Showing papers on "Trace metal published in 1999"
TL;DR: In this paper, the authors used iron as a conservative tracer to differentiate natural from anthropogenic components of bulk sediment metal concentrations in the Southern California Bight (SCB), and established baseline relationships between iron and eight trace metals were established using data from nonimpacted sites distant from known point and non-point sources of pollution.
370 citations
TL;DR: In this article, cross-flow ultrafiltration studies were carried out in the Trinity river estuary of Galveston Bay in July, 1993, May, 1994 and July 1995 to study the phase speciation for a number of metals (e.g., Cd, Cu, Co, Fe, Ni, Pb, Zn) in estuarine waters.
261 citations
TL;DR: In this paper, a lysimetric experiment was conducted to evaluate the environmental risks associated with the disposal of sewage sludge composts (SSC) containing trace metal contents below the recommended limit values established by the French legislation.
209 citations
TL;DR: The particle concentration effect (p.c.) is an unexpected decline in partition coefficients (Kd) as suspended particulate matter (SPM) increases as mentioned in this paper, which has been attributed to a variety of causes, but most often to the existence of colloidal forms of the adsorbate, which are included, in error, in the dissolved fraction when calculating Kd.
198 citations
TL;DR: In this article, a review of cellulose sorbents for solid phase extraction is presented based on 42 literature references and shows favorable properties for this purpose, depending on the functional groups attached, the sorbent can be directly used for sorption or can be loaded with ligands specifically binding certain species.
Abstract: Regardless the progress in detectability of various instrumentation for trace metal determination, the preconcentration steps are very often needed for the analysis of environmental samples. Among the different techniques that can be used for this purpose, solid-phase extraction using various sorbents has been developed very intensively in recent years. Besides preconcentration, it can also be used for matrix removal necessary in some procedures or for the speciation of trace elements. This review is based on 42 literature references and shows favorable properties of cellulose sorbents for this purpose. Depending on the functional groups attached, the sorbent can be directly used for sorption of target analytes or can be loaded with ligands specifically binding certain species. Applications are reviewed for conventional batch procedures, flow-injection sample processing, and speciation of certain trace elements.
197 citations
TL;DR: It was shown that conventional chemical kinetics can be used to predict the toxicity of copper in these bioassays and the hydrodynamic characteristics of the bioassay chambers were determined to better describe the exposure of the organisms to free Cu2+.
Abstract: The rate of reaction of trace metal ions is an important consideration when studying the chemistry of trace metals in natural waters. The application of speciation models to natural water systems requires knowledge of kinetics if reactions are slow. Most bioassay and toxicity tests conducted in static and flow-through systems have not taken reaction kinetics into account. Therefore, results from these studies may overestimate the toxicity in the receiving waters. In the present study, the kinetics of the interaction of Cu(II) with humic acid (HA) and its influence on the toxicity of copper to Ceriodaphnia dubia were investigated by both chemical kinetic studies using a copper ion selective electrode and bioassay tests using a continuous flow-through bioassay system. A two-ligand site with first-order rate constants model gave a very good description of experimental kinetic data of the change of free Cu2+ concentration. Average k1 was 1.85/h and average k2 was 0.094/h. Bioassay tests indicated that different reaction times of copper with HA solution produced different toxic effects to organisms. We determined the hydrodynamic characteristics of the bioassay chambers to better describe the exposure of the organisms to free Cu2+. The bioassays supported the free ion activity model that the bioavailability and therefore toxicity of copper was directly correlated to the free Cu2+ concentration rather than to the total copper concentration. It was further shown that conventional chemical kinetics can be used to predict the toxicity of copper in these bioassays. This study supports the importance of considering reaction kinetics when studying the chemistry of trace metals in natural waters.
189 citations
TL;DR: Stripping voltammetry is very suitable for ship-board and in-situ applications because of the portability, low cost and capability for automation of the voltammetric instrumentation as discussed by the authors.
185 citations
TL;DR: The use of dendrochemistry for monitoring historical changes in trace metal deposition and mobilisation of metals in soils is evaluated, and stable Pb isotope ratios in tree-rings were used to show that sacred fir is not a useful monitor of Pb deposition because Pb accumulates in the heartwood.
148 citations
140 citations
TL;DR: The concentration of several trace elements in bone of end-stage renal failure patients is disturbed, and some of the trace metals under study might share pathways of absorption, distribution, and accumulation.
