Abstract
The distribution of natural radionuclide γ-ray activities and their respective annual effective dose rates, produced by 40K, 226Ra and 232Th, were determined for sand samples collected along the coast of four Brazilian States: S?o Paulo (SP), Rio de Janeiro (RJ), Espírito Santo (ES) and Bahia (BA). For some specific beaches, the values of the annual effective dose rates or γ-ray radiation hazard indices exceed the average worldwide exposure of due to natural sources and the limits proposed by Organization for Economic Co-operation and Development for building materials. The average values of the radium equivalent activities were evaluated and found to be in Mambucaba (RJ), in Buena (RJ), in Anchieta (ES), in Meaipe (ES), in Guarapari (ES), in Vitória (ES), in Serra (ES), in S?o Mateus (ES), in Porto Seguro (BA) and in Itacaré (BA). These values are above the limit of recommended for the safe use of building materials for dwellings by OECD.
Article Outline
1. Introduction
2. Material and methods
2.1. Sample collection and preparation
2.2. Calibration and measurements by γ-ray spectrometry
2.3. Estimation of dose rate
2.4. γ-ray radiation hazard indexes
3. Results
4. Conclusions
Acknowledgements
References