• 关键词：幼儿园  地表灰尘  重金属  健康风险  开封市

• 基金项目：河南省重点科技攻关项目(No.0721021500);教育部和河南省共建河南大学项目(No.SBGJ090101)

• 王晓云
• 1. 河南大学资源与环境研究所, 开封 475004; 2. 河南大学环境变化与水土污染防治河南省高校重点学科开放实验室, 开封 475004

• 马建华
• 1. 河南大学资源与环境研究所, 开封 475004; 2. 河南大学环境变化与水土污染防治河南省高校重点学科开放实验室, 开封 475004

• 侯千
• 1. 河南大学资源与环境研究所, 开封 475004; 2. 河南大学环境变化与水土污染防治河南省高校重点学科开放实验室, 开封 475004

• 段海静
• 1. 河南大学资源与环境研究所, 开封 475004; 2. 河南大学环境变化与水土污染防治河南省高校重点学科开放实验室, 开封 475004

• 摘要：在开封市采集31个幼儿园的地表灰尘样品,用火焰原子吸收分光光度法(F-AAS)分别测定其>0.25mm、0.25～0.15mm、<0.15mm和多粒级混合样品的Pb、Zn、Cr、Cu和Ni含量,应用EF法和HI法探讨了灰尘重金属富集特征和针对幼儿的健康风险.结果表明:灰尘Pb、Zn、Ni、Cu和Cr平均含量分别为242.99、297.32、52.57、38.92和82.13mg·kg^-1,均不同程度地超过了中国潮土背景值.灰尘Pb、Zn和Cr富集明显,属于人为源重金属;Cu和Ni分别属于混合源和自然源重金属.老城区、工业区和交通要道附近的幼儿园灰尘重金属含量明显高于其它区域.灰尘Pb主要富集在大颗粒上,Zn主要富集在小颗粒上,而Cu、Cr和Ni在不同粒级上的富集无明显差别.由于细颗粒所占灰尘总量的比例最大,中颗粒所占比例最小,所以各个重金属在不同粒级中的质量百分数均为细颗粒(50.03%)>粗颗粒(29.55%)>中颗粒(18.43%).手-口摄入灰尘是幼儿重金属暴露的主要途径.不同重金属的健康风险大小顺序为Pb>Cr>Ni>Zn>Cu,个别样点存在不同程度的Pb、Cr健康风险,其中HI_Pb>1样点有8处,HI_Cr>1的样点仅有1处,分别占样点总数的25.81%和3.23%.开封市绝大多数幼儿园的地表灰尘不存在重金属健康风险.

• Abstract：Samples of surface dust were collected from thirty-one kindergartens in Kaifeng. The concentrations of Pb,Zn,Cr,Cu and Ni in different size-fractionated (<0.15,0.15～0.25 and >0.25 mm in diameter) samples and in the mixed samples with all size fractions were determined by flame atomic absorption spectrophotometry (F-AAS). The accumulations of heavy metals in dust were analyzed using Enrichment Factor (EF),and health risks of heavy metals to young children were assessed using Health Index (HI). The results show that the average concentrations of Pb,Zn,Ni,Cu and Cr in the samples are 242.99,297.32,52.57,38.92 and 82.13 mg·kg^-1 respectively,which all exceed the background values in the fluvo-aquic soils of China. The metals Pb,Zn and Cr,mainly from human activities and enriched in dust significantly,are anthropogenic source metals; Ni,mainly from natural factors,is a natural source metals,while Cu,both from human activities and natural factors,is a mixed source metals. The samples from the old downtown area,industrial area and near major roads are polluted with heavy metals much more heavily than those in other areas of the city. It was also found that Pb is mainly enriched in the coarse fraction (>0.25 mm) of dust,Zn in the fine fraction (<0.15 mm),and Cu,Cr and Ni in all size fractions of dust without significant differences. The particle compositions of dust are fine 55%,coarse 28% and medium 17%,while the average mass percents of all heavy metals in the different size fractions are 50.03% in fine dust,29.55% in coarse and 18.43% in medium. The main exposure pathway of heavy metals to young children is hand-to-mouth ingestion. The HIsindicate that heavy metals have different levels of health risk to young children (Pb>Cr>Ni>Zn>Cu),in eight (25.8%) kindergartens HI_Pb>1,and one (3.2%) HI_Cr>1. Ahealth risk from Pb and Cr exists in some kindergartens; but generally,there is no health risk of heavy metals associated with surface dust in most kindergartens in Kaifeng.

• Key words：kindergarten  surface dust  heavy metal  health risk  Kaifeng City

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