长江朱杨江段几种鱼类体内重金属铅、镉和铬含量的研究

摘要

2010年7-10月和2011年4月在长江干流朱杨江段采集8种鱼样本,其中瓦氏黄颡鱼(Peheobagrus vachelli)、鲤鱼(Cyprinus carpio)、鲇(Silus asotus)、圆筒吻(绚)(Rhinogobio cylindricus)、大眼鳜(Siniperca kneri)和鲫鱼(Cyprinus auratus)等6种鱼的3龄样本4～8尾,铜鱼1～4龄样本32尾,圆口铜鱼1～3龄样本38尾.对各样本体内铅(Pb)、镉(Cd)、铬(Cr)的含量进行了检测.结果显示,所有鱼体样本体内均检测到存在这3种重金属离子.其中3龄组鱼体内Pb的平均含量为(1.885 ～2.731) μg/g,Cd的平均含量为(0.107 ～0.236) μg/g,Cr的平均含量为(0.514 ～0.918)μg/g.8种鱼类体内所含Pb和Cd均超过我国食品安全标准,而Cr含量均未超标.对铜鱼和圆口铜鱼不同年龄组间的Pb、Cd和Cr含量进行了比较.Pb在铜鱼3龄组体内的含量与2龄组差异不显著(P＞0.05),但显著高于1龄组(P＜0.05)；2龄组和1龄组之间差异不显著(P＞0.05).Pb在圆口铜鱼3龄组的含量显著高于2龄和1龄组(P＜0.05),但2龄和1龄组之间差异不显著(P＞0.05).Cd和Cr在两种鱼各自不同年龄组间差异均不显著(P＞0.05).回归分析显示,Pb在铜鱼和圆口铜鱼体内的含量与体长或体重均存在着极显著正相关关系(P＜0.01),Cd的含量与体长或体重之间仅在圆口铜鱼中存在显著正相关关系(P＜0.05)；而在这两种鱼中Cr的含量与体长或体重之间的相关性均不显著(P＞0.05).结果显示,长江朱杨江段该8种鱼体均受到重金属Pb和Cd污染；Pb在铜鱼和圆口铜鱼体内的含量表现出了随年龄增长而增加的生物积累作用,Cd仅在圆口铜鱼中表现出了与年龄相关的生物累积作用.%During July to October in 2010 and April in 2011, eight fish species were collected from the Zhuyang section of the Yangtze River in Chongqing. The samples consisted of 4 ~ 8 specimens for the fish of 3 years old respectively in Siniper-ca kneri, Rhinogobio cylindricus, Cyprinus awatus, Cyprinus carpio, Pelteobagrus vachelli and Silurus asotus, and 32 specimens for the fish of 1 -4 years old in Coreius heterodon and 38 specimens for 1 ~3 years old in Coreius guichenoti. The concentrations of Pb, Cd, and Cr in each sample were measured and the three heavy metals were detected in every samples. The mean concentrations of Pb in 3 years old samples ranged from 1. 885 to 2. 731 μg/g, Cd ranged from 0. 107 to 0. 236μg/g and Cr from 0. 514 to 0. 918 μg/g. Either the concentrations of Pb or Cd in the eight species exceeded the national safety criteria for food in China, but Cr didnt. The concentrations of Pb, Cd, and Cr were compared among the different age groups in the same species respectively for C. heterodon and C. guichenoti. There was no significant difference for the concentrations of Pb in C. heterodon between 3 and 2 age groups, and also between 2 and 1 age groups. But the concentration of Pb in 3 age groups was significantly higher than that in the 1 age groups (P<0.05). The concentration of Pb in C. guickerwli for 3 age groups was significantly higher than that for the 1 or 2 age groups (P < 0. 05 ) , and the difference between 2 and 1 age groups was not statistically significant There was no significant difference for the concentrations of Cd and Cr in either C. heterodon or C. guichenoti among different age groups. Regression analysis showed that there was a significant positive correlation for Pb concentrations in either C. heterodon or C. guichenoti respectively with its body length or body weight (P < 0. 01). And such the relationship between the concentrations of Cd and body length or body weight only occured in the C. guichenoti (P<0. 05). However, the correlation for the concentrations of Cr with body length or body weight could be found in neither C. heterodon nor C. guichenoti. The results suggested that the fish from the Zhuyang section of the Yangtze River were polluted by Pb and Cd. It was suggested that bioaccumulation of Pb, increased with age in the C. heterodon and C. guichenoti, and that Cd was only found in the C. guichenoti.