sup(210)PO determination in estuarine sediments from Baixada Santista, SP Brasil

Abstract

The objective of the present work is to determine 210Po activity concentration in estuarine sediments from Baixada Santista. The area comprehends nine cities in the Brazilian coast (Bertioga, Guarujá, Santos, São Vicente, Cubatão, Praia Grande, Mongaguá, Itanhaém and Peruíbe). It is one of the most important industrial areas in Brazil due to the large number of industries operating in Cubatão, such as steel, petrochemical and fertilizer industries. That, together with a large population, causes a negative impact on marine biota. The cores were obtained from São Vicente and Bertioga by extracting profiles up to 1 meter depth with a Piston core sampler. The samples were prepared and treated with both physical and chemical processes. The physical processes include drying, grinding and sieving. The chemical preparation consists of a series of acid digestion till total dissolution and destruction of organic matter. After the acid digestion, the samples were filtered and evaporated till dryness. The residue was then dissolved in HCl 6.25 M. Po was spontaneously deposited in mirror finished silver disc, for 2 hours at 90 °C and constant agitation. The disc was then counted in a surface barrier alpha detector for 200,000 seconds. Three cores were analyzed so far, two from São Vicente and one from Bertioga.