【摘要】 突发性镉污染事件能造成水体剧烈"瞬态污染"。鱼类对水体和底泥中镉的摄入吸收导致镉在鱼类组织器官中富集,周边当地居民食用受镉污染的鱼类可能存在人体健康风险。以龙江突发性镉污染事件为例,以不同类型鱼类为研究对象,于2012年2月-2013年12月期间对广西龙江进行6次采样调查,分析了不同食性和生活水层鱼类肌肉的镉含量以及基于污染指数法和健康风险评价模型研究其污染水平和健康风险。调查结果表明,从不同时段看,突发事件初期鱼类肌肉中镉含量均较高,污染较严重,其中杂食性鱼类污染指数在4.73-5.65之间,底层鱼类污染指数在5.13-6.75之间,在采取应急处置措施后以及流水冲刷稀释下鱼类肌肉对镉的累积量逐步降低;根据食性排序,不同食性鱼类肌肉的污染水平为:杂食性>肉食性>草食性;不同生活水层鱼类肌肉其排序为:底层>中下层>中上层;在健康风险方面,受镉污染的杂食性鱼类和底层鱼类均分别相比于其他食性和水层的鱼类呈现出更大的健康风险值,但除突发事件初期事件发生点附近的S5(风险值为9.03×10^-5?a^-1)外,其他各监测断面鱼类肌肉中镉的平均健康风险均未超过国际防辐射委员会（ICRP）推荐的污染物所致健康危害的个人年风险最大可接受值(5.0×10^-5?a^-1),因而当地居民摄食本次镉污染事件的鱼类的潜在健康风险很小,但在突发事件初期应重视人们食用含镉杂食性鱼类和底层鱼类的健康风险。更多还原

【Abstract】 The transient water pollution as a result of emergent cadmium contamination leads to cadmium accumulation in the tissues and organs of fish species through intake of cadmium from the aqueous and sedimental environment. Dietary intake of these fish species, an essential part of a balanced diet, threaten the health of local residents. To examine the pollution levels and the health risks caused by emergent cadmium contamination, this study focused on the emergent cadmium contamination event in Longjiang River. Fish species residing in different water layers of Longjiang River with different feeding habits were sampled from February,2012 to December, 2013 for six times in total, and cadmium concentrations in fish muscle were analyzed based on the pollution indexes and the health risk modelling method. Results showed that the cadmium concentrations in fish muscle at the early stage of this event were higher than those at other stages, indicating heavier pollution. At this stage, the pollution indexes of omnivorous and demersal fish species ranged from 4.73 to 5.65 and from 5.13 to 6.75 respectively. Cadmium concentrations gradually declined because of the implementation of urgent corrective actions and the flushing and dilution method. From the perspective of feeding habits, pollution levels of fish muscle followed the descending order of omnivorous>carnivorous>herbivorous. Meanwhile,pollution levels of fish species residing in different water layers decreased in the order of demersal>middle bottom layer>middle upper layer. Therefore, omnivorous and demersal fish species posed higher health risks of dietary cadmium intake compared with those residing in other water layers with other feeding habits. Except for the S5 point at the early stage of this event(risk value:9.03×10^-5?a^-1), all the average values of health risk at other sampling locations of the monitoring cross section were lower than 5.0×10^-5?a^-1, the maximum acceptable value of contaminant-led health risks for a person per year specified by the International Commission on Radiological Protection（ICRP）. This reveales that dietary intake of the fish species in this cadmium contamination event poses relative lower potential risks to the health of local residents, but health risks from the omnivorous or demersal fish species at the early stage deserve attention.更多还原