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PubMed2006

Trace metal enrichments in core sediments in Muthupet mangroves, SE coast of India: application of acid leachable technique.

Core sediments from Mullipallam Creek of Muthupet mangroves on the southeast coast of India were analyzed for texture, CaCO(3), organic carbon, sulfur and acid leachable trace metals (Fe, Mn, Cr, Cu, Ni, Co, Pb, Zn and Cd). Textural analysis reveals a predominance of mud while CaCO(3) indicates dissolution in the upper half of the core, and reprecipitation of carbonates in reduction zones. Trace metals are diagenetically modified and anthropogenic processes control Pb and, to some extent, Ni, Zn and Fe. A distinct event is identified at 90 cm suggesting a change in deposition. Strong relationship of trace metals with Fe indicates that they are associated with Fe-oxyhydroxides. The role of carbonates in absorbing trace metals is evident from their positive relationship with trace metals. Comparison of acid leachable trace metals indicates increase in concentrations in the study area and the sediments act as a sink for trace metals contributed from multiple sources.

Acids↗

PubMed2004

Groundwater acidification and the mobilization of trace metals in a sandy aquifer.

The acidification of groundwater due to acid rain impact and the mobilization of the trace metals Ni, Be, Cd and Co was studied in a noncalcareous sandy aquifer. The groundwater is acidified down to pH 4.4 in the upper 3-4 m of the saturated zone. There is a sharp acidification front and below that the pH increases to 5.2-6.5. The acid zone groundwater contains an Al concentration of approximately 0.2 mM. These observations could be explained by a reactive transport model for downward groundwater movement based on ion exchange and equilibrium with Al(OH)3. At the acidification front, the Al3+ in groundwater exchanges for sorbed Ca2+ and Mg2+ and the coupled dissolution of Al(OH)3 causes the pH to increase. The downward migration rate of the acidification front is 3.5-5.0 cm/yr. Trace metals (Ni, Be, Cd and Co) are found to accumulate near the acidification front. Downward moving, low pH, and trace metal containing groundwater passes the acidification front, and the trace metals adsorb as the pH increases. The acidification front moves downward at a slower rate, and in this process the heavy metals are desorbed. Accordingly, the acidification front functions as a geochemical trap where trace metals accumulate, and their amount will increase with time. Different surface complexation models were explored to explain the behavior of Ni. Neither a simple iron oxide surface complexation model nor ion exchange could explain the field observations of the Ni distribution. The sediment appeared, even at low pH, to have a much stronger affinity toward Ni than predicted by the iron oxide model. The discrepancy can be accounted for in the model by increasing the Ni binding strength constant in combination with an increased number of reactive sites.

Acid Rain↗

PubMed1982

Anatomically-related variations in trace-metal concentrations in hair.

Scalp-hair analysis is used as an indicator of trace-metal concentrations in the human body. The major shortcoming of this approach is the inability to differentiate between endogenous and exogenous trace metals. Our analyses show no correlation between the concentrations of calcium, magnesium, copper, iron, or zinc in scalp hair and pubic hair in 67 donor-matched hair samples. We interpret this as a strong indication that exogenous trace metals make a significant contribution to the results for trace metals in human hair.

Body Burden↗

PubMed2004

Trace metal availability and effects on benthic community structure in floodplain lakes.

Effects of contaminants on communities are difficult to assess and poorly understood. We analyzed in situ effects of trace metals and common environmental variables on benthic macroinvertebrate communities in floodplain lakes. Alternative measures of trace metal availability were evaluated, including total metals, metals normalized on organic carbon (OC) or clay, simultaneously extracted metals (SEM), combinations of SEM and acid-volatile sulfide (AVS), and metals accumulated by detritivore invertebrates (Oligochaeta). Accumulated metal concentrations correlated positively with sediment trace metals and negatively with surface water dissolved OC. Sixty-eight percent of the variation in benthic community composition was explained by a combination of 11 environmental variables, including sediment, water, and morphological characteristics with trace metals. Metals explained 2 to 6% of the community composition when SEM-AVS or individual SEM concentrations were regarded. In contrast, total, normalized, and accumulated metals were not significantly linked to community composition. We conclude that examination of SEM or SEM - AVS concentrations is useful for risk assessment of trace metals on the community level.

Aluminum Silicates↗

PubMed1995

Effect of trace metals on synthesis of exoproteins and exotoxins by Staphylococcus aureus.

