【摘要】 选择西安市城区5处典型地段为采样点,检测了冬季大气颗粒物PM_2.5和PM₁₀的质量浓度,分析了PM_2.5和PM₁₀中所含Fe、Mn、Cu、Zn、Cd、Pb元素含量。结果显示:西安市冬季大气PM_2.5和PM₁₀的平均质量浓度分别为193.4,315.2μg/m³,是GB 3095—2012《环境空气质量标准》中的二级标准限值的2.6,2.1倍;PM_2.5/PM₁₀为0.51～0.78,说明大气颗粒物以PM_2.5为主;6种重金属在大气颗粒物中含量水平存在差异,含量高低依次为Zn≈Fe>Pb>Mn>Cu>Cd,其中Fe、Cu、Zn、Cd、Pb更容易聚集在PM_2.5中;PM₁₀中Fe（2 856μg/m³）的浓度最高,商业集密区、交通繁忙区和居民集中区的多数重金属元素高于文教区和公园。采用改进后的估算模型进行人体暴露量的估算和风险评估,结果表明:重金属元素的暴露途径强弱顺序为手口摄入>皮肤接触>呼吸摄入;PM_2.5和PM₁₀中所含Pb、Cd、Mn的非致癌健康风险（HI介于1.99～6.16,超过1）处于较高水平,对人体健康存在威胁;Cd在PM_2.5和PM₁₀中的致癌健康风险(R为2.54×10^-6和3.70×10^-6,低于10^-4)处于较低水平,但不能忽视其综合作用及长期累积危害。更多还原

【Abstract】 Five typical locations were selected as sampling points to measure the mass concentrations of PM_2.5 and PM₁₀ in winter, and analyze the contents of six heavy metals such as Mn, Fe, Pb, Zn, Cd and Cu contained in PM_2.5 and PM₁₀. The results showed that: the average concentrations of PM_2.5 and PM₁₀ in winter were 193.4 μg/m³ and 315.2 μg/m³ respectively in winter of Xi’an, which were 2.6 and 2.1 times as the second-class standard limits in Ambient Air Quality Standard. PM_2.5/PM₁₀ value ranged from 0.51 to 0.78, implying that PM_2.5 dominated the atmospheric particulate matters; contents of the 6 heavy metals in the atmospheric particulate matters were different, with the order of Zn≈Fe>Pb>Mn>Cu>Cd, among which Fe, Cu, Zn, Cd and Pb were more likely to accumulate in PM_2.5; the concentration of Fe（2856μg/m3） in PM₁₀ was the highest, and most of the heavy metal elements in commercial intensive, busy traffic and residential areas were higher than those in cultural and educational districts and parks. The improved estimation model was used for estimation of human exposure and risk assessment, and the results showed that: the intensity sequence of the exposure routes of heavy metal elements in ambient air was hand-mouth uptake>skin contact>respiration ingestion; the non-carcinogenic health risks of Pb, Cd and Mn in PM_2.5 and PM₁₀ were at a high level（1.99～6.16,>1）, posing a threat to human health; the carcinogenic health risk of Cd in PM_2.5 and PM₁₀(R was 2.54×10^-6, 3.70×10^-6,<10^-4) were low, but its harm to human health due to its comprehensive effect and long-term cumulative effects in environment could be ignored.更多还原