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PubMed2005

The influence of the Amazonian floodplain ecosystems on the trace element dynamics of the Amazon River mainstem (Brazil).

The purpose of this paper is to forecast the role of riverine wetlands in the transfer of trace elements. One of the largest riverine wetlands in the world is the floodplain (várzea) of the Amazon River and its tributaries (Junk and Piedade, 1997). The central Amazon wetlands are constituted by a complex network of lakes and floodplains, named várzeas, that extend over more than 300,000 km2 (Junk, W.J., The Amazon floodplain--a sink or source for organic carbon? In Transport of Carbon and Minerals in Major World Rivers, edited by E.T. Degens, S. Kempe, R. Herrera, SCOPE/UNEP; 267-283, 1985.) and are among the most productive ecosystems in the world due to the regular enrichment in nutrients by river waters In order to understand if the adjacent floodplain of Amazon River have a significant influence on the trace element concentrations and fluxes of the mainstem, the concentrations of selected elements (i.e., Al, Mn, Fe, Co, Cu, Mo, Rb, Sr, Ba, and U) have been measured in the Amazon River water (Manacapuru Station, Amazonas State, Brazil) and in lake waters and plants (leaves) from a várzea(Ilha de Marchantaria, Amazonas State, Brazil) during different periods of the hydrological cycle. Four plant species (two perennial species: Pseudobombax munguba and Salix humboldtiana, and two annual herbaceous plants: Echinochloa polystachya and Eichhornia crassipes) were selected to represent the ecological functioning of the site. Time series obtained for dissolved Mn and Cu (<0.20 microm) in Amazon River water could not be explained by tributary mixing or instream processes only. Therefore, the contribution of the waters transiting the floodplains should be considered. These results suggest that the chemical composition of the waters draining these floodplains is controlled by reactions occurring at sediment-water and plant-water interfaces. Trace elements concentrations in the plants (leaves) vary strongly with hydrological seasonality. Based on the concentration data and the biological productivity of floodplain ecosystems, a first order approximation of trace element storage (permanent or temporary) in the vegetation of these floodplains was made. It was found that floodplain-mainstem elemental fluxes make a significant contribution to the dissolved flux of the Amazon River. This study is part of the Brazilian_French joint research program Hybam (Hydrology and Geochemistry of the Amazonian Basin).

Brazil↗
PubMed2006

Sediment reference concentrations of seldom monitored trace elements (Ag, Be, In, Ga, Sb, Tl) in four Swedish boreal lakes--comparison with commonly monitored elements.

This paper presents reference and recent acid-leachable concentrations of some seldom monitored trace elements (SMTE; Ag, Be, Ga, In, Sb and Tl) in sediments from four boreal oligotrophic lakes in a south to north transect in Sweden. For comparison commonly monitored trace elements (As, Cd, Co, Cr, Cu, Ni, Pb and Zn) are included as well as those of relevance for redistribution processes (Al, Ca, Fe, Mg and Mn). Pore water pH and the corresponding solid/solution distribution coefficients (Kd) indicated that redistribution of the elements due to acidification is minor. The depth of impact was defined as the level in the sediment where the mean values became constant on successive exclusion of metal concentrations in overlying strata. Reference concentrations were calculated below the depth of impact. The present concentration changes are estimated by the ratio between the average concentration above the depth of impact and the reference concentration. Reference concentration ranges for the SMT-elements are (mg/kg, dry wt.): Ag 0.16-0.66; Be 1.6-3.7; Ga 2.0-5.1; In 0.05-0.22; Sb 0.05-0.11 and Tl 0.17-0.70. The concentration ratios for these elements ranged in the two most southern lakes from 1.5 to 4.5 and in the two northern ones from 0.6 to 1.6. A high correlation between Kd for the SMT-elements, and iron, except for Sb and Tl, infer that the biogeochemistry of iron is quantitatively important for the accumulation of these elements. The reference concentration ranges for the commonly monitored trace elements are (mg/kg, dry wt.): As 7.0-29.6; Cd 0.33-0.98; Co 5.7-23.8; Cr 15.2-26.1; Cu 27.6-58.4; Ni 5.4-20.8; Pb 44-96. The corresponding concentration ratios were 1.2-18 (second highest 3.9) in the two most southern lakes and 0.8-1.6 in the two northern ones. Declining ratios were found from south to north, most obvious for cobalt and zinc. The copper ratios did not show a regional pattern, partly because of the impact from old mine waste. Increased concentrations of Ag, Be, Ga, In, Sb and Tl in recent sediments up to 4.5 times the reference levels in combination with the geographical pattern infer an elevated loading of these elements.

