The Gamma Dose Assessment and pH Correlation for Various Soil Types at Batu Pahat and Kluang Districts, Johor, Malaysia

摘要

An assessment of absorbed dose and radiation hazard index as well as its relationship with soil pH was performed in this study. The area was chosen due to its variety of soil types from the Alluvial and the Sedentary group. The radioactivity concentration levels and the soil acidity were measured using the Canberra GC3518 high pure germanium with a relative efficiency of 35% at 1.3 MeV and the Takemura Soil pH and Moisture Tester (DM15), respectively. Overall results show the Holyrood-Lunas soil of Alluvial group recorded the highest external terrestrial gamma radiation dose rate (TGRD) of 286.4±37.9 nGy h~(-1) and radioactivity concentrations of 78.1±8.9 Bq kg~(-1) (~(226)Ra), 410.5±55.4 Bq kg~(-1) (~(232)Th) and 56.4±8.8 Bq kg~(-1) (~(40)K), respectively, while the Peat soil of Alluvial group recorded the lowest TGRD of 4.4±2.7 nGy h~(-1) and radioactivity concentrations of 4.8±1.7 Bq kg~(-1) (~(226)Ra), 3.1±1.1 Bq kg~(-1) (~(232)Th) and 6.1±2.0 Bq kg~(-1) (~(40)K), respectively. The estimated mean outdoor annual effective dose, the mean radium equivalent activity (R_(eq)) and the mean external (H_(ext)) and internal hazard index (H_(int)) associated with the alluvial and sedentary soil group were evaluated at 0.15 and 0.20 mSv, 280 and 364 Bq kg~(-1), H_(ext)= 0.78 and 1.01, and H_(int)= 0.93 and 1.26, respectively. Correlation analysis between ~(238)U, ~(232)Th and ~(40)K with soil pH level for alluvial group was r= +0.68, +0.48 and 0, respectively, while for sedentary soil, the Pearson's, r= -0.30, -0.90 and +0.14, respectively.