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Showing papers on "Trace metal published in 1995"


Book ChapterDOI
TL;DR: In this article, the authors focus on the interaction between metal cations and dissolved polyfunctional organic compounds of low molecular weight and their potential role in heavy metal contamination of soil and groundwater.
Abstract: Publisher Summary This chapter focuses on the nature of interaction among trace metals in soil solution, dissolved organics in soil solution, and solid surfaces. The interaction between metal cations and dissolved polyfunctional organic compounds of low molecular weight is important because of its role in mineral-weathering and soil-forming processes and its potential role in heavy metal contamination of soil and groundwater. The chapter presents the organics and metals in the soil solution. Dissolved organics that interact with soil constituents and trace metal ions are of two major kinds: a range of low-molecular-weight organic acids—including polyphenols, simple aliphatic acids, amino acids, sugar acids, and hydroxamate siderophores; and a series of soluble humic/fulvic acids. Numerous environmental issues arise in relation to the interaction of metal ions with soluble organics. Some of these include the phytoavailability of metals, plant nutrient availability, toxicological effects of coordinated metal ions on aquatic and marine organisms, and transport of contaminants, particularly in relation to implications for surface and groundwater quality and soil genesis. All of these issues are highly dependent on the nature and concentration of the contaminant in the soil solution phase. Extant research indicates that low-molecular-weight ligands in soil solution may either enhance or retard reactions with solid surfaces—depending on the functional groups on the organic molecule, soil surface properties, and soil solution conditions. It is imperative that increased research efforts be devoted to evaluating the effects of these organics on metal reactions in the soil.

261 citations


Journal ArticleDOI
TL;DR: In this article, Wells et al. showed that the single largest reservoir of iron in the surface waters of HNLC regions may be the biota itself, and that the removal of iron from surface waters is fairly well constrained within a geochemical (i.e. mean residence time) perspective.

258 citations


Journal ArticleDOI
TL;DR: In this article, the authors show that colloidal material plays a fundamental role in determining the behavior of both conservative and non-conservative trace metals during estuarine mixing, and that colloids may control to a large extent the fate of trace metals as well as their net input from the rivers to the Kara Sea.

228 citations


Journal ArticleDOI
TL;DR: In this article, the authors examined the kinetics of desorption of Cd and Co from two Fe oxides, goethite and ferrihydrite, and from two Mn oxides (hausmannite and cryptomelane).
Abstract: Oxides of Fe and Mn in soils are capable of sorbing large amounts of trace metal ions and can therefore be important in controlling trace metal concentrations in soil solution, and hence trace metal bioavailability in soils. There is, however, relatively little information on the rates of desorption of trace metals from oxide materials or on the factors affecting desorption rates. The objective of this study was to examine the kinetics of desorption of Cd and Co from two Fe oxides, goethite and ferrihydrite, and from two Mn oxides, hausmannite and cryptomelane. The concentrations of Cd and Co specifically sorbed by the oxides at pH 6.0 were greater for the Mn oxides than for the Fe oxides. The metals were also much less readily desorbed from the Mn than the Fe oxides and, in general, Cd was more readily desorbed than Co from all four oxides. Increasing the initial sorption period from 1 to 15 wk substantially decreased the proportion of sorbed Cd or Co subsequently desorbed from goethite, with a similar but much smaller effect also observed with the Mn oxides. Desorption kinetics for both Cd and Co were found to be described well by assuming either the occurrence of two simultaneous first-order desorption reactions, or by a continuous distribution of reaction sites, distributed lognormally with respect to desorption first-order rate constant. With increasing initial sorption period, the parameters obtained from fitting either type of kinetic equation to the experimental data could be interpreted as indicating a movement of metal ions to sites with slower desorption reactions.

225 citations


Journal ArticleDOI
TL;DR: In this article, the authors found that the roots acted as effective filters for transport of metals to the shoots and rhizomes, and the rhizosphere may provide a particularly effective, locally oxidized environment for metal precipitation and adsorption outside the root.

