Effect of geochemical properties (pH, conductivity, TDS) on natural radioactivity and dose estimation in water samples in Kulim, Malaysia

AbstractNatural radioactivity (226Ra, 232Th, and 40K) concentrations and geochemical properties (pH, conductivity, TDS) were determined in water samples in Kulim, Malaysia using gamma spectrometry and potentiometry, respectively. The activity concentration of 226Ra, 232Th and 40K were ranged from 0.74 ± 0.04 to 7.40 ± 2.16 mBq l−1, 0.55 ± 0.03 to 6.45 ± 2.16 mBq l−1 and 40.3 ± 3.3 to 243.3 ± 9.3 mBq l−1, respectively. A negative correlation was obtained between 226Ra, 232Th concentrations versus pH, however, no such relation was found with conductivity and total dissolved solids. Annual cumulative effective doses due to intake of 226Ra, 232Th and 40K for age group 1–5 y, 5–10 y, 10–15 y, and ≥18 y were calculated to be 1.77 µSv y−1, 1.55 µSv y−1, 1.4 µSv y−1, and 1.82 µSv y−1, respectively. The results for annual effective dose due to intake of 226Ra show that children at the age of 1–5 y are at risk as compared to the other age groups. The annual effective doses due to intake of all three radionuclides i...