乌鲁木齐市大气颗粒物中重金属的污染特征及风险水平评价

为了解乌鲁木齐市新疆农业大学大气颗粒物（TSP、PM₁₀、PM₅、PM_2.5）中Cu、Mn、Zn、Pb、Cr、Cd 6种重金属元素的分布特征及其经呼吸摄入方式带来的健康风险，采用崂应2050型大气综合采样器于2018年春季、夏季、秋季、冬季分别进行样品采集，使用TAS-990原子吸收分光光度计测定颗粒物中的重金属元素.结果表明:①新疆农业大学2018年四季ρ（TSP）、ρ（PM₁₀）、ρ（PM₅）、ρ（PM_2.5）范围分别为93.17~257.14、70.57~202.29、57.58~147.96、48.71~147.46 μg/m3.②各季节重金属平均质量浓度在不同大气颗粒物中均呈ρ（Zn）> ρ（Cu）> ρ（Pb）> ρ（Cr）> ρ（Mn）> ρ（Cd）的趋势.③不同大气颗粒物中重金属非致癌总风险均呈儿童高于成人的特点，HI（非致癌风险总值）均小于限值（1），Cd、Cr经呼吸途径产生的ILCR（终身增量致癌风险）为3.07×10-6~2.36×10-5.④I_geo（地累积指数）结果表明，大气颗粒物中Mn的I_geo平均值为-2.43，表现为无污染；Cr的I_geo平均值为0.78，表现为无-中污染；Cu和Pb的I_geo平均值分别为4.53、4.33，表现为重-极重污染；Zn和Cd的I_geo平均值分别为5.68、7.18，表现为极重污染.研究显示，新疆农业大学大气颗粒物中Cd、Cr对人体无致癌风险，但Zn与Cd的污染较重，应及时对乌鲁木齐市实施相应管控措施. 

Pollution Characteristics and Risk Assessment of Heavy Metals in Atmospheric Particulates in Urumqi City

In order to study the distribution characteristics and health risk assessment of toxic heavy metals, including Cu, Mn, Zn, Pb, Cr and Cd in atmospheric particulate matter, samples were collected at Xinjiang Agricultural University living area in 2018. The heavy metal contents were quantified by a TAS-990 atomic absorption spectrophotometer. It can be concluded that:(1) The average concentrations of TSP, PM₁₀, PM₅ and PM_2.5 in each season were 93.17-257.14, 70.57-202.29, 57.58-147.96 and 48.71-147.46 μg/m3 in Xinjiang Agricultural University. (2) The average concentrations of heavy metals in different atmospheric particulates in each season were ρ(Zn) > ρ(Cu) > ρ(Pb) > ρ(Cr) > ρ(Mn) > ρ(Cd). (3) The results of health risk assessment indicated that the non-cancer risks of Cu, Zn, Pb and Mn in different particulates were higher in children than adults, the total non-cancer risk (HI) was less than the limit value (1) and the carcinogen risks of Cd, Cr were 3.07×10-6-2.36×10-5. (4) The results of geo-accumulation index analysis (I_geo) showed that I_geo average of Mn was -2.43 in atmospheric particulate, indicating that is was not contaminated; Cr was 0.78, which indicates no to medium pollution; Cu and Pb were 4.53, 4.33, respectively, which was moderate and severe pollution; Zn and Cd were 5.68, 7.18, respectively, which showed heavy pollution. The study shows that Cd and Cr in atmospheric particles at Xinjiang Agricultural University had no carcinogenic risk to human body, and the pollution of Zn and Cd were relatively severe, so Urumqi City should take corresponding control measures in time.