氯化石蜡在稻田生境中的生物累积、转移和放大过程

In recent years, the issue on contamination of persistant organic pollutants (POPs) is highly concerned. The research on migration and transformation of POPs in abiota and biota environment promote us to get better knowledge on its environmental behavior and ecological effects as well as to control the potential hazards to food safety, human health and ecosystem. For this reason, chlorinated paraffins (CPs), one of the emerging contaminants, which have been paid little attention, are selected as target compounds. The study will focus on the paddy field close to Shanghai Jinshan Industrial Park. Through research on the characteristics and exposure levels of CPs contamination in biota from the study area, it aims 1) to study their bioaccumulation and distribution mechanisms in rice, 2) to explore their transferring process through the food chain and the biomagnification effect in paddy field ecosystem and 3) to evaluate the potential risk to ecosystem and human health. The results are expected to provide a scientific reference for ecological risk assessment and pollution control of POPs. In addition, it could supply basic information for better implementation of the Stockholm Convention in China.

近年来，持久性有机污染物（POPs）的环境污染问题日益突出，研究POPs在环境介质及生物体中的迁移转化行为，有助于我们深刻认识它们的环境行为和生态效应，更有效地控制其对食品安全、人体健康和生态系统的潜在危害。有鉴于此，本研究以新兴污染物氯化石蜡（chlorinated paraffins，CPs）为目标化合物，以上海市金山第二工业园区附近稻田为研究区域，通过对稻田生境内动、植物体短链氯化石蜡（SCCPs）和中链氯化石蜡（MCCPs）含量的分析，系统研究其在水稻体内的富集特征和分配特性，探讨其在稻田生境中的食物链传递过程及其生物放大效应，并对其潜在的生态风险及其摄入的人体健康风险进行评估。研究结果将为POPs 的生态风险评价和污染控制提供科学依据，同时也为我国更好地履行《斯德哥尔摩公约》提供基础资料。

本研究利用APCI-QTOF-MS对稻田生境中的土壤、水稻和野生生物体内的SCCPs、MCCPs及LCCPs进行了定量分析，在世界范围内首次报道了SCCPs、MCCPs及LCCPs在水稻不同器官组织中的分布、野生生物体内的LCCPs的污染特征。此外，通过对不同生长阶段、不同组织器官水稻样品CPs的积累与转运行为研究发现探明土壤-水稻根系和大气-水稻叶面是其重要的CPs积累途径；探讨了CPs在野生生物体内的积累特征，明确CPs在稻田野生生物体中的累积特性和同族体组成特征，揭示摄食习性和栖息地特性是CPs累积种间差异的关键因素；研究了CPs稻田生境的生物放大效应（首次报道了LCCPs的BMF因子）发现SCCPs、MCCPs及LCCPs均具有生物放大效应；通过对稻蛙和蛇体内CPs的器官组织研究，印证了CPs的肝脏代谢能力和代际迁移效应。上述结果对于我们了解CPs在动植物体内赋存特征、迁移转化行为，及其环境生态效应有着重要意义。