title: Metal contamination in campus dust of Xi'an, China: a study based on multivariate statistics and spatial distribution.
abstract: The concentrations of As, Ba, Co, Cr, Cu, Mn, Ni, Pb, V and Zn in campus dust from kindergartens, elementary schools, middle schools and universities of Xi'an, China were determined by X-ray fluorescence spectrometry. Correlation coefficient analysis, principal component analysis (PCA) and cluster analysis (CA) were used to analyze the data and to identify possible sources of these metals in the dust. The spatial distributions of metals in urban dust of Xi'an were analyzed based on the metal concentrations in campus dusts using the geostatistics method. The results indicate that dust samples from campuses have elevated metal concentrations, especially for Pb, Zn, Co, Cu, Cr and Ba, with the mean values of 7.1, 5.6, 3.7, 2.9, 2.5 and 1.9 times the background values for Shaanxi soil, respectively. The enrichment factor results indicate that Mn, Ni, V, As and Ba in the campus dust were deficiently to minimally enriched, mainly affected by nature and partly by anthropogenic sources, while Co, Cr, Cu, Pb and Zn in the campus dust and especially Pb and Zn were mostly affected by human activities. As and Cu, Mn and Ni, Ba and V, and Pb and Zn had similar distribution patterns. The southwest high-tech industrial area and south commercial and residential areas have relatively high levels of most metals. Three main sources were identified based on correlation coefficient analysis, PCA, CA, as well as spatial distribution characteristics. As, Ni, Cu, Mn, Pb, Zn and Cr have mixed sources - nature, traffic, as well as fossil fuel combustion and weathering of materials. Ba and V are mainly derived from nature, but partly also from industrial emissions, as well as construction sources, while Co principally originates from construction.
authors.affiliation: School of Tourism and Environment, Shaanxi Normal University, Xi'an 710062, PR China.
authors.forename: Hao
authors.initials: H
authors.lastname: Chen
authors.affiliation: School of Tourism and Environment, Shaanxi Normal University, Xi'an 710062, PR China. Electronic address: luxinwei@snnu.edu.cn.
authors.forename: Xinwei
authors.initials: X
authors.lastname: Lu
authors.affiliation: Department of Civil Engineering, University of British Columbia, Vancouver V6T 1Z4, Canada. Electronic address: lli@civil.ubc.ca.
authors.forename: Loretta Y
authors.initials: LY
authors.lastname: Li
authors.affiliation: School of Tourism and Environment, Shaanxi Normal University, Xi'an 710062, PR China.
authors.forename: Tianning
authors.initials: T
authors.lastname: Gao
authors.affiliation: School of Tourism and Environment, Shaanxi Normal University, Xi'an 710062, PR China.
authors.forename: Yuyu
authors.initials: Y
authors.lastname: Chang
mesh_terms: D002681:China; D016000:Cluster Analysis; D004391:Dust / Q000032:analysis*; D004784:Environmental Monitoring; D004787:Environmental Pollution / Q000706:statistics & numerical data*; D008670:Metals / Q000032:analysis*; D025341:Principal Component Analysis; D012574:Schools / Q000706:statistics & numerical data*; D012987:Soil / Q000737:chemistry; D012989:Soil Pollutants / Q000032:analysis*; D062211:Spatio-Temporal Analysis
chemical_list: D004391:Dust; D008670:Metals; D012987:Soil; D012989:Soil Pollutants
keywords: Dust; Metals; Multivariate statistics; Source; Spatial analysis