Short-time activation analysis of environmental materials

The sensitivity of NAA using 18 short-lived activation products has been investigated under both steady state (250keV) and pulse activation conditions. Enhancement factors increase with decreasing half-lives of the nuclides under investigation. The purely instrumental analysis of lead using 207Pbm was performed by a combination of pulse height analysis (PHA) and decay curve analysis. The method has been tested by the use of NBS-SRM 1648 Urban Particulates. Pb, Br, and Cl were determined by this technique in car exhaust emissions, and the distributions of Pb and 35 other elements in different particle size fractions of roadside dusts were investigated by INAA, ICP-AES and AAS. The results show that Cr, Fe, Co and As were enriched near industrial areas, while Zn, Cu, Cd, Pb and Br concentrations were higher near traffic areas. The possibility of determining up to 40 elements using their short-lived activation products is reported. In future the following points will be investigated: (1) multielement analysis by INAA, XRPD and ME of aerosols and roadside dusts collected in the vicinity of different mining processes (phosphate, iron and granite) and heavy industries (i.e. cement, steel, battery production); (2) evaluation of the data by different cluster analysis and pattern recognition programs to standardize a suitable model for the characterization of different sources of contamination, and (3) investigation of the ability of short-time activation analysis to determine up to 40 short-lived nuclides non-destructively or after chemical preconcentration. 19 refs, 5 figs, 16 tabs