Radiation hazard indices of soil and water samples in Northern Malaysian Peninsula

The radioactivity quantity and quality were determined in soil and water samples in Northern Malaysian Peninsula (NMP) using HPGe spectroscopy and GR-135 spectrometer. The 226Ra, 232Th and 40K concentrations in soil samples are 57±2, 68±4 and 427±17 Bq kg−1, respectively, whereas in water samples were found to be 2.86±0.79, 3.78±1.73 and 152±12 Bq l−1, respectively. These concentrations are within those reported from literature in other countries in the world. The radiological hazard indices of the samples were also calculated. The mean values obtained from soil samples are 186 Bq kg−1, 88 nGy h−1, 108 μSv y−1, 0.50 and 0.65 for Radium Equivalent Activity (Raeq), Absorbed Dose Rates (DR), Annual Effective Dose Rates (ED), External Hazard Index (Hex) and Internal Hazard Index (Hin) respectively, whereas, for water samples were found to be 20, 10, 13, 0.05 and 0.06, respectively. All the health hazard indices are well below their recommended limits, except in two soil sampling sites which were found to be ⁎025 (1.1 Hex) and ⁎026 (1.1 Hex, 1.6 Hin). The calculated and the measured gamma dose rates had a good correlation coefficient, R=0.88. Moreover, the average value radon is 20 (in the range of 7–64) Bq m−3, a positive correlation (R=0.81) was observed between the 222Rn and 226Ra concentrations in samples measured by the SNC continuous radon monitor (model 1029, Sun Nuclear Corporation) and HPGe detector, respectively. Some soils in this study with Hin and Hex<1 are suitable for use in agriculture and as building materials. Also, in this study Hin and Hex<1 for water samples, therefore, water after processing and filtration is safe and suitable for use in household and industrial purposes.

► For calculated and measured γ_dose, R=0.88. ► R=0.81 for 222Rn and 226Ra. ► Hex and Hin<1.