183 citations


Journal ArticleDOI
TL;DR: A review of trace metal uptake over the last 30 years, evidence is sought for specific mechanisms controlling transepithelial metal uptake or loss, and their possible relationship with pumps controlling the regulation of physiologically-important electroytes.

179 citations


Journal ArticleDOI
TL;DR: In this article, the authors provided an overview of the geochemical features of large Chinese river/estuary systems. But they did not provide an estimate of the chemical flux of trace metals to the ocean through Chinese estuaries.
Abstract: Based on the data from extensive estuarine studies over 10 years (1983–93), the present work provides an overview of the geochemical features of large Chinese river/estuary systems. Elevated concentrations of major elements are observed in Chinese rivers from north to south, which is attributed to intense weathering and erosion over the drainage basins. Trace metal levels in Chinese rivers are relatively low and similar to those from large and less disturbed world aquatic systems (e.g. Amazon and Orinoco). In the estuaries, particulate elements show stable distributions in the mixing zone especially when absolute concentrations are normalized to aluminium and/or scandium. Dissolved trace metals may have either conservative and/or active (non-conservative) distributions or both in Chinese estuaries. Wherever non-conservative distributions are observed, trace elements may be remobilized and/or scavenged from solution depending upon river discharge, sedimentary dynamics and element. Biological uptake and regeneration of trace metals becomes more important in high salinity areas further offshore the riverine effluent plumes than inside. Correlation of heavy metals with grain size and operational chemical forms reveals a high proportion of elements associated with the fine size fraction compared to total sediments and elevated labile fractions in bottom sediments in anthropogenically disturbed systems. Finally, an estimate is made towards the chemical flux of trace metals to the ocean through Chinese estuaries.

173 citations


Journal ArticleDOI
TL;DR: Some crustaceans appear able to counteract to varying degrees such physicochemical effects by what appear to be physiological responses, for example, to low salinity, and cast light on the mechanisms of trace metal uptake by crustacean.

172 citations


Journal ArticleDOI
TL;DR: Down-core variations of aluminum-normalized enrichment factors for these metals demonstrate that the sediments of this estuary have remained relatively 'pristine' with respect to trace metal contamination since 1860.
Abstract: Sabine-Neches Estuary, near Beaumont, TX, receives wastewater effluents from over 160 industrial and municipal treatment plants. The concentrations of trace metals (Co, Cr, Cu, Ni, Pb, and Zn), Al, Fe, Mn, and organic carbon were determined in four dated sediment cores. A reliable geochronology and reconstruction of the history of trace metal inputs of these sediments was possible because the 239,240 Pu profiles closely trace the bomb fallout history into the environment. Down-core variations of aluminum-normalized enrichment factors for these metals demonstrate that the sediments of this estuary have remained relatively 'pristine' with respect to trace metal contamination since 1860. While the concentrations of Pb and Zn at various depths in the sediment column are slightly enriched, Co, Cr, Cu, and Ni are depleted. The sedimentary and biogenic particles that are presently being deposited are also depleted in trace metals. Lack of strong enrichment for trace metals like Cu can be attributed to the short residence time of water, low salinity conditions, and possibly strong complexation of these metals with organic matter.

163 citations


Book ChapterDOI
01 Jan 1995
TL;DR: In this article, the main features of the soil biogeochemical system governing the behaviour of trace elements are: (1) heterogeneous distribution of compounds and components; (2) seasonal and spatial alteration of major soil variables; (3) transformation of element species; (4) transfer between phases; and (5) bioaccumulation.
Abstract: Behaviour of trace metals in soils depends upon complex reactions among micro-and macro cations and anions, and different components of various soil phases: solid, aqueous and gaseous. The main features of the soil biogeochemical system governing the behaviour of trace elements are: (1) heterogeneous distribution of compounds and components; (2) seasonal and spatial alteration of major soil variables; (3) transformation of element species; (4) transfer between phases; and (5) bioaccumulation.

