Assessment of spatial distribution and radiological hazardous nature of radionuclides in high background radiation area, Kerala, India

The concentration and distribution of the natural radionuclides (238U, 232Th and 40K) have been analyzed for the beach sediments of Kerala with an aim of evaluating the radiation hazards. The ranges of activity concentrations of 238U, 232Th and 40K are BDL—1187±21.7 Bq/kg, BDL—5328±23.2 Bq/kg and BDL—693±31.2 Bq/kg respectively. Radiological parameters such as absorbed dose rate, annual effective dose equivalent, annual gonadal dose equivalent, radium equivalent, hazard index, gamma Index, activity utilization index and excess lifetime cancer risk are calculated to know the complete radiological hazardous nature. Concentration of radionuclides (238U and 232Th) and all the calculated radiological parameters are higher in site number S23 (Chavara beach) due to the presence of rich deposits of black sands. Average concentrations of radionuclides (238U and 232Th) and all calculated radiological parameters are higher than the recommended level. Both univariate and multivariate statistical analyses were applied effectively to assess the distribution of the radionuclides. Univariate statistical analysis shows that the confirmation of infrequent extreme deviations of all radioactive variables. Cluster analysis shows that light minerals play a role in cluster I sampling sites and heavy minerals may be played in sampling sites of other clusters. Calculated activity ratio confirmed the presence of light and heavy minerals in above mentioned sampling sites. The Kerala beach sediments pose significant radiological threat to the people living in the area and tourists going to the beaches for recreation or to the sailors and fishermen involved in their activities in the study area.

► The concentration and distribution of the natural radionuclides have been analyzed for the Kerala beach sediments.
► Average concentrations of 238U and 232Th, and all calculated radiological parameters are higher than the recommended level.
► Univariate statistical analysis shows the confirmation of infrequent extreme deviations of all radioactive variables.
► Cluster analysis shows the role of light and heavy minerals.
► The present sediments pose significant radiological threat to the peoples.