中文摘要：

为探讨儿童个体PM2.5暴露水平及来源,分别于2010年5月17日—6月24日（夏季）和11月8日—12月3日（冬季）对36名9~12岁小学生进行个体PM2.5暴露样品的采集和分析.结果表明：天津市某小学儿童夏、冬两季个体PM2.5暴露浓度（以质量浓度计）分别为（74.7±29.5）和（122.4±42.3）μg/m3,冬季暴露水平高于夏季,可能与冬季取暖有关.两季PM2.5载带的Al和Si,Zn、Pb和Mn的质量浓度分别呈显著相关;夏、冬两季SO42-和NO3-质量浓度之和分别占个体PM2.5暴露浓度的43.3%和39.5%.夏、冬两季NO3-和SO42-质量浓度平均值之比分别为2.3和0.6,说明夏季机动车排放为主导源,冬季则为固定源（如工业源和燃煤源）.冬季OC（有机碳）和EC（无机碳）质量浓度分别高于夏季,与PM2.5质量浓度的季节变化趋势一致.源解析结果表明,天津市儿童夏季PM2.5暴露的来源为二次源、机动车排放、土壤尘、工业源和机动车添加剂,贡献率分别为30.4%、28.9%、12.8%、20.8%和7.1%;冬季则为二次源、机动车排放、土壤尘、工业源、燃煤源和道路尘,贡献率分别为26.5%、24.5%、13.7%、10.3%、19.9%和5.1%.

英文摘要：

To investigate the exposure characteristics and potential sources of fine particulate matter（ PM2.5）,a panel study was conducted for children in a primary school in Tianjin.Thirty-six children aged from 9 to 12 were selected,and their personal exposures to PM2.5were monitored in summer（ May 17-June 24） and winter（ November 8-December 3） in 2010.The results showed that the mass concentrations of personal PM2.5exposure in winter（（ 122.4 ± 42.3） μg/m3） were higher than those in summer（（ 74.7 ± 29.5） μg/m3）,which might be related to heating in the cold season.Significant correlations were found between Si and Al,as well as Zn,Pb and Mn in both monitoring periods by Spearman correlation analysis.The total concentrations of SO42-and NO3-accounted for 43.3% of PM2.5in summer,and 39.5% in winter.The ratio of NO3-/SO42-was 2.3 in summer,indicating that mobile sources were the principal source of personal PM2.5exposure; while in winter, the ratio was 0.6, indicating that stationary sources were the primary contributor.Concentrations of organic carbon（ OC） and elemental carbon（ EC） in winter were higher than those in summer,which was consistent with the seasonal trend of PM2.5.Results of source apportionment analysis showed that secondary sources,vehicle exhaust,soil,industrial sources and vehicle additives contributed 30.4%, 28.9%,12.8%,20.8% and 7.1%,respectively,to PM2.5exposure of children in summer; whereas in winter, secondary sources,vehicle exhaust,soil,industrial sources,coal combustion and road dust contributed 26.5%, 24.5%, 13.7%, 10.3%,19.9% and 5.1%,respectively.