138 citations


Journal ArticleDOI
TL;DR: Evidence presented shows that the balance of trace metal ions is critical for normal skin and repair mechanisms following injury, and xenobiotic ions can impair this balance, leading to pathological change.
Abstract: The human environment contains more than 50 metal or metalloid elements. At least 15 are recognized as trace elements, with zinc, calcium, copper, magnesium, and iron having specific roles in skin morphogenesis and function. The present review focuses on the presumed role of metal ions in the skin, their competition for carrier proteins, and membrane receptors. Evidence presented shows that the balance of trace metal ions is critical for normal skin and repair mechanisms following injury. Xenobiotic ions can impair this balance, leading to pathological change. The skin acts as an organ of elimination of excess trace metals and xenobiotic ions from the body, but mechanisms of voidance vary for different metals.Metal ions are an important cause of allergies, and evidence is presented to show that the majority of metals or metal compounds can induce allergic changes. Except for chromium and nickel, which are among the most common human allergens, animal models have provided little information.At leas...

Journal ArticleDOI
TL;DR: The latest information on emissions and sources of trace metals can be found in this article, where the emission inventories for trace metals have become available only recently, and the information on trace metal sources and trace metal emissions have not yet been available.
Abstract: Global emission inventories, being the key information for the global budgets of trace metals, have become available only recently. The latest information on emissions and sources of trace metals o...

Journal ArticleDOI
TL;DR: The reproductive state and body size in C. iridescens exerts an important influence on the accumulation (and variability) of these trace metals, which may influence interpretations with respect to low chronic or short-term contamination.

Book ChapterDOI
01 Jan 1995
TL;DR: In this paper, the transformation and movement of selected trace metals, metalloids, and radionuclides between phases and/or compartments in lakes, arising from biologically and chemically mediated redox reactions, is discussed.
Abstract: This chapter encompasses the transformation and movement of selected trace metals, metalloids, and radionuclides between phases and/or compartments in lakes, arising from biologically and chemically mediated redox reactions. Thus, it is concerned with the spatial and temporal distributions and speciation of trace elements in solution, in suspended particles, and in sediments. It updates and complements an earlier overview (Sholkovitz 1985), which considered the redoxrelated behavior of alkaline earth elements and 137CS.

Journal ArticleDOI
TL;DR: High concentrations of PCBs were detected in sediments and organisms from Winter Quarters Bay, Antarctica, and induction of EROD activity in in vitro rat hepatoma H4IIE cell bioassays by tissue extracts correlated with known levels of PCB contamination in invertebrate tissues.
Abstract: Polycyclic aromatic hydrocarbons (PAH), polychlorinated biphenyls (PCBs), pesticides, and trace metal concentrations in McMurdo Sound and Arthur Harbor, Antarctica, sediments and marine biota are reported. Biomarkers of contaminant exposure, biliary metabolites and EROD assays, were also measured. Hydrocarbon and trace metal contamination are generally limited to within hundreds of meters of human settlements. Local releases of fossil fuels, disposal of waste materials, and aging of ship and station structures contribute to contamination. High concentrations of PCBs were detected in sediments (250-4200 ng g{sup -1}) and organisms (up to 420 ng g{sup -1}) from Winter Quarters Bay (WQB). Trace metal and PAH sediment concentrations rarely exceed levels known to cause toxic effects in marine organisms, whereas PCBs in WQB often do. Biological responses to exposure include the formation of PAH metabolites and the inducement of the P4501A detoxification system in fish. Induction of EROD activity in in vitro rat hepatoma H4IIE cell bioassays by tissue extracts correlated with known levels of PCB contamination in invertebrate tissues. Local sources of contaminants greatly exceed those attributable to long-distance atmospheric transport. 31 refs., 4 figs.

Journal ArticleDOI
TL;DR: Study into the partitioning of trace metals between the dissolved phase and suspended solids in two major UK estuaries found total extractable trace metals on the Mersey suspended sediment to be a factor of two greater than that found in the Humber.

Journal ArticleDOI
TL;DR: In this paper, the Tarnowskie Gory region, the most contaminated area of Upper Silesia, is contaminated with Cd, Pb and Zn, and the geometric means of concentrations of these elements in the soils are as follows ( in mg/kg, dry wt.): Cd 3.2; Pb 102.3; Zn 270.2.

