摘要
随着塑料制品的广泛应用,塑料微粒污染问题日益加剧。纳米塑料(nanoplastics,NPs)因粒径较小(≤1000 nm)及独特的物理化学性质,对其生态环境和人类健康的潜在威胁已引发广泛关注。然而,当前针对NPs的毒性评估体系仍存在显著不足,其在生物体内的检测分析技术也具有一定局限性,这严重制约了对其毒性效应的深入解析。为此,本研究通过合成2种粒径(80 nm和200 nm)的钯掺杂纳米塑料(Pd-NPs),以大型溞(Daphnia magna)为模式生物,系统评估了纳米塑料对其生理学特征及运动行为的毒性效应。基于生物动力学数据与毒性测试结果,进一步构建毒代动力学-毒效动力学(toxicokinetic-toxicodynamic,TK-TD)模型,作为生物动力学框架,旨在为纳米塑料的毒性机制阐明、环境风险评估及安全阈值制定提供科学依据。急性毒性试验的结果表明,200 nm Pd-NPs的48 h半数致死浓度(LC_(50))为7 mg·L^(-1),而80 nm Pd-NPs在最高暴露浓度(100 mg·L^(-1))下存活率仍超过50%,表明其急性毒性显著弱于200 nm Pd-NPs。生理及运动行为指标显示,与空白对照组相比,暴露组大型溞的游泳距离、心率和附肢蜷曲率均有所降低,综合评估200 nm Pd-NPs的毒性显著高于80 nm Pd-NPs。引入的TK-TD模型侧重于大型溞对纳米塑料的摄取和净化,同时将NPs的积累与其诱导的生物毒性影响联系起来,排泄速率常数k_(e)(0.04~0.05 h^(-1))的变化较为稳定,而摄取速率常数k_(u)则因粒径的大小和浓度而异,模型计算出80 nm和200 nm Pd-NPs在大型溞中的无效应浓度(NEC)分别为8.64 mg·L^(-1)和2.82 mg·L^(-1),高于报告的环境相关浓度(0.01~1 mg·L^(-1)),预测这2种NPs在现有的环境水平下对大型溞的毒性风险较低。本研究不仅为完善纳米塑料毒性评估体系提供了科学依据,还为生物体内纳米塑料的精准检测提供了新的技术思路,增强了对尺寸依赖性摄取行为影响NPs毒性的理解,对深入理解其生态风险具有重要意义。
Plastic pollution is escalating due to the widespread use of plastics.Nanoplastics(NPs,≤1000 nm)have drawn significant attention due to their small size and unique physicochemical properties,which may threaten ecosystems and human health.However,current toxicological frameworks for assessing NPs remain incomplete,and in vivo detection methods are limited,hindering detailed analysis of their toxic effects.We synthesized palla-dium-doped NPs(Pd-NPs)with diameters of 80 nm and 200 nm and evaluated their toxic effects on physiological traits and swimming behavior in Daphnia magna.Based on biokinetic data and toxicity test results,we developed a toxicokinetic-toxicodynamic(TK-TD)model as a biokinetic framework to provide a scientific basis for elucidating NP toxicity mechanisms,assessing environmental risks,and establishing safety thresholds.In acute toxicity tests,200 nm Pd-NPs exhibited an LC_(50)(median lethal concentration)of 7 mg·L^(-1)after 48 hours,whereas 80 nm Pd-NPs maintained>50% survival at 100 mg·L^(-1),indicating significantly lower acute toxicity.Physiological and behavioral metrics showed that D.magna exposed to Pd-NPs exhibited reduced swimming distance,heart rate,and appendage curling rate compared to controls.Notably,200 nm Pd-NPs demonstrated greater overall toxicity than their 80 nm counterparts.The TK-TD model focused on NP uptake and depuration in Daphnia,linking NP accumulation to biological effects.The elimination rate constant(k_(e))remained stable(0.04-0.05 h^(-1)),while the uptake rate constant(k_(u))varied with particle size and concentration.Modeled no-effect concentrations(NECs)were 8.64 mg·L^(-1)(for 80 nm NPs)and 2.82 mg·L^(-1)(for 200 nm NPs).Both values exceed environmentally relevant concentrations(0.01-1 mg·L^(-1)),suggesting low toxicity risk to D.magna under current environmental conditions.This study advances toxicity assessment methodologies for NPs,introduces a precision in vivo detection approach,and deepens understanding of how size-dependent uptake influences NP toxicity.These insights enhance our ability to evaluate ecological risks posed by NPs.
作者
李成彬
霍思彤
颜能
史建波
LI Chengbin;HUO Sitong;YAN Neng;SHI Jianbo(School of Environmental Studies,China University of Geosciences,Wuhan 430074,China;State Key Laboratory of Environmental Chemistry and Toxicology,Research Center for Eco-Environmental Sciences,Chinese Academy of Sciences,Beijing 100085,China)
出处
《生态毒理学报》
北大核心
2026年第1期331-343,共13页
Asian Journal of Ecotoxicology
基金
国家自然科学基金资助项目(42207319)
国家重点研发计划(2024YFC3714600)。
