Distribution of 226Ra, 232Th and 40K in soils and sugar cane crops at Corumbataí river basin, São Paulo State, Brazil
Fabiano Tomazini da Conceiçãoa, Daniel Marcos Bonottob, Jairo Roberto Jiménez-Ruedab, José Arnaldo Frutuoso Rovedaa
aDepartamento de Engenharia Ambiental/UNESP/Sorocaba, Avenida Três de Março, nº 511, CEP 18087-180, Alto da Boa Vista, Sorocaba, São Paulo, Brazil
bInstituto de Geociências e Ciências Exatas (IGCE)/UNESP/Rio Claro, Avenida24-A, nº 1515, C.P. 178, CEP 13506-900, Bela Vista, Rio Claro, São Paulo, Brazil
Applied Radiation and Isotopes - Volume 67, Issue 6, June 2009, Pages 1114-1120.
ABSTRACT
The common use of phosphate fertilizers NPK and amendments in sugar cane crops in Brazilian agriculture may increase the 226Ra, 232Th and 40K activity concentrations in soils and their availability for plants and human food chain. Thus, the main aim of this study was to evaluate the distribution of 226Ra, 232Th and 40K insoils and sugar cane crops in the Corumbataí river basin, São Paulo State, Brazil. The gamma spectrometry was utilized to measure the 226Ra, 232Th and 40K activity concentration in all samples. The soil-to-sugar cane transfer factors (TF) were quantified using the ratio between the radionuclide activity concentration in sugar cane and its activity concentration in soil. The results show that, although radionuclides incorporated in phosphate fertilizers and amendments are annually added in the sugar cane crops, if utilized in accordance with there commended rates, their use does not lead to hazards levels in soils. The soil-to-sugar cane transfer of radionuclides occurred in the following order 40K>226Ra>232Th. Therefore, under these conditions, radionuclides intake through consumption of sugar is not hazardous to human health.
Keywords: Radionuclides in soil; Phosphate fertilizers and amendments; Soil-to-sugar cane transfer; Human health |