Environmental Monitoring↗
PubMed1991

[Trace elements of iatrogenic origin].

Iatrogenic microelementoses are diseases and pathological processes caused by the deficiency or excess of trace elements in the body due to medical treatment performed for preventive, diagnostic and therapeutical purposes. It is suggested to differentiate iatrogenic hypomicroelementoses developing due to the deficiency of essential trace elements from those resulting from the excessive intake and accumulation in the organs and tissue of both essential and toxic trace elements. Examples of both groups of iatrogenic microelementoses are presented.

Humans↗
PubMed1999

The IAEA worldwide intercomparison exercises (1990-1997): determination of trace elements in marine sediments and biological samples.

Four major worldwide intercomparison exercises for the determination of trace elements in various environmental matrices were completed by the IAEA Marine Environment Laboratory since 1990: SD-M-2/TM, deep sea marine sediment; IAEA-350, tuna fish homogenate; IAEA-356, contaminated coastal sediment and IAEA-140, sea plant (Fucus sp.). These intercomparison exercises aim at enabling individual laboratories to monitor their performance. The results of these exercises allowed us to make an overall evaluation of the quality of data provided for environmental assessment and to identify the trends of analytical performance in the determination of trace elements over the years. The number of participants in each exercise varied between 68 and 130, and permits statistical evaluation of the performance for a number of elements. For each intercomparison exercise, the performance of the participant laboratories was assessed by comparing reported results with established reference values calculating 'Z-scores'. The results show that for each sample matrix, the values reported by some laboratories were far from satisfactory in the earlier exercises, in particular for Cd, Cr and Pb. Nevertheless, over time, a general improvement of performance can clearly be seen for all elements. Moreover, there was a noticeable increase in the number of laboratories with good performance in the two most recent exercises, observed both for biological and for sediment matrices. However, the determination of trace elements such as Cd, Cr, Pb and Hg in low level environmental samples still remains a major challenge to the analysts. For this reason and in order to assess the current performance of laboratories for low environmental levels of contaminants, the future intercomparison exercises will concentrate on low level sediment and fish samples.

Animals↗
PubMed1990

Gradient centrifugation to isolate platelets for determination of trace elements by neutron-activation analysis.

A nonionic iodinated compound, Nycodenz, was used for density-gradient isolation of platelets before analysis for trace elements by instrumental neutron activation. The platelet samples were almost free from plasma and erythrocytes, and the trace element contribution from additives was insignificant for the elements investigated. The reproducibility of the trace element analysis in platelets attests to the usefulness of density-gradient separation. Platelet samples were obtained twice, three weeks apart, from 10 healthy young women (ages 24 +/- 2 years). The mean (SD) concentrations were as follows: Se, 0.62 (0.16) mg/L and 4.7 (1.4) ng/10(9) platelets; Zn, 44 (10) mg/L and 333 (80) ng/10(9) platelets; Rb, 3.0 (0.5) mg/L and 23 (5) ng/10(9) platelets; and Cs, 24 (5) micrograms/L and 0.18 (0.04) ng/10(9) platelets.

Adult↗
PubMed2004

Speciation of protein-bound trace elements by gel electrophoresis and atomic spectrometry.

The metabolism of trace elements, in particular their binding to proteins in biological systems is of great importance in biochemical, toxicological, and pharmacological studies. As a result there has been a sustained interest over the last two decades in the speciation of protein-bound metals. Various analytical approaches have been employed, combining efficient separation of metalloproteins by liquid chromatography or electrophoresis with high-sensitivity elemental detection. Slab-gel electrophoresis (GE) is a key platform for high-resolution protein separation, and has been combined with autoradiography and various atomic spectrometric techniques for in-gel determination of protein-bound metals. Recently, the combination of GE with state-of-the-art inductively coupled plasma-mass spectrometry (ICP-MS), particularly when linked to laser ablation (LA) for direct gel interrogation, has opened up new opportunities for rapid characterization of metalloproteins. The use of GE and atomic spectrometry for the speciation of protein-bound trace elements is reviewed in this paper. Technical requirements for gel electrophoresis/atomic spectrometric measurement are considered in terms of method compatibilities, detection capability and potential usefulness. The literature is also surveyed to illustrate current status and future trends.

Autoradiography↗
PubMed2001

Effect of vitamin and trace-element supplementation on cognitive function in elderly subjects.

