New magnetic proxies to reveal source and bioavailability of heavy metals in contaminated soils.

Environmental magnetism plays an important role in monitoring heavy metal pollution, but most studies are confined to indicating only the levels of heavy metals using magnetic parameters. This study established new magnetic proxies for accurately depicting the sources and bioavailability of heavy metals in contaminated soils. We observed different relationships between χ and SIRM in the soils contaminated by non-ferrous metal smelting compared to those polluted by coal combustion and steel smelting.

Inputs and sources of Pb and other metals in urban area in the post leaded gasoline era.

The contamination status of heavy metals in urban environment changes frequently with the industrial structure adjustment, energy conservation and emission reduction and thus requires timely investigation. Based on enrichment factor, multivariate statistical analysis and isotope fingerprinting, we assessed comprehensively the inputs and sources of heavy metals in different samples from an urban area that was less impacted by leaded gasoline exhaust. The road dust contained relatively high levels of Cr, Pb and Zn (with enrichment factor >2) that originated from both exhaust and non-exhaust traffic emissions, while the moss plants could accumulate high levels of Pb and Zn from the deposition of traffic exhaust emission.

Comparison of heavy metal bioaccessibility between street dust and beach sediment: Particle size effect and environmental magnetism response.

Direct ingestion of urban sediment particles represents an important pathway of human exposure to heavy metals. The effect of particle sizes on metal bioaccessibilities in human digestive system has not been fully understood. In this study, an in-vitro simulation experiment (PBET), along with environmental magnetic measurements, is conducted on two urban sediments (street dusts and beach sediments) with different particle sizes (Φ31.

Geochemical cycle of mercury associated with wet deposition and inflows in a subalpine wetland.

Subalpine wetland is a mercury (Hg) sensitive ecosystem, but there is poor understanding of Hg behavior in this typical wetland. Here, distribution and speciation of Hg in waters of a subalpine wetland (Dajiuhu) in China were investigated, and an initial model of the Hg geochemical cycle in the wetland was established based on Hg mass balance calculations. Concentrations of both total Hg (THg, 9.

Distribution patterns and sources of heavy metals in soils from an industry undeveloped city in Southern China.

The accumulations of heavy metals in urban soils are derived from natural parent materials and complex anthropogenic emission sources. This paper investigated metal contamination in urban soils at an industry undeveloped city (Haikou) in southern China, an ideal place to quantitatively assess the contribution of metals from different sources. The concentrations of most heavy metals in the urban soils of Haikou were much lower than their guideline values and that of those from other big cities in China.

Effects of exogenous dissolved organic matter on the adsorption-desorption behaviors and bioavailabilities of Cd and Hg in a plant-soil system.

Dissolved organic matter (DOM) is one of the most active soil components and plays critical direct and indirect roles in heavy metal migration, transformation, bioavailability, and toxicity in soils. In this study, isothermal adsorption/desorption experiments and pot experiments were performed and samples were physically characterized to study the effects of different sources of DOM on adsorption and desorption behavior and bioavailability of Cd and Hg in a plant-soil system. The results showed that microbial DOM promoted Cd and Hg adsorption in soil and decreased Cd and Hg bioavailability to pak choi (Brassica chinensis Linn.

Profiles, source identification and health risks of potentially toxic metals in pyrotechnic-related road dust during Chinese New Year.

Potentially toxic metal (PTM) pollution in road dust is of great concern, however, our understanding of PTMs released by pyrotechnic displays and their adverse impacts on human health in road dust is limited. Here, we studied PTM pollution levels and Pb isotope signatures in pyrotechnic ash and road dust (aged dust and pyrotechnic-influenced dust) samples from eight cities in China during Chinese New Year and carried out a human health risk assessment. Pyrotechnic ash had higher values of Cr, Co, Ni, Cu, Zn, As, Sr and Pb but lower values of Mn and Cd than Chinese background soil.

Methylmercury production in a paddy soil and its uptake by rice plants as affected by different geochemical mercury pools.

The formation of neurotoxic methylmercury (MeHg) in paddy fields and its accumulation by rice plants is of high environmental concern. The contribution of different geochemical mercury (Hg) pools in paddy soils to MeHg production and its accumulation by rice seedlings is not well-studied up to now. Therefore, we investigated the impact of different inorganic Hg forms, including HgCl, nano-particulated HgS (nano-HgS), Hg bound with dissolved organic matter (Hg-DOM), β-HgS, and α-HgS, at levels of 5 mg Hg/kg soil and 50 mg Hg/kg soil, on the production of MeHg in the soil during rice growing season.

Apportionment of sources of heavy metals to agricultural soils using isotope fingerprints and multivariate statistical analyses.

Apportioning sources of environmental pollutants is key to controlling pollution. In this study, the sources of heavy metals to 234 agricultural soils from the Jianghan Plain (JHP) (∼22454 km) in central China were discriminated between using Cd and Pb isotope compositions and multivariate statistical analyses. Concentrations of some metals in JHP soils (0.

Source discrimination of atmospheric metal deposition by multi-metal isotopes in the Three Gorges Reservoir region, China.

Concentrations of heavy metals, as well as isotopic compositions of mercury (Hg) and lead (Pb), in mosses (Bryum argenteum) from the Three Gorges Reservoir (TGR) region were investigated to decipher the sources of atmospheric metals in this region. Higher contents of metals (0.90 ± 0.