Contribution to the external gamma dose rate from 137Cs and 40K activity concentrations determined along the vertical profile of sandy beaches

VELASCO H., RIZZOTTO M., MERKIS N., BELLI M AND SANSONE U

JOURNAL OF RADIOANALYTICAL AND NUCLEAR CHEMISTRY

Springer

Lugar: Budapest; Año: 2007 vol. 273 p. 395 - 399

0236-5731

Sampling sites, located along the Calabria and Basilicata Regions coastal beaches (south of Italy), were selected to assess the external gamma dose rate in air, 1 m above ground, and to estimate the fraction attributable to the radiocaesium and radiopotassium contents along the vertical sand profile. Mean values for the gamma dose rate were: 76 ± 30 nGy h-1. 137Cs and 40K deposition density in sand samples were determined for each sampling site (mean values 0.24 ± 0.22 kBq m2 and 178 ± 88 kBq m2 respectively). The 137Cs external dose rate contribution was assessed using a Monte Carlo simulation code. The method gives an estimation of the contribution to the external gamma dose rate of each sand layer along the vertical profile. The dose rate associated with the 137Cs content in sand was 0.16 ± 0.14 nGy h-1. The cosmic radiation and 40K contributions to the external gamma dose rate were estimated using the UNSCEAR methodologies. The values obtained were 34 ± 3 nGy h-1 and 18 ± 9 nGy h-1 respectively.