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Absorption and retention studies of trace elements and minerals in rats using radiotracers and whole-body counting.

A description is given of a whole-body counting technique using radiotracers, permitting the determination of true absorption and endogenous excretion of trace elements and minerals in the rat in vivo. This non-invasive counting method involves oral and intraperitoneal administration of tracer doses of a radioisotope in a cross-over fashion and subsequent measurement of the whole-body retention in a whole-body counter. Thus, true absorption can be determined in one animal which contributes to the reduction of animal use. To study the variations in counting response due to radioisotope distribution, to size or shape of the animal body, the influence of the position of a point source and distribution over different phantoms to simulate various body sizes are experimentally evaluated for 64Cu, 65Zn, 59Fe and 28Mg. Results from 2 studies, with 64Cu and 28Mg, as an example for a trace element and a mineral respectively, are presented and illustrate that absorption as measured by apparent absorption does not necessarily reflect true absorption. True absorption as determined by the whole-body retention method using radioisotopes corrects for faecal losses of endogenous origin.

Absorption↗

[Vitamins and trace elements in nutrition. Update 2005].

In Germany sales of vitamin and trace element supplements are 1,2 billion Euros per year. In the light of this dimension and the increasing tendency toward food fortification, medicine and nutritional science have to state their point of view, where supplementation is useful, where it might be useful, and where it is useless or possibly dangerous. Supposing a balanced diet, nutritional requirements are covered in adults. Only in the area of calcium, folic acid, iodine, and vitamin D a gap in supplies can be discovered in average nutrition. Those requirements should be covered with a balanced diet. The intention of supplementation in this field is the potential health benefit of a requirement-exceeding supplementation. Especially antioxidants are sometimes suggested to have such effects. From a scientific view a general recommendation, especially for multivitamin supplementation, cannot be given. In contrast to young adults, elderly persons frequently suffer from single or general micronutrient deficiencies. The intention of supplementation in this field is the coverage of nutritional requirements and the therapy of specific nutritional deficiencies, which should be compensated, even though scientific evidence in some fields is weak.

Adolescent↗

Lipid and trace element composition of human milk.

The recent work on lipids and trace elements in human milk has been reviewed. Lipids in human milk are specially important for the development of the central nervous system of the infant, in addition to being a source of nutrients. Recent studies revealed that the concentration of total lipids was low in milk samples from Indian women belonging to the low socio-economic group: linoleic acid constituted a high percent of the fatty acids. The bile-stimulated lipase activity of milk was higher in Ethiopian than in Swedish milk samples. Vitamin D sulphate, the water soluble conjugate of vitamin D, was present in higher concentrations than that reported for vitamin D in lipid fraction; however, the antirachitic activity of vitamin D sulphate is yet to be studies. Copper, zinc, and magnesium concentrations were high in sampled obtained during the first month of lactation. Copper and zinc levels continued to fall gradually till the end of one year lactation. The mean concentrations of zinc and copper in mature milk samples from Indian mothers were similar to those in American samples, though both the samples showed wide variation. A high proportion of zinc in milk was bound to proteins.

Copper↗

The influence of biosolids treatment files on the mobility of metal trace elements.

The production of sludge in France is estimated to be about 900,000 metric tons dry matter per year and 60% of this is recycled onto agricultural land. At present, the long term future of this procedure is open to question and among the different arguments being put forward are the levels of metallic trace elements and the risk of accumulation in soils. This study presents the behaviour of metallic trace elements in sludges from three different treatment procedures: thickened liquid sludges, dewatered sludges and dried sludges. These biosolids are mixed with a clay soil and then placed in a temperature and humidity controlled glasshouse. Several containers are seeded with ryegrass and compared with controls. For the three harvests, covering all the amendments studied (including non-amended soil), the differences are not really representative. Absorption by the ryegrass is low in all cases. For the cadmium, the chromium, the nickel and the lead, the roots are 5 to 10 times more concentrated than the leaves. The majority of these elements stay absorbed in the roots, regardless of the amendment used. The addition of the sludges has considerably reduced the uptake of water in ryegrass throughout its growth cycle. Quite apart from their fertilizing qualities, wastewater treatment plant sludges could offer important implications for irrigation.