Abstract: Background: Little is known about trace metal alterations in the bones of dialysis patients or whether particular types of renal osteodystrophy are associated with either increased or decreased skeletal concentrations of trace elements. Because these patients are at risk for alterations of trace elements as well as for morbidity from skeletal disorders, we measured trace elements in bone of patients with end-stage renal disease.
Methods: We analyzed bone biopsies of 100 end-stage renal failure patients enrolled in a hemodialysis program. The trace metal contents of bone biopsies with histological features of either osteomalacia, adynamic bone disease, mixed lesion, normal histology, or hyperparathyroidism were compared with each other and with the trace metal contents of bone of subjects with normal renal function. Trace metals were measured by atomic absorption spectrometry.
Results: The concentrations of aluminum, chromium, and cadmium were increased in bone of end-stage renal failure patients. Comparing the trace metal/calcium ratio, significantly higher values were found for the bone chromium/calcium, aluminum/calcium, zinc/calcium, magnesium/calcium, and strontium/calcium ratios. Among types of renal osteodystrophy, increased bone aluminum, lead, and strontium concentrations and strontium/calcium and aluminum/calcium ratios were found in dialysis patients with osteomalacia vs the other types of renal osteodystrophy considered as one group. Moreover, the concentrations of several trace elements in bone were significantly correlated with each other. Bone aluminum was correlated with the time on dialysis, whereas bone iron, aluminum, magnesium, and strontium tended to be associated with patient age. Bone trace metal concentrations did not depend on vitamin D intake nor on the patients’ gender.
Conclusions: The concentration of several trace elements in bone of end-stage renal failure patients is disturbed, and some of the trace metals under study might share pathways of absorption, distribution, and accumulation. The clinical significance of the increased/decreased concentrations of several trace elements other than aluminum in bone of dialysis patients deserves further investigation.
136 citations
TL;DR: Trace and major elements were measured in sediment cores collected at the shelf and continental slope of the Banc d'Arguin (Mauritania) sediment.
TL;DR: In this paper, the localization of metal within and around roots of water hyacinth (Eichhornia crassipes) growing in a wetland receiving urban run-off was studied by energy dispersive X-ray microanalysis of sections from freeze-substituted roots.
Abstract: Metal localization within and around roots of water hyacinth (Eichhornia crassipes) growing in a wetland receiving urban run-off was studied by energy dispersive X-ray microanalysis of sections from freeze-substituted roots. Sampling randomly from an order of magnitude gradient in metal concentrations (Cu and Pb) allowed us the opportunity to identify general patterns of metal localization. Iron was present at high levels at the root surface, and this may have been a root plaque as described for wetland plants with roots anchored in flooded soils. Iron levels decreased centripetally across the root and were higher in cell walls than within cells. Trace metals (Cu, Zn and Pb) were not localized at the root surface. In contrast with iron, trace metal levels increased centripetally across the root, tended to be higher inside cells and were highest within cells in the stele. Variability of localization was high for all metals analysed. Multivariate statistical analyses (principal components analysis and multidimensional scaling) were useful for identifying overall patterns in elemental distribution.
TL;DR: In this paper, a trace metal sequential extraction scheme based on the classical Tessier procedure was used to determine whether readsorption and redistribution processes occur during the metal extraction from oxic sediments of the Odiel Marshes Natural Park (Southwest Spain).
TL;DR: In this paper, the mixing zones of the Tinto and Odiel rivers which drain the South Iberian pyrite belt were studied in the early stages of mixing, showing that Nitrate concentrations which are influenced by urban and industrial effluents showed an important maximum in early stages, as do the metals.
TL;DR: Both the “anthropogenic” and “natural” trace metal concentrations andspatial distributions were similar among and within the forested and suburban creek-marsh systems.
