石家庄市采暖季道路降尘PM2.5重金属元素健康风险评价

为了解城市道路降尘中重金属元素对道路环境工作人员和普通上班族在道路环境中的健康风险水平,于采暖季用降尘法收集石家庄市铺装道路尘样品,并利用再悬浮系统将粒径小于2.5μm颗粒物悬浮至滤膜上,分析PM2.5中载带的Cr、Mn、Co、Ni、Cu、Zn、As、Cd、Pb等9种重金属元素的健康风险。结果表明:道路降尘PM2.5中重金属3种暴露途径的暴露量顺序由大到小为手-口摄入、皮肤接触、呼吸吸入;产生的非致癌风险在1×10^-7~1×10^-1,对道路环境工作人员和普通上班族不存在非致癌风险;道路环境工作人员的致癌风险R(Cr)>10-6,致癌总风险Rtotal>10-6,存在致癌风险;普通上班族的Rtotal<10-6,不存在致癌风险;道路环境工作人员的致癌风险和非致癌风险均大于普通上班族,重金属元素的非致癌风险和致癌风险约为普通上班族7.7倍。

Health risk assessment of heavy metal contaminants in road dust PM2.5 from urban areas of Shijiazhuang during heating seasons

In order to identify and comprehend the risks faced by the road environmental workers and the ordinary office workers from the 9 kinds of heavy metals,we have collected the road dust-falling samples during the winter,with the particle sizes being smaller than 2.5μm suspended in the air.For the research goal,we have managed to detect the heavy metal concentration samples of PM2.5 in the road fallen dust to filter by using the ICPMS and ICP-OES,a re-suspension system,and then,analyzed the health risk indexes of the 9 kinds of heavy metal elements,including those of Cr,Mn,Co,Ni,Cu,Zn,As,Cd and Pb.The results of our analysis can be shown as follows:the average concentration rates of Cr(4215.89 mg/kg),Mn(282.36 mg/kg),Co(6.49 mg/kg),Ni(65.51 mg/kg),Cu(502.08 mg/kg),Zn(558.26 mg/kg),As(18.33 mg/kg),Cd(2.45 mg/kg)and Pb(167.49 mg/kg)in the road dust prove all higher than the background rates in the soil of Hebei Province.And,the health risk assessment indicates that the heavy metal contaminants in the said dust fall of PM2.5 are taken in by the sufferers mainly through their hands and mouth,which imply that the noncarcinogenic risk contents absorbed by the 2 kinds of workers should be between 1×10^-7-1×10^-1.Therefore,there is no carcinogenic risk both for the road environment workers and ordinary office workers.The order of carcinogenicity risk indexes of the said 9 kinds of heavy metal contaminants can be found and determined in the following descending order:Cr>As>Co>Ni>Cd,whereas the carcinogenic risk order faced by the road environmental workers has been discovered as R(Cr)>1×10-6 and Rtotal>1×10-6.The situation of pollution suggests that there does exist carcinogenicity risk from Cr to the road environmental workers,though no carcinogenic risk to be suffered by the ordinary workers because Rtotal<1×10-6,that is,7.7 times greater than that taken in by the ordinary workers.