Study On The Distribution Of Novel Brominated Flame Retardants,Polycyclic Aromatic Hydrocarbons And The Derivatives In Vegetable Leaf Particles

Novel brominated flame retardants(NBFRs),polycyclic aromatic hydrocarbons(PAHs),and the derivatives of polycyclic aromatic hydrocarbons including nitro polycyclic aromatic hydrocarbons(NPAHs),methyl polycyclic aromatic hydrocarbons(MPAHs),chlorinated polycyclic aromatic hydrocarbons(CIPAHs)which have high toxicity have been raised high concern.The research is an important part of the diet exposure risk assessment.Vegetable ingestion is an important pathway to human exposure to these pollutants.These strong hydrophobic organic pollutants is likely deposited to the vegetable leaf with the particle and then absorbed into vegetable,which caused harm to human health.In order to evaluate the uptake of different size particles and NBFRs,PAHs,NPAHs,MPAHs and CIPAHs attached with particles by vegetable leaf,the content of particles with diameter of>100?m,10-100?m,2.5-10?m and 0.2-2.5?m and the distribution of NBFRs,PAHs,NPAHs MPAHs and CIPAHs in particles with different size were determined in this paper.(1)The total concentrations of particles in the leaves and wax layers of the southern autumn vegetables(SAVs),the southern spring vegetables(SSVs),the northern autumn vegetables(NAVs)and the northern spring vegetables(NSVs)are 117g/cm2,55g/cm2,319g/cm2and 545g/cm2,respectively.The adsorption amount of each particle by vegetables was leaf surface>wax layer.Particles in leaf surface accounted for about 95%of total particulate matter.The particle size distribution of leaf surface and wax layer was measured by weight,and the particle size distribution was as follows:>100?m accounted for about 36%,10-100?m accounted for about 56%,2.5-10?m accounted for about 5.6%,0.2-2.5?m accounted for about 2.5%,respectively.In the same season,the amount of adsorbed particulate matter in leaves of northern Chinese cabbage was higher than that of southern Chinese cabbage.From the point of view of seasons,the content of particulate matter adsorbed by vegetables in northern China in spring was higher than that in autumn,while particles adsorbed by vegetables in spring in southern was lower than in autumn.(2)The concentrations of NBFRs in particles of SAVs,SSVs,NAVs and NSVs were 14?g/g,12?g/g,1.6?g/g and 7.1?g/g,respectively.The contents of PAHs in particles of SAVs,SSVs,NAVs and NSVs were 4851 pg/g,11791 ?g/g,4351 ?g/g and 8361?g/g,respectively.The contents of NPAHsin particles of SAVs,SSVs,NAVs and NSVs were 12?g/g,17?g/g,8.9?g/g and 17?g/g,respectively.The contents of MPAHs in particles of SAVs,SSVs,NAVs and NSVs were 189?g/g,54?g/g,15?g/g and 68?g/g,respectively.The contents of CIPAHs in particles of SAVs,SSVs,NAVs and NSVs were 4.6?g/g,0.29?g/g,0.20?g/g and 0.53?g/g,respectively.From the distribution of pollutants in different size particles,the size of 0.2-2.5?m has the highest concentration of pollutants.And the content of pollutants which absorbed in particles in wax was higher than that in leaf.(3)The main chemicals of NBFRs in particles were 2-Ethylhexyl-2,3,4,5-tetrabromobenzoate(EHTBB),Decabromodiphenyl ethane(DBDPE),Hexachlorocyclopentadienyl-Dibromocyclooctane(HCDBCO),Hexabromocyclododecanes(HBCD).The composition of PAHs in the total particulate matter was:4-5 ring PAHs accounted for about 50%,6 ring accounted for about 38%,2 ring and 3 ring accounted for about 12%.3-Nitrofluoranthene(3NF)and 2,7-Dinitrofluorene(2,7DNF)accounted for 18%and 28%of NPAHs in particulate matter,respectively.2-Methylnaphthalene(2-MNAP)and 2-Methylchrysene(2-MeC)accounted for 25%and 35%of MPAHs in particulate matter,respectively.The content of 1,8-Dichloronaphthalene(1,8-DCN)in CIPAHs was the highest,accounting for 57%.