Microplastics (MPs) and endocrine disrupting chemicals are ubiquitous pollutants in marine environments, but their combined ecological risk is unclear. This study exposed male marine medaka (Oryzias melastigma) to 10 ng/L 17α-ethynylestradiol (EE₂) alone or EE₂ plus 2, 20, and 200 μg/L polystyrene MPs for 28 days to investigate the impacts of MPs on the reproductive disruption of EE₂. The results showed that 10 ng/L EE₂ alone did not affect biometric parameters, while co-exposure to EE₂ and 20, 200 μg/L MPs suppressed the growth and decreased gonadosomatic and hepatosomatic indices. Compared to EE₂ alone, EE₂ plus MPs exposure significantly increased plasma 17β-estradiol (E₂) levels in a dose-dependent manner, and co-exposure to EE₂ and 20, 200 μg/L MPs significantly increased the ratios of E₂/testosterone (T). Moreover, EE₂ plus MPs exposure elevated the transcription levels of estrogen biomarker genes vitellogenin and choriogenin, and estrogen receptor (ERα and ERβ). Morphological analysis also showed that co-exposure to EE₂ and MPs induced more severe damage to the testes and livers, indicating that MPs increased the toxicity of EE₂. The actual EE₂ concentrations in the solution increased with the exposure concentrations of MPs, suggesting that MPs changed the fate and behavior of EE₂ in the seawater. These findings demonstrate that MPs could increase the estrogenic effects of EE₂ on marine fish, suggesting that the combined health risk of MPs and endocrine disrupting chemicals on marine organisms should be paid great attention.

微塑料 (MPs) 和内分泌干扰化学品是海洋环境中普遍存在的污染物，但它们的综合生态风险尚不清楚。本研究将雄性海洋青鳉 ( Oryzias melastigma )暴露于 10 ng/L 17α-乙炔雌二醇(EE ₂ ) 单独或 EE ₂加2、20和 200 μg/L 聚苯乙烯 MPs 28 天，以研究 MPs 对生殖的影响EE _{2 的}中断。结果表明，单独使用10 ng/L EE ₂不会影响生物特征参数，而同时暴露于 EE ₂和 20, 200 μg/L MPs 会抑制生长并降低性腺体和肝体指数。与单独的EE ₂相比，EE ₂加上 MPs 暴露以剂量依赖性方式显着增加血浆 17 β-雌二醇 (E ₂ ) 水平，并且共同暴露于 EE ₂和 20, 200 μg/L MPs 显着增加 E ₂ /睾酮 (T)的比率。此外，EE ₂加 MPs 暴露提高了雌激素生物标志物基因卵黄蛋白原和绒毛膜原蛋白以及雌激素受体（ERα和ERβ）的转录水平。形态学分析还表明，同时接触EE ₂和MPs 对睾丸和肝脏造成更严重的损伤，表明MPs 增加了EE ₂的毒性。实际的EE溶液中的₂浓度随着 MPs 的暴露浓度而增加，表明 MPs 改变了海水中 EE ₂的命运和行为。这些发现表明 MPs 可以增加 EE ₂对海洋鱼类的雌激素作用，表明 MPs 和内分泌干扰化学物质对海洋生物的综合健康风险应引起高度重视。