【摘要】 突发镉污染事件能引起江河水体恶化,破坏水生态环境和威胁人类健康.本研究为证实突发镉污染事件引起生态环境风险,以不同类型鱼类以及鱼类不同组织器官为研究对象,分别前后6次对龙江进行采样调查,并对各鱼类根据水层和食性进行分类及分析.调查结果表明,前3次调查鱼类肌肉镉含量显著高于后3次调查鱼类肌肉镉含量;草食性,肉食性和杂食性鱼类不同组织器官镉的含量大小均可排序为:肾>肝>肠>鳃>卵>鳞≈肌肉,且3种类型肾的镉含量均显著高于其他任何组织器官(P<0.05);鱼类同一组织器官镉的含量根据不同水层鱼类依次为:底层鱼类>中下层鱼类>中上层鱼类.不同食性鱼类肌肉中镉平均富集系数BAF从大到小依次为杂食性,肉食性和草食性,分别为8.32、6.33和5.15;不同生活水层鱼类肌肉中镉平均富集系数大小排序为:底层鱼类(8.18)>中下层鱼类(7.70)>中上层鱼类(4.99).更多还原

【Abstract】 Emergent cadmium pollution can cause water quality deterioration in rivers,which destroys the aquatic eco-environment and poses threats to human health.Fish species in these aquatic systems are prone to such pollution incidents and act as important indicators of the pollution level.Because cadmium enters the systematic circulation of fish and is non-biodegradable,the investigation of cadmium accumulation in fish bodies provides insights into the detrimental effects of cadmium pollution on the aquatic biological system.This research aims to validate the eco-environmental risks associated with emergent cadmium pollution incidents based on the investigation of the different tissues and organs of diverse fish species.The investigation was conducted six times along the Longjiang River using sampling methods during which all fish species were also classified and analyzed based on the water layer they reside in and their feeding habits.The results show that the cadmium concentration in the fish tissues is significantly higher in the former three investigations compared with that of the latter three analyses.For herbivorous,carnivorous,and omnivorous fish species,the cadmium concentration of their different tissues and organs follows the order:kidney > liver > gut > gill > egg > scale≈ muscle.The cadmium concentration in the kidney is significantly higher(P<0.05) than that in any other organs of the fish species.This agrees with the fact that the kidney intensively metabolizes and accumulates heavy metals.The cadmium concentration in the same tissues or organs of the fish species living in different water layers follows the trend:demersal fish species > middle lower-layer species > middle upper-layer species.The sequence of the cadmium bioaccumulation factors in the muscles of different fish species is omnivore > carnivorous >herbivorous,that is,8.32,6.33,and 5.15,respectively,while the bioaccumulation factors in the muscles of the fish species in different water layers decrease in the following sequence:demersal fish species(8.18) > middle bottom-layer fish species(7.70) >middle upper-layer fish species(4.99).These experimental results indicate the biomagnification effects in heavy metal-polluted aquatic environments,where the bioaccumulation of heavy metals by fish is related to both the overall pollution level and local residential environment.更多还原