Magnetic records of heavy metal pollution in urban topsoil in Lanzhou, China

Abstract

This study is a systematic analysis of the magnetic characteristics and heavy metal elements in soil samples collected from Lanzhou City, China. The 117 surface soil samples were measured to study the feasibility and effectiveness of environmental magnetism for evaluating heavy metal pollution in urban soils. Results of the study indicate that low-coercivity magnetite dominates the magnetic properties in the samples. The high values of the soil magnetic mineral concentration parameters and low values of magnetic particle size parameters are distributed throughout the northern area of Xigu District, the industrial zones of the eastern section of Chengguan District and the districts of the narrow sections connecting Chengguan District and the other three districts; these parameters are fundamentally consistent with the distribution of the high values of the Pollution Load Index and Nemerow Pollution Index. Semi-quantitative studies which use the environmental magnetic method to monitor pollution of heavy metals (such as As, Cr, Cu, Ni, Pb, Zn, and Fe) Chin Sci Bull, 2013, 58: 384395, doi: 10.1007 Anthropogenic activities, especially industrial processes, give rise to harmful emissions containing various magnetic minerals occurring in different amounts. These emissions are absorbed by the soil, sediments and plants through the atmosphere and runoff processes, and then change the circulation and existing conditions of the magnetic materials, therefore these special magnetic characteristics of the modern environment are all marked by human activities. The structure, type, concentration and particle size of these magnetic particles differ from those of the primary and secondary magnetic minerals occurring in the environment [1][2][3][4][5][6][7]. Moreover, magnetic particles are associated with elevated metal concentrations [8][9][10][11][12][13][14], especially Cu, Pb and Zn originating from paint, fuel additives, tyres and particulates from moving parts. Most researchers [15][16][17] consider that the heavy metals caused by combustion, such as copper, chromium, arsenic, zinc and lead, are always accompanied by iron oxide, and magnetic particles are strongly adsorbent and carriers of heavy metals, so the magnetic parameters may be an effective indicator of the content of certain pollutants. Environmental magnetism has become one of the main focuses of current research in pollution history reconstruction, monitoring the present environmental pollution, and tracing and separating the sources of pollution. The atmosphere [18][19][20][21], street dustfall [22][23][24][25], soil [1][2][3][4][5][6][7][8][9][10][11], sediment [12][13][14], leaves [26][27][28][29] and tree rings [30] are usually used as the research targets. Analysis is developed from a single Wang B, et al. Chin Sci Bull January (2013) Vol.58 No.3 385 pollution source to multiple pollution sources and multivariate data analysis, and in some studies semi-quantitative models are created. Low field magnetic susceptibility measurements have been succes...

Geochemical evidence for seasonal variations in potential loess sources of the western Chinese Loess Plateau

“…At the present sample site, previous studies have found that the pollutants are mainly Zn, Cd, Cr, Cu, As, Pb, Sb, Se, and Mo (e.g., Xiao et al, 2010Xiao et al, , 2013Xiao et al, , 2014Zhang et al, 2011;Lin et al, 2012;Wang et al, 2012Wang et al, , 2013, and this was confirmed in the present study by the principal component analysis (PCA) of the elements in the fallout. For instance, for all samples collected, the PCA results show that six principal components (PCs) were extracted (Table S2).…”

Method Development and Surface Utilization: Monitoring Environment in Urban Society Through Analytical Chemistry

“…There were more reports on each particular problem relating to the environment of the urban area. One type of pollution can be traced back to the metal contamination in soils, heavy metal and magnetic properties of topsoil (Wang et al, 2013).…”

Magnetic measurements of roadside topsoil pollution in an active volcanic region: Mt. Hakusan, Japan

“…, Wang et al . ). Although such environmental magnetic investigations have been applied widely in various locations and countries, only a very few systematic magnetic investigations have been reported in Japan on the spatial distribution of roadside pollution (Kawasaki et al .…”

“…Environmental magnetic investigations of roadside topsoil have been shown to be a highly efficient method for studying the spatial distribution of dust particles derived from passing vehicles because such investigations are nondestructive, rapid, and cost-effective (e.g. Hoffmann et al 1999, Wang et al 2013. Although such environmental magnetic investigations have been applied widely in various locations and countries, only a very few systematic magnetic investigations have been reported in Japan on the spatial distribution of roadside pollution (Kawasaki et al 2015(Kawasaki et al , 2017.…”