Search results for "Trace element"
showing 10 items of 321 documents
Has long-term metal exposure induced changes in life history traits and genetic diversity of the enchytraeid worm Cognettia sphagnetorum (Vejd.)?
2004
We studied whether long-term metal exposure has affected life history traits, population growth patterns and genetic diversity of the asexual enchytraeid worm Cognettia sphagnetorum (Vejd.). Enchytraeids from metal contaminated and uncontaminated forest soil were compared by growing them individually in the laboratory and by following their population development in patchily Cu contaminated microcosms. Genetic differences between the two native populations were studied using allozyme electrophoresis. Individuals from the contaminated site had slower growth rate and they produced fewer fragments of larger size when compared to individuals from the uncontaminated site. In patchily Cu contamin…
Oral intake of cadmium, cobalt, copper, iron, lead, nickel, manganese and zinc in the university student's diet.
1993
A duplicate diet meal study was carried out with a group of university students living in a hostel, in order to estimate the intake of Zn, Cd, Co, Cu, Fe, Mn, Ni and Pb. Zn, Cu, Fe, Mn and Ni were determined by flame atomic absorption spectrophotometry and Cd, Co and Pb by graphite furnace atomic absorption spectrophotometry after a nitric acid wet digestion procedure. The estimated intake values from the contents of breakfast, lunch, dinner and drinks were compared with the values of the Provisional Tolerable Daily Intake (PTDI) in the case of Cd and Pb, Recommended Dietary Allowances (RDA) of Co, Fe and Zn and Estimated Safe and Adequate Dietetic Daily Intake (ESADDI) of Cu and Mn. Neithe…
Polycyclic aromatic hydrocarbons (PAHs) and their oxygen-containing derivatives (OPAHs) in soils from the Angren industrial area, Uzbekistan.
2009
We measured the concentrations and depth distribution (0-10, 10-20 cm) of 31 PAHs and 12 OPAHs in soils at eleven equidistant sampling points along a 20-km transect in the Angren industrial region (coal mine, power plant, rubber factory, gold mine), Uzbekistan to gain an insight into their concentrations, sources, and fate. Concentrations of all compounds were mostly much higher in the 0-10 cm than in the 10-20 cm layer except in disturbed soil close to the coal mine. Proximity to one of the industrial emitters was the main determinant of PAH and OPAH concentrations. The Sigma31PAHs concentrations correlated positively with the Sigma7 carbonyl-OPAH (r=0.98, p<0.01), Sigma5 hydroxyl-OPAH (r=…
Trace element systematics of tourmaline in pegmatitic and hydrothermal systems from the Variscan Schwarzwald (Germany): The importance of major eleme…
2013
article An extensive data set on the compositional variation of tourmaline from granitic pegmatites, from migmatitic gneisses and from various types of hydrothermal veins from the Schwarzwald, Germany, is provided. The investigated tourmalines are members of the alkali and X-vacant groups representing mostly dravite- schorl solid solutions with some analyses belonging to the foitite-Mg-foitite series. Oxygen isotope data on quartz-tourmaline pairs indicate formation temperatures between 550 and 350 °C for most of the quartz-tourmaline veins. Most of the tourmalines show strong sector zonation, fractionating certain major (e.g., Na, Mg), minor (e.g., Ti, Ca) and trace elements (e.g., Sr, Pb,…
Goldschmidt Abstracts 2010 – F
2010
We report on two novel procedures for the determination of several trace elements in seawater, including elements characterized by very low abundance (sub-0.1 to 1 ng l-1) in the ocean, such as REEs, Hf, and Th. Our methods are based on the procedure developed recently by Bayon et al. [1], and applied successfully to a wide range of geological samples. It involves addition of a Tm spike and pre-concentration using co-precipitation, prior to analysis by inductively coupled plasma-sector field mass spectrometry (ICP-SFMS). The addition of a small amount of Tm to the sample produces a positive Tm anomaly in the resulting REE pattern, which allows calculation of precise trace element concentrat…
Comparison of metals and essential trace elements levels between Autistic Spectrum Disorders cases and their sibs in Sicily (southern Italy)
2016
Introduction: A role of metals exposure and essential trace element deficiency in Autistic Spectrum Disorders (ASD) etiology has been suggested by epidemiologic studies, but conclusive evidence on this topic is still lacking and controversial. We compared metals and essential trace element levels between cases both with their brothers and healthy children. Methods: The diagnosis of ASD were performed by ADOS and ADI-R according to DSM IV (Diagnostic and Statistical Manual of Mental Disorders) criteria. Hair samples were collected from cases and sibs by single cutting from the occipital region. The samples were cut to lengths of about 1.5–2 cm using clean stainless steel scissors. Approximat…
Exposure to trace elements by hair mineral analysis. Mining , volcanic and urban areas
2015
Concerns about the effects of environmental exposure to metals and metalloids on human health have driven the scientific community to find reliable tools and methodologies for assessing the impact of emission of toxic metals from anthropogenic sources or through natural anomalous levels of metals in water, soil and air. Biological monitoring has been extensively employed with this end in view and blood, urine, hair and nails are the biological materials mostly collected and analyzed for the levels of multiple metals. With respect to blood and urine, whose metal concentrations decrease rapidly after the exposure period, hair and nails appear to be of greater value in evaluating past and cont…
Trace-element partitioning between amphibole and silicate melt.
2007
Knowledge of the partitioning behavior of trace elements between solid and liquid is a prerequisite for modern igneous and mantle petrology. Most of the mathematical models simulating melt generation, migration and evolution within the mantle and/or the crust require the availability of reliable solid/liquid partition coefficients for the mineral phases involved in the process. Calcic amphiboles are extremely important for the understanding of lithospheric processes because of both their common occurrence in a variety of igneous and metamorphic rocks types and their capability of hosting a large number of geochemically important trace elements. A series of studies on the partitioning behavi…
Metals in Scalp Hair from Relapsing-Remitting Multiple Sclerosis Patients (RRMS)
2014
We measured the concentrations of 21 chemical elements (TE) in hair of 48 Sicilian patients with RRMS compared with 51 controls (HC). MS patients showed a significantly (p<0.01) lower hair concentration of Al and Rb and higher hair concentration of U compared to HC. The percentage of MS patients showing hair elemental concentrations greater than the 95th percentile of controls was 20% for Ni, 19% for Ba and U, and 15% for Ag, Mo and Se. The ratio Zn/Cu varied from 17 to 19, with no significant differences between HC and MS groups or between individuals differentiated by gender. No significant association was found between levels of each TE and age, disease duration, Expanded Disability Stat…