Absorption↗

The 'mysterious' disease in Swedish moose. Concentrations of trace elements in liver and kidneys and clinical chemistry. Comparison with experimental molybdenosis and copper deficiency in the goat.

Moose (Alces alces L.) affected by a disease with unknown aetiology were compared with healthy moose regarding trace element concentrations in liver and kidneys, as well as certain clinical chemical parameters of blood plasma. The diseased moose showed decreased hepatic concentrations of Cu, Cd and Mg. Renal concentrations of Cd, Co, Mg and Mn were also decreased. Substantially increased concentrations in both liver and kidneys were seen for Al, Ca, Fe, Pb and Zn, while Se and Mo were increased in liver tissue. The hepatic levels of Mo in the affected moose were 36% higher and Cu was approximately 60% lower than in reference animals collected in 1982. The most important clinical chemical changes were decreased concentrations of bilirubin, thyroxine (T4) and the liver-specific enzymes GLDH and g-GT. Also, the activities of the enzymes CuZn-SOD and GSH-Px in erythrocytes were decreased. Increases were recorded for free fatty acids (NEFA), the muscle-specific enzyme CK, but especially for urea and insulin. Changes in the plasma protein pattern were also discernible after electrophoresis on agarose gel membranes, indicating chronic immunostimulation. All the observed changes in trace element concentrations and clinical chemical parameters are compatible with molybdenosis and secondary Cu deficiency in ruminants and most of the parameters are in agreement with those found in experimental copper deficiency and molybdenosis in the goat. It is, therefore, suggested that the moose disease with previously unknown aetiology is mainly caused by molybdenosis.

Animals↗

The relation between selenium, zinc and copper concentration and the trace element dependent antioxidative status.

An imbalance in the antioxidative system was connected with the development of a number of pathological processes. In order to receive values of a healthy group and to evaluate pathological changes of the trace element dependent antioxidative status in future, we investigated 99 healthy volunteers (45 male and 54 female, mean age 37.4 +/- 11.7 years). We determined the concentrations of Se, Cu and Zn, the concentrations of malondialdehyde (MDA) and the activities of the Se dependent glutathione peroxidase (GSH-Px) and the Zn/Cu dependent superoxide dismutase (SOD). The plasma concentrations (mean +/- SD) for Se, Cu and Zn were 0.84 +/- 0.10 micromol/l, 15.6 +/- 2.78 micromol/l and 12.6 +/- 1.80 micromol/l, resp., and for non protein-bound and protein bound MDA 0.27 +/- 0.07 micromol/l and 1.11 +/- 0.25 micromol/l, resp. The activity of GSH-Px in plasma and erythrocytes was 130 +/- 20.8 U/l and 19.8 +/- 4.18 U/mg Hb, resp. and of SOD in erythrocytes 3,159 +/- 847.2 U/g Hb. In plasma positive correlations have been found between Se concentrations and GSH-Px activities (p < 0.002, r = 0.31) and between GSH-Px activities and concentrations of non protein-bound MDA (p = 0.004, r = 0.28). A negative correlation has been observed between GSH-Px activities in plasma and in erythrocytes. The higher the concentrations of Cu in erythrocytes, the higher were the activities of SOD (p = 0.03, r = 0.22) and GSH-Px in erythrocytes (r = 0.26, p = 0.01), while an increasing activity of GSH-Px in these cells correlated with a decreasing concentration of non protein-bound MDA (r = -0,31, p = 0.002). An increase in BMI was connected with an increase in protein-bound MDA and a decrease in GSH-Px activities in pLasma (p = 0.002 and r = 0.23). As the results demonstrate, Se and Cu concentrations in erythrocytes can improve the trace element dependent antioxidative status.

Antioxidants↗

Trace elements in serum from Pakistani patients with acute and chronic ischemic heart disease and hypertension.

