Multielemental hair composition of Brazilian Indian populational groups by instrumental neutron activation analysis

In the present paper, for the first time the multielemental composition of hair samples of Indian populations living in the Xingu Park Reservation, in the Brazilian Amazonic region has been determined, by INAA. Irradiations were carried out at the Interfaculty Reactor Institute (Delft, The Netherlands) and, using a combination of different irradiation and decay times, about 40 elements could be determined in the hair. Previous analysis made at the Radiochemistry Division of IPEN/CNEN-SP (Brazilian Nuclear Energy Commission) of hair samples of a Brazilian control population allowed the determination of 20 elements, also by INAA. Comparison of the data obtained for the Indian populations and the controls showed very significant differences in elemental compositions for some elements, like Hg, Mn and Al while for others, like Cu and Zn, the concentrations were similar. A discussion of the differences found for other elements also is made in the present paper.IPEN, BR-05422970 Sao Paulo, BrazilDelft Univ Technol, Interfac Reactor Inst, NL-2629 JB Delft, NetherlandsUniv Fed Sao Paulo, Dept Prevent Med, BR-04039031 Sao Paulo, BrazilUniv Fed Sao Paulo, Dept Prevent Med, BR-04039031 Sao Paulo, BrazilWeb of Scienc

Determination of mercury and selenium in hair samples of Brazilian Indian populations living in the Amazonic region by NAA

Biomonitoring of mercury contamination of Brazilian Indian population groups living in the Xingu Park, a reservation situated in the Amazonic region, has revealed very high levels of mercury in hair samples as compared to controls. Total mercury was determined by INAA in most of the tribes living in the Park and methylmercury was determined by CVAAS in samples with total mercury above 10 mg/kg. Due to the fact that selenium seems to protect animals against the toxic effects of methylmercury, it was considered also of interest to determine its concentrations in the hair samples with very high mercury levels. Selenium was determined by INAA via the short-lived radionuclide Se-77m (T-1/2 = 17.45 s). the correlations between selenium and mercury concentrations in Brazilian controls and in the Indian population groups are discussed.IPEN CNEN SP, Div Radiochem, BR-05422970 São Paulo, BrazilDelft Univ Technol, Interfac Reactor Inst, Delft, NetherlandsJozef Stefan Inst, Dept Environm Sci, Ljubljana, SloveniaUniversidade Federal de São Paulo, Dept Prevent Med, São Paulo, BrazilUniversidade Federal de São Paulo, Dept Prevent Med, São Paulo, BrazilWeb of Scienc