Abstract: Twenty-eight tidal creeks were sampled along the South Carolina coast in the summer of 1995 to determine the levels of sediment trace metal contamination associated with different types and varying levels of human development in their watersheds. The particle size and total organic carbon (TOC) content of creek sediments in developed watersheds (i.e., industrial, urban, and suburban) were similar to that in watersheds with little or no development (i.e., forested or reference). Those trace metals commonly associated with urban and industrial sources, including Cu, Cr, Pb, Zn, Cd, and Hg, were in significantly higher concentrations in tidal creeks located in industrial/urban watersheds compared to the suburban and forested watersheds. Sediment trace metal concentrations were similar for creeks located in suburban and forested watersheds and 2 to 10 times lower than the creeks located in industrial/urban watersheds. Concentrations of trace metals primarily associated with the natural weathering of basement rock, including Al, Fe, As, Ni, and Mn, were not significantly different among watershed types. Four of the tidal creek–salt marsh systems were extensively sampled from the creek channel to the marsh-upland interface to characterize sediment trace metal spatial distributions within creek-marsh systems. Sediment particle size, TOC, and trace metal concentrations varied spatially within each creek-marsh system depending on the type of development in the watershed and the probable source of metals. The creek-marsh system selected to represent the industrial development had significantly higher “anthropogenic” trace metal concentrations compared to the other creek-marsh systems. This system also had trace metal distributional patterns that appeared to be associated with several localized sources of metals on the marsh surface. Both the “anthropogenic” and “natural” trace metal concentrations andspatial distributions were similar among and within the forested and suburban creek-marsh systems.
TL;DR: It is suggested that the establishment of sediment quality criteria must consider sediment as a potentially important source for metal uptake in benthic invertebrates.
Abstract: Assimilation efficiencies (AEs) of trace elements (Ag, Cd, Co, Se and Zn) in a marine deposit-feeding polychaete, Nereis succinea, from ingested sediments were measured using a pulse-chase radiotracer feeding technique. Radiolabeled sediments were encapsulated and fed to the worms for 1 h, after which the worms were allowed to depurate their ingested materials for 3 d. The ranges of AEs were 12 to 36% for Ag, 5 to 44% for Cd, 35 to 96% for Co, 29 to 60% for Se and 21 to 59% for Zn. Trace metal assimilation was little affected by sediment source and sediment grain size. Metals (Ag, Cd, Co and Zn) associated with anoxic sediments were assimilated with a significantly lower efficiency than metals from oxic sediments. The AE of Cd decreased with the duration of sediment radiolabeling; AEs of Ag, Co, Se and Zn were weakly affected by sediment aging. Metal uptake in worms from the dissolved phase was proportional to metal concentration in the dissolved phase, although there was some evidence of Cd and Zn regulation in response to an increase in ambient concentrations. Uptake rate constants were highest for Ag, followed by Zn > Co > Cd > Se. By incorporating metal influx from both the dissolved and particulate (sediment) phases, a bioenergetic-based kinetic model indicates that most (>98%) of the Cd, Co, Se and Zn in polychaetes arises from sediment ingestion due to the high ingestion rates of these animals and the low uptake rate of metals from the dissolved phase (porewater or overlying water). For Ag, approximately 5 to 35 % is due to uptake from the dissolved phase. Our study suggests that the establishment of sediment quality criteria must consider sediment as a potentially important source for metal uptake in benthic invertebrates.
TL;DR: In this paper, a new method was developed for the rapid determination of V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Cd and Pb in diluted seawater, requiring just 50 µL of seawater and no reagents other than pure nitric acid.
Abstract: Understanding the trace metal marine geochemistry of temporally variable coastal systems requires intensive sampling programs with attendant analytical burdens. Most established techniques for multi-element trace metal determinations are slow, require a skilled chemist, and are not easily automated. Advances in sample introduction systems and ICP-MS instrumentation now provide marine chemists with the sensitivity and mass resolution necessary to determine many trace metals at natural concentrations in coastal seawater. A new method has been developed for the rapid (10 samples h
–1
) determination of V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Cd and Pb in diluted seawater, requiring just 50 µL of seawater and no reagents other than pure nitric acid. A sensitivity of 800 000-1 200 000 cps ppb
–1
86
Sr in a 10% sea water matrix is obtained when microconcentric desolvating nebulization is combined with a shielded torch and hot plasma high resolution ICP-MS. Analyses are standardized by a matrix-matched external calibration curve with variations in sensitivity corrected by normalizing to the natural internal standard Sr, a conservative ion in seawater. The method thus depends on mass bias stability for each analyte relative to Sr, which was examined as a function of forward power and matrix and found to be optimized at 1100-1350 W. Precision and accuracy are limited by appropriate correction for blanks, which derive mainly from the ICP-MS introduction system, and are equivalent to about 10% of typical coastal seawater concentrations for these metals. Preliminary evaluation of a new low-flow nebulizer (µFlow, Elemental Scientific, Omaha, NE, USA) suggested lower blanks and compatibility with solutions high in total dissolved solids compared with standard microconcentric designs. Determination of dissolved concentrations in reference seawater (CASS-3) demonstrate very good agreement with certified values (within 95% confidence limit) and a precision of 3-12% (1σ) for all elements except Cr (15%). The utility of the method is demonstrated by the determination of spatial trends for these metals in a transect of seawater samples from shelf waters off southern New Jersey, USA. The new technique is sufficiently sensitive to determine some of these metals in open ocean seawater and, with minor modifications, should be applicable to a larger suite of analytes in a wide variety of natural waters.
