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Concentrations of potentially toxic elements were determined in the soil solution of two soils (acidic sandy and slightly acidic clay loam) treated with phosphate rocks having high Cd content in a pot experiment. Relative concentrations characterizing the mobility of metals (expressed as soil solution concentrations in percentage of their “total” amounts in the phosphate rock-treated soil) decreased with increasing phosphate rock rates in the sandy soil. Mn@Sr>Cd@Co were the most, while Pb and Cr the least mobile elements. The relative concentrations in the clay loam soil were much lower than in the sandy soil and they practically remained constant with increasing phosphate rock rates. It was concluded that in the experimental time frame the environmental risk did not increase with the increase of phosphate rock rate. 

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Ferrites have been used to separate a wide range of substances such as dissolved metal species, particulate matter, and organic and biological materials; they have been used almost exclusively for metal waste treatment applications. However, ferrites can be used to remove and concentrate selected trace metals in a wide variety of feed solutions requiring analysis. A brief overview of ferrite properties and recent applications for trace metal recovery and concentration will be presented.

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In continuation, of an early study of trace metal /TM/ccontent of Greek lignites and power plant ashes, taken to assess mobilization of TM in Greece by the operation of power plants, new data are presented. Both power plant sites in Greece, i. e. /a/ Northern /Ptolemais, Kardia/, and /b/ Southern /Megalopolis/ have been examined for trace metal content in ashes and in locally used lignites. Instrumental neutron activation analysis /INAA/ was used to determine the content of about 30 minor and major elements. The uranium content of southern Greek lignites was found again to be exceptionally high. The new data are correlated with those of our previous investigation.

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Both present-day and historical head-hair samples up to 300 years old are being analysed by neutron activation for more than 30 trace elements. This study, designed to determine an historical base-line for the human intake of trace metals and to provide an evaluation of the present-day rate of increase and sources of environmental pollution, has direct forensic applicability. Modern samples being analysed in this study include hair from U. S. Naval Academy midshipmen and U.S. Air Force Academy cadets obtained upon arrival at the Academies in mid-1971 and again at later intervals during which trace-metal equilibration due to fixed diets and environmental conditions is presumed to occur. A wide variety of factors such as age, sex, hair structure and color, geographic location, general diet, socieconomic status are being considered in evaluating the analysis data. Examples of some of the initial data obtained from the analysis of the first three sets of Naval Academy midshipmen hair are presented.

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Two single doses of X-ray radiation, i.e., 75 cGy and 4.0 Gy were applied on male Swiss albino mice. Quantitative changes in concentrations of trace metals like copper, zinc, cadmium and chromium in the whole body irradiated mice skin at several post-irradiated time intervals were studied in comparison to that of control animals. Observations indicate that irradiation induce redistribution of trace metals studied in skin at different post-irradiation time intervals.

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Within the framework of the Protection of the Environment programme of the JRC-Ispra of the European Community, research on trace metal exposure and health effects is concerned primarily with the toxicological assessment of present levels of trace metals in the tissues of exposed and unexposed populations. Main activities are: (1) microdetermination of trace elements in human tissues in order to generate an accurate and reliable data base on the levels and biochemical forms of trace metals in differently exposed humans; (2) metabolism and biochemical mechanisms involving trace metals to assess the toxicological significance of the current levels of the elements in the human body. Few selected applications related to the different steps of the biochemical toxicology research are shown. They concern the long-term behaviour of trace metals at the target tissues of laboratory animals, the biological monitoring of vanadium in workers during maintenance operations at an oil fired power plant for energy production, and the biochemical mechanism of methylation of arsenic in vivo.

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Twenty-two radiochemical separation procedures for neutron activation analysis (NAA) of environmental and biological samples are presented. They are currently applied in the context of trace metal research related to the protection of the environment and human health. The radiochemical procedures are related to the separations of the elements into groups which allow the determination of up to 50 elements in each sample or to specific separations for single elements. The experience gained in the application of these radiochemical separations over more than ten years allows us to consider them as reliable for sensitive determinations of trace metals in environmental and biological samples.

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The normal concentration levels of trace metals in several kinds of tissues of even-toed ungulates have been determined by instrumental neutron activation analysis, photon activation analysis, and flame atomic absorption spectrometry. In the present work the concentrations of 13 elements (Ag, Br, Ca, Co, Cu, Fe, Mg, Mn, Mo, Na, Rb, Se, and Zn) were analyzed.

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Trace metal advection and diffusion in natural porous and fractured materials have been investigated by using radiotracers. Three case studies are presented: 1) Se infiltration in granite cores in the presence of pyrite, 2) Co advection in quartz sand columns containing a layer of MnO2, and 3) Cr diffusion in clay. It is shown that the migration processes are controlled by surface mediated redox transformations.

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The possibility to use the bronchoalveolar lavage (BAL) in combination with analytical methods for trace metal analysis such as neutron activation analysis (NAA), inductively coupled plasma (ICP) and electrothermal atomic absorption spectroscopy (ETASS) for the determination of trace elements in the lung of living subjects has been investigated. In particular more than 30 elements have been determined: (1) in physiological solutions used for bronchopulmonary lavage (blank values) (2) in BALs of volunteer patients (unexposed subjects) (3) in BALs of occupational workers affected by pulmonary fibrosis as diagnosed by clinical methods (exposed subjects). Although the number of cases with metal exposure studied by NAA-BAL method is too limited to draw definitive conclusions the results suggest that the procedure can provide interesting qualitative information on metals which would be actually retained in the lung tissue. However, although the method may become of importance when integrated with clinical examinations further investigations are necessary to establish qualitative relations between trace metal levels determined in the BAL and the total elemental content of the lung tissue.

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