Jiangsu Key Laboratory of Chemical Pollution Control and Resources Reuse, School of Environmental and Biological Engineering, Nanjing University of Science and Technology, Nanjing 210094, Jiangsu Province, China.
Jiangsu Key Laboratory of Chemical Pollution Control and Resources Reuse, School of Environmental and Biological Engineering, Nanjing University of Science and Technology, Nanjing 210094, Jiangsu Province, China.
Sci Total Environ. 2021 Feb 20;756:143986. doi: 10.1016/j.scitotenv.2020.143986. Epub 2020 Dec 2.
Co-occurrence of microplastics and chemicals was a complex environmental issue, whereas little concerned on the effect of microplastics on the toxicity of chemicals. In this study, we studied the changes of toxicity of triphenyl phosphate (TPhP) to zebrafish, in the presence of micro-polystyrene (MPS, 5.8 μm) and nano-polystyrene (NPS, 46 nm). Results indicated that separate MPS and NPS had no acute toxicity and little reproductive toxicity on zebrafish. TPhP alone was a highly toxic substance with a median lethal concentration (LC) of 976 μg/L, the presence of MPS and NPS did not have significant effect on the acute toxicity of TPhP. TPhP alone stimulated the enlargement of liver and gonad of fish (except the testis) by 1.25-2.12 fold, and the presence of NPS further aggravated this stimulation by 1.23-2.84 fold, while MPS did not. The gonadal histology indicated that comparing with TPhP alone, the addition of MPS and NPS further inhibited the process of spermatogenesis and oogenesis, even causing obvious lacunas in testis and atretic follicles oocytes in ovary. Meanwhile, TPhP did not significantly disturb the hormone homeostasis (E/T) and vitellogenin (Vtg) content in fish, but the presence of NPS increased the E/T ratio and Vtg content in male fish, while slightly decreased those in female fish, which implying that effects of PS was sex-dependent. As a result, the egg production, the fertilization rate and hatchability of eggs significantly reduced after combined TPhP+PS exposure, demonstrating that co-occurrence of TPhP and PS, especially NPS, could greatly impaired the reproductive performance of zebrafish.
微塑料和化学物质的共存是一个复杂的环境问题，而人们对微塑料对化学物质毒性的影响关注甚少。在这项研究中，我们研究了微聚苯乙烯（MPS，5.8μm）和纳米聚苯乙烯（NPS，46nm）存在时，磷酸三苯酯（TPhP）对斑马鱼毒性的变化。结果表明，单独的 MPS 和 NPS 对斑马鱼没有急性毒性和生殖毒性。TPhP 本身是一种高毒性物质，半数致死浓度（LC）为 976μg/L，MPS 和 NPS 的存在对 TPhP 的急性毒性没有显著影响。TPhP 单独作用使鱼的肝脏和性腺（除精巢外）增大 1.25-2.12 倍，NPS 的存在进一步将这种刺激作用加重 1.23-2.84 倍，而 MPS 则没有。性腺组织学表明，与 TPhP 单独作用相比，添加 MPS 和 NPS 进一步抑制了精子发生和卵子发生过程，甚至导致精巢明显出现空洞和卵巢中闭锁卵泡卵子。同时，TPhP 没有显著扰乱鱼类的激素平衡（E/T）和卵黄蛋白原（Vtg）含量，但 NPS 的存在增加了雄性鱼类的 E/T 比值和 Vtg 含量，而略微降低了雌性鱼类的 E/T 比值和 Vtg 含量，这表明 PS 的影响具有性别依赖性。因此，在联合 TPhP+PS 暴露后，鱼的产卵量、受精率和孵化率显著降低，表明 TPhP 和 PS 的共存，特别是 NPS 的存在，会极大地损害斑马鱼的生殖性能。
