Abstract:

Plastics are slowly degraded in the natural environments. Accumulations of plastic pollutants have become one of the most concerning issues. Plastics with very small particle size were defined as nanoplastics (NPs). Although NPs’ particle size is still controversial, similar to other engineered nano-particles, NPs exert many negative influences on environments. Presence and accumulations in organisms of NPs pose a series of toxic effects, influencing organisms’ growth, reproduction and endocrine systems. Therefore, NPs threaten many organisms, including human beings. Although NPs pollution has been one of the most concerned environmental issues, it is extremely limited to investigate the toxic effects of NPs on soils and organisms. In this context, this study reviewed the toxic effects of NPs themselves including additives and degradation products as well as combined toxicity of NPs and other pollutants (organic and inorganic). This study also investigated the influence of NPs on terrestrial ecosystem including flora, fauna and soil, summarized current research trends and identified knowledge gaps. These knowledge gaps include the toxicity of secondary NPs through degradation processes, the influence of NPs on real organisms and the combined toxicity of environment-NPs-organisms-pollutants on soil environment. Filling these knowledge gaps can provide theoretical bases for comprehensive and scientific assessments of NPs’ ecological risks.

Key words: nanoplastics, environmental pollution, toxic effects, ecological risks, terrestrial ecology, plastic pollutants

摘要：

塑料在自然环境中降解缓慢，塑料污染物的积累不可避免地成为人们关注的问题。尺寸微小的塑料被定义为纳米塑料（NPs）。虽然NPs的尺寸尚存在争议，但与其他工程纳米颗粒类似，NPs可造成多种不利的环境影响。NPs的存在和在生物体内的积累会对生物体产生一系列毒性效应，影响生物体的生长、繁殖和内分泌系统等。因此，NPs对包括人类在内的较多生物都构成威胁。尽管NPs污染已成为最令人关注的环境问题之一，但目前有关NPs对土壤环境及生物体的毒害效应等的研究仍然较少。旨在综述NPs本身的毒害效应（包括其中的添加剂）、降解产物和与其他环境污染物（有机污染物、无机污染物）耦合后的复合毒性以及NPs对陆生生态环境，包括植物、动物以及土壤产生的综合影响，并总结本领域内的研究现状和不足。主要的研究不足包括对经过降解等过程形成的次级NPs的毒性效应尚未深入开展，NPs对真实生物体的影响研究仍具有局限性，针对环境-NPs-生物-污染物的交互耦合机制对土壤环境的毒害效应仍需进一步探究。针对这些研究不足开展相应的科研探究工作能为全面科学地评价NPs的生态风险提供理论支撑。

关键词: 纳米塑料, 环境污染, 毒性效应, 生态风险, 陆地生态, 塑料污染物