Staphylococcus aureus did not grow in chemically defined medium completely free of trace metals. At low concentrations all the trace metals showed stimulating effect on growth and exoprotein production. Increasing concentrations of Ca2+ and Mg2+ were growth stimulatory whereas Co2+, Cu2+, Fe3+, Mn2+, Ni2+ and Zn2+ were inhibitory. The amount of exoprotein and haemolytic exotoxins produced in relation to final viable count increased with increasing concentrations of growth inhibitory trace metals whereas it decreased with increasing concentrations of Ca2+ and Mg2+. Trace metals did not show significant influence on amount of haemolytic exotoxins produced in relation to total exoproteins. The results indicate presence of a common regulatory mechanism for all types of exoproteins produced by S. aureus.

Bacterial Proteins↗

PubMed1996

Bottom sediments of the Arabian Gulf--III. Trace metal contents as indicators of pollution and implications for the effect and fate of the Kuwait oil slick.

The trace metal contents of 71 core samples collected in 1992 from the bottom sediments of the Arabian Gulf are used to determine the regional distribution of concentration and pollution levels of these substances in the region. Chronic contamination was recorded in seven locations: the northwestern area (Fe), the northeastern area (Fe, V and Ni), the north-central area (V and Ni), the central area (Fe, Pb, V and Ni), the south-central area (Cu), the eastern area (Cu) and the southeastern area (Fe, V and Ni). Present-day contamination was identified in three locations only: the north-central area (V), the central area (Pb, V and Ni) and the southeastern area (Fe, V and Ni). Diversified natural and anthropogenic inputs may have provided the sources of this contamination. The V/Ni ratios of recent marine sediments cannot be used in identifying oil spillages or in oil-sediment correlation studies. Positive correlations are found between increasing trace metal concentration and decreasing carbonate content and grain size, verifying that adsorption onto muds is the primary mechanism of trace metal concentration in marine sediments. Correlations with TOC (total organic carbon) contents indicate that organic matter is a significant concentrator only in the case of Pb and Cu. With the exception of the Fe contamination in the northwest area due to river transport, all chronic and present-day trace metal concentrations are within the permissible natural background levels in the western offshore areas, including the two areas thought to be polluted by the Kuwait oil slick, thereby supporting the idea that airborne fallout from oil fires was deposited in a limited coastal area between Kuwait and Bahrain, and verifying that the oil slick had minimal effect on the state of pollution by trace metals in the Arabian Gulf.

Journal Article↗

PubMed2001

The interpretation of body trace metal concentrations in neogastropods from Hong Kong.

Three species of neogastropods, i.e., Thais clavigera, Thais luteostoma and Morula musiva, were collected from 12 sites in the coastal waters of Hong Kong, including clean and known metal-enriched ones. Accordingly, body trace metal concentrations varied greatly. Copper and zinc body concentrations compared poorly with those of accepted biomonitors and presumed metal contamination profiles. Much is known about the feeding ecology of neogastropods on local shores and where direct observational data were not available, their diets could, nevertheless, be estimated reliably. Accumulated metal concentrations can be interpreted with regard to dietary history. T. luteostoma, for example, had body copper concentrations of 51.8 microg g(-1) on an exposed shore and a diet of mainly barnacles. In contrast, on a sheltered shore (but only some 250 m distant) where the diet consisted mainly of oysters, body copper concentrations were approximately 15 times greater at 833 microg g(-1). Similar results were obtained for T. clavigera. The results of this analysis suggest that neogastropods can play a significant role in trace metal trophic transfer studies, especially as their representatives are intertidally and subtidally ubiquitous and can be spatially separated into tropical specialists and temperate generalists.

Animals↗

PubMed1996

Spatial and temporal variations of trace metals in bottom sediments of Peter the Great Bay, the Sea of Japan.

New data on trace metal distribution in bottom sediments of Peter the Great Bay (the Sea of Japan) are presented. Much higher concentrations were detected near the most likely anthropogenic sources of trace metal inputs (waste water discharges from Vladivostok and Nakhodka, and the Vladivostok coastal landfill). Sediments in these contaminated areas were up to 700 ppm in Zn, 530 ppm in Pb, 7 ppm in Cd and 3 ppm in Hg. River runoff is of minor importance as a metal source in the investigated areas. The spatial distribution of trace metals outside the areas directly influenced by sewage discharges is regulated by natural processes such as sediment sorting by grain size. Based on radiometric dating of sediment cores, increases in the trace metal content of bottom sediments near Vladivostok begun in approximately 1945.