We examined sera from 159 patients with ischemic heart disease and hypertension and from 50 apparently healthy control subjects for content of trace elements, cholesterol, triglyceride, and enzymes. Concentrations of copper, cobalt, cholesterol, and triglyceride were increased in all patients, but calcium was decreased in patients with hypertension, acute myocardial ischemia, and acute myocardial infarction. Also accompanying acute myocardial infarction were decreased concentrations of zinc and iron but increases in nickel, aspartate aminotransferase, alanine aminotransferase, and lactate dehydrogenase. Magnesium concentration was lower in patients with acute myocardial ischemia. In acute myocardial infarction, the concentrations of copper, zinc, and iron were higher after 21-30 h (as compared with the values at 0-10 h), by which time concentrations of calcium, magnesium, cobalt, and alanine aminotransferase had decreased. The variation in concentration of trace elements in serum from cases of ischemic heart disease and hypertension corresponds to the severity of the disorder.

Adult↗

Available iron and zinc in major lean meat cuts and their contribution to the recommended trace element supply in Switzerland.

The objective of the present study was to analyze iron and zinc in major lean meat cuts in order to estimate the contribution of the average lean meat consumption in Switzerland (1995) for these trace elements. Iron, heme iron and zinc contents were analyzed in following muscles: pork (longissimus dorsi muscle and shoulder), beef (longissimus dorsi muscle and shoulder), veal (longissimus dorsi muscle) and chicken (breast and thigh). Beef and pork shoulder were the best sources of iron, heme iron and zinc. Pork and veal longissimus dorsi muscle and chicken were relatively poor in these trace elements. With an average daily lean meat consumption of 105 g, iron and zinc intake were about 1.1 mg/d and 3.8 mg/d, respectively. Recommendations for daily iron intake were met to 11% (men) and 7% (women) and for zinc to 25% (men) and 32% (women). Applying a modified Monsen model, the requirements for absorbed iron were met in the range of 10-30% and 7-20% for men and women, respectively. Taking into account a zinc absorption rate from meat of about 20-36%, the daily requirements for absorbed zinc were covered to 32-56%. In conclusion, the average amount of lean meat as consumed in Switzerland was high enough to be an important source of available iron and zinc, particularly for people with low iron and zinc status.

Adult↗

Concentrations of selected trace elements in human milk and in infant formulas determined by magnetic sector field inductively coupled plasma-mass spectrometry.

Magnetic sector field inductively coupled plasma-mass spectrometry (ICP-MS) was applied to the reliable determination of the 8 essential trace elements cobalt (Co), chromium (Cr), copper (Cu), iron (Fe), manganese (Mn), nickel (Ni), selenium (Se), and vanadium (V) as well as the 7 nonessential and toxic elements silver (Ag), aluminum (Al), arsenic (As), gold (Au), platinum (Pt), scandium (Sc), and titanum (Ti) in 27 transitory and mature human milk samples and in 4 selected infant formulas. This advanced instrumentation can separate spectral overlaps from the analyte signal hampering significantly the determination of many trace elements by conventional ICP-MS. Moreover, superior detection limits in the picogram per liter range can be obtained with such magnetic sector field instruments. Therefore, this is the first study to report, the concentrations of the elements Ag, Au, Pt, Sc, Ti, and V in human milk and in infant formulas. Concentrations of Ag (median: 0.41 microg/L; range: < 0.13-42 microg/L) and Au (median: 0.29 microg/L; range 0.10-2.06 microg/L) showed large variations in human milk that might be associated with dental fillings and jewelry. Pt concentrations were very low with most of the samples below the method detection limit of 0.01 microg/L. Human milk concentrations of Co (median: 0.19 microg/L), Fe (380 microg/L), Mn (6.3 microg/L), Ni (0.79 microg/L), and Se (17 microg/L) were at the low end of the corresponding reference ranges. Concentrations of Cr (24.3 microg/L) in human milk were five times higher than the high end of the reference range. For Al (67 microg/L), As (6.7 microg/L), and V (0.18 microg/L), most of the samples had concentrations well within the reference ranges. All elemental concentrations in infant formulas (except for Cr) were approximately one order of magnitude higher than in human milk.

Adult↗

Accumulation of metals, trace elements and semi-volatile organic compounds on exterior window surfaces in Baltimore.

