Microplastics have emerged as one of the most significant threats to the Earth's ecosystems due to their persistence,ability to carry high loads of contaminants,and biotoxicity.The Tibetan Plateau is a hotspot for...Microplastics have emerged as one of the most significant threats to the Earth's ecosystems due to their persistence,ability to carry high loads of contaminants,and biotoxicity.The Tibetan Plateau is a hotspot for global biodiversity conservation,but its ecosystem is fragile.This study systematically investigated the characteristics,distribution,sources,and ecological risk of microplastics in rivers and lakes across the Tibetan Plateau using the Laser Direct Infrared Imaging Spectroscopy(LDIR).The results indicated that the mean abundances of microplastics in water and sediments were 4250 items/m^(3)(n=50)and 3750 items/kg(n=44),respectively.Microplastics with small sizes(50-200μm),characterized by transparent and white fragments,were predominant.The most common polymers identified were polyamide(PA),polyurethane(PU),polyethylene terephthalate(PET),polyvinyl chloride(PVC),polypropylene(PP),and polyethylene(PE).Water sampling sites near urban/suburban effluent outfalls showed high levels of contamination.Microplastics in water are primarily derived from sewage effluent and atmospheric deposition.No single driver has been identified as the key factor influencing the spatial distribution of microplastics in water.The abundance of microplastics in sediments was significantly negatively correlated with the distance to the nearest city/town(p<0.01,R=-0.56)and significantly positively correlated with precipitation(p<0.01,R=0.60).Discarded or landfilled plastic waste is a major source of microplastics in sediments,which accumulate through transport by stormwater runoff caused by precipitation.Three ecological risk assessment models for microplastics were applied,and the high proportion of hazardous polymers such as PU,PVC,and PA was found to be responsible for the high ecological risk in the study area.This study provides an accurate and detailed exploration of the characteristics,sources,and spatial distribution of microplastic pollution by advanced automatic detection method in rivers and lakes on the Tibetan Plateau.展开更多
Airborne microplastics(MPs)are important pollutants that have been present in the environment for many years and are characterized by their universality,persistence,and potential toxicity.This study investigated the e...Airborne microplastics(MPs)are important pollutants that have been present in the environment for many years and are characterized by their universality,persistence,and potential toxicity.This study investigated the effects of terrestrial and marine transport of MPs in the atmosphere of a coastal city and compared the difference between daytime and nighttime.Laser direct infrared imaging(LDIR)and polarized light microscopy were used to characterize the physical and chemical properties of MPs,including number concentration,chemical types,shape,and size.Backward trajectories were used to distinguish the air masses from marine and terrestrial transport.Twenty chemical types were detected by LDIR,with rubber(16.7%)and phenol-formaldehyde resin(PFR;14.8%)being major components.Three main morphological types of MPs were identified,and fragments(78.1%)are the dominant type.MPs in the atmosphere were concentrated in the small particle size segment(20-50μm).The concentration of MPs in the air mass from marine transport was 14.7 items/m^(3)-lower than that from terrestrial transport(32.0 items/m^(3)).The number concentration of airborne MPs was negatively correlated with relative humidity.MPs from terrestrial transport were mainly rubber(20.2%),while those from marine transport were mainly PFR(18%).MPs in the marine transport air mass were more aged and had a lower number concentration than those in the terrestrial transport air mass.The number concentration of airborne MPs is higher during the day than at night.These findings could contribute to the development of targeted control measures and methods to reduce MP pollution.展开更多
基金supported by the National Natural Science Foundation of China(42322105)Outstanding Youth Fund of Gansu Province(23JRRA612)Postdoctoral Fellowship Program of CPSF(GZC20232952).
文摘Microplastics have emerged as one of the most significant threats to the Earth's ecosystems due to their persistence,ability to carry high loads of contaminants,and biotoxicity.The Tibetan Plateau is a hotspot for global biodiversity conservation,but its ecosystem is fragile.This study systematically investigated the characteristics,distribution,sources,and ecological risk of microplastics in rivers and lakes across the Tibetan Plateau using the Laser Direct Infrared Imaging Spectroscopy(LDIR).The results indicated that the mean abundances of microplastics in water and sediments were 4250 items/m^(3)(n=50)and 3750 items/kg(n=44),respectively.Microplastics with small sizes(50-200μm),characterized by transparent and white fragments,were predominant.The most common polymers identified were polyamide(PA),polyurethane(PU),polyethylene terephthalate(PET),polyvinyl chloride(PVC),polypropylene(PP),and polyethylene(PE).Water sampling sites near urban/suburban effluent outfalls showed high levels of contamination.Microplastics in water are primarily derived from sewage effluent and atmospheric deposition.No single driver has been identified as the key factor influencing the spatial distribution of microplastics in water.The abundance of microplastics in sediments was significantly negatively correlated with the distance to the nearest city/town(p<0.01,R=-0.56)and significantly positively correlated with precipitation(p<0.01,R=0.60).Discarded or landfilled plastic waste is a major source of microplastics in sediments,which accumulate through transport by stormwater runoff caused by precipitation.Three ecological risk assessment models for microplastics were applied,and the high proportion of hazardous polymers such as PU,PVC,and PA was found to be responsible for the high ecological risk in the study area.This study provides an accurate and detailed exploration of the characteristics,sources,and spatial distribution of microplastic pollution by advanced automatic detection method in rivers and lakes on the Tibetan Plateau.
基金supported by the National Natural Science Foundation of China (No.42075107)the Fundamental Research Funds for the Central Universities (No.2022YJSDC05)+1 种基金the China Scholarship Council (No.202206430058)the Yueqi Scholar Fund of China University of Mining and Technology (Beijing).
文摘Airborne microplastics(MPs)are important pollutants that have been present in the environment for many years and are characterized by their universality,persistence,and potential toxicity.This study investigated the effects of terrestrial and marine transport of MPs in the atmosphere of a coastal city and compared the difference between daytime and nighttime.Laser direct infrared imaging(LDIR)and polarized light microscopy were used to characterize the physical and chemical properties of MPs,including number concentration,chemical types,shape,and size.Backward trajectories were used to distinguish the air masses from marine and terrestrial transport.Twenty chemical types were detected by LDIR,with rubber(16.7%)and phenol-formaldehyde resin(PFR;14.8%)being major components.Three main morphological types of MPs were identified,and fragments(78.1%)are the dominant type.MPs in the atmosphere were concentrated in the small particle size segment(20-50μm).The concentration of MPs in the air mass from marine transport was 14.7 items/m^(3)-lower than that from terrestrial transport(32.0 items/m^(3)).The number concentration of airborne MPs was negatively correlated with relative humidity.MPs from terrestrial transport were mainly rubber(20.2%),while those from marine transport were mainly PFR(18%).MPs in the marine transport air mass were more aged and had a lower number concentration than those in the terrestrial transport air mass.The number concentration of airborne MPs is higher during the day than at night.These findings could contribute to the development of targeted control measures and methods to reduce MP pollution.