Journal Article↗

PubMed2004

Mobility of trace metals in retention pond sediments.

This paper presents the results of a study on trace metal mobility in the sediments of several road and urban infiltration/decantation ponds in France; the trace metal concentrations are indeed high. The potential mobility of trace metals (cadmium, nickel, chromium, copper, lead and zinc) was evaluated by application of the sequential extraction BCR protocol. Results have been compared with those from the IHSS protocol, which allows for the extraction of various forms of organic matter. Cadmium is the most easily exchangeable element in the case of variations in physical-chemical conditions (50% to 60% of Cd is exchangeable and 70% to 80% of Cd remains within the fulvic acid fraction) and is thus easily releasable within an acidic medium. Zinc is also potentially mobile and stays mainly concentrated in fulvic acids, except in the case of the Ronchin sediment (more than 50% in humin). In contrast, nickel and chromium are primarily present in the residual fraction and do not exhibit high mobility. Copper and lead are concentrated in both the humic acid fraction (IHSS protocol) and the organic phase (BCR scheme); consequently, their mobility is limited.

Cities↗

PubMed2003

Capillary electrophoresis of trace metals in highly saline physiological sample matrices.

Trace metal ions in highly saline samples such as urine were determined with capillary electrophoresis (CE) without desalting or off-line preconcentration. By mixing with a dye, 4-(2-pyridylazo) resorcinol (PAR), the metal ions were converted into anionic complexes having strong absorbance near 500 nm. A large volume of the metal-PAR complex sample solution injected into a coated capillary was stacked isotachophoretically and separated under a reverse potential. The salt anion (chloride) and PAR in the sample matrix acted as the leading and terminating electrolytes, respectively. In a sample containing a 250 mM NaCl matrix, more than 400-fold enhancement in the absorbance detector response was realized compared to the normal CE injection mode. Combination of the dye complexation and isotachophoretic stacking provided excellent detection limits (S/N = 3) for three trace metal ions in the low ppb range (Fe(2+), 0.7 ppb, Ni(2+), 0.4 ppb; Zn(2+), 1.2 ppb) with absorbance detection. The migration time reproducibility was excellent (relative standard deviations: standard samples < 1%, urine samples approximately 1%). The proposed method is convenient and fast, and the sample analysis can be completed within 20 min.

Animals↗

PubMed1998

Preparation of urine samples for trace metal determination: a study with aluminium analysis by inductively coupled plasma optical emission spectrometry.

Urinary analysis of trace metals forms a significant role in clinical chemistry, but the optimal preparation and analysis of urine samples has not been investigated. Human urine is generally supersaturated with dissolved solids. Therefore, samples often precipitate following collection. X-ray microanalysis showed that this precipitate was predominantly rich in calcium and phosphorus but could include some trace metals from urine, potentially lowering their concentrations in solution. Hence, the precipitate must be fully redissolved for accurate analysis of trace metals in urine. Methods are emphasized for the best collection and preparation of urine samples for subsequent trace metal analysis; in this work inductively coupled plasma optical emission spectrometry (ICPOES) was used for the analysis of aluminium. For optimal accuracy, peak profiles were collected over 396.147 nm-396.157 nm. Urinary aluminium levels were investigated from 10 healthy volunteers and concentrations were obtained using either aqueous, pooled or individual urine-based standard curves. Since urine has a highly variable matrix, individual sample-based standards, which are unique to that particular sample, gave the most accurate results. However, where sample size is small or sample numbers are unfeasibly large, pooled sample-based standards give good approximations to within 15% and, with appropriate validation, other elements as internal standards could also be used for approximations. Aqueous standards should be avoided. Spike-recovery experiments confirmed these data since individual sample based standards showed optimal recovery [99.3 (4.4)%], while pooled sample-based standards were a close proxy [101.6 (9.2)%] but aqueous standards were inappropriate [137.4 (12.8)%]. Postprandial urinary aluminium levels of the 10 volunteers were [7.2 (3.7)micrograms/L] after analysis using individual sample-based standard curves.

Aluminum↗

PubMed2000

Trace metal speciation and bioavailability in urban soils.

