Platinum-group and other traffic-related heavy metal contamination in road sediment, Guangzhou, China

Abstract

Purpose Human exposure to particulate matter emitted from on-road motor vehicles includes complex mixtures of heavy metals from tyres, brakes, part wear, and resuspended road sediment. The purpose of this study was to determine the concentrations of 14 platinum-group and other trafficrelated heavy metals in road sediment within the metropolitan area of Guangzhou, China, with a view to identifying their sources and assessing the extent of anthropogenic influence on heavy metal contamination of road sediment. Materials and methods Thirty-five samples of road sediment were collected. The concentrations of Cr, Mn, Ni, Cu, Zn, La, Ce, Mo, Cd, Pb, Ba, and Rh were measured by inductively coupled plasma-mass spectrometry. Pt and Pd were analyzed by isotopic dilution-inductively coupled plasma-mass spectrometry. Multivariate statistical analysis and enrichment factor methods were employed to identify the sources of these heavy metals and to assess anthropogenic influences on their occurrence. Results and discussion The mean concentrations of Pt, Pd, Rh, Cr, Mn, Ni, Cu, Zn, La, Ce, Mo, Cd, Pb, and Ba in the road sediment samples were 68. 24, 93.15, 23.85, 147.5, 712.3, 47.24, 177.5, 1254, 47.50, 96.62, 4.91, 3.00, 198.1, and 641.3 ng g −1 , respectively. Very weak to significant linear positive correlations were found among the various heavy metals. The elemental composition of road sediment was dominated by five principal components. Three clusters were identified through cluster analysis, and enrichment factors were calculated relative to soils in China. The sources and degree of contamination of the heavy metals are discussed based on the results. Conclusions The mean concentrations of heavy metals are higher than background values, especially for Pt, Pd, Rh, Cd, and Zn. Four main sources are identified: (1) Pt, Pd, and Rh were derived from traffic sources; (2) La, Ce, Mn, and Ba were derived mainly from natural sources; (3) Cr, Ni, Cu, Mo, Cd, and Pb showed mixed traffic-industry sources; and (4) Zn originated mainly from industrial sources. Enrichment factor analysis supported this source identification and further indicated that contamination of road sediment in Guangzhou is extremely high for Pt, Pd, and Rh; moderate to very high for Cd, Zn, Pb, Cu, and Mo; and minimal for Cr, Ni, La, Ce, and Ba.

A method for determination of PGE–Re concentrations and Os isotopic compositions in environmental materials

“…Automobile catalytic converters are the only known source of road dust PGE in the Guangzhou region. 9,14,29 The Os concentrations in Guangzhou road dust samples displayed a narrow range from 0.05 to 0.08 ng g À1 (mean of 0.07 AE 0.01 ng g À1 ), and 187 Os/ 188 Os ratios range from 0.82 to 1.23 (mean of 1.08 AE 0.17). These values are consistent with those in Guangzhou road dust samples reported by Qi et al 14 (Fig.…”

“…Fig.1Road dust sampling sites with their corresponding average daily traffic in the brackets. Revised from the study of Zhong et al29 …”

Fingerprinting and tracing the sources of soils and sediments: Earth and ocean science, geoarchaeological, forensic, and human health applications

“…Numerous studies have qualitatively inferred the sources of sediment in urban aquatic systems (e.g., rivers, lake/reservoirs and estuaries; Charlesworth et al, 2000;Zhong et al, 2012). Many of these have used multivariate statistical approaches such as principal components analysis (PCA) and cluster analysis (CA) to match the contaminant properties of sediment (e.g., metals, PCBs) to those of potential sources.…”

Identification of traffic-related metals and the effects of different environments on their enrichment in roadside soils along the Qinghai–Tibet highway

“…In addition to Pb, the heavy metals Cd, Cr, Cu, Ni and Zn were later recognized and examined in roadside environments (Münch, 1993;Viard et al, 2004). Many other elements, such as As, Co, Sb, Se, Sr, V and the Pt group heavy metals, have been shown to have increased contents in soils near roads with heavy traffic (Thorpe and Harrison, 2008;Zhong et al, 2012). The Pt group heavy metals in particular have attracted much attention as roadside contaminants as a result of their use in catalytic converters (Bozlaker et al, 2013).…”