珠江三角洲4种淡水养殖鱼类重金属的残留及食用风险评价

摘要

为全面了解珠江三角洲淡水水产品中重金属污染现状,评估其生态风险与食用安全,于2014年8月至2015年8月采集罗非鱼、草鱼、乌鳢及鳜鱼主要养殖鱼类样品共计57份,采用原子荧光光谱仪(AFS),电感耦合等离子体质谱(ICP-MS)仪进行分析测定,并采用单因子污染指数(Pi)、重金属污染指数(MPI)、每周可耐受摄入量(PTWI)以及食入健康风险指标(Ri总)分别评估其污染程度、食用安全性与健康风险.结果表明,样品中Cr、Ni、Cu、Zn、As、Cd、Hg、Pb的含量范围分别为0.020~3.240, 0.020~0.800,0.110~1.100,0.190~19.970,0.030~1.480,nd~0.606,0.003~0.118,0.040~0.803 mg·kg-1(湿重), Cr、As、Cd、Pb在水产品中超标率大小依次为As(7.0%),Pb(7.0%),Cd(5.3%),Cr(1.8%).Pi结果表明,目前珠江三角洲养殖水域水产品中Cu与Zn残留处于正常范围内,Cr和Hg有少量样品为轻度污染,Pb、Cd与As存在重度污染样品,所占比例为2.86%、6.02%和5.74%.MPI结果显示不同水产品污染程度为乌鳢鳜鱼罗非鱼草鱼,总体上各种水产品MPI依然处于较低的水平;食用安全性结果显示,目前成人每周摄入水产品是安全的,但乌鳢Cr,罗非鱼As含量较高分别达到PTWI的37.76 %和19.51%,表明水产品中Cr、As残留可能存在一定的食用安全隐患.健康风险模型结果显示,所有样品均未超过国际辐射防护委员会(ICRP)的推荐的最大可接受水平(5×10-6a-1).综合分析珠江三角洲淡水养殖主要水产品可知,其尚未出现明显的污染安全问题,但As与Cr等元素的潜在风险值得进一步关注.%In order to investigate the heavy metal pollution of the cultured freshwater fish and its ecological risk,as well as the human health risk,the total 57 fish samples were collected from fish pond of Pearl River Delta.Heavy metals were determined by AFS and ICP-MS.The results showed that the concentration range such as Cr,Ni,Cu, Zn,As,Cd,Hg and Pb in aquatic products, were 0.020-3.240, 0.020-0.800, 0.110-1.100, 0.190-19.970, 0.030-1.480,nd-0.606,0.003-0.118 and 0.040-0.803 mg·kg-1(wet weight), respectively.The freshwater fish was subject to certain degree pollution by Cr,As,Cd,Pb with exceeding rates of As (7.0%),Pb (7.0%),Cd (5.3%),Cr (1.8%).The assessment adopted single factor pollution index(Pi),and the results indicated that for Cu and Zn,all fish samples did not exceed the allowable criteria,and for Cr and Hg,1%-5% of samples exceeded the allowable criteria of"Light Pollution",while for Pb,Cd and As,2.86%,6.02% and 5.74% of the samples reached the crite-ria of"Heavy Pollution". The MPI results showed heavy metal pollution in Ophicephalus argus was the most severe,followed by Siniperca chuatsi and Oreochromis spp, while it was slight in Ctenopharyngodon idellus. The evaluation of edible safety of heavy metals in aquatic products was acceptable, based on the model of health risk assessment recommended by US EPA.The health risk assessment indicated that the carcinogenic and non-carcino-genic risks value of heavy metal ingestion were below the maximal acceptable level(5×10-6a-1),recommended by International Commission on Radiation(ICRP).In summary,there is a certain degree of pollution in the freshwater fish in Pearl River Delta region,especially for As and Cr pollution.More attention should be paid to the pollution status,edible safety and health risk.