中国城市道路灰尘重金属污染的多维异质性解析：基于地域、城市规模与职能的Meta分析

Multidimensional Heterogeneity Analysis of Heavy Metal Pollution in Road Dust across Chinese Cities: A Meta-Analysis Based on Region, Scale, and Function

摘要: 城市快速发展使中国道路灰尘重金属污染愈加凸显，已严重影响城市居民健康。尽管道路灰尘污染研究受到广泛关注，但现有研究多局限于单一城市或相邻城市，缺乏全国尺度、跨区域、跨城市类型的系统整合和评估。该研究基于中国知网(CNKI)和Web of Science数据库2000~2024年间发表的61篇文献，采用Meta分析方法，系统评估了中国城市道路灰尘中Cr、Cd、Cu、Pb、Zn、Ni六种重金属的污染特征，并从地域、城市规模和城市职能三个维度进行异质性解析。结果表明，六种重金属的合并效应值均显著高于土壤背景值(95%置信区间均不包含0)，其中Cd的增幅最为突出，达1386.46%。亚组分析显示，东北地区Cd污染最重，西部地区Pb和Zn污染突出，东部地区呈现多种重金属复合污染特征；中小型城市污染水平普遍高于大城市和特大城市，而资源能源型和制造业城市重金属污染程度明显高于服务业城市。发表偏倚检验显示结果具有较好的稳健性。该研究为识别我国城市道路灰尘重金属污染的空间分异特征及制定差异化治理策略提供了科学依据。

Abstract: The rapid urbanization in China has exacerbated heavy metal pollution in road dust, posing a growing threat to the health of urban residents. Although road dust pollution has received extensive research attention, existing studies are largely confined to single cities or adjacent urban areas, leaving a gap in systematic integration and assessment at the national scale across regions and city types. Based on 61 peer-reviewed articles published between 2000 and 2024 in the CNKI and Web of Science databases, this study employed a meta-analytic approach to systematically evaluate the pollution characteristics of six heavy metals (Cr, Cd, Cu, Pb, Zn, and Ni) in road dust across Chinese cities. Heterogeneity was further analyzed from three dimensions: geographical region, urban scale, and urban function. The results showed that the pooled effect sizes of all six heavy metals were significantly higher than the corresponding soil background values (95% confidence intervals did not include zero), with Cd exhibiting the most pronounced increase of 1386.46%. Subgroup analysis revealed that Cd pollution was most severe in Northeast China, Pb and Zn pollution were prominent in Western China, and Eastern China displayed a multi-metal contamination pattern. In terms of urban scale, small and medium-sized cities generally exhibited higher pollution levels than large cities and megacities. Functionally, resource-based and manufacturing cities showed significantly higher heavy metal accumulation compared to service-oriented cities. Publication bias tests indicated that the results were robust. This study provides a scientific basis for identifying spatial heterogeneity in heavy metal pollution in urban road dust and for formulating differentiated pollution control strategies in Chinese cities.