Duan Hai-Jing, Shen Hao-Xin, Peng Chao-Yue, Ren Chong, Wang Yan-Feng, Liu De-Xin, Wang Yu-Long, Guo Rui-Chao, Ma Jian-Hua
College of Geography and Environmental Science, Henan University, Kaifeng 475004, China.
Key Laboratory of Geospatial Technology for the Middle and Lower Yellow River Regions, Ministry of Education, Henan University, Kaifeng 475004, China.
Huan Jing Ke Xue. 2024 Jun 8;45(6):3502-3511. doi: 10.13227/j.hjkx.202307013.
In order to reveal the influence of urban transportation systems on the quality of urban ecological environment, this study selected surface dust from bus stops, which is strongly disturbed by transportation, as the research object. The contents of eight heavy metals (V, Cr, Co, Ni, Cu, Zn, Cd, and Pb) in the dust were determined through inductively coupled plasma mass spectrometry (ICP-MS) and inductively coupled plasma atomic emission spectroscopy (ICP-ASE). The spatial distribution characteristics and pollution levels of the eight heavy metals in the dust were analyzed using the geo-accumulation index method. A combined qualitative (correlation analysis and principal component analysis) and quantitative (absolute principal component scores-multiple linear regression model (APCS-MLR)) method was used to explore the sources of heavy metals in surface dust near bus stops. The spatial distribution characteristics of heavy metals from different sources were elucidated using the Kriging interpolation method. The health risk assessment model proposed by the United States Environmental Protection Agency was used to evaluate the human health risks. The results showed that the average values of (V), (Cr), (Co), (Ni), (Cu), (Zn), (Cd), (Pb), and (As) in the bus stop surface dust were 68.36, 59.73, 5.81, 19.34, 40.10, 208.32, 1.01, and 49.46 mg·kg, respectively. The concentrations of heavy metals (Cd, Zn, Pb, Cu, and Cr) in the dust were all higher than the background values in the surrounding dust, exceeding them by 3.37, 2.70, 2.01, 1.95, and 1.28 times, respectively. The order of the geo-accumulation index for the eight heavy metals was Cd > Zn > Pb > Cu > Cr > V > Ni > Co, with Cd, Zn, Cu, and Pb in the dust indicating mild pollution levels and the others showing no pollution. The source analysis results showed that Cr, Co, and Ni were natural sources, whereas Cu, Zn, Pb, and Cd were traffic sources, and V was derived from a combination of industrial and natural sources. The APCS-MLR results indicated that the average contribution rates of the four sources were as follows:natural source (34.17 %), traffic source (29.84 %), industrial-natural mixed source (14.64 %), and unknown source (21.35 %). The spatial distribution map of the contribution rate of the traffic source was consistent with the trends of traffic volume and bus route density distribution. According to the health risk assessment, the cancer risk and non-cancer risk for children were both higher than those for adults. Cr was the main non-cancer factor, and Cd was the main cancer-causing factor. Natural and traffic sources contributed the most to non-cancer risk and cancer risk, respectively.
为揭示城市交通系统对城市生态环境质量的影响，本研究选取受交通强烈干扰的公交站点地表灰尘作为研究对象。通过电感耦合等离子体质谱法（ICP-MS）和电感耦合等离子体原子发射光谱法（ICP-AES）测定灰尘中8种重金属（V、Cr、Co、Ni、Cu、Zn、Cd和Pb）的含量。采用地累积指数法分析灰尘中8种重金属的空间分布特征和污染水平。运用定性（相关性分析和主成分分析）与定量（绝对主成分得分-多元线性回归模型（APCS-MLR））相结合的方法探究公交站点附近地表灰尘中重金属的来源。利用克里金插值法阐明不同来源重金属的空间分布特征。采用美国环境保护局提出的健康风险评估模型评估人体健康风险。结果表明，公交站点地表灰尘中（V）、（Cr）、（Co）、（Ni）、（Cu）、（Zn）、（Cd）、（Pb）和（As）的平均值分别为68.36、59.73、5.81、19.34、40.10、208.32、1.01和49.46 mg·kg。灰尘中重金属（Cd、Zn、Pb、Cu和Cr）的浓度均高于周边灰尘的背景值，分别超出3.37、2.70、2.01、1.95和1.28倍。8种重金属的地累积指数顺序为Cd＞Zn＞Pb＞Cu＞Cr＞V＞Ni＞Co，灰尘中的Cd、Zn、Cu和Pb表明为轻度污染水平，其他则无污染。源分析结果表明Cr、Co和Ni为自然源，而Cu、Zn、Pb和Cd为交通源，V来自工业源和自然源的混合。APCS-MLR结果表明4种来源的平均贡献率如下：自然源（34.17%）、交通源（29.84%）、工业-自然混合源（14.64%）和未知源（21.35%）。交通源贡献率的空间分布图与交通量和公交线路密度分布趋势一致。根据健康风险评估，儿童的致癌风险和非致癌风险均高于成人。Cr是主要的非致癌因素，Cd是主要的致癌因素。自然源和交通源分别对非致癌风险和致癌风险贡献最大。
