微塑料的迁移转化及其生态风险研究进展

Research progress on the migration and transformation of microplastics and environmental risks

微塑料因轻薄、微小、易吸附等特点,在陆地出现后随水流进入大海,随气流暂时悬浮于空气中,随动植物、土壤活动等深入土壤内部,进入地下水中汇流入海,再因退潮、干湿沉降等原因从水、大气环境再次进入土壤;并有可能通过植物和水生动物食物链传递从而对人体健康产生潜在风险。本文通过计算微塑料的综合危害指数(污染负荷指数和潜在生态风险指数)得出结论:微塑料虽然对环境危害较大,但目前尚处在可接受的风险范围之内,然而如果人类仍不加节制,肆意生产和使用塑料,在80年后微塑料将给生态系统带来极大风险。目前由于技术限制很难集中有效地收集处理微塑料,微塑料在迁移过程中很难分解代谢,所以应重点从源头控制来减少微塑料的产生。同时,由于人们对微塑料的认知仍处于初级阶段,因而深入了解微塑料与污染物的联合作用和对生态环境的破坏作用,完善微塑料风险评价模型成为当前的首要任务。

The interactive migration and transformation pathways of microplastics in the environment mainly include that microplastics enter the sea with water flow first and then suspend in the air with air currents due to the properties of lightness and small size. Ultimately, the suspended microplastics accumulate in soil or sediment, which might be ingested by plants or animals or even humans. Therefore,the hazard index of microplastics was calculated using the pollution load index and the potential ecological risk index to evaluate the level and evolution trend of environmental risk posed by microplastics in this paper. So far, the potential risk of microplastics was within an acceptable range,while this value would increase to the limitation value of national standard within 80 years if this uncontrolled plastic utilization still extended. Therefore, the reduction of plastics production might be an effective approach to control microplastics due to technical limitations on intensively and effectively removal of microplastics and decompose and metabolize microplastics in the environment. At the same time, since people’s cognition of microplastics was still in its infancy, it was the current primary task to deeply understand the combined effects of microplastics and pollutants and their destructive effects on the ecological environment, and to improve the microplastics risk assessment model.