溢油污染潮间带大型底栖动物体内总石油烃含量及风险动态

以溢油污染潮间带大型底栖动物无齿螳臂相手蟹为对象,研究其体内TPH含量分布及动态变化,并开展健康风险评估,判断污染区域生态系统修复与恢复措施的有效性,从而为类似溢油事故的处理处置提供参考.分别在采取应急处置后、应急处置1 a后和二次修复1 a后采集了沉积物和相关生物体样品,采用紫外分光光度法和荧光分光光度法测得TPH含量.结果表明,二次修复1 a后生物体内脏和肌肉组织中TPH含量较应急处置1 a后呈显著下降趋势(p0.05),分别下降了64.28%~83.81%和27.44%~48.02%,生物体内脏组织中TPH含量明显高于肌肉组织,且二者呈现显著正相关关系(p0.01).二次修复1 a后生物体内脏和肌肉组织中TPH含量与应急处置后沉积物中TPH含量呈明显的线性关系(y=0.001x+4.3831,R2=0.9089;y=0.0004x+1.7744,R2=0.8705),表明溢油事故造成的沉积物污染是影响生物体内TPH累积的一个重要因素.同时,人体健康风险评估结果显示,应急处置1 a后和二次修复1 a后生物体体内的TPH暴露风险指数均处于可接受水平,采取二次修复后,暴露风险指数有明显下降趋势,较应急处置后下降了62.81%~82.31%.研究结果表明应急和修复措施均取得了一定效果,可为今后类似事故处理处置提供参考.

Content and risk dynamic of the total petroleum hydrocarbon in the body of benthic invertebrate in the intertidal zone polluted by oil spill

In order to judge the effectiveness of regional ecosystem restoration measures and to provide references for disposal of similar oil spill accidents, the distribution and dynamic variation of Total Petroleum Hydrocarbon (TPH) in the typical macrobenthos (Chiromantes dehaani) around intertidal zone polluted after an oil spill accident was studied, and exposure assessment approach by US EPA was applied to evaluate the human health risk. The sediments and organisms samples were collected respectively after emergency disposal, one year after emergency disposal and one year after secondary restoration. The TPH were measured using ultraviolet spectrophotometry and fluorescence spectrophotometry. The results show that the content of TPH in organism viscera and muscle tissue one year after secondary restoration reduced significantly (p<0.05) compared with that one year after emergency disposal, which dropped by the range of 64.28%~83.81% and 27.44%~48.02%, respectively. The content of TPH in visceral tissue was significantly higher than that in muscle tissue, and there was a significant positive correlation between the two groups (p < 0.01). The TPH content in the visceral and muscle tissue one year after secondary restoration had an obvious linear relationship with that in the sediment after emergency disposal (y=0.001x+4.3831,R²=0.9089;y=0.0004x+1.7744,R²=0.8705), indicating that sediment pollution caused by oil spill was an important factor affected TPH accumulation in organisms. The human health risk assessment indicated that exposure risk index values of TPH in organisms one year after secondary restoration was significantly lower than that one year after emergency disposal, and decreased by 62.81%~82.31%, while both of them were acceptable. It is shown that emergency and restoration measures had achieved certain effects, which can provide guidance for the similar oil spill accident disposal in the future.