Journal ArticleDOI
TL;DR: In this article, both dissolved and particulate trace metals (Cd, Co, Cu, Fe, Mn, Ni, Pb and Zn) were measured on samples collected simultaneously in the central and southern North Sea (below 56°N) during four cruises covering the seasonal cycle.
Abstract: Measurements of both dissolved and particulate trace metals (Cd, Co, Cu, Fe, Mn, Ni, Pb and Zn) were made on samples collected simultaneously in the central and southern North Sea (below 56°N), during four cruises covering the seasonal cycle. Analyses of trace metals in both phases were undertaken using similar analytical protocols, and the data subjected to rigorous quality controls. Clean techniques were used throughout sampling and analysis. Trace metal concentrations ranged from those characteristic of waters entering the shelf region from the North Atlantic Ocean to values which in some cases were two orders of magnitude higher. Marked increases in concentrations were often associated with waters directly influenced by riverwaters, but the results showed that the distributions could be influenced by processes other than fluvial inputs. The redox-sensitive metals, Fe and Mn, were influenced at some sites, including those overlying areas of fine-grained sediments, by benthic inputs associated with seasonal changes in oxidation-reduction conditions in the benthic interfacial zone. The behaviour of metals which are not redox-sensitive (Cd, Zn) in some cases paralleled those of Fe and Mn, suggesting an association with Mn-or Fe-rich solid phases, or with organic matter. However, seasonal variations in concentrations of Cd and Zn were not directly linked to the cycle of biological utilization and regeneration of nutrients, suggesting that their geochemistry is more influenced by boundary inputs. Resuspension of Pb-rich sediments, long-range transport of Pb-rich suspended particulate matter (SPM), and enhanced, though diffuse, atmospheric inputs of lead were considered to have contributed to the elevated concentrations of particulate Pb (mass metal/mass sediment) in the water column during winter. Estimates of partitioning (K D s) were derived from the dissolved and particulate data for each of the metals over the seasonal cycle. For the more particle-reactive metals (Co, Fe, Mn, Pb), transport in the suspended particulate phase is a significant, sometimes dominant factor. In contrast, for Cd, Cu and Zn, transport in solution will dominate under almost all conditions in the southern North Sea. Furthermore, the values of K D , for a particular metal, varied widely, partly in response to seasonal differences in the relative contributions of lithogenous and biogenous particles to the particles in suspension. Only for Cu and Zn during the winter could the partitioning be described by a narrow range of K D values covering the observed concentrations of SPM. The data from this study give unique information concerning the contemporaneous distribution of dissolved and particulate trace metals in the southers North Sea and they provide a baseline against which the effects of reductions of inputs into the North Sea may be more accurately assessed. Viewed in combination, the dissolved and particulate data have yielded new insights into mechanisms affecting trace metal cycling and transport, essential in the development of coupled hydrodynamic-geochemical models.

Journal ArticleDOI
TL;DR: In this article, the trace metal profiles agree in general with previously reported profiles from the Atlantic Ocean, and they conclude that the sampling and analytical methods employed for this effort, while still in need of improvement, are sufficient for obtaining accurate concentration data on most trace metals in the major water masses of the oceans, and to enable some evaluation of the biogeochemical cycling of the metals.

Journal ArticleDOI
TL;DR: In this paper, changes in the properties of soil solution in the rhizosphere of developing radish plants were investigated, and it is hypothesized that this is partly a result of Ca-metal-ligand equilibrium in solution with higher Ca concentrations in unplanted soil leading to more of the Cd and Zn in solution existing in the uncomplexed state.
Abstract: Changes in the properties of soil solution in the rhizosphere of developing radish plants were investigated. Variations in these properties were expected to affect the distribution and speciation of metals in the soil and soil solution. Applications of essential nutrients were linked to plant transpiration rates and prevented excess addition of nutrient ions, so that subtle changes in soil solution composition would not be obscured. Soil solution pH, the concentration of dissolved organic carbon (DOC) and the concentrations of major and trace elements in solution were found to vary over time. Strict control of fertilizer additions led to the maintenance of a relatively low ionic strength in the soil solution, and under such conditions trace metal solubility appeared to be highy influenced by the concentration of DOC. A chemical speciation analysis was performed which showed that, while dissolved Cd and Zn were largely uncomplexed in unplanted soil, Cd and Zn in the rhizosphere existed mainly as complexed forms. It is hypothesized that this is partly a result of Ca-metal-ligand equilibrium in solution, with higher Ca concentrations in unplanted soil leading to more of the Cd and Zn in solution existing in the uncomplexed state. Changes in the concentrations of uncomplexed Cd and Zn with time gave the best correlations with changes in plant uptake of these metals over time, supporting the hypothesis that plants mainly absorb the free metal ion from soil solution.

