Measurement of the
terrestrial gamma radiation dose rates was carried out in the
district of Port Dickson, Malaysia. The
survey of
terrestrial gamma radiation dose rates is of interest to assessment of radiological health physics. Gamma ray detector using Nal (Tl) scintillation was chosen as a technique, due to the easiness of use, high sensitivity and possibility of identification of an inadvertent contamination. The
average of terrestrial gamma radiation dose-rate measured is 296 ± 6 nGy h-1 and the average of population-weighted value is 240 nGy h-1. The average of the annual effective dose is 0.29 mSv. The relationship of terrestrial gamma radiation dose rates with underlying of soil types and geological formation at Port Dickson district was determine. Such investigation of terrestrial gamma radiation dose rate in environment can be useