食物中典型持久性有机污染物(POPs)的生物可给性研究综述

The Bioaccessibility of Typical Persistent Organic Pollutants(POPs) in Food Matrix: A Review

持久性有机污染物（POPs）因其对人体的潜在危害而成为暴露风险评价关注的焦点.但是,以往的健康风险评价通常仅关注人体的外暴露水平,忽视了污染物从体外向体内输移过程中生物可给性对暴露水平的影响,因而可能造成暴露风险的高估或低估,以及主要暴露源的误判.在人体的3 大暴露途径（饮食暴露、呼吸暴露和皮肤接触暴露）中,饮食暴露被证明为最主要的暴露途径.食物中POPs 的生物可给性（bioaccessibility）指食物中能够被人体消化系统消化进入液相且可能被肠道吸收利用的那部分POPs 占总POPs 含量的比例,生物可给性的引入使内暴露取代外暴露成为饮食暴露风险评估的基础,其结果将更加接近人体暴露的真实情况.本文在查阅大量文献的基础上,以4 种典型POPs-多氯联苯（PCBs）、多溴联苯醚（PBDEs）、多环芳烃（PAHs）及有机氯农药（OCPs）为主线,系统总结了食物中POPs 生物可给性的研究现状,包括各研究所采用的消化模拟方法和POPs 自身理化性质、食物基质性质、消化模拟参数等因素对生物可给性的影响,进而说明不同污染物生物可给性的差异.我们发现,动物源性食物POPs 生物可给性在3.0%-84.5%之间,而植物源性食物POPs生物可给性则为2.6%-59.9%,可见生物可给性在POPs 膳食暴露风险评价中是极其重要的.此外,文章还阐述了现有研究在食物基质的选择和预处理、消化环境的设置以及消化液的配置等诸多方面存在的问题,并针对这些不足之处对今后的研究方向进行了展望,呼吁建立和发展更加科学有效的研究体系.文章对完善和发展健康风险评价理论、技术和方法,具有一定的积极意义.

Persistent organic pollutants (POPs) were the focus of attention in the field of exposure and risk assessment because of their potential adverse effects on human health. However, most previous studies of health risk assessment merely focused on the level of external exposure, neglecting the influence of bioaccessibility, which explained the digestion ratio of contaminants in food. As a result, mistakes like overestimation or underestimation of exposure risk as well as the misjudgment of the main exposure sources will be made possibly. Among the three routes of human exposure, diet was proved to be the main source compared with inhalation and dermal contact. The bioaccessibility of POPs in food matrix refers to the proportion of POPs that can be digested and possibly be absorbed in the total POPs in food. The introduction of bioaccessibility, whose data can better reflect the real situation of human exposure, makes the replacement of external exposure by internal exposure to be the basis of diet exposure risk assessment.In this paper, four typical POPs including polychlorinated biphenyls (PCBs), polybrominated diphenyl ethers (PBDEs), polycyclic aromatic hydrocarbons (PAHs) and organochlorine pesticide (OCPs) were focused, and the current state of studies about the bioaccessibility of POPs in food was systematically summarized, including the digestion methods used in each researches, the influences of matrix properties, and experimental environment on bioaccessibility, and the difference of bioaccessibilities of various contaminants. The bioaccessibility of POPs were 3.0%~84.5% and 2.6%~59.9% for animal-based and plant-based food, respectively, it means that the bioaccessibility was extremely important in exposure risk assessment of POPs through digestion pathway. Besides, this paper stated the insufficiency of present studies in the selection and pretreatment of food matrix, the design of experimental environment and the preparation of digestive juices, and raised a prospect of further studies according to those deficiency, appealing for the establishment of a more scientific and effective research system. This paper has practical significance in developing the theory, techniques, and methods of health risk assessment research.