Journal ArticleDOI
TL;DR: In this article, the effect of reducing conditions on the cycling of trace metals in anoxic waters was investigated using the iminodiacetic acid type chelating resin (Chelex 100).

Journal ArticleDOI
TL;DR: In this article, the distribution of Cd, Pb, Cu and Zn in oxic carbonate sediments from the Krka estuary was studied by a sequential extraction technique, designed to distinguish: exchangeable cations (F1), carbonates (F2), hydrous oxides of Fe and Mn (F3), organic matter (F4) and residual fractions (F5).

Journal ArticleDOI
01 Jan 1995-Analyst
TL;DR: In this article, the role of soil organic matter was highlighted by particle size fractionation combined with density fractionation, and experiments were carried out on both control and sludge-treated soil samples coming from a field trial on a crusting loamy soil 12 years after the end of sewage sludge application.
Abstract: Fractionation methods including physical rather than chemical dispersion were applied to soil samples in order to study interactions between soil constituents and trace metals. In particular, the role of soil organic matter was highlighted by particle size fractionation combined with density fractionation. In order to take into account the trace metal background content, experiments were carried out on both control and sludge-treated soil samples coming from a field trial on a crusting loamy soil 12 years after the end of sewage sludge application. Comparison of trace metal distributions between these two samples permitted a speciation approach. The collected samples were separated into eight particle size fractions, and the most abundant fraction in mass among coarser fractions, the 50–100 µm fraction, was also separated by flotation on water into two density fractions. Total chemical analyses of all these fractions were performed for major elements and Cd, Cr, Cu, Ni, Pb and Zn. In both field trial plots, retention of trace metals was found not only in the finest fractions ( 50 µm). The organic carbon contents in the particle size fractions followed the same trends, but different organic C distributions between the two experimental treatments were observed. The light isolated samples after density separation had high organic C contents, and in sludge-treated plots their trace metal contents were higher than in any other bulk particle size fractions. In control plots, however, they were also abnormally high. These facts are discussed, and a simple test is proposed to define soil pollution status.

Journal ArticleDOI
TL;DR: In this article, the dominance of wet trace element deposition to the tropical North Atlantic Ocean over dry input is proven by analysis results of rain samples from shipboard sampling, which revealed a net trace metal flux from the atmosphere into the ocean in the vicinity of the intertropical convergence zone (ITCZ).

Journal ArticleDOI
TL;DR: In this article, the speciation of trace metals in seawater based on the voltammetric (DPASV) titration of ligands by metal addition is considered, which allows the determination of the total metal amount, the "labile" fraction, the ligand concentration and the related conditional stability constant.
Abstract: The speciation of trace metals in seawater based on the voltammetric (DPASV) titration of ligands by metal addition is considered. The method allows the determination of the total metal amount, the “labile” fraction, the ligand concentration and the related conditional stability constant. Analytical problems related to sample contaminations during sampling, filtration and storage, displacement of complexing equilibria in freeze storage, the kinetics of the reaction of complexation and the potential kinetic lability of organic complexes are discussed and possible solutions presented. Data on quality control tests carried out to verify the accuracy of the laboratory procedure for trace metal determination in seawater are reported.

