Radioactivity and radiation hazard evaluation in the environment of coastal Kerala, India

Systematic investigations on the radiation level and distribution of natural radionuclides in the soils and sands of coastal Kerala were carried out to evaluate the radiation hazard. The gamma-dose rate in the high background area of coastal Kerala is exceptionally high compared with normal background areas. The activity concentrations of ²³²Th, ²²⁶Ra and ⁴⁰K in soil and sand samples of coastal Kerala are comparable with the literature values reported for the other environs as well as the world average values, when high background areas are excluded. However, the ²³²Th activity in high background areas is orders of magnitude higher. The radium equivalent activity, external hazard index, internal hazard index and the annual gonadal dose equivalent associated with the radionuclides were calculated and compared with international recommended values to assess the radiation hazard.