基于毒性效应的间隙水致毒物质鉴别技术进展

沉积物作为污染物迁移转化过程中重要的"源"和"汇",与整个生态系统及人类健康有着密切联系。间隙水很大程度上反映了水体沉积物的污染状况,同时可以真实反映生物的实际暴露情况,间隙水中关键致毒物质的鉴别是科学准确地评价间隙水及沉积物毒性与风险的重要基础。毒性鉴别评估(Toxicity Identification Evaluation,TIE)和效应引导的污染物识别(Effect Directed Analysis,EDA)技术作为致毒物质识别的主要方法,已在沉积物和间隙水的致毒物筛选中得到了初步的应用。本文介绍并比较了常用的间隙水提取方法,总结了TIE和EDA在间隙水致毒物质异位及原位鉴别方面的应用与发展,及鉴别过程中使用到的基本毒性量化方法与其适用条件。在当前间隙水关键致毒物质识别研究的基础上,指出了异位分析难以避免毒性损失和有机污染物鉴别方面的局限等问题,并提出应推广原位毒性试验技术且进一步发展有机物的精细分离技术和质谱识别技术等发展方向。

Development of Identification of Key Toxicants in the Pore Water

Sediments act both as a sink and as a long-term source of toxicants, and are associated with potential ecological and human health risks closely. However, the pore water acts as a bridge for toxicants from sediment to biota, and only the freely dissolved molecules and rapidly desorbing molecules from sediments are bioavailable, Therefore, the identification of key toxicants in the pore water is necessary to risk assessment and comprehensive treatment of the pore water and sediment. Toxicity Identification Evaluation (TIE) and Effect Directed Analysis (EDA) have been successfully applied in toxicants screening and identification. In this paper, the extraction methods for the pore water were reviewed and compared. Application and development of TIE and EDA in identification of toxicants in the pore water are summarized, and the toxicity quantification methods with their restrictions were also proposed. On the basis of current studies, limitations and prospect of toxicants identification in the pore water were discussed, the loss of toxicity in ex situ bioassays and the challenge in identification of organic toxicants were also highlighted.