Journal ArticleDOI
TL;DR: The results indicate that in groundwater situations, where more than one metal is present, the effect of other metals must be considered in predicting metal speciation.
Abstract: In this study we investigated the effects of competing trace metals and Ca2+ on Cd(II), Pb(II), and Cu(II) complexation by humic acid extracted from groundwater in Orange County, California. Two types of titration experiments were conducted, those using a single metal and those in which the humic acid had been preequilibrated with a competing metal (either a trace metal or Ca2+). The labile metal concentration in the titration was determined by differential pulse polarography (DPP). Results show the different effects of competing trace metal ions and the effect of Ca2+. Both trace metals and Ca2+ do not compete effectively with Cd(II) complexation. While no effects of Cu(II) on Pb(II) complexation were observed, the presence of Cd(II) appeared to slightly enhance the binding between Pb(II) and humic acid. The addition of Pb(II) decreased the amount of Cu(II) complexation, but Cd(II) caused a slight increase at the lower concentrations. Calcium, however, decreased the amount of complexation for all three metals. Results indicate that the metals are not necessarily competing for the same sites. Conformational changes that occur when trace metals bind to the different sites may cause this competing or enhanced effect. Since Ca(II) is introduced at two orders of magnitude higher in concentration than the trace metals, it can outcompete the trace metal for sites where electrostatic interactions dominate. The results indicate that in groundwater situations, where more than one metal is present, the effect of other metals must be considered in predicting metal speciation.

Journal ArticleDOI
TL;DR: In this paper, the first results of dissolved (total concentration and hydrophobic fraction) and particulate trace metals (core sediment and suspended matter) in the lagoon of Venice were presented.

Journal ArticleDOI
TL;DR: The shell of P. vulgata is rejected for potential use in environmental trace metal monitoring because the environmental availability of elements at the three sites was not reflected in the trace metal concentrations of the shells.

Journal ArticleDOI
TL;DR: In this article, ground water monitoring at a newly installed, seasonal-use, domestic septic system located on poorly buffered (CaCO3 equivalent content ≤ 1.6 wt.%) lacustrine silt, has revealed the development of an acidic ground-water plume.
Abstract: Four years of detailed ground-water monitoring at a newly installed, seasonal-use, domestic septic system located on poorly buffered (CaCO3 equivalent content ≤ 1.6 wt.%) lacustrine silt, has revealed the development of an acidic ground-water plume. Acid, generated by the partial oxidation of effluent NH4+ dissolved organic carbon (DOC), and possibly sulfide minerals present in the sediment, has resulted in a distal plume core zone with pH values in the range of 4.4 to 5.0. The acidic zone, where NH4+ does, however, persist (> 2 mg/1, as N) and where DOC remains elevated (6–13 mg/1), is associated with high average concentrations of the trace metals Fe (4.7 mg/1), Al (1.9 mg/1), and Mn (3.6 mg/1). Attenuation of nitrogen along the plume core flowpath is indicated by a decrease in the N/ Cl− ratio from an effluent value of 1.7, to a plume value of only 0.5 after 4 m of subsurface flow. Increased SO42− levels observed in the zone of N depletion suggest that attenuation can be at least partly attributed to reduction of plume NO3− by oxidation of reduced S present in the sediment. PO43− has not migrated significantly beyond the infiltration bed gravel layer, demonstrating that PO43− mobility is limited in these sediments (retardation factor > 10).

Journal ArticleDOI
TL;DR: In this paper, trace metal concentrations (Fe, Mn, Ni, Cu, Co, Cd, Cr and Zn) have been measured in estuarine and marine shrimp P. stylirostris.
Abstract: Trace metal concentrations (Fe, Mn, Ni, Cu, Co, Cd, Cr and Zn) have been measured in estuarine and marine shrimp P. stylirostris collected in the Pacific coast of Mexico. Estuarine individuals (juveniles) had higher concentrations of Fe and Mn than marine individuals (adults). Size-dependent relationships were observed and differed among the elements examined. A negative slope was found for Co, Fe, Mn and Ni in estuarine juvenile shrimps, while for Cu the opposite tendency occurred. In marine adults a positive slope was observed for Cd, Co, Cr and Cu. These findings may be due to two factors: (1) that P. stylirostris spends part of its life-cycle in estuarine/lagoon environments where it is more likely to be exposed to higher levels of bioavailable trace metals (natural and anthropogenic contributions) and/or (2) different metabolic requirements of young and older specimens, which is especially applicable to copper.