State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing, Jiangsu, 210023, China.
Nanjing Institute of Environmental Sciences, Ministry of Ecology and Environment, Nanjing, Jiangsu, 210042, China.
Chemosphere. 2019 Dec;236:124334. doi: 10.1016/j.chemosphere.2019.07.065. Epub 2019 Jul 10.
Different shapes of microplastics are widely detected in the environment and organisms and most of them remain in the gut. However, the influences of shapes on the bioaccumulation and toxicity of microplastics in the gut are largely unknown. Three shapes (bead, fragment, and fiber) of microplastics of comparable size in one dimension were prepared to exposure to zebrafish. The accumulation and toxicities of microplastics in the gut were detected. Shape-dependent accumulation in the gut was observed with the order of fibers (8.0 μg/mg) > fragments (1.7 μg/mg) > beads (0.5 μg/mg). The accumulation of microplastics caused multiple toxic effects in fish intestine, including mucosal damage, and increased permeability, inflammation and metabolism disruption. Based on these toxic effects, microplastic fibers resulted in more severe intestinal toxicity than microplastic fragments and beads did. Furthermore, microplastics also induced gut microbiota dysbiosis and specific bacteria alterations, which will provide novel insights into the potential mechanism of microplastics causing intestinal toxicities in fish. Our results also suggested that shape-depended effects should not be ignored in the health risk assessment of microplastics.
不同形状的微塑料在环境和生物体内广泛被检测到，其中大多数仍存在于肠道内。然而，微塑料形状对肠道内生物累积和毒性的影响在很大程度上尚未可知。本研究制备了三种尺寸相当的一维形状（珠状、碎片状和纤维状）的微塑料，用于暴露于斑马鱼体内。检测了微塑料在肠道内的累积和毒性。结果发现，肠道内的累积存在形状依赖性，纤维状微塑料（8.0μg/mg）的累积量>碎片状微塑料（1.7μg/mg）>珠状微塑料（0.5μg/mg）。微塑料的累积导致了鱼类肠道的多种毒性效应，包括黏膜损伤、通透性增加、炎症和代谢紊乱。基于这些毒性效应，纤维状微塑料引起的肠道毒性比碎片状和珠状微塑料更为严重。此外，微塑料还诱导了肠道微生物群落失调和特定细菌的改变，这将为微塑料引起鱼类肠道毒性的潜在机制提供新的见解。我们的研究结果还表明，在评估微塑料的健康风险时，不应忽视形状依赖性效应。
