Translocation of 14C-polystyrene nanoplastics into fish during a very-low concentration dietary exposure.
Translocation of 14C-polystyrene nanoplastics into fish during a very-low concentration dietary exposure.
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DOI：
10.1016/j.chemosphere.2023.140058
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发表时间：
2023-09
期刊：
影响因子：
8.8
通讯作者：
N. Clark;Astrid C. Fischer;Lee Durndell;Tamara S. Galloway;Richard C. Thompson
中科院分区：
文献类型：
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作者：
N. Clark;Astrid C. Fischer;Lee Durndell;Tamara S. Galloway;Richard C. Thompson
由于分析方面的限制，对极低暴露浓度下动物饮食中纳米塑料积累的评估受到限制。本研究采用了一种小体积合成半稳定的14c - ps NPs（通过苯乙烯聚合）的方法，用于环境研究。该方法是用未标记的材料开发的，最终聚苯乙烯产品的主要粒径为35±8 nm（通过透射电子显微镜测量）。然后将该方法应用于14c标记的苯乙烯，以生产放射性标记的聚苯乙烯纳米塑料（14C-PS NPs）。将14c - ps NPs （top-dress）添加到市售鱼饲料中，测量浓度为27.9±2.1 kBq kg - 1(n= 5)，相当于5.9 μg聚苯乙烯kg - 1饲料。鱼（虹鳟鱼；Oncorhynchus mykiss）以每日体重2%的比例饲喂该饲料，为期两周。在第3、7和14天分别取鱼的中肠、后肠、肾和肝，并测量组织放射性（通过液体闪烁计数测定）。在对照样品中检测到一些背景活性（例如，在后肠和肝脏中分别检测到1-16和4-11 Bq g−1），这是由于自然背景荧光。实验结束时，与对照组相比，后肠和肝脏的放射性显著升高（分别为25.3和15.0 Bq g−1），表明纳米聚苯乙烯的积累。在肝脏中，这相当于1.8 μg聚苯乙烯g−1干重。本研究证实了纳米颗粒在脊椎动物体内的低环境相关浓度积累，并强调了放射性标记是一种适合探索纳米塑料生物积累及其潜在影响的方法学方法。
Assessing the dietary accumulation of nanoplastics in animals following very-low exposure concentrations is restricted due to analytical limitations. This study adapted a method for synthesising semi-stable14C-PS NPs (through styrene polymerisation) in small volumes for deployment in environmental studies. The method was developed with non-labelled material where the final polystyrene product had a primary particle size of 35 ± 8 nm (as measured by transmission electron microscopy). This method was then applied to14C-labelled styrene to produce radiolabelled polystyrene nanoplastics (14C-PS NPs). The14C-PS NPs were added (top-dressed) to a commercially available fish feed, with a measured concentration of 27.9 ± 2.1 kBq kg−1(n= 5), equating to 5.9 μg polystyrene kg−1feed. Fish (rainbow trout;Oncorhynchus mykiss) were fed this diet at a ration of 2% body weight per day for a period of two weeks. On day 3, 7 and 14, the fish were sampled for the mid intestine, hind intestine, kidney and liver, and measured for tissue radioactivity (determined by liquid scintillation counting). Some background activity was detected in the control samples (e.g., 1–16 and 4–11 Bq g−1in the hind intestine and liver, respectively) which is due to natural background fluorescence. By the end of the experiment, the hind intestine and liver had significantly elevated radioactivity (25.3 and 15.0 Bq g−1, respectively) compared to the control, indicating the accumulation of nano polystyrene. In the liver, this equated to 1.8 μg polystyrene g−1dry weight. This study confirms the accumulation of nano particles in vertebrates at low, environmentally relevant concentration, and highlights radiolabelling as a methodological approach suitable for exploring the bioaccumulation of nanoplastics and potential impacts.