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Summary  

Neutron activation analysis, using Au as flux monitor, was applied to determine the concentrations of Br, Cl, K and Na in blood of healthy male and female blood donors, selected from blood banks and hematological laboratories from different regions of Brazil. The aims of this study were to collect more reference values of the Brazilian population as well as to perform hematological investigations. The advantages as well as the limitations of using this nuclear procedure are discussed.

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Abstract  

Sixteen minor and trace element contents of diet samples from three different social population groups in Taiwan were determined. Samples were prepared using duplicate portion technique by collecting the 15 subjects ate and drank during a 3-day period. Samples were homogenized, freeze-dried, and elemental concentration of minor and trace elements were determined by instrumental neutron activation analysis. Elemental concentrations and daily dietary intake of the elements were compared with those in the other nations, and possible origins were discussed.

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Summary  

The objective of this study was to use synchrotron radiation total reflection X-ray fluorescence analysis (SR-TXRF) for the determination of metals and other elements in food available to the population in commercial establishments, in order to evaluate the risks of contamination by these products. The analyzed species were vegetables, leafy vegetables, fruits, cereal and grain. The results indicated that some species were contaminated by Cr, Cu, Zn and Pb with concentrations much higher than the reference values.

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Abstract  

In this paper, the physical and chemical methods used in our laboratory for the measurement of99Tc in natural samples are reviewed. Levels of99Tc in rainwater, algae, and freshwater samples are given. In addition, and estimation of the radiological impact of99Tc to the population, derived from our earliear atmospheric99Tc measurements, is presented. For rainwater, levels of137Cs are also given for comparison.

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Abstract  

The Environmental Protection Agency has estimated that 20,000 lung cancer deaths per year may be related to radon exposure. This paper briefly describes the approach used to derive the Agency's central estimate of risk to the population. The weight-of-evidence for classifying radon as a known human carcinogen and the uncertainties associated with estimating risks from radon exposure provide an important context for these estimates and are briefly discussed.

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Abstract  

The minor and trace element content of diet samples from two different social population groups were determined. Samples were prepared by duplicate portion technique by colecting everything 16 subjects ate and drank during a 3-day period. Samples were homogenized, freeze-dried and elemental concentrations of Br, Co, Cr, Cs, Fe, K, Na, Rb, Sc, Se and Zn were determined by instrumental neutron activation analysis. Elemental concentrations and daily dietary intake of the elements were compared with the diets of other nations.

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The content of heavy metals in human hair may serve as an indicator of occupational or environmental exposure to metal compounds. However, before such exposure can be determined, the level of the element in a "normal" population must be established. The concentration of uranium in human hair was measured by flow injection — inductively coupled plasma mass spectrometry (FIAS-ICPMS) after acid digestion of the hair samples. All hair samples were rinsed in order to remove external contamination prior to the digestion in a 2:1 solution of concentrated nitric acid and 30% hydrogen peroxide. The limit of detection of the method, for a 50 mg hair sample, was 0.015µg/g, mainly due to the presence of impurities in the hydrogen peroxide. The range of uranium concentration in the initial test group was found to be 0.01–0.18 µg/g. The mean and median values of the entire study population were 0.062 and 0.050 µg U/g hair, respectively. Differences between the following sub-populations: male and female, smokers and non-smokers and people below and above 45 years of age were examined. The only statistically significant difference was found in the latter group (p = 0.03).

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Abstract  

Atmospheric contamination pattern by Pu-radionuclides over a 30 km zone of the Chernobyl nuclear power plant in 1987–1988 has been examined. Aerosol samples were analyzed for isotopic composition by using gamma- and alpha-spectrometric, and radiochemcal methods. Preliminary analysis of isotopic and fractional composition of aerosols carried out earlier indicated that over the first few months after the Chernobyl accident the relative contribution of238,239,240Pu to air contamination was lowered as compared with beta-active products. At present, however, alpha-active plutonium isotopes became the dominant radioactive contaminants of the atmosphere and the concentrations of238,239,240Pu inhaled fractions turned out to be lower than the limiting permissible values based on the USSR radiation safety standards for radioactive contamination of the atmosphere for the limited part of population exposed to radionuclides. Neverheless, it is necessary to know even moderate levels of atmospheric contamination by Pu-radionuclides, since their long impacts on the personnel operating in the 30 km zone of the Chernobyl NPP and population residing in the adjavent regions have not been studied properly. So, the risks for population health of such impacts cannot be generally excluded from consideration.

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. S TEINER , C. , G ARCIA , M. & Z ECH , W. , 2009 . Effects of charcoal as slow release nutrient carrier on NPK dynamics and soil microbial population: pot experiments with ferralsol substrate . In: Amazonian Dark Earths: Wim Sombroek

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Abstract  

The objective of this study was to evaluate the concentrations of essential and toxic elements in hair of children in Tanzania in order to assess their nutritional status. 141 samples of hair from boys and girls living in Tanzania were analyzed using instrumental neutron activation analysis (INAA). The mean concentration levels of Zn and Cu were lower whilst those of other elements were in the same range as the hair elemental concentrations reported in the literature. The lower concentrations of Zn might be related to the diet of mainly cereals with low animal proteins consumed by most of the Tanzanian population.

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