Coastal tidal flats have received considerable attention in recent years,as they provide a direct channel for the discharge of terrestrial microplastics into the ocean.Land reclamation is occurring increasingly freque...Coastal tidal flats have received considerable attention in recent years,as they provide a direct channel for the discharge of terrestrial microplastics into the ocean.Land reclamation is occurring increasingly frequently in coastal tidal-flats;however,the environmental impacts of these activities remain unclear.Therefore,this pioneering study assessed the microplastic emission characteristics of reclamation geotextiles and performed a risk assessment accordingly.Morphological characterization of geotextile samples collected from five sites in Dongtai,China,provided evidence of sedimentary weathering.Based on several assumptions,the average abundance of microplastics in soil covered by geotextiles was estimated to reach 349137 particles/kg dry weight,with the total microplastic load in the reclaimed area estimated to be 20.678.06 t.Compared with previous studies,this research demonstrates that coastal reclamation areas store a high concentration of microplastics,aggravating marine microplastic pollution.Moreover,conditional fragmentation model results revealed that the weathering and distribution characteristics of soil microplastics in coastal tidal-flat areas exhibit spatial heterogeneity,being more easily affected by natural factors(such as tides)than those in inland areas.As a result of tides,the annual discharge of geotextile-originating microplastics from the studied areas into the ocean was approximately 2465.52960.77 t.These findings prove that the risks posed by engineering-microplastics are significant,indicating that further investigations are required on the precise laws of transfer and migration,as well as the toxicity mechanisms,in order to improve analytical techniques and policies in this field.展开更多
基金The authors gratefully acknowledge the support provided by the National Natural Science Foundation of China(Grant No.21876044)the Fundamental Research Funds for the Central Universities(China)(No.B200202110)the Priority Academic Program Development of Jiangsu Higher Education Institutions(China).
文摘Coastal tidal flats have received considerable attention in recent years,as they provide a direct channel for the discharge of terrestrial microplastics into the ocean.Land reclamation is occurring increasingly frequently in coastal tidal-flats;however,the environmental impacts of these activities remain unclear.Therefore,this pioneering study assessed the microplastic emission characteristics of reclamation geotextiles and performed a risk assessment accordingly.Morphological characterization of geotextile samples collected from five sites in Dongtai,China,provided evidence of sedimentary weathering.Based on several assumptions,the average abundance of microplastics in soil covered by geotextiles was estimated to reach 349137 particles/kg dry weight,with the total microplastic load in the reclaimed area estimated to be 20.678.06 t.Compared with previous studies,this research demonstrates that coastal reclamation areas store a high concentration of microplastics,aggravating marine microplastic pollution.Moreover,conditional fragmentation model results revealed that the weathering and distribution characteristics of soil microplastics in coastal tidal-flat areas exhibit spatial heterogeneity,being more easily affected by natural factors(such as tides)than those in inland areas.As a result of tides,the annual discharge of geotextile-originating microplastics from the studied areas into the ocean was approximately 2465.52960.77 t.These findings prove that the risks posed by engineering-microplastics are significant,indicating that further investigations are required on the precise laws of transfer and migration,as well as the toxicity mechanisms,in order to improve analytical techniques and policies in this field.
