聚乙烯微塑料与镉联合暴露对赤子爱胜蚓的毒性效应及交互作用评估  

Toxic effects and interaction evaluation of polyethylene microplastics and cadmium combined exposure on earthworm Eisenia fetida

作　　者：杨晓霞[1] 张雪梅[1] 舒晓 谢蔓莉 龚久平[1] 杨俊英[1] 李必全[1] 柴勇[1] 刘剑飞[1] YANG Xiaoxia;ZHANG Xuemei;SHU Xiao;XIE Manli;GONG Jiuping;YANG Junying;LI Biquan;CHAI Yong;LIU Jianfei(Institute of Agricultural Quality Standard and Testing Technology,Chongqing Academy of Agricultural Sciences,Chongqing 401329)

机构地区：[1]重庆市农业科学院农业质量标准与检测技术研究所,重庆401329

出　　处：《环境科学学报》2024年第7期482-496,共15页Acta Scientiae Circumstantiae

基　　金：重庆市农业科学院市级财政项目(No.cqaas2023sjczqn009);重庆市自然基金面上项目(No.CSTB2022NSCQ-MSX0303)。

摘　　要：将蚯蚓(赤子爱胜)分别暴露于不同浓度(0.5、2.5、10、20 g·kg^(-1))的聚乙烯(PE)微塑料(30~50μm)与镉(Cd,1、10 mg·kg^(-1))单独或复合污染土壤中28 d.以个体生长及繁殖、细胞色素P450亚酶(CYP1A2、CYP2B6、CYP2C9与CYP3A4)和小分子代谢标记物(代谢组学)多指标为受试终点,并采用生物标记物响应指数法(Biomarker response index,BRI)和联合效应加成指数法(Effect addition index,EAI),评估PE微塑料与Cd复合污染毒性效应及交互作用.暴露试验结果显示,联合胁迫能显著影响Cd的生物累积.联合暴露下,蚯蚓体内Cd的积累受微塑料浓度的影响显著.PE与Cd的交互作用随效应水平的增加由拮抗作用转变为协同作用.20 g·kg^(-1) PE与1 mg·kg(-1) Cd联合暴露,以及10~20 g·kg(-1) PE与10mg·kg^(-1) Cd联合暴露下,CYP2B6及CYP3A4活力显著低于对照水平,提示蚯蚓氧化损伤的产生.基于代谢组识别出的前10位重要的小分子代谢物分别为:十二羟基十二烷酸、3'-磷酸腺苷、肌苷、喹啉酸、亚麻酸衍生物(9Z,11E,13S,15Z)-13-羟基十八碳-9,11,15-三烯酸(13(S)-HOT)、硬脂酸、尿苷、L-胱硫醚、胸苷酸与亮氨酸.PE与Cd联合暴露下,上述小分子代谢物水平均发生显著平变化.PE与Cd联合暴露的毒性作用模式与蚯蚓自身解毒能力受损、脂质代谢、嘌呤、嘧啶代谢及氨基酸代谢紊乱有关.本研究结果有助于精准评估土壤PE微塑料与Cd的复合生态风险,为提升PE微塑料与Cd复合污染生态风险的认知提供科学依据.Earthworms Eisenia fetida were exposed to polyethylene(PE) microplastics(30~50 μm) at different concentrations(0.5,2.5,10,20 g·kg^(-1)) and cadmium(Cd,1,10 g·kg^(-1)) alone or in combination in soils for 28 d.Individual growth and reproduction,cytochrome P450 sub-enzymes(CYP1A2,CYP2B6,CYP2C9,and CYP3A4),and small molecule metabolic markers(metabolomics) were used as the test endpoints in this study.The biomarker response index(BRI) and combined effect addition index(EAI) were applied to evaluate the toxic effects and interactions of PE and Cd combined pollution.The results showed that the combined stress can significantly affect the bioaccumulation of Cd.Under the combined exposure,the accumulation of Cd in earthworms is significantly influenced by microplastics' concentration.The interaction between PE and Cd transferred from the antagonism to the synergism with the increase of effect level.Under the combined exposure of 20 g·kg^(-1) PE and 1 mg·kg^(-1) Cd,as well as the combined exposure of 10~20 g·kg^(-1) PE and 10 mg·kg^(-1) Cd,the activities of CYP2B6 and CYP3A4 were both significantly lower than the control level,indicating the occurrence of oxidative damage in earthworms.The top 10 important small molecule metabolites identified through metabolomics are 12-hydroxydodecanoic acid,3'-AMP,inosine,quinolinic acid,13(S)-HOT,stearidonic acid,uridine,L-cystathionine,and dTMP.Under the combined exposure of PE and Cd,significant changes were observed in all levels of the ten important metabolites.The toxic mode of combined exposure of PE and Cd is related to the impaired detoxification ability of earthworms,and the disorder of the lipid metabolism,purine and pyrimidine metabolism,and amino acid metabolism.The current results contribute to the precise assessment of the combined ecological risk of soil PE and Cd,and provide a scientific basis for enhancing the understanding of the combined pollution ecological risk of PE and Cd.

关 键 词：赤子爱胜蚓 聚乙烯(PE)微塑料 镉 细胞色素P450亚酶 代谢组学 变化水平 生物标记物响应指数法 效应加成指数法 

分 类 号：X171.5[环境科学与工程—环境科学]