Depth profile study of natural radionuclides in the environment of coastal Kerala

The present work investigated the activity concentrations of natural radionuclides ²²⁶Ra, ²³²Th and ⁴⁰K in beach sand samples along coastal Kerala including high background radiation area. The activity of ²³²Th ranges from below detectable level to 23029.9 Bq kg^-1 with a mean value of 2660.2 Bq kg^-1 for 0-10 cm depth interval. For 10-20 cm depth, the ²³²Th activity ranged from below detectable to 4452.2 Bq kg^-1 with a mean value of 815.5 Bq kg ^-1. The variation of ²²⁶Ra activity with depth is parallel with the ²³²Th activity distribution in beach sand. Its activity varied from below detectable to 5169.5 Bq kg^-1 with a mean value 487.6 Bq kg^-1 at 0-10 cm depth. For 10-20 cm depth interval, the ²²⁶Ra activity ranges from below detectable to 1823.6 Bq kg ^-1 with a mean value 296.0 Bq kg^-1. Similarly the activity varies from below detectable to 1826.6 Bq kg^-1 with a mean value of 211.0 Bq kg^-1 for a depth interval of 20-30 cm. The activity of ⁴⁰K at different depth is also discussed. Statistical analysis of radioactivity was also carried out. The results of these investigations are presented in this paper.