Zhang Yu-Hang, Gao Rong-Yao, Zhu Few, Fu Li-Min, Zhang Jian-Ping
Key Laboratory of Advanced Light Conversion Materials and Biophotonics, School of Chemistry and Life Resources, Renmin University of China, Beijing, 100872, China.
Intelligent Scientific Systems Co., Beijing, 100085, China.
Chemosphere. 2024 Dec;369:143765. doi: 10.1016/j.chemosphere.2024.143765. Epub 2024 Dec 4.
Microplastics and nanoplastics (MPs/NPs) are emerging contaminants ubiquitous in the environment. These particles can act as carriers of hydrophobic organic compounds (HOCs), such as chlorpyrifos (CPF), an organophosphorus insecticide. This study investigates the acute toxicity of CPF combined with model polystyrene nanoplastics (PS-NPs) using Daphnia magna as a model organism. The uptake and accumulation of luminescence-labelled 240 nm PS-NPs were visualized and quantified during co-exposure tests. Heart rates were measured using a video-based method, and IC values for heart rate were calculated to assess the acute toxicity of CPF. The results demonstrate that PS-NPs alone have no acute toxicity, while CPF exhibits high toxicity, with an IC of 50.8 μg/L. However, in the presence of 50 μg/L PS-NPs, the IC increased to approximately 400 μg/L, indicating an antagonistic effect of PS-NPs on CPF toxicity. The adsorption of CPF onto PS-NPs can reduce the concentration of free CPF, leading to aggregation and sedimentation of CPF-PS-NP clusters, thereby decreasing the uptake of CPF by D. magna. This interaction between CPF and PS-NPs in D. magna exemplifies the toxicity-attenuating effects and potential load capacity of nanoplastics for HOCs.
微塑料和纳米塑料（MPs/NPs）是环境中普遍存在的新兴污染物。这些颗粒可以作为疏水性有机化合物（HOCs）的载体，如毒死蜱（CPF），一种有机磷杀虫剂。本研究以大型溞为模式生物，研究了CPF与模型聚苯乙烯纳米塑料（PS-NPs）联合作用的急性毒性。在共暴露试验中，对发光标记的240 nm PS-NPs的摄取和积累进行了可视化和定量分析。采用基于视频的方法测量心率，并计算心率的半数抑制浓度（IC）值，以评估CPF的急性毒性。结果表明，单独的PS-NPs没有急性毒性，而CPF表现出高毒性，IC为50.8 μg/L。然而，在存在50 μg/L PS-NPs的情况下，IC增加到约400 μg/L，表明PS-NPs对CPF毒性具有拮抗作用。CPF在PS-NPs上的吸附可以降低游离CPF的浓度，导致CPF-PS-NP聚集体的聚集和沉淀，从而减少大型溞对CPF的摄取。大型溞中CPF与PS-NPs之间的这种相互作用体现了纳米塑料对HOCs的毒性减弱效应和潜在负载能力。
