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Shi G.,Polar Research Institute of China | Chen Z.,East China Normal University | Bi C.,East China Normal University | Wang L.,East China Normal University | And 3 more authors.
Atmospheric Environment | Year: 2011

Urban and suburban road dust samples were collected in the most populated city of China, Shanghai. Size fractions of dust particles were analyzed; metal levels of the dust were also measured. Human exposure to individual toxic metals through road dust was assessed for both children and adults. The results showed that dust particles from urban and suburban road were presented similar size distribution pattern, with most particles in the range of 100-400μm. Urban road dust consisted of higher proportions of inhalable, thoracic and respirable particles with increased risk of adverse effects to human. In general, mean grain sizes of urban road dust were smaller than suburban dust. Total organic carbon contents and levels of Pb, Cd, Cu, Zn, Ni, Cr in urban dust were higher than those of suburban dust. But the concentrations of As and Hg from suburban dust were higher, indicting a different main source. The exposure pathway which resulted in the highest level of risk for human exposed to road dust was ingestion of this material, which was followed by dermal contact. Except for some locations, risk values of both cancer and non-cancer obtained in this study were in the receivable range on the whole. Children had greater health risks than adults. The overall risks of non-cancer in urban area were higher than those in suburban area, but the values of cancer in the two areas were comparable. As for the aggregate noncarcinogenic risk, Pb was of most concern regarding the potential occurrence of health impacts. Of the three carcinogenic metals As, Cr and Cd, the only mean risk higher than 10-6 was Cr, accounting for a great percentage (95%) of the overall risk of cancer. Hence, potentially adverse health effects arising from Pb and Cr in road dust should arouse wide concern. © 2010 Elsevier Ltd.

Shi G.,Polar Research Institute of China | Shi G.,East China Normal University | Chen Z.,East China Normal University | Bi C.,East China Normal University | And 4 more authors.
Environmental Pollution | Year: 2010

A set of toxic metals, i.e. As, Hg, Pb, Cd, Cu, Zn, Ni and Cr, in urban and suburban SDSs were investigated comparatively in the biggest metropolitan area of China, Shanghai. Results showed that all of the metals except As were accumulated greatly, much higher than background values. Geo-accumulation index indicated that metal contamination in urban SDSs was generally heavier than that in suburban SDSs. Potential ecological risk index demonstrated that overall risks caused by metals were considerable. Cd contributed 52% to the overall risk. Multivariate statistical analysis revealed that in urban SDSs, Zn, Ni, Cd, Pb, Cu and Cr were related to traffic and industry; coal combustion led to elevated levels of Hg; soil parent materials controlled As contents. In suburban SDSs, Pb, Cu, As and Cd largely originated from traffic pollution; Zn, Ni and Cr were associated with industrial contaminants; Hg was mainly from domestic solid waste. © 2009 Elsevier Ltd. All rights reserved.

Shi G.,Polar Research Institute of China | Shi G.,Brown University | Teng J.,Shanghai Chongming Dongtan National Nature Reserve | Ma H.,Polar Research Institute of China | And 2 more authors.
Global Biogeochemical Cycles | Year: 2015

Metals and metalloids in continental precipitation have been widely observed, but the data over open oceans are still very limited. Investigation of metals and metalloids in marine precipitation is of great significance to understand global transport of these elements in the atmosphere and their input fluxes to the oceans. So shipboard sampling of precipitation was conducted during a Chinese National Antarctic Research Expedition campaign from Shanghai, China, to Zhongshan Station, East Antarctica, and 22 samples (including 17 rainfall and 5 snowfall events) were collected and analyzed for concentrations of Pb, Ni, Cr, Cu, Co, Hg, As, Cd, Sb, Se, Zn, Mn, and Ti. Results show that concentrations of both metals and metalloids vary considerably along the cruise, with higher concentrations at coastal sites and lower values on the south Indian Ocean. Although only soluble fractions were determined for elements, concentrations in this study are generally comparable to the reported values of marine rain. Enrichment factor analysis shows that most of metals and metalloids are enriched versus crustal sources, even in the samples collected from remote south Indian Ocean. In addition, metals and metalloids in precipitation are also very enriched above sea-salt abundance, indicating that impacts of sea-salt aerosols on their concentrations are negligible. Main sources of metals and metalloids were explored with the aid of multivariate statistical analyses. The results show that human emissions have far-reaching distribution, which may exert an important influence on the solubility of elements in precipitation. This investigation provides valuable information on spatial variation and possible sources of trace elements in precipitation over the open oceans corresponding to understudied region. © 2015. American Geophysical Union. All Rights Reserved.

Shi G.,Polar Research Institute of China | Shi G.,East China Normal University | Chen Z.,East China Normal University | Teng J.,Shanghai Chongming Dongtan National Nature Reserve | And 5 more authors.
Environmental Research | Year: 2012

In China's largest city, Shanghai, dry deposition fluxes of Cd, Pb, As and Hg were 137, 19354, 2897 and 9.4μgm -2a -1, respectively in an urban area, intermediate in a suburban area, and 51.7, 5311, 1703 and 7.3μgm -2a -1, respectively in a rural area. Enrichment factors were Cd>Pb>As>Hg. Seasonal variations of metals differed: Pb and As were dominated by fossil fuel combustion, Cd was related to industrial pollution, and natural source controlled Hg levels. © 2012 Elsevier Inc.

Shi G.,Polar Research Institute of China | Shi G.,East China Normal University | Chen Z.,East China Normal University | Teng J.,Shanghai Chongming Dongtan National Nature Reserve | Li Y.,Polar Research Institute of China
Tellus, Series B: Chemical and Physical Meteorology | Year: 2015

A 12-month investigation of total mercury (Hg) in event-based precipitation was performed in China's biggest industrial base, Yangtze River Delta, a hotspot of anthropogenic Hg emissions. Concentrations of total Hg in precipitation were measured, and the spatial and temporal variations of Hg were addressed. The results show that Hg concentrations (median=92 ng L-1) are comparable to the reports of other cities in China, but higher than those of remote sites. In spatial, Hg levels are significantly higher in urban and suburban precipitation than in rural samples. The pH, precipitation depth and antecedent drying period appear to be potential factors influencing Hg concentrations in precipitation, but in general no strong correlation was found between Hg and individual parameters. A seasonal variation of Hg in precipitation was found, and the concentrations in winter are generally higher, possibly associated with fossil fuel combustion. In addition, the dominant wind direction was found to be a factor influencing seasonal pattern of Hg by atmospheric transport of air pollutants. The backward trajectories suggest that local sources, for example, emissions from coal combustion and industry activities, are possibly important contributors to Hg in precipitation. © 2015 G. Shi et al.

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