced a range of feminized phenotypes in males. Significantly, exposure also increased the proportion of genetic females with vitellogenic oocytes from 51 to 96%, raising the possibility that estrogen pollution could impact populations of annually spawning fish species through advancing female reproduction by at least a year. However, there was no evidence that river origin affected sensitivity to estrogens in either sex. Thus, we conclude that chronic exposure to low level EE2 has reproductive health outcomes for both male and female roach, but we find no evidence that the nature or magnitude of the response is affected by the population origin.
实验性暴露旨在评估废水处理厂（WwTW）废水中雌激素对鱼类种群构成的风险，但很少考虑到不同种群对雌激素化合物的敏感性是否存在差异。尽管有证据表明，与雌激素反应相关的基因在野生种群中发生了选择，并且基因型可能会影响雌激素反应，但这一点仍未得到考虑。在这项研究中，我们比较了两年暴露于低测量浓度（1.3ng/L）的乙炔雌二醇（EE2）对来自两条受 WwTW 废水严重污染的河流和两条没有已知 WwTW 废水污染的河流的亲代罗非鱼（Rutilus rutilus）的性发育的影响。EE2 的暴露显著降低了遗传雄性的比例，并诱导了雄性的一系列雌性表型。值得注意的是，暴露还将具有卵黄生成卵母细胞的遗传雌性的比例从 51%增加到 96%，这增加了雌激素污染通过至少提前一年推进雌性生殖的可能性，可能会对每年产卵的鱼类种群产生影响。然而，没有证据表明河流起源会影响两性对雌激素的敏感性。因此，我们得出结论，慢性低水平 EE2 暴露对雄性和雌性罗非鱼的生殖健康都有影响，但我们没有发现任何证据表明反应的性质或程度受到种群起源的影响。
