Distribution of environmentally sensitive elements in residential soils near a coal-fired power plant: Potential risks to ecology and children’s health

One hundred and twelve soil samples were collected from residential areas surrounding a coal-fired power plant at Huainan City, Anhui Province, China. The concentrations of environmentally sensitive elements (ESEs As, Cd, Cr, Cu, Hg, Mn, Ni, Pb, V and Zn) in soil samples were determined, and their potential ecological and health risks were assessed. Mean concentrations of ESEs in the downwind soils of the power plant are relatively higher than those in the upwind soils, pointing to a potential ESEs input from coal combustion. The calculated ecological risk of ESEs in soils indicates a relatively low ecological risk. Hazard quotient (HQ) of ESEs in downwind soils is 1.5, suggesting a potential health risk for children. However, the carcinogenic risk values of ESEs in soils are within the acceptable non-hazardous range of 1E−06–1E−04.     

Contamination by arsenic and other trace elements of tube-well water along the Mekong River in Lao PDR

Arsenic and other trace element concentrations were determined for tube-well water collected in the Lao PDR provinces of Attapeu, Bolikhamxai, Champasak, Savannakhet, Saravane, and Vientiane. Water samples, especially from floodplain areas of central and southern Laos, were significantly contaminated not only with As, but with B, Ba, Mn, U, and Fe as well. Total As concentrations ranged from <0.5 μg L⁻¹ to 278 μg L⁻¹, with over half exceeding the WHO guideline of 10 μg L⁻¹. 46% of samples, notably, were dominated by As(III). Samples from Vientiane, further north, were all acceptable except on pH, which was below drinking water limits. A principal component analysis found associations between general water characteristics, As, and other trace elements. Causes of elevated As concentrations in Lao tube wells were considered similar to those in other Mekong River countries, particularly Cambodia and Vietnam, where young alluvial aquifers give rise to reducing conditions.     

Concentration of trace elements in feathers of three Antarctic penguins: Geographical and interspecific differences

Antarctica is often considered as one of the last pristine regions, but it could be affected by pollution at global and local scale. Concentrations of Al, Cr, Mn, Fe, Ni, Cu, Zn, As, Se, Cd and Pb were determinated by ICP-MS in feathers (n = 207 individuals) of gentoo, chinstrap and Adélie penguin collected in 8 locations throughout the Antarctic Peninsula (2006-2007). The highest levels of several elements were found in samples from King George Island (8.08, 20.29 and 1.76 μg g⁻¹ dw for Cr, Cu and Pb, respectively) and Deception Island (203.13, 3.26 and 164.26 μg g⁻¹ dw for Al, Mn and Fe, respectively), where probably human activities and large-scale transport of pollutants contribute to increase metal levels. Concentrations of Cr, Mn, Cu, Se or Pb, which are similar to others found in different regions of the world, show that some areas in Antarctica are not utterly pristine.     

Interactions between accumulation of trace elements and macronutrients in Salix caprea after inoculation with rhizosphere microorganisms

Although the beneficial effects on growth and trace element accumulation in Salix spp. inoculated with microbes are well known, little information is available on the interactions among trace elements and macronutrients. The main purpose of this study was to assess the effect of phytoaugmentation with the rhizobacteria Agromyces sp., Streptomyces sp., and the combination of each of them with the fungus Cadophora finlandica on biomass production and the accumulation of selected trace elements (Zn, Cd, Fe) and macronutrients (Ca, K, P and Mg) in Salix caprea grown on a moderately polluted soil. Dry matter production was significantly enhanced only upon inoculation with Agromyces sp. Regarding the phytoextraction of Cd and Zn, shoot concentrations were mostly increased after inoculation with Streptomyces sp. and Agromyces sp. + C. finlandica. These two treatments also showed higher translocation factors from roots to the leaves for both Cd and Zn. The accumulation of Cd and Zn in shoots was related to increased concentrations of K. This suggests that microorganisms that contribute to enhanced phytoextraction of Cd and Zn affect also the solubility and thus phytoavailability of K. This study suggests that the phytoextraction of Zn and Cd can be improved by inoculation with selected microbial strains.     