Journal Article•
TL;DR: In this article, a model for trace metals that considers in-stream transport, metal oxide precipitation-dissolution, and pH-dependent sorption is presented, which is applied to a pH-modification experiment in an acid mine drainage stream.
Abstract: A model for trace metals that considers in-stream transport, metal oxide precipitation-dissolution, and pH-dependent sorption is presented. Linkage between a surface complexation submodel and the stream transport equations provides a framework for modeling sorption onto static and/or dynamic surfaces. A static surface (e.g., an iron- oxide-coated streambed) is defined as a surface with a temporally constant solid concentration. Limited contact between solutes in the water column and the static surface is considered using a pseudokinetic approach. A dynamic surface (e.g., freshly precipitated metal oxides) has a temporally variable solid concentration and is in equilibrium with the water column. Transport and deposition of solute mass sorbed to the dynamic surface is represented in the stream transport equations that include precipitate settling. The model is applied to a pH-modification experiment in an acid mine drainage stream. Dissolved copper concentrations were depressed for a 3 hour period in response to the experimentally elevated pH. After passage of the pH front, copper was desorbed, and dissolved concentrations returned to ambient levels. Copper sorption is modeled by considering sorption to aged hydrous ferric oxide (HFO) on the streambed (static surface) and freshly precipitated HFO in the water column (dynamic surface). Comparison of parameter estimates with reported values suggests that naturally formed iron oxides may be more effective in removing trace metals than synthetic oxides used in laboratory studies. The model's ability to simulate pH, metal oxide precipitation-dissolution, and pH-dependent sorption provides a means of evaluating the complex interactions between trace metal chemistry and hydrologic transport at the field scale.
TL;DR: Significantly higher concentrations of trace metals were obtained in the viscera of the polycultured fish than those in the flesh, which suggested that viscerA played an important role in storing trace metals in fish.
TL;DR: In this paper, a series of 10 dry deposition samples were collected on a surrogate plate over a period of 8 months at Cap Ferrat, a site on the Western Mediterranean coast, and analysed for Al, Fe, Mn, Ni, Co, Cr, Zn and Pb.
TL;DR: In this article, two source-rock sequences in the Perija Range, Maracaibo Basin, were geochemically analyzed in order to find environmentally controlled characteristic fingerprints, and trace metals and sulfur concentrations were found to be closely related with the physicochemical conditions during deposition of the rocks.
TL;DR: In this article, a series of transects at the 6°W meridian including the Polar Frontal region (PFr), the southern Antarctic Circumpolar Current area (sACC area) and the Weddell Gyre Boundary Front (WGBF) were conducted.
TL;DR: It is concluded that the exposure of the crustaceans to raised trace metal availabilities has not been sufficient to select for a reduction in dissolved trace metal uptake rates, even in the case of the in situ populations of amphipods.
Abstract: This study set out to investigate the possible effect of life history strategy on the trace metal biology of crustaceans living in coastal sites contaminated by high availabilities of toxic metals. Amphipods brood their young, parents and offspring staying in the same habitat. Therefore a population of amphipods living in a trace-metal-rich estuary would have been selected over generations for any physiological adaptation reducing the potential toxic action of the trace metals, such as reduced rates of uptake of metals from solution. Crabs, on the other hand, are dispersed by a planktonic larval phase, the zoea, increasing the probability that the parents of individuals inhabiting a metal-rich estuary would have lived in a remote location not exposed to selection pressure to reduce metal uptake rates. Uptake rates of the dissolved trace metals Zn, Cd and Ag were, therefore, measured in amphipods Orchestia gammarellus and crabs Carcinus maenas and Pachygrapsus marmoratus from coastal sites in Britain and France exposed to different degrees of trace metal enrichment, in order to test 3 hypotheses: (1) the mean metal uptake rates of amphipods and crabs from a metal-rich site would be lower than those of the same crustaceans from a control site; (2) the mean metal uptake rates of amphipods would show a greater reduction from those of control amphipods than would those of equivalent crabs; (3) the mean metal uptake rates of amphipods from metal-rich sites would show smaller coefficients of variation than those of equivalent crabs. In practice the mean metal uptake rates of both amphipods and crabs did not show consistent significant differences between the crustaceans from the metal-rich and control sites. Furthermore there was no evidence to conclude that the coefficients of variation of the mean uptake rates of amphipods from the relatively metal-rich sites are lower than those of crabs from the same sites. It is concluded that the exposure of the crustaceans to raised trace metal availabilities has not been sufficient to select for a reduction in dissolved trace metal uptake rates, even in the case of the in situ populations of amphipods. It is relevant that a suite of physiological mechanisms for the amelioration of the potential toxic effects of trace metals is available to coastal invertebrates, and it remains possible that other physiological processes promoting metal tolerance may be active to differing degrees in crustaceans from metal-rich habitats.
