RESUMO
Soon after the Chernobyl nuclear accident, the air-pumping stations in Pavia (northern Italy) were alerted. In a few days, a rapid increase in radionuclide concentration in air particulates was observed. Consequently, an environmental radioactivity monitoring programme was started in which several matrices such as soil, grass, vegetables and cows' milk were subjected to direct gamma-ray spectrometry. The radioactivity distribution and its variation with time is presented, discussed and compared with other available data. Detection limits, precision and accuracy are also reported, and depth profiles in soils for 137Cs are presented and correlated with soil quality parameters. A survey of environmental radioactivity in soil, in a search for residual Chernobyl fallout, was carried out and a map of the 137Cs distribution over a large area in northern Italy is presented and discussed.
Assuntos
Acidentes , Poluentes Radioativos do Ar/análise , Radioisótopos de Césio/análise , Contaminação Radioativa de Alimentos/análise , Leite/análise , Reatores Nucleares , Cinza Radioativa/análise , Poluentes Radioativos do Solo/análise , Ração Animal , Animais , Bovinos , Feminino , Geografia , Humanos , Itália , Ucrânia , Verduras/químicaRESUMO
A substoichiometric isotopic dilution method was coupled to the standard addition technique for the determination of trace-level cadmium. 109Cd carrier-free as a radiotracer and extraction with dithizone in chloroform were used. A preconcentration procedure, which also cuts down the main interferences, for tap and natural waters was suggested. The sensitivity and accuracy of the method are discussed.
Assuntos
Cádmio/análise , Abastecimento de Água/análise , Técnica de Diluição de Radioisótopos , Oligoelementos/análiseRESUMO
The present investigation of the cellular distribution of lanthanum was undertaken in order to control the validity of the "Lanthanum method" used for the study of the cell calcium compartments. The presence of lanthanum was evaluated in the isolated guinea-pig heart and its subcellular fractions perfused with a lanthanum-containing Tyrode solution. Lanthanum was determined by instrumental neutron activation analysis. Under the adopted experimental conditions (30-min incubation in the presence of 12.5 microM lanthanum), lanthanum is carried across the cell membrane and is taken up by subcellular organelles. These results confirm the limited validity of investigations based on of the "Lanthanum method".