DISTRIBUTION AND GRAIN-SIZE PARTITIONING OF METALS IN BOVFOM SEDIMENTS OF AN EXPERIMENTALLY ACIDIFIED WISCONSIN LAKE1

ABSTRACT: A study of concentrations and distribution of major and trace elements in surficial bottom sediments of Little Rock Lake in northern Wisconsin included examination of spatial variation and grain-size effects. No significant differences with respect to metal distribution in sediments were observed between the two basins of the lake, despite the experimental acidification of one of the basins from pH 6.1 to 4.6. The concentrations of most elements in the lake sediments were generally similar to soil concentrations in the area and were well below sediment quality criteria. Two exceptions were lead and zinc, whose concentrations in July 1990 exceeded the criteria of 50 μg/g and 100 μg/g, respectively, in both littoral and pelagic sediments. Concentrations of some elements, particularly Cu, Pb, and Zn, increased along transects from nearshore to midlake, following a similar gradient of sedimentary organic carbon. In contrast, Mn, Fe, and alkali/alkaline-earth elements were at maximum concentrations in nearshore sediments. These elements are less likely to partition to organic particles, and their distribution is more dependent on mineralogical composition, grain size, and other factors. Element concentrations varied among different sediment grain-size fractions, although a simple inverse relation to grain size was not observed. Fe, Mn, Pb, and Zn were more concentrated in a grain-size range 20–60 tm than in either the very fine or the coarse fractions, possibly because of the aggregation of smaller particles cemented together by organic and Fe/Mn hydrous-oxide coatings.     

Trace elements in camel tissues from a semi-arid region

Trace and minor element concentrations differ in animal tissues as the result of the surrounding environment (feeding plants, soil contaminated with food and drinking water) and animal absorption of these elements. Concentrations of Ag, Au, Ca, Co, Cr, Cu, Fe, K, Mg, Mn, Na, Ni, and Zn were determined from different tissues of camel (inter-costal, scapula, sirloin, flank, front knuckle and front limb) from the semi-arid areas of the Aswan desert (Wadi El-Allaqi) and from Aswan city, Egypt. The study included an assessment of these same elements in the desert and city plants used as food by the camels and in soils from the study areas. The results reveal that camel tissues from the desert areas exhibited higher concentrations of Na, Mg, K, Au, Ag, Cu, Co and Zn than in those of the city camels. These higher levels of element are because of the high concentrations of the same elements in the desert plants and soil of the desert area. This, in turn, depends upon the geological formation differences between the desert area and the city area. Camel tissues appear to concentrate high levels of Mn, Ni, Co and Mg in the scapula while flank portions concentrate high levels of Mg and K. The levels of elements in the camel tissues under study were within the recommended safety baseline levels for camel health and human use, as well as within the appropriate limits in the desert and city plants for camel use.     

高邮地震台地电阻率观测精度干扰原因分析及排除方法

对高邮台地电NS向ρs的观测精度在2002 07 24雷雨后出现降低的现象进行了分析排查,发现是一交流接触器在遭雷击时烧坏,导致交流电三相中的一相对地漏电,与变压器中的零线形成回路所致。从而排除了配电房漏电的干扰,保证了观测资料的质量。     

MANGANESE IN LACUSTRINE ECOSYSTEMS: A REVIEW1

This paper serves as a literature review of manganese in fresh water. The major aspects of manganese occurrence discussed are: (1) sources, (2) geochemistry, (3) manganese-iron relationships, (4) effects on the fauna and flora and (5) detection.     

Radiocesium in North San Francisco Bay and Baja California coastal surface waters

Radiocesium, 137Cs, and rare earth elements (REEs) were determined in suspended material and dissolved fractions of waters across the salinity gradient in North San Francisco Bay (estuary). We describe the variation of this conservative isotope tracer with salinity and sediment load. REE data are used to differentiate marine and terrigenous source terrains for suspended material and dissolved fractions. We estimate that about 1-4 x 10(10) Bq of 137Cs migrates annually on suspended material through the North Bay. In addition, 137Cs concentrations were measured in surface waters off Baja California. Combined in situ water density (sigma(t)) and 137Cs data distinguish between California Current and Gulf of California water, and delineate areas of upwelling, where nutrient-rich, deep Pacific Intermediate water, with little or no 137Cs, is brought to the surface off promontories along Baja California.     

A FINITE ELEMENT MODEL OF CONTAMINANT MOVEMENT IN GROUNDWATER1

ABSTRACT. Transient, two-dimensional solutions are developed which describe the movement and distribution of a conservative substance in a stream-aquifer system. The solutions are obtained by solving sequentially the groundwater flow and mass transport equations. A variational approach in conjunction with the finite element method is used to solve the groundwater flow equation. Galerkin's approach coupled with the finite element method is used to solve the mass transport equation. Linear approximated triangular elements and a centered scheme of numerical integration are employed to calculate the hydraulic head distribution and the concentration of solute in the flow region. The linear approximation used to define the concentration function within each element is not appropriate for cases involving steep concentration gradients. For such cases, higher order approximations are necessary to assure the continuity of gradients across interelemental boundaries. Numerical examples that illustrate the applicability of the model are presented.