Organic films have been found to develop on window surfaces [Diamond et al., Environmental Science and Technology 34 (2000a) 2900]. The film contains organic compounds that are in dynamic equilibrium with the gas-phase in air, and organic and inorganic compounds and elements associated with deposited air particles. In this study, the exterior surfaces of windows were sampled in downtown and suburban Baltimore, Maryland. Higher concentrations of PCBs, PAH, metals and trace elements were found at downtown than a suburban site. PCBs in the films at downtown sites were dominated by penta and hexa homologue groups and PAH signatures resembled that of vehicle emissions. Twenty-six metals and trace elements were separated into two groups according to their enrichment factors (EF). Ag, Hg, Se, Sb and Zn had EF > 100, suggesting anthropogenic sources of these metals in the films; whereas Fe, Ca, Co, Cr and others had EF <10, suggesting a crustal origin. An unusual profile dominated by deca- and nona- PCBs and relatively higher concentrations of Ag, Hg and Zn may be attributable to emissions from a medical waste incinerator. Dry deposition fluxes of selected metals on windows were 1.4-94 times higher on windows with than without films, indicating that the film increases the dry deposition of particles and their associated chemicals. This implies that film development, which is associated with elevated VOC and SOC emissions to urban air, will increase film development that will, in turn, increase the accumulation of other atmospherically deposited constituents such as metals.

Air Pollutants↗

Comparative study of the suitability of three lichen species to trace-element air monitoring.

To investigate the suitability of three lichen species (Cetraria islandica, Evernia prunastri, and Ramalina farinacea) as transplants to trace-element air biomonitoring, they were exposed on substratum-free supports, from July 1996 until July 1997, in three European countries with different climates (Germany, Italy, Romania), at six sites with different types of air pollutants (two in each country). After 2, 4, 6, and 12 months of exposure, some portions of thallus were collected, prepared, and measured by instrumental neutron activation analysis (INAA) at the Institute of Physics and Nuclear Engineering in Bucharest and by energy dispersive X-ray fluorescence analysis (EDXRFA) at the University of Hohenheim in Stuttgart. Fifteen environmentally relevant elements: As, Br, Ca, Co, Cr, Cu, Fe, K, Mn, Ni, Pb, S, Sb, V, and Zn were determined. The analytical results were compared statistically. To study the distribution of the trace-elements between the lichens and the lichen throughfall water inside a virtual column, the throughfall water was collected under the lichen transplants during 6 and 12 months. The dried residues were analysed by INAA at Bucharest. The accumulating capacity for all investigated species is evident. For a comparative evaluation, the initial element contents, the "accumulation factors" relative to the bulk deposition, the interspecies "calibration factors", and the "retention efficiencies", defined as ratios of the lichen enrichment to the sum of this enrichment and the content in the lichen throughfall water, were considered. These criteria attest the best suitability for Evernia prunastri, followed by Ramalina farinacea and Cetraria islandica.

Air Pollutants↗

[Evaluation of immunity in children from rural localities and the levels of trace elements in environmental objects].

Immunity was evaluated in 890 schoolchildren living in rural localities of the Central and Western lands of the Orenburg Region. There was a correlation between the immunological parameters of the examinees and the levels of trace elements in environmental objects. The children's immunity showed unilateral changes in the studied parameters as compared with the regional standards. The closest correlation was found between the absolute count of T lymphocytes, stab neutrophils, the levels of IgA, IgM in children and the content of I, Sr, Mn, Cr in cereals and vegetables, as well as between the levels of IL-2 and alpha-TNF and the blood concentrations of Cu, Fe, Cr, Ni, Co in the examined children. The immunological changes may result from the imbalance of trace elements in the studied environmental objects and biological substrates.

Catchment Area, Health↗

[Effects of ecological environment in Qinba Mountains on hair trace element contents of local inhabitants].

Determinations of Zn, Fe, Ca, Cu, Mg, Al, Se, Mn, Cr and Pb contents in the hairs of 136 children aged 0-13 and of 22 adults in the Qinba Mountains showed that the contents of test trace elements except Mg were abnormal in different degrees. The Al, Mn and Cr contents were highly excessive, their mean values being 2.04, 1.67 and 2.07 times as the highest value of normal range, and the people excessive in three elements occupied 83.54%, 77.85% and 72.78%, respectively. On the other hand, Zn and Se contents were in shortage, with the mean values being only 91.96% and 68.33% of the lowest value of normal range, and the people deficient in Zn and Se occupied 69.62% and 79.11%, respectively. Based on the local environmental geochemistry, this paper analyzed the possible causes of this abnormal status in trace elements and its harm.

