Pollution Characteristics And Source Apportionment Of Heavy Metals And Rare Earth Elements In Atmospheric Particles Of Quanzhou City

Atmospheric Particle is one of the major pollutants in the atmospheric environment.The particulate matter itself poses a threat to human health and can adsorb toxic chemical components to increase its toxicity.It is of great significance for air pollution controlling to study the concentration and distribution of chemical components in atmospheric particles.In this paper,the pollution characteristics and sources of metal elements and rare earth elements in dustfall,TSP and PM2.5 from different functional areas of Quanzhou City were analyzed.The main conclusions of the study as follow:The concentrations of metals in the dustfall of Quanzhou City presented significant spatial difference.The results of enrichment factor and geo-accumulation index indicated that Cd,Hg,Zn,Ca,Pb,Cu,Ni and Sr showed relatively higher enrichment degree and pollution level.The results of ecological risk index showed that the comprehensive ecological risk of heavy metals was very high in the dustfall of all functional areas.Cd and Hg contributed 95.56% to the comprehensive potential ecological risk index.The multivariate statistical analysis demonstrated that the elements of V,Fe,Ba,Bi,Ni,Sr,Pb,Cs,Sc,Zn,Cd were mainly from industrial and vehicle emission;Th,U,Rb,Y,Ti were mainly derived from soil dust;Li,Mn,Cu,Hg,Cr,Co,Ca were mainly from coal combustion.The contribution ranges of parent soil,coal combustion and vehicle emission to the Pb in the dustfall were29.41%-64.00%,22.53%-60.48% and 3.13%-13.47%,respectively,calculated by a ternary hybrid model;The plots of 87Sr/86 Sr vs 1/Sr showed that Sr in the dustfall was dominated by coal combustion and vehicle emission.ΣREE in the dustfall of Quanzhou City presented significant spatial difference.The lower coefficient variation of ΣREE in residential,heavy traffic,commercial area indicated homogeneous sources of REE.The chondrite-normalized REE patterns were all of the rightward inclined type with the enrichment of LREE relative to HREE and showed obvious negative Eu anomalies.The results of La CeV diagramdemonstrated that REE in the dustfall of residential area,heavy traffic area and commercial area were mainly derived from traffic source and soil dust,followed by coal combustion,δEu vs.ΣREEs diagram and HREEN/MREEN vs.La N diagram further explained that vehicle emission was the main anthropogenic source of REE in the dustfall of heavy traffic area and commercial area.The REE in the dustfall of Quanzhou City were less affected by steelworks emissions and cement plant dust and there were additional REE sources in the dustfall of industrial and agricultural area different from other functional areas.The concentration of TSP in Quanzhou City presented spatial difference with the sequence of industrial area > heavy traffic area > residential area >commercial area.The elements of As,Cd,Bi,Sb,Zn,Sn,Sr and Pb showed relatively higher enrichment degree and pollution level.The comprehensive ecological risk of heavy metals was very high in TSP of all functional areas.Cd showed extremely high potential ecological risk,followed by As and Pb.The elements of Fe,Pb,Y,Mn,Th,Sn,Zn,Rb,U,Cr,Ni,V,Ga were mainly from soil dust,industrial and vehicle emission;Zr,Bi,Cd,Co,Cu were mainly derived from coal combustion;Ge,Ba,Sc,Li,Hf,Ti,Sb,As,Sr,Ta,As were mainly from soil dust and coal combustion.ΣREE in TSP of Quanzhou City presented spatial difference with the sequence of heavy traffic area > commercial area > residential area > industrial area.The average contents of REEs in TSP were basically fit the law of crustal distribution,indicating that soil dust was one of its sources.The chondrite-normalized REE patterns were all of the rightward inclined type with the enrichment of LREE relative to HREE and showed slight positive Pr anomalies and negative Eu anomalies.δEu vs.MREEN/MREEN* diagram and δCe vs.δEu diagram explained that REE in TSP of Quanzhou City were mainly derived from soil dust,coal combustion and traffic source,followed by steelworks emissions and cement plant dust.The average concentration of PM2.5 in annual sampling period of Quanzhou City was 40.55 μg·m-3.The seasonal variation of concentrations of other metals in PM2.5 was consistent with the seasonal variation of PM2.5 concentration.The concentrations of metals in PM2.5 presented significant spatial difference with the sequence of residential and industrial area > residential and commercial area > scenicarea.The elements of Cd,Sb,Bi,Zn,Cu,In,Pb,Tl,Ni,Cr,V showed relatively higher enrichment degree.The results of health risk assessment showed that non-carcinogenic risk of heavy metals in PM2.5 of Quanzhou City was relatively low,which presented seasonal difference with the sequence of winter > summer >autumn > spring;Cr existed a certain degree of carcinogenic risk while carcinogenic risk of other heavy metals was extremely low,which presented seasonal difference with the sequence of winter > autumn > summer > spring.Both non-carcinogenic and carcinogenic risk of heavy metals in four seasons and different functional areas presented the sequence of children > adult men > adult women.The elements of Zr,Hf,Y,Sr,Ba,Th,U,Ta,Co were mainly from soil dust;Cr,Cu,Ni,Sc,V were mainly derived from industrial emission;Pb,Bi,Cd,Zn were mainly from coal combustion and vehicle emission;In,Cs,Sb,Tl,Li,Rb,Ga,Mo were mainly from industrial and vehicle emission.ΣLREE,ΣHREE,ΣREE in PM2.5 of Quanzhou City presented significant difference in four seasons and different functional areas.The correlation between PM2.5 concentration and ΣREE showed that there was a certain correlation in spring,summer and winter,while no obvious correlation in autumn.The chondrite-normalized REE patterns of PM2.5 and potential source were all of the rightward inclined type with the enrichment of LREE relative to HREE and showed obvious negative Eu anomalies.The results of LaCeSm,La CeV diagram demonstrated that REE in PM2.5 were mainly derived from steelworks emissions and cement plant dust in spring and autumn,while mainly from soil dust,steelworks emissions and cement plant dust,coal combustion and vehicle emission.ΣREE vs.εNd,143Nd/144 Nd vs.La N,143Nd/144 Nd vs.LREE/HREE and δEu vs.εNd diagram demonstrated that PM2.5 of Quanzhou City were mainly derived from traffic source,followed by coal combustion,and less affected by soil dust and steelworks emissions.