Abstract：
Growing focus has been drawn to the continuous detection of high estrogens levels in the soil environment. Additionally, microplastics (MPs) are also of growing concern worldwide, which may affect the environmental behavior of estrogens. However, little is known about effects of MPs occurrence on estrogens degradation in soil. In this study, polyethylene microplastics (PE-MPs) were chosen to examine the influence on six common estrogens (estrone (E1), 17α-estradiol (17α-E2), 17β-estradiol (17β-E2), estriol (E3), diethylstilbestrol (DES), and 17α-ethinylestradiol (17α-EE2)) degradation. The results indicated that PE-MPs had little effect on the degradation of E3 and DES, and slightly affected the degradation of 17α-E2, however, significantly inhibited the degradation of E1, 17α-EE2, and 17β-E2. It was explained that (i) obvious oxidation reaction occurred on the surface of PE-MPs, indicating that PE-MPs might compete with estrogens for oxidation sites, such as redox and biological oxidation; (ii) PE-MPs significantly changed the bacterial community in soil, resulting in a decline in the abundance of some bacterial communities that biodegraded estrogens. Moreover, the rough surface of PE-MPs facilitated the estrogen-degrading bacterial species (especially for E1, E2, and EE2) to adhere, which decreased their reaction to estrogens. These findings are expected to deepen the understanding of the environmental behavior of typical estrogens in the coexisting system of MPs.
摘要：
持续检测土壤环境中的高雌激素水平已引起越来越多的关注。此外,微塑料(MPs)在世界范围内也越来越受到关注，这可能会影响雌激素的环境行为。然而,关于MPs发生对土壤雌激素降解的影响知之甚少。在这项研究中,选择聚乙烯微塑料(PE-MPs)来检查对六种常见雌激素(雌酮(E1)，17α-雌二醇(17α-E2),17β-雌二醇(17β-E2),雌三醇(E3),己烯雌酚(DES),和17α-炔雌醇（17α-EE2））降解。结果表明,PE-MPs对E3和DES的降解影响不大,轻微影响17α-E2的降解，然而，显著抑制E1、17α-EE2和17β-E2的降解。解释了(i)PE-MPs表面发生明显的氧化反应,表明PE-MPs可能与雌激素竞争氧化位点，如氧化还原和生物氧化；（ii）PE-MPs显著改变了土壤中的细菌群落，导致一些生物降解雌激素的细菌群落的丰度下降。此外，PE-MPs的粗糙表面促进了雌激素降解细菌物种（尤其是E1，E2和EE2）的粘附，降低了他们对雌激素的反应。这些发现有望加深对MPs共存系统中典型雌激素的环境行为的理解。
