鄱阳湖河湖交错区软体动物重金属富集与迁移特征分析  

Heavy metal enrichment and migration characteristics in the mollusks from the river-lake ecosystems of the Poyang Lake

作　　者：张学儒 曾欢 张华[2] 黄琪[2] 张乐瑶 ZHANG Xueru;ZENG Huan;ZHANG Hua;HUANG Qi;ZHANG Leyao(School of Public Management,Hebei University of Economics and Business,Shijiazhuang 050061;Key Laboratory of Poyang Lake Wetland and Watershed Research Ministry of Education/School of Geography and Environment,Jiangxi Normal University,Nanchang 330022)

机构地区：[1]河北经贸大学公共管理学院,石家庄050061 [2]江西师范大学地理与环境学院/鄱阳湖流域湿地与流域研究教育部重点实验室,南昌330022

出　　处：《环境科学学报》2022年第9期452-463,共12页Acta Scientiae Circumstantiae

基　　金：国家自然科学基金项目(No.42061018);鄱阳湖湿地与流域研究教育部重点实验室开放基金(No.PK2019003)。

摘　　要：河湖交错区是鄱阳湖流域重金属污染物进入湖泊的主要通道,也是重金属富集的场所.本文通过在鄱阳湖河湖交错区采集软体动物样品,分析样品的肌肉和内脏中铁(Fe)、锰(Mn)、铜(Cu)、锌(Zn)、铬(Cr)、镍(Ni)、砷(As)、镉(Cd)、铅(Pb)和锑(Sb)的含量,利用生物-沉积物累积因子和碳氮稳定同位素对鄱阳湖软体动物重金属的富集特征及营养结构和食源关系进行研究,并利用综合目标危险系数进行健康风险评估.结果表明:①鄱阳湖软体动物重金属含量存在显著的种间和组织间的差异,且受体长体重的稀释作用,与所在栖息地的关系不大,但与区域背景环境存在明显的对应关系,均低于水产限量标准值.软体动物对重金属Cu、Zn和Cd具有明显的富集能力,蚌(圆顶珠蚌、三角帆蚌、背瘤丽蚌和褶纹冠蚌)易从环境中富集更多的Mn和Cd,而螺(铜锈环棱螺和大沼螺)则易富集Cu和Zn;②软体动物δ^(13)C值为-29.84‰~-21.13‰,δ^(15)N值为4.09‰~11.51‰,螺和蚌存在明显不同的食物来源.软体动物中的重金属并不随δ^(15)N值的变化表现出显著的改变,但与δ^(13)C值存在显著的线性关系;其中Cu和Zn与δ^(13)C值表现为显著的正相关关系,而Mn、Cr、As、Cd、Pb和Sb表现为显著的负相关关系;③健康风险评估结果表明,不论是成人还是儿童,综合目标危险系数(TTHQ)均大于1,表明鄱阳湖河湖交错区软体动物重金属的富集会对人群食用产生较为显著的健康风险,其中Mn和As是主要的贡献者,且食用蚌的风险略高于螺.研究结果可为鄱阳湖水生态安全、水生生物多样性保护及食品安全评估提供科学依据和理论支撑.The river-lake ecosystems are the main channel for heavy metal pollutants to enter the lake and being enriched with high levels of heavy metals.In this study,the mollusks were collected in the sediment from the river-lake ecosystems and the levels of heavy metals(Fe,Mn,Cu,Zn,Cr,Ni,As,Cd,Pb,and Sb)in their muscles and viscera were determined.The relationships between the levels of heavy metals and nutrient structure,food sources of mollusks were explored with biota-sediment accumulation factor and carbon and nitrogen stable isotope rations,and the potential health risk were evaluated with Target Hazard Quotients(THQ).The results indicated that:①the levels of heavy metals in the mollusks were significantly affected by species,organs,and body length and weight significantly.And the levels of heavy metals in the mollusks,lower than their aquatic limit values,obviously matched those in regional background environment,but not habitat.Mollusks have significant enrichment capacity for heavy metals Cu,Zn and Cd.with clams being more prone to enrichment of Mn and Cd from the environment,while snails are prone to enrichment of Cu and Zn.②δ^(13)C ratios of the mollusks ranged from-29.84‰to-21.13‰,andδ^(15)N ratios ranged from 4.09‰to 11.51‰.There were distinctly different food sources for snails and mussels.The levels of heavy metals in the mollusks did not change accompanying withδ^(15)N ratios variation,but had a significant linear relationship withδ^(13)C ratios.The levels of Cu and Zn presented significant positive correlations withδ^(13)C ratios,while Mn,Cr,As,Cd,Pb and Sb showed significant negative correlations withδ^(13)C ratios;③all TTHQs of heavy metals in mollusks for the adult and the child,were greater than 1,indicating the consumption of the benthonic fauna could cause significant health risk due to heavy metals exposure.The THQ for Mn and As in the mollusks were main contributors for TTHQ,and the risk of clams consumption was slightly higher than that of snails.The results of this study pro

关 键 词：鄱阳湖 河湖交错区 软体动物 重金属 碳氮稳定同位素 

分 类 号：X523[环境科学与工程—环境工程] X171.5