Urban soils often contain concentrations of trace metals that exceed regulatory levels. However, the threat posed by trace metals to human health and the environment is thought to be dependent on their speciation in the soil solution rather than the total concentration. Three inactive railway yards in Montréal, Québec, were sampled to investigate the speciation and bioavailability of Cd, Cu, Ni, Pb and Zn. Soil solutions were obtained by centrifuging saturated soil pastes. In the soil solutions, up to 59% of the dissolved Cd was in its free ionic form. For Cu, Pb and Zn, organic complexes were the predominant species. Over 40% of Ni was present as inorganic complexes if the solution pH exceeded 8.1. Multiple regression analyses showed that pH and total metals in soil were significantly correlated with the activities of free metal ions, except for Cd(2+), which only had a weak correlation with soil pH. Free, dissolved and total soil metals were tested for their ability to predict metal uptake by plants in the field. However, none of these metal pools were satisfactory predictors. The results indicated that in these urban soils, trace metals were mainly in stable forms and bioavailability was extremely low.

Journal Article↗

PubMed2005

Release of trace metals, sulfate and complexed cyanide from soils contaminated with gas-purifier wastes: a microcosm study.

Deposited gas-purifier wastes are commonly contaminated with trace metals, sulfate and cyanide (CN) compounds. We investigated their release from three soils contaminated with gas-purifier wastes into solution in microcosm experiments under varying redox conditions (E(H) 170-620 mV). The soils differed in pH (2.2; 4.9; 7.4) and featured low amounts of trace metals, but large amounts of total S and total CN. The pH governed trace metal release in the case of the acidic soil and CN release in the case of the slightly alkaline soil. The redox potential controlled trace metal and CN release in the case of the moderately acidic soil. Sources of dissolved SO(4)(2-) were dissolution of gypsum, desorption from Fe oxides and probably oxidation of elemental S. The geochemical behaviors of trace metals (soluble under acidic and reducing conditions) and CN (soluble under alkaline and oxidizing conditions) were diametrically opposed.

Calcium Sulfate↗

PubMed2004

Present state and historical changes of trace metal pollution in Kaoping coastal sediments, southwestern Taiwan.

Surface and gravity-cored sediments were collected from the Kaoping coastal area off southwestern Taiwan to determine particle size, organic carbon, trace metal concentration and enrichment factor (EF), 210Pb dating, and 206Pb/207Pb ratio for determining present and historical metal pollution. Surface distributions of trace metals ranged from 0.02 to 0.13 mg/kg for Cd (EF: 0.16-1.65), from 35 to 189 mg/kg for Cr (EF: 0.85-2.92), from 25 to 64 mg/kg for Ni (EF: 0.53-2.38), from 10 to 32 mg/kg for Pb (EF: 1.20-4.94), and from 29 to 129 mg/kg for Zn (EF: 1.18-3.50). Trace metal concentrations correlate closely with distributions of mud (<63 microm) and organic carbon which accumulate largely around river mouths and within the Kaoping Canyon. With the exception of Cd, Cr and Ni in certain areas with rather coarse sediments, metals were generally elevated above the baseline levels over the studied area. Metals were also relatively enriched in areas with high contents of mud and organic carbon. Sedimentation rates derived from the excess 210Pb data in core sediments sampled from the canyon illustrate metal pollution beginning around 1970 that is corresponding to the booming time of economic growth in Taiwan. Meanwhile, the status of Pb pollution in core sediments is verified by an inversed correlation between 206Pb/207Pb ratios and Pb concentrations. Anthropogenic Pb and other metals in the studied area were apparently derived primarily from the Kaoping River and accumulated around the river mouth and within the Kaoping Canyon. The Kaoping Canyon appears to act as a major sink for river borne trace metals.

Carbon↗

PubMed2006

Trace metal levels in sediments deposited in urban stormwater management facilities.