OBJECTIVE: To determine whether supplementation with vitamins and trace elements in modest amounts influences cognitive function in apparently healthy, elderly subjects. METHODS: The study was designed as a randomized, double-blind, placebo-controlled trial. Ninety-six, apparently healthy, independent men and women older than 65 y of age were recruited and randomized to receive a supplement of trace elements and vitamins or a placebo daily for 12 mo. Blood-nutrient levels were estimated at baseline and at the end of the study. The major outcome measure assessed was cognitive function consisting of immediate and long-term memory, abstract thinking, problem-solving ability, and attention. RESULTS: Eighty-six subjects completed the 1-y trial. The supplemented group showed a significant improvement in all cognitive tests (P < 0.001 to 0.05) except long-term memory recall (P > 0.1). Those whose blood-nutrient levels were below the reference standard showed lower responses on cognitive tests. There was no significant correlation between individual nutrient levels and performance on various cognitive function tests. CONCLUSIONS: Cognitive functions improved after oral supplementation with modest amounts of vitamins and trace elements. This has considerable clinical and public health significance. We recommend that such a supplement be provided to all elderly subjects because it should significantly improve cognition and thus quality of life and the ability to perform activities of daily living. Such a nutritional approach may delay the onset of Alzheimer's disease.

Aged↗
PubMed2002

[The application of inductively coupled plasma atomic emission spectrometry/mass spectrometry in the trace elements and speciation analysis of traditional Chinese Medicine].

A review on the content and speciation analysis of trace element in traditional chinese medicine (TCM) by ICP-AES/MS was presented. The study is mainly focused on the following subjects: sample digestion techniques; determination and speciation analysis of trace elements. The development trend of this area in the near future is briefly introduced. 58 references are cited. The results show that the microwave digestion techniques is a idea pretreatment method of sample for tradition chinese medicine; ICP-AES/MS and all kinds of hyphenated techniques for atomic optical/mass spectrometry/chromatography are very useful for the determination and speciation analysis of trace elements in TCM.

Drug Contamination↗
PubMed1976

Trace elements in water and congenital malformations of the central nervous system in South Wales.

The concentrations of 20 trace elements were determined by atomic absorption spectrophotometry on representative samples of tap-water collected from 48 local authority areas in South Wales. The associations between twelve trace elements and central nervous system (CNS) malformation rates for the 48 areas were examined. Significant correlations for four trace elements were observed. Of these, Al was positively correlated while for the remaining three-Ca, Ba, and Cu-negative associations were found. Regression analysis of the data suggested that the relationships between Ba and Cu with CNS malformation rates were improtant than those of Al and Ca.

Aluminum↗
PubMed1976

Whole blood trace element concentrations during total parenteral nutrition.

Samples of whole blood in eight patients on long-term total parenteral nutrition (TPN) and in four who served as controls were analyzed for trace element concentrations of Au, Br, Cu, Mn, Cr, Sb, Fe, Zn, Co, Hg, Rb, and Se. The concentrations of essential elements in the patients deviated significantly from those in the control group. The Mn concentration in blood was consistently higher in patients, owing to the high Mn concentration in the nutrient solutions. A reciprocal relationship between Cu and Zn was demonstrated in one patient. Some trace element concentrations are correlated with the duration of malabsorption and the amount of oral intake during TPN. This study shows that patients on TPN may have abnormal trace element profiles and that TPN currently does not supply the necessary concentrations of trace elements.

Adolescent↗
PubMedDate not supplied

Trace element patterns and seasonal variability of dust precipitation in a low polluted city--the example of Karlsruhe/Germany.

Urban areas of different land uses can be distinguished by their specific patterns of atmospheric dust and trace element precipitation. Dusts emitted from industrial areas with fossil fuel processing, for instance, are enriched in V, Ni and Co. Cluster analysis groups sampling sites based on their specific element patterns. The resulting groups correspond to the surrounding land use: Urban sampling sites were identified showing similar patterns of dust and trace element precipitation as a reference site; dusts of other urban sites were influenced by diffuse pollution (caused by non-point and dispersed pollution sources), or by specific industrial emissions. Cluster analysis was also used to characterize the chemical dust composition. Three clusters of typical element associations were distinguished. These clusters represent the dust matrix, diffuse urban pollution and pollution due to fossil fuel processing. Dust precipitation and chemical dust composition show seasonal variations. Dust precipitation and concentrations of trace elements in the precipitated dust are negatively correlated during the annual courses. The highest concentrations of trace elements occur during winter, whereas the highest precipitations of dust were found during summer. This finding stresses that both, precipitation and concentration have to be addressed for the environmental assessment of urban dusts.

