Search Results

You are looking at 81 - 90 of 334 items for :

  • "population" x
  • Chemistry and Chemical Engineering x
  • All content x
Clear All

Abstract  

The intake of aluminum, arsenic, cadmium, lead and mercury via the daily diet by Iranian population groups was determined. The relevant daily diets were prepared through dietary recording and duplicate portion, and the trace elements were measured using analytical methods based on NAA, ICP and AAS. The results for the Iranian diets are discussed and compared with corresponding ones from other countries. The project has been performed in the frame of a co-ordinated research project of the International Atomic Energy Agency with participants from various countries.

Restricted access

Abstract  

We have collected sixteen total diet samples from two socioeconomic groups in Turkey by duplicate portion techniques. Samples were homogenized with titanium-blade homogenizer, freeze dried and analyzed for their minor and trace elements mostly by neutron activation analysis. Bread and flour samples were also collected from the same regions and analyzed similarly by instrumental neutron activation analysis. We have determined concentrations of more than 25 elements in total diets, bread and flour, and fiber and phytate in total diets. We have determined daily dietary intakes of these population groups, probable source of elements through correlation coefficients, and enrichment factor calculations.

Restricted access

Abstract  

In this study, blood serum trace elements, biochemical and hematological parameters were obtained to assess the health status of an elderly population residing in São Paulo city, SP, Brazil. Results obtained showed that more than 93% of the studied individuals presented most of the serum trace element concentrations and of the hematological and biochemical data within the reference values used in clinical laboratories. However, the percentage of elderly presenting recommended low density lipoprotein (LDL) cholesterol concentrations was low (70%). The study indicated positive correlation between the concentrations of Zn and LDL-cholesterol (p < 0.06).

Restricted access

Abstract  

Over the last decades the acceleration of the industrialization and urbanization processes together with the intensive agricultural practices have resulted in an impact on the Piracicaba river basin, state of São Paulo, Brazil. The source rivers drain from an area of low population density, absence of heavy industries, non-significant agriculture, native forest and reforestation, the opposite is found in the middle part of the basin. Samples of riverbed sediments were collected along the basin for chemical analysis. Results showed that the source rivers still preserve their natural characteristics, while the Atibaia river in the middle part shows signs of pollution from the agricultural activity, industrial effluents and urban sewage.

Restricted access

Abstract  

In 1999 investigation, the needles of Sabina chinesis L. from 11 hot spot tourist cities extending over China were collected as biomonitors for evaluation of atmospheric elemental differences in those cities. Thirty five elements were determined by instrumental neutron activation analysis (INAA). The experimental data reflected the environmental alteration in the cities that have different geographical position, population burden and industrialized level. Eventually by using the data processed by factor analysis (FA) and subsequent cluster analysis (CA), the cities were grouped into six sorts of the urban atmospheric deposition with corresponding elements.

Restricted access

Abstract  

Periodically increasing and decreasing enthusiasm has accompanied the studies of medical significance of human hair elemental composition for at least two decades. In this field, nuclear analytical methods play an extremely important role, especially the instrumental neutron activation analysis (INAA). This paper tries to add some new knowledge to this problem. Two approaches are used — comparison of individual hair composition with certain diagnoses in clinic groups and comparison of population data with medical statistics. Rather large samples and multielement mathematical procedures helped reveal strong correlations valuable for diagnostic and health screening.

Restricted access

Abstract  

New experimental data has been obtained on heavy metal and rare-earth element concentrations in environmental objects, namely pine needles and soils, caused by atmospheric pollution in different regions of the Kola Peninsula. The investigation was performed with the use of epithermal neutron activation analysis at the IBR-2 fast pulsed reactor. Analysis of nearly 40 element distribution in pine-needles and solids from the studied geographical points testifies of a strong contamination source —the nickel smelting complex in Monchegorsk. The contamination levels for Ni, Co, Cr, Se, and others are also high and may be hazardous to the population of this region because some of these elements are carcinogenic.

Restricted access

Abstract  

The distribution of natural radionuclides,40K,226Ra, and232Th, in freshwater sediments and in coal-fired power-plant ash repositories has been tested for lognormality. Thereafter, lognormality for natural radionuclide concentration frequency distribution was accepted with a high probability. The lognormal natural radionuclide distribution in sediments and coal-ash indicated single population groups. The anthropogenic modifications of the natural radionuclide concentrations in the environment are indicated. The adsorbed dose rates, in mGy y–1, in air from gamma field of the natural radionuclides were calculated.

Restricted access

Abstract  

The sandwiched pellet technique using Makrofol-E plastic track detectors has been employed to determine trace quantities of uranium in nine brands of flavored chewing tobaccos consumed by the Indian population. In this technique the nuclear reaction,235U(n,f), is used for the quantitative estimation of uranium. The maximum value of uranium (1.88 ppm) has been found in raw tobacco leaves (Surti), while the minimum (0.13 ppm) in Tulsi (Double Zero brand). Other seven brands showed intermediate values of U-contents which are also reported in this paper. These values are compared with the U-contents reported in the literature for other forms of tobaccos.

Restricted access

Abstract  

The 11 th CITES Conference in 2000 decided to maintain a total worldwide ban on trade of elephant ivory. The 12 th Conference in 2002 decided to allow a conditional trade in stockpiled ivory in 2004. Reopening of the ivory trade would require methods to identify the origin of the ivory so that legal ivory can be distinguished from the black-market ones. In this study, we describe the X-ray fluorescence multi-element analysis of ivory samples from various regions of Africa and Southeast-Asia to characterize ivory of the various elephant populations.

Restricted access