Intestinal absorption and biomagnification of organic contaminants in fish, wildlife, and humans
Intestinal absorption and biomagnification of organic contaminants in fish, wildlife, and humans
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DOI：
10.1897/03-545
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发表时间：
2004-10-01
影响因子：
4.1
通讯作者：
McLachlan, MS
中科院分区：
文献类型：
--
作者：
Kelly, BC;Gobas, FAPC;McLachlan, MS
有机化学品生物蓄积潜力的监管评估方法建立在膳食吸收和生物放大的经验测量和机制模型的基础上。本研究回顾了有关水生和陆地食物链生物体中有机化学品的肠道吸收和生物放大机制和模型的最新知识状况，还讨论了这些模型对评估有机化学品生物累积潜力的影响。评估了四种机制模型，包括生物质转化、消化或胃肠放大、胶束介导的扩散和脂肪冲洗扩散。这些模型包含许多相似之处，代表了对化学生物累积过程理解的演变。生物放大模型之间的一个重要区别是，肠道对摄入污染物的吸收是仅通过串联阻力的被动分子扩散发生，还是通过并联附加平流运输机制的促进扩散发生（即胃肠道胶束内的分子运送）。这种差异会影响物理化学特性的选择，从而最好地预测商业化学品在水生和陆地食物链中的生物累积潜力。目前利用 K-OW 阈值标准来评估化学生物累积潜力的监管举措已被证明无法识别呼吸空气的动物中的某些生物累积物质。我们敦促进一步研究有机化学品的膳食吸收和生物放大作用，以开发更好的模型来评估有机化学品的生物累积性。
Methods for the regulatory assessment of the bioaccumulation potential of organic chemicals are founded on empirical measurements and mechanistic models of dietary absorption and biomagnification. This study includes a review of the current state of knowledge regarding mechanisms and models of intestinal absorption and biomagnification of organic chemicals in organisms of aquatic and terrestrial food chains and also includes a discussion of the implications of these models for assessing the bioaccumulation potential of organic chemicals. Four mechanistic models, including biomass conversion, digestion or gastrointestinal magnification, micelle-mediated diffusion, and fat-flush diffusion, are evaluated. The models contain many similarities and represent an evolution in understanding of chemical bioaccumulation processes. An important difference between the biomagnification models is whether intestinal absorption of an ingested contaminant occurs solely via passive molecular diffusion through serial resistances or via facilitated diffusion that incorporates an additional advective transport mechanism in parallel (i.e., molecular ferrying within gastrointestinal micelles). This difference has an effect on the selection of physicochemical properties that best anticipate the bioaccumulative potential of commercial chemicals in aquatic and terrestrial food chains. Current regulatory initiatives utilizing K-OW threshold criteria to assess chemical bioaccumulation potential are shown to be unable to identify certain bioaccumulative substances in air-breathing animals. We urge further research on dietary absorption and biomagnification of organic chemicals to develop better models for assessing the bioaccumulative nature of organic chemicals.