Air Pollutants↗
PubMed2003

Trace elements analysis of Echinacea purpurea--herbal medicinal.

Elemental composition of Echinacea purpurea (Asteracae), grown in Serbia under strongly controlled conditions, has been studied. To distinguish elemental patterns of different parts of the plant, the content of Zn, Fe, Cu, Mn, Ca, Mg, Sr, Ni, and Li in root versus upper plant parts were determined, by flame atomic absorption and flame atomic emission spectrometry. Analyses of the mentioned elements in soil and in an ethanolic extract of E. purpurea were made, too. The trace element data were evaluated by multivariate methods, i.e. principal component analysis and hierarchical cluster analysis. This revealed two groups of elements (I: Fe, Cu, Mn, Li; II: Ca, Mg, Zn, Ni), while trace element profiles of root, stem, leaves, and flowers of this plant differed significantly. However, no significant difference in the trace element patterns between the summer and the autumn harvest samples was found.

Echinacea↗
PubMed1994

Trace elements in canvasbacks (Aythya valisineria) wintering in Louisiana, USA, 1987-1988.

We determined trace element concentrations in livers of canvasbacks (Aythya valisineria) collected at Catahoula Lake and the Mississippi River Delta, Louisiana during, the winter of 1987-1988. Forty percent of canvasbacks wintering at Lake Catahoula had elevated concentrations of lead (>6.7 microg g(-1) dry weight) in the liver; 33% had concentrations consistent with lead intoxication (>26.7 microg g(-1)). Based on the number of canvasbacks that winter at Lake Catahoula and the frequency of lead exposure there, more than 5% of the continental population of canvasbacks may be exposed to lead at Lake Catahoula alone. Lead concentrations in livers differed among months and were higher in males than females, but were not different in adults and immatures. Concentrations of selenium and mercury in livers of females differed among months but not by age or location. Cadmium concentrations in livers differed by age, location and month of collection, but not by sex. Frequencies and concentrations of trace elements not commonly associated with adverse effects on avian species (aluminum, arsenic, copper, iron, magnesium, manganese, nickel, silver, vanadium and zinc) are presented. Except for the elevated concentrations of lead at Catahoula Lake, all trace elements were at background concentrations.

Journal Article↗
PubMedDate not supplied

Trace-element status in milk and plasma of Kuwaiti and non-Kuwaiti lactating mothers.

There is a wide variation in the reported data on the concentrations of trace elements in human milk from different countries, but such data are not available for Kuwait. The objective of this study was to analyze the concentration of zinc, copper, manganese, and iron in milk and plasma of Kuwaiti and non-Kuwaiti mothers during prolonged lactation. Milk samples (from 34 donors) were collected early in the morning before feeding the infant. Trace elements were analyzed using atomic absorption spectrophotometry. Protein content and activity of superoxide dismutase were assayed spectrophotometrically. Concentration of zinc, copper, iron, and total protein and activity of superoxide dismutase in milk and of only zinc in plasma of Kuwaiti mothers were significantly higher than those of non-Kuwaitis. Concentration of zinc, copper, manganese, and total protein in milk of both groups decreased as lactation continued but that of milk iron and plasma trace elements remained unchanged. The data of Kuwaiti mothers are consistent with those of previous reports on hyperuricemia, and the prevalence of obesity was found to be higher in the Kuwaiti population than in other countries. High protein content in association with high concentration of trace elements in milk of Kuwaiti versus non-Kuwaiti mothers may indicate that protein content in milk is an important determining factor for the concentration and bioavailability of these elements.

Adult↗
PubMed1999

Impact of trace elements and vitamin supplementation on immunity and infections in institutionalized elderly patients: a randomized controlled trial. MIN. VIT. AOX. geriatric network.

