塑料添加剂的环境迁移、毒性测试与风险筛查:进展与挑战

Environmental Migration,Toxicity Testing and Risk Screening for Plastic Additives:Advances and Challenges

塑料和微塑料污染日益严峻,因此引发了对塑料添加剂释放现象的广泛关注,塑料添加剂在固废处置和回收过程中会大量向环境中释放。塑料添加剂种类繁多,功能多样,数量庞大,其复杂性使得其评估工作面临巨大挑战,尤其是目前塑料添加剂的风险评估工作尚未建立起完善的体系。本研究对现有塑料添加剂的释放迁移研究、毒性测试及风险预测方法进行梳理,并基于塑料添加剂在种类、功能、添加量、监管、数据可用性等方面对公开信息的塑料添加剂逐级筛查,最终从1万多种现有塑料添加剂中筛选出106种值得关注的未监管添加剂物质。然后综合以下4项危害性指标,包括基于QSAR模型预测的物质毒性作用方式和危害等级、各化学品机构评估的PBT/PMT性质(持久性、生物累积性、迁移性、毒性)、生态毒性数据可用性、是否纳入化学品未来评估计划(CoRAP,ECHA),使用毒理学优先指数(ToxPi)方法按照等权重计算综合得分并排序,通过层次聚类分析对其进行优先级分类,提出相应风险评估优先序和研究关注的建议。结果表明,这其中很多尚未监管的塑料添加剂物质的潜在生态风险可能被低估。最后,我们提出对微塑料未来的研究挑战应主要聚焦在填补危害数据缺口和技术方法空白,包括其迁移释放机制、环境转化、混合效应及对生态系统的潜在影响等方面。

Plastic and microplastic pollution have become increasingly severe,raising widespread concern,and specifically regarding the risk of the release of plastic additives(PAs).The disposal and recycling of plastic solid waste,particularly in landfill and incineration processes,result in the substantial release of PAs into the environment.These additives are predominantly discharged by wastewater treatment plants,and infiltrate the water environment through various processes such as atmospheric deposition,soil erosion,groundwater infiltration,and surface runoff.The leaching of PAs poses threats to aquatic organisms as these additives can persistently migrate through various biological carriers.Micro-and nano-plastics(MNPs),acting as carriers,also make key contributions to the continuous release and accumulation of PAs in aquatic environments.However,the extensive variety,functions,quantities and complex compositions of plastic additives present formidable challenges in their assessment.This study presented the state-of-the-art research on the environmental release and migration,toxicity testing and risk prediction methods of existing PAs,and screened the risk of typical currently unregulated PAs via a step-by-step workflow combining toxicological priority index(Tox Pi)framework.The public information of existing PAs was retrieved and screened step by step based on the factors such as type,function,additive proportion,regulation,data availability,and so on.Finally,106 currently unregulated PAs of concern were selected for further risk evaluation.Then,four hazard variables were selected,including the mode of action and hazard classification level predicted by QSAR models,the PBT/PMT hazard(P-persistence,B-bioaccumulation,M-migration,T-toxicity),the ecotoxicity data availability(abundance of available toxicity data for aquatic organisms),as well as the hit count to be included in the community rolling action plan(CoRAP)by ECHA.Comprehensive scale-transformed scores of the variables were calculated and ranked via the framework of ToxPi.The 106 evaluated plastic additives were finally classified into five priority levels for risk assessment and three classifications for research concerns using h ierarchical cluster analysis.The results suggested that the ecological risk of currently unregulated PAs might be underestimated.Due to the data gap of hazard(especially for ecotoxicity)and limitations in methodology,we p roposed the challenges in the scientific research and risk management of PAs,including the mechanism of m igration and transformation,the mixture effects,and potential threats on ecosystems.