Plastic pollution is one of the most serious environmental issues worldwide. The negative influence of plastics on aquatic organisms has increasingly concerned, especially the influence of microplastic (MPs). In the present study, the toxicology of nano-sized MPs (nMPs) and micron-sized MPs (mMPs) were comparatively studied. Goldfish larvae were exposed to 10, 100 and 1000 μg/L nMPs and mMPs for 1, 3 and 7 days. The enrichment of MPs, body length, heart rate, motor ability, microscopic and ultrastructure of intestine, liver, gill and muscle tissue, as well as the oxidative stress were analyzed. Results showed that both 70 nm and 50 μm MPs were accumulated in the digestive tract of larvae. MPs at high concentrations could induce oxidative stress, destroy intestine, liver and gill tissues, increase heart rate, and inhibit growth and swimming speed of the larvae. The most important finding was that nMPs could enter into the muscle tissue through the epidermis of the larvae. It could cause damage to muscle tissue, destroy nerve fibers, inhibit acetylcholinase (AchE) activity, and show great adverse effects on larval movement than mMPs. In conclusion, both nMPs and mMPs at higher concentrations can cause damage to fish larvae and nMPs are potentially more hazardous.

中文翻译：

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纳米和微米级微塑料对金鱼Car鱼幼虫的毒性比较。

塑料污染是全球最严重的环境问题之一。塑料对水生生物的负面影响日益引起人们的关注，尤其是微塑料（MPs）的影响。在本研究中，对纳米级MP（nMPs）和微米级MP（mMPs）的毒理学进行了比较研究。金鱼幼虫分别暴露于10、100和1000μg/ L nMP和mMP中，1、3和7天。分析了MP的富集，体长，心律，运动能力，肠，肝，腮和肌肉组织的显微和超微结构以及氧化应激。结果表明，在幼虫的消化道中同时积累了70 nm和50μm的MP。高浓度的MP会引起氧化应激，破坏肠，肝和g组织，增加心率，并抑制幼虫的生长和游泳速度。最重要的发现是nMP可以通过幼虫的表皮进入肌肉组织。与mMPs相比，它可能会损坏肌肉组织，破坏神经纤维，抑制乙酰胆碱酶（AchE）活性，并对幼虫的移动显示出极大的不利影响。总之，较高浓度的nMP和mMP都可能对鱼的幼虫造成损害，nMP的危害更大。