BACKGROUND: Antioxidant supplementation is thought to improve immunity and thereby reduce infectious morbidity. However, few large trials in elderly people have been conducted that include end points for clinical variables. OBJECTIVE: To determine the effects of long-term daily supplementation with trace elements (zinc sulfate and selenium sulfide) or vitamins (beta carotene, ascorbic acid, and vitamin E) on immunity and the incidence of infections in institutionalized elderly people. METHODS: This randomized, double-blind, placebo-controlled intervention study included 725 institutionalized elderly patients (>65 years) from 25 geriatric centers in France. Patients received an oral daily supplement of nutritional doses of trace elements (zinc and selenium sulfide) or vitamins (beta carotene, ascorbic acid, and vitamin E) or a placebo within a 2 x 2 factorial design for 2 years. MAIN OUTCOME MEASURES: Delayed-type hypersensitivity skin response, humoral response to influenza vaccine, and infectious morbidity and mortality. RESULTS: Correction of specific nutrient deficiencies was observed after 6 months of supplementation and was maintained for the first year, during which there was no effect of any treatment on delayed-type hypersensitivity skin response. Antibody titers after influenza vaccine were higher in groups that received trace elements alone or associated with vitamins, whereas the vitamin group had significantly lower antibody titers (P<.05). The number of patients without respiratory tract infections during the study was higher in groups that received trace elements (P = .06). Supplementation with neither trace elements nor vitamins significantly reduced the incidence of urogenital infections. Survival analysis for the 2 years did not show any differences between the 4 groups. CONCLUSIONS: Low-dose supplementation of zinc and selenium provides significant improvement in elderly patients by increasing the humoral response after vaccination and could have considerable public health importance by reducing morbidity from respiratory tract infections.

Aged↗
PubMed1999

[Changes in trace elements in epithelial cells of oral submucous fibrosis].

OBJECTIVES: To assay the concentrations of the trace elements in intranuclei and extranuclei between oral submucous fibrosis (OSF) and normal buccal membrane, to observe the relationship between the trace elements and OSF, and finally to understand the mechanism of OSF. METHODS: The concentrations of the trace elements of internuclei and extranuclei in OSF epithelial cells were assayed in computer automatic process by electron probe micro-analysis. RESULTS: The concentrations of Cu, Zn, S, and As in OSF were significantly lower than those in the normal buccal membrane (P < 0.01). The concentrations of Se and Mo were significantly higher than those in the normal buccal membrane(P < 0.01). CONCLUSION: The epithelial cells of OSF are seriously damaged by the low level of Cu and Zn and high level of Se in intracell. These changes are the element bases that OSF has canceration trend.

Copper↗
PubMed1979

Trace elements in man.

It is likely that most, if not all, of the elements found to be essential in animals will be shown to be so for man, and the clinical picture produced by deficiency of the elements in the human patient will differ little from that seen in the animal, although this has been established for only five elements (I, Fe, Cu, Co and Zn). However, the link between lack of a given element in the soil and a human patient is far less direct and much more complex than that met with in the animal grazing on deficient pastures, except in isolated primitive communitis. Zn is the most protean of the trace elements and has been chosen to illustrate this in human practice. Excesses of essential elements (both trace and major) give rise to toxic effects and the importance of a proper balance especially of the transitional elements in the human diet is discussed with special reference to Cu, Zn and Fe. Certain non-essential trace elements are individual and community hazards: Cd, Pb and Hg are the principal offenders for humans. Mankind is now largely dependent on grassland products, cereals and livestock with increasing dominance of the former in human nutrition. This has reduced the bioavailability of trace elements so that study of trace metals, especially Zn and Cu, in skeletal and dental remains at human burial and occupation sites should prove useful in assessing the consequences of this striking change in dietary habits.

Biological Evolution↗
PubMed1995

Effect of dietary antioxidant trace element supply on cardiac tolerance to ischemia-reperfusion in the rat.

Over a 10-week period, female Wistar rats received a diet containing various levels of four trace elements (Zn, Cu, Mn, Se), co-factors of antioxidant enzymes (superoxide dismutase SOD, glutathione peroxidase GPx), in order to examine the influence of supplementation or deficiency of these elements (i) on tissue antioxidant enzyme defence systems, and (ii) on the susceptibility of the myocardium to ischemia-reperfusion injury. At the end of the dietary treatment, hearts were perfused at constant flow (11 ml/min) before being subjected to 15 min of total global normothermic ischemia, followed by reperfusion. The effects of the various diets (deficient, standard or supplemented) were estimated by studying functional recovery of various cardiac parameters (left ventricular developed pressure LVDP, dP/dtmax, heart rate x LVDP) as well as ultrastructural tissue characteristics. Furthermore, SOD and GPx activities were measured before ischemia and at the end of the reperfusion period. Results suggest that: (a) the activity of antioxidant enzymes increased or decreased significantly when diet was respectively supplemented with, or deficient in, trace elements, but was not further modified by an ischemia-reperfusion episode: (b) the recovery of cardiac function during reperfusion, and ventricular myocardial ultrastructure were significantly improved under the influence of trace element supplementation when compared to both standard and deficient groups. These results illustrate the protective effect of trace elements which are co-factors of antioxidant enzymes in limiting ischemia-reperfusion induced injury, and suggest a possible use in the field of anti-ischemic therapy.

Administration, Oral↗