Characteristics of solids recovered from stormwater best management practice (BMP) facilities, including stormwater ponds, constructed wetlands, an infiltration basin, a biofilter, a stormwater treatment clarifier, and three-chamber oil and grit separators were described with respect to their metal chemistry. The reported trace metal concentrations in BMP sediments were assessed against the Ontario Sediment Quality Guidelines. Between 80 to 100% of all samples were marginally-to-intermediately polluted by Cd, Cr, Cu, Fe, Pb, Mn, Ni and Zn. Severe pollution of sediments was noted for Cr (122 microg/g), Cu (151 and 196 microg/g), Mn (1,259 and 1,433 microg/g), and Zn (1,116 microg/g), at several facilities studied, and even higher levels of metals were reported in the literature for certain oil and grit separators. With respect to individual BMPs, the severe pollution was found in sediments from oil and grit separators (for Cd, Cr, Cu, Pb and Zn), the stormwater clarifier sludge (Cu, Mn and Zn), a biofilter (Cu and Mn), an industrial area stormwater pond (Cu only), and a commercial/residential pond (Cr only). Finally, the chemical pollution of pond sediment triggered toxicity testing at some of the facilities studied, and sediment toxicity was confirmed at several sites.

Canada↗

PubMed1986

In vitro inhibition of Na-K-ATPase by trace metals: relation to renal and cardiovascular damage.

The potential role of trace metals in the pathogenesis of various disease states, especially of renal and cardiovascular disease, has been recognized increasingly. Moreover, altered membrane transport was recently incriminated to play a role in renal tubular syndromes, such as the Fanconi syndrome, as well as in the pathogenesis of volume dependent hypertension. We therefore investigated the possible in vitro effects of various trace metals on Na-K-ATPase, the biochemical correlate of active cellular transmembrane sodium and sodium-dependent transport. To more closely mimic the in vivo situation, we deliberately chose as enzyme source renal tissue homogenate, which may contain protective agents. Under these experimental conditions, the metals studied inhibited the enzyme quantitatively in the following order: Hg greater than Pb greater than Cd greater than Ur greater than Cu greater than Zn greater than Mn greater than Ba greater than Ni greater than Sr. Enzyme kinetic studies showed that Hg, Pb, and Cd competitively, and Cu noncompetitively, inhibited the enzyme. In general, Mg-ATPase was significantly less sensitive to the trace metals. Accumulation of these metals may present serious health hazards by producing a general defect in cell membrane transport. From the other metals studied, i.e., Mn, Ba, Ni and Sr, some may have toxic effects via other mechanisms, whereas some may exert a protective role against toxicity of other agents including metal ions.

Animals↗

PubMed1976

Influence of cadmium and other trace metals on human alpha1-antitrypsin: an in vitro study.

The effect of trace metals on plasma alpha1-antitrypsin was studied in vitro by adding known concentrations of trace metals, either alone or in combination, to plasma. Cadmium was the only trace metal that reduced the concentration of alpha1-antitrypsin and depressed the trypsin inhibitory capacity. No such effects were found with divalent lead, mercury, nickel, iron, and zinc ions. The present study appears to offer a plausible explanation for the emphysema that occurs in industrial workers exposed to cadmium.

Cadmium↗

PubMed2026

Associations between multiple essential trace metal concentrations and risk of hyperuricemia: insights from a central Chinese population.

Previous studies have indicated that levels of individual essential trace metals are related to hyperuricemia (HUA), but evidence on their combined effects is limited. To address this gap, the associations of individual and joint levels of 12 essential trace metals (manganese, selenium, nickel, chromium, cobalt, tin, iron, molybdenum, zinc, strontium, vanadium, and copper) with the risk of HUA were investigated in 2,021 adults recruited from Hunan Province, China. Inductively coupled plasma mass spectrometry (ICP-MS) was employed to determine urinary metal concentrations. Logistic regression, Bayesian kernel machine regression (BKMR), and quantile g calculation (Qgcomp) were applied to evaluate the associations of single and mixture metal concentrations with HUA. Of the participants, 516 (25.53%) were diagnosed with HUA. Inverse associations were found between vanadium, chromium, manganese, iron, cobalt, selenium, strontium, and molybdenum levels and HUA, with ORs ranging from 0.63 to 0.91. Conversely, a positive association was observed between zinc concentration and HUA [OR (95% CI): 1.17 (1.01, 1.37)]. Both BKMR and Qgcomp models showed a negative overall effect of essential trace metals on HUA risk, with strontium (- 43.6%) and vanadium (- 27.8%) being the main contributors. In addition, formal interaction tests revealed significant effect modification by age for tin and by BMI for zinc. In conclusion, the levels of essential trace metals were linked to a decreased risk of HUA, and these associations were modified by age and BMI only for specific metals.

Humans↗