| 摘要: |
| 为进行西安市秋冬季PM2.5中金属元素来源解析及健康风险评价，采集2019年10月至2020年1月的PM2.5颗粒物样品，实验分析样品中PM2.5及8种金属元素浓度。结果表明：采样期间西安市PM2.5平均质量浓度为99.44 µg∙m−3，是国家环境空气质量二级标准值的1.3倍，世界卫生组织指导标准值的6.6倍；金属元素浓度大小依次为Al＞Zn＞Mn＞Pb＞Cu＞As＞Cr＞Ni。随着污染等级增加，Pb增幅最大，Cr增幅最小。富集因子结果表明重金属元素浓度受人为污染影响明显，Pb和Zn因子高达194.9和172.2。相关性分析表明Zn-Mn-Cu、As-Pb存在较强相关性。PMF源解析结果表明PM2.5中金属元素的主要来源为扬尘源、交通源、燃煤源和工业源，贡献率分别为42.6%、29.6%、24.6%和3.2%。利用EPA健康风险暴露模型评估金属元素对成人和儿童的非致癌及致癌风险水平，发现Cr对成人存在致癌风险，As对儿童具有非致癌风险。成人的致癌风险主要途径为呼吸吸入，儿童则为手口摄入途径。燃煤源对成人和儿童的非致癌风险及致癌风险贡献较大。 |
| 关键词: PM2.5 金属 来源解析 健康风险 |
| DOI：10.7515/JEE232030 |
| CSTR：32259.14.JEE232030 |
| 分类号: |
| 基金项目:中国科学院“西部之光”人才培养引进计划（XAB2021YN06） |
| 英文基金项目:CAS “Light of West China” Program (XAB2021YN06) |
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| Source apportionment and health risk assessment of metals in PM2.5 during autumn-winter of 2019 in Xi’an City |
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ZHANG Yongle, LI Haihong, ZHANG Yingliang, LIU Fan, ZHANG Ningning
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1. College of Environmental and Chemical Engineering, Xi’an Polytechnic University, Xi’an 710048, China
2. Chang’an Branch of Xi’an Ecological Environment Bureau, Xi’an 710100, China
3. Xi’an Institute for Innovative Earth Environment Research, Xi’an 710061, China
4. Key Laboratory of Aerosol Chemistry & Physics, Institute of Earth Environment, Chinese Academy of Sciences, Xi’an 710061, China
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| Abstract: |
| Background, aim, and scope In recent years, PM2.5 has become one of the most severe air pollutants worldwide and an essential factor in forming “smog” during the autumn-winter period. Xi’an, an important city in terms of economy and culture in China, suffers from heavy air pollution events in autumn and winter, seriously affecting local people’s health. Therefore, conducting a metal source and health risk assessment of PM2.5 in Xi’an during autumn and winter is essential to control air pollution and reduce human health threats. Materials and methods PM2.5 filter samples were collected from October 2019 to January 2020 in Xi’an City, and the concentrations of eight metal elements (Al, Cr, Mn, Ni, Cu, Zn, As, and Pb) were analyzed. Combined with enrichment factor and correlation analysis, the source analysis of metal elements was conducted through the positive matrix factorization model (PMF). Finally, the EPA health risk model and PMF analysis results were used to evaluate the non-carcinogenic and carcinogenic risks of metallic elements in adults and children. Results During the sampling period, the average mass concentration of PM2.5 in Xi’an was 99.44 µg·m−3, and the enrichment factors of Zn (172.2) and Pb (194.9) among the eight metal elements were high. The correlation between Zn-Mn (0.85), Mn-Cu (0.67) and Cu-Zn (0.66) was significant. The sources of the eight metal elements were dust, traffic, coal-burning, and industrial sources, with their contributions being 42.6%, 29.6%, 24.6%, and 3.2%. The respiratory inhalation pathway is the main pathway of non-carcinogenic risk and carcinogenic risk in adults, and the main path of carcinogenic risk in children is hand-mouth ingestion. The primary sources of non-carcinogenic risk for adults and children from metals in PM2.5 in Xi’an in the autumn and winter of 2019 were traffic and coal-burning sources, while the primary sources of carcinogenic risk were dust and coal-burning sources and industrial sources. Discussion During the sampling period, the average mass concentration of PM2.5 in Xi’an was 1.3 times higher than the national standard (35 μg·m−3) and 6.6 times higher than the WHO standard (15 μg·m−3). The cumulative average concentration of 8 metal elements in PM2.5 is 990.58 ng·m−3, with the concentration of Cr was 22.4 times higher than the WHO standard (0.25 ng·m−3). From moderate quality to hazardous quality, the concentrations of metal elements all manifested an escalating trend, with Pb exhibiting the most significant increase. Zn and Pb were seriously affected by anthropogenic pollution. Zn-Mn-Cu and As-Pb had a strong correlation, indicating that these elements may have a common source. The primary sources of metals in PM2.5 in Xi’an City are attributed to dust, traffic, and coal-burning. Cr had a cancer risk in adults, and As had a non-cancer risk in children. Coal burning was the primary source that contributed the most to the non-carcinogenic risk and carcinogenic risk in adults and children. Conclusions The primary sources of eight metals in PM2.5 in Xi’an were dust, traffic, coal-burning, and industrial sources. There were non-carcinogenic risks and carcinogenic risks for adults and children, and coal-burning sources contribute more to the health risks of adults and children. Recommendations and perspectives To reduce heavy metal pollution in Xi’an and the threat to people’s health, attention should be paid to the impact of coal burning, traffic, and dust sources. Coal burning should be strictly controlled to reduce pollutant emissions. |
| Key words: PM2.5 metals source apportionment health risk |
