Abstract
This study aims to obtain the baseline data on environmental terrestrial radiation and to assess the corresponding health risk in Johor Bahru District, Johor, Malaysia. The mean activity concentrations of Th-232, Ra-226 and K-40 were 119 +/- A 6, 51 +/- A 4 and 158 +/- A 21 Bq kg(-1), respectively. Primordial radionuclide Th-232 is the main contributor to gamma dose rate and the mean found to be 135 nGy h(-1). Gross alpha and gross beta activity concentrations in water were 0.012 +/- A 0.003 and 0.234 +/- A 0.018 Bq L-1, respectively.