典型人工纳米材料及其吸附态污染物在水生食物链中的传递与生物放大作用

The trophic transfer and biomagnification of Manufactured Nanomaterials (MNMs) in food chain has become one of the research frontiers and hotspots in the field of environmental science in recently. In addition, it is well known that MNMs can adsorpt pollutants in water, which raise the concern that MNMs may affect the behaviors of pollutants in water environment. In the last few years, there are some evidences showing MNMs can enhance the bioaccumulation of pollutants in organisms and eventually cause toxicity. Based on these results, one would argue that the MNMs could also exert influences on the trophic transfer and biomagnification of pollutants in an aquatic food chain, bringing unpredictable consequences to the environment and humans. However,until recently, very few studies have been investigated on the issues mentioned above, which can not meet the need for the assessment of environmental effects and health risks of MNMs. To address these problems, on the basis of preliminary studies and, using typical MNMs (with mass production and wide use) as experimental subjects, this project will conduct: 1) a more systematic study on the trophic transfer and biomagnification of different MNMs in the aquatic food chain; 2) to further explore the impacts of MNMs on the food chain biomagnification behavior of their co-existing pollutants in water.The results of this project will contribute to a deep understanding on the environmental effects and ecological risks of MNMs.

人工纳米材料（MNMs）的食物链传递和生物放大研究已成为环境科学领域的前沿和热点。MNMs对污染物的吸附，可能会对污染物在水生食物链中的传递与生物放大产生影响，给环境和人类带来难以预料的后果。目前，相关的研究仍极为匮乏，无法满足对MNMs环境效应和健康风险评估的需要。本课题针对上述问题，在前期研究基础上，以产量大且用途广的典型MNMs为实验对象，通过构建水生食物链和利用现代分析技术与仪器：1）较为系统的研究不同类型MNMs在水生食物链中的传递行为和生物放大作用；2）在此基础上，重点研究MNMs对水中主要污染物食物链传递与生物放大行为的影响，并初步探索MNMs影响污染物食物链传递与放大作用的可能原因，为深入理解MNMs进入环境后的特殊毒性作用过程与机制，和有效防范其生态风险提供科学依据。

人工纳米材料（MNMs）的食物链传递和生物放大研究已成为环境科学领域的前沿和热点。MNMs对污染物的吸附，可能会对污染物在水生食物链中的传递与生物放大产生影响，给环境和人类带来难以预料的后果。本课题针对上述问题，首先开展典型MNMs的水环境行为表征，了解MNMs进入水环境后的理化性质及其动态特征；随后以金属氧化物纳米材料nTiO2和碳纳米材料nC60为代表，完成MNMs在淡水食物链（大型蚤到斑马鱼）和海水食物链（卤虫到大菱鲆）中的传递行为研究，结果未发现MNMs生物放大的发生。进一步考察多种MNMs对现存污染物包括Cd、Cu和Phe等的生物富集与生物毒性的影响。结果发现，无论nTiO2还是nC60都会在生物体内蓄积，而且不同的生物对纳米材料的生物蓄积不同，大型蚤对纳米材料的生物浓缩系数最高，对nTiO2的富集甚至可高达1.18×106L/Kg，斑马鱼最低，对nTiO2的富集最高仅有1.81×102L/Kg；nTiO2和nC60均会促进污染物Cd和Phe在生物体内的富集，增强菲和镉对卤虫和大型蚤的毒性，毒性增强幅度往往呈倍数增加。为深入探索MNMs对污染物食物链传递及生物放大的影响。课题继续以nTiO2和nC60为对象，Phe和Cd为受试污染物，开展复合污染下食物链传递实验。结果发现nTiO2（1mg/L）存在下，通过食物链传递可显著增强菲在大菱鲆体内的累积并延长菲在大菱鲆体内的平衡时间，但却降低菲从卤虫到大菱鲆的生物放大系数，表明nTiO2尽管加剧了菲的食物链传递，但同时却降低了菲的生物放大效应。在1mg/L浓度nC60存在下，通过食物链传递的Cd在斑马鱼体内的累积和排出并未出现明显差异；但在10mg/L浓度nC60存在下，平台期时斑马鱼对Cd的累积量明显降低，且对Cd的排出速率加快，同样降低了Cd的生物放大效应。课题研究结果表明，污染物与MNMs共存下的复合毒性作用十分复杂，相关的作用机制仍有待进一步深入挖掘。