Adolescent↗

Trace elements in the sweat of acclimatized persons.

Sweat samples were collected from the arms of 15 normal, healthy subjects while they exercised on a cycle ergometer at room temperature. Samples were analysed for copper, zinc, manganese, nickel, cadmium and aluminium by atomic absorption spectrophotometry. Mean sweat levels determined for each element were as follows: 358.1 micrograms/l for Zn, 486.8 micrograms/l for Cu, 3.10 micrograms/l for Mn and 1.91 micrograms/l, 69.9 micrograms/l and 15.0 micrograms/l for Cd, Ni and Al, respectively. It appears that substantial quantities of trace elements are excreted in the sweat of those sweating habitually. Our findings suggest that the influence of diet in replenishing the body stores of trace elements and the conservation of these elements by the kidneys may play a part in preventing the occurrence of chronic deficiency states in acclimatized persons.

Acclimatization↗

Risk-based evaluation of the exposure of children to trace elements in playgrounds in Madrid (Spain).

Eighty samples of sandy substrate were collected in November 2002 and 2003, from 20 municipal playgrounds in Madrid (Spain) to assess the potential adverse health effects of the exposure of children to trace elements in this material during their games. In each playground, two 500 g samples were collected, dried at 45 degrees C for 48 h, sieved below 100 microm, acid digested and analyzed by ICP-MS. Doses contacted through ingestion and inhalation and the dose absorbed through the skin were calculated using USEPAs hourly exposure parameters for children and the results of an in situ survey. The toxicity values considered in this study were mostly taken from the US DoEs RAIS compilation. The results of the risk assessment indicate that the highest risk is associated with ingestion of soil particles and that the trace element of most concern is arsenic, the exposure to which results in a cancer risk value of 4.19 x 10(-6), close to the 1 x 10(-5) probability level deemed unacceptable by most regulatory agencies. Regarding non-cancer effects, exposure to playground substrate yields an aggregate Hazard Index of 0.28, below the threshold value of 1 (with As, again, as the largest single contributor, followed by Pb, Cr, Al and Mn). Although the uncertainties associated with the estimates of toxicity values and exposure factors should be reduced before any definite conclusions regarding potential health effects are drawn, risk assessment has proven to be a very useful tool to identify the contaminants and exposure pathways of most concern in urban environments.

Environmental Exposure↗

Drought changes the dynamics of trace element accumulation in a Mediterranean Quercus ilex forest.

We conducted a field drought manipulation experiment in an evergreen oak Mediterranean forest from 1999 to 2005 to investigate the effects of the increased drought predicted for the next decades on the accumulation of trace elements that can be toxic for animals, in stand biomass, litter and soil. Drought increased concentrations of As, Cd, Ni, Pb and Cr in roots of the dominant tree species, Quercus ilex, and leaf Cd concentrations in Arbutus unedo and of Phillyrea latifolia codominant shrubs. The increased concentration of As and Cd can aggravate the toxic capacity of those two elements, which are already next or within the levels that have been shown to be toxic for herbivores. The study also showed a great reduction in Pb biomass content (100-135 gha(-1)) during the studied period (1999-2005) showing the effectiveness of the law that prohibited leaded fuel after 2001. The results also indicate that drought increases the exportation of some trace elements to continental waters.

Arsenic↗

[Intersexual differences in the levels of trace elements in amniotic fluid in the 2d trimester of pregnancy].

The authors assessed during comprehensive examination of amniotic fluid obtained by transabdominal amniocentesis on account of genetic indication during the second trimester of normal pregnancy between the 15th and 22nd week of gestation four selected trace elements - Zn, Cu, Pb and Cd, using the method of atomic absorption spectrometry. One of the criteria for evaluation of the results was also the relationship of the concentration of the selected trace elements and sex of the foetus. In 157 amniotic fluids collected during the 16th-19th week of gestation they recorded a significantly elevated lead level in male foetuses. During the 17th week normal pregnancy they found also a significantly increased zinc concentration in amniotic fluid of female foetuses. The authors are so far unable to interpret these interesting results which will be the subject of future investigation.

Amniotic Fluid↗