TL;DR: N-Ethylmaleimide, which specifically binds to sulfhydryl groups, reduced the influx of Ag, Cd and Zn, implying that the transport of these metals is carrier-mediated by proteins or other SH-containing compounds, whereas trace metal uptake in clams was generally unaffected by this compound.
TL;DR: In this article, the concentrations of Fe, Mn, Zn, Cr, Cu, Pb, Ni, Cd, and Ag were determined in soft tissue and shell material of mussel Mytilus edulis collected in the winter season from five coastal sites in the northeast of England.
TL;DR: Copper and zinc concentrations of the cosmopolitan green seaweeds Enteromorpha intestinalis and Ulva lactuca were obtained for the first time from various sites within Otago Harbour, southern New Zealand as discussed by the authors.
TL;DR: The results indicated that the colloidally complexed forms were bioavailable to shrimp, and the total activity level of radiotracer differed between the two treatments.
Abstract: A large fraction of the trace metal pool in estuarine and coastal waters is complexed with colloidal-sized macromolecular organic matter. Bioaccumulation and bioavailability studies of trace metals have generally utilized free-ionic dissolved metal ions. Consequently, little is known about the uptake and depuration kinetics of the colloidally bound species. Chemical characteristics such as the relative hydrophobicity of these metal-colloid complexes may alter their bioavailability by interfering with or enhancing transport across membrane lipid bilayers. We used radiotracers to compare the bioaccumulation and sites of accumulation of colloidally complexed and free-ionic forms of Ag, Cd, Ba, Fe, Sn, Zn, Co, Hg, and Mn in juvenile brown shrimp Penaeus aztecus. In this paper, we present the results from 14-d uptake and bioaccumulation studies in which shrimp could take up radiotracers only from the water. Our results indicated that the colloidally complexed forms were bioavailable to shrimp. Uptake kinetics appeared to be similar in the two treatments for most metals, although by the end of the uptake study, the whole-body activities of Ba, Sn, and Zn were significantly higher in shrimp exposed to free-ionic metals. While the hepatopancreas appeared to be the site of highest accumulation on a mass-specific basis for both treatments, the total activity level of radiotracer differed between the two treatments. In the colloidally complexed treatment, the majority of total tracer activity was associated with the hepatopancreas while shrimp exposed to free-ionic metals exhibited the highest proportion of total activity in the abdomen. The mechanisms underlying these differences remain to be tested.
TL;DR: In this article, the uptake of Taraxacum officinale Weber (dandelion) growing on abandoned industrial sites, community gardens and parks in urban Montreal was measured to evaluate trace metal bioavailability.
Abstract: Uptake of Cu, Zn, Mn, Pb, and Cd by Taraxacum officinale Weber (dandelion) growing on abandoned industrial sites, community gardens and parks in urban Montreal was measured to evaluate trace metal bioavailability. Total soil trace metal concentrations exceeded the Canadian remediation levels only in the industrial sites, but tissue concentrations at all land use types were normal. Multiple regression analysis suggests that available PO4 may reduce uptake of Cu and Zn. It is evident that sites classified as contaminated on the basis of total soil metal may have low levels of bioavailability. Key words: Trace metals, urban contaminated soils, dandelion
TL;DR: In this paper, the authors investigated the relationship between discharge and metal concentrations in the Pinelands watershed, a coastal plain region characterized by low-pH waters and highly weathered soils.