Neutron activation analysis of soil samples collected at different points of the metropolitan region of Sao Paulo, Brazil

This article analyses samples from the soil of Sao Paulo metropolitan region (SPMR) aiming posterior study on the influence of his elementary composition in the elements accumulated by the lichen. The article analyses soils samples from various points at SPMR) and at the clean region of Parque Intervales, Mata Atlantica, SP by using the neutron activation analysis. The concentration of the elements As, Br, Co, Fe, Hf, K, Nd, Rb, Sb, Th, U, Zn and rare earths were determined, and comparative studies were also performed between the concentrations obtained for the samples collected at different sampling points. The samples collected at IPEN and Congonhas presented high La and Nd concentrations when compared with the other ones. The high Ce, Th and U concentrations were obtained for the IPEN soil samples. Besides, the As and Br presented the highest values at the Santo Andre, Capuava and Cerqueira Cesar. The clean region samples of Parque Intervales presented lower concentrations related to most of collected points at the SPMR, excepted the elements Sc and Rb. The quality control were evaluated by analysing the reference certificated materials Soil 7 and Buffalo River Sediment. (author)