微塑料对重金属在斑马鱼体内富集分布的影响及毒性增敏效应机理

There has been widespread concern about the pollution of microplastics in waters. In natural waters, microplastics pollution is usually a combined pollution, which is not only caused by single microplastics but also caused other pollutants, such as heavy metals. The latest research shows that microplastics could act as a vector in transporting heavy metals into organisms and induce adverse effects. Our preliminary study indicates that microplastics accumulate and distribute in organisms in a size-dependent manner, which may affect the accumulation and distribution of the heavy metals transported by microplastics. In addition, microplastics can also induce inflammation and oxidative stress in tissues, which may inhibit the activity and detoxification of metallothionein and finally increase the sensitivity of specific tissues to heavy metal toxicity. In order to confirm these hypothesis, systemic studies will be conducted in this project. Microplastics with different characteristics and heavy metals will be selected as research object. Zebrafish will be used as a model. Quantitative analysis based on fluorescent labeling technology and bio-omics methods will be used to investigate the influence of microplastics on accumulation and distribution of heavy metals in zebrafish, the effects of microplastics on heavy metal toxicities in specific tissues, the related sensitizing effects and underlying molecular mechanisms. This study will provide new ideas for the research of the combined toxicity of microplastics and heavy metals and provide scientific basis for the environmental health risk assessment of microplastics.

水体微塑料污染已受到广泛关注。实际水环境中的微塑料污染并非单一微塑料所致，往往伴随着重金属等污染物产生复合污染。最新研究表明微塑料能够成为重金属的传播载体，并携带其进入生物体产生危害。前期工作表明，微塑料在生物体内的富集和分布具有粒径依赖性，这可能会影响被微塑料载运的重金属在体内的富集分布；微塑料会导致生物体产生炎症反应和氧化应激，这些损伤可能会抑制金属硫蛋白活性，进而影响其重金属解毒作用，增加特定组织对重金属毒性的敏感度。为证实以上假设，本项目拟以不同特性的微塑料和重金属为研究对象，以斑马鱼为模式生物，借助微塑料荧光标记定量分析方法和生物组学技术，研究微塑料对重金属在斑马鱼体内富集分布的影响，探讨微塑料对重金属在特定组织毒性的影响，明确其对重金属毒性的增敏效应并阐明分子机理。本研究可为微塑料和重金属的联合毒性研究提供新思路，并为微塑料的环境健康风险评价提供科学依据。

水体微塑料污染受到广泛关注，而实际水环境中微塑料往往与重金属及有机污染物共存产生复合污染。已知微塑料会进入生物体富集并产生氧化损伤等生物毒性，但微塑料对重金属等环境污染物的载体作用，以及微塑料携带污染物在生物体内的富集规律及复合毒性尚不明确。针对这一问题，本研究系统开展了微塑料对重金属及有机污染的吸附及影响因素研究；微塑料对重金属及有机污染物在斑马鱼体内富集分布的影响研究；微塑料对重金属及有机污染物生物毒性的影响研究；微塑料对重金属及有机污染物毒性增敏效应的分子生物学机理研究。研究结果表明：（1）微塑料能够吸附重金属及有机污染物，微塑料的材质和粒径对其吸附作用影响显著，越小吸附能力越强；（2）微塑料能够转运重金属及有机污染物进入生物体，并显著增加污染物在生物组织内的富集量；（3）微塑料和重金属及有机污染物的复合暴露，可以显著增加污染物的生物毒性，其机理一方面是微塑料导致污染物的生物富集量增加，另一方面是微塑料与污染物复合暴露导致了毒性协同效应。研究结果为微塑料与环境污染物的联合毒性研究探索了创新思路，为微塑料的环境健康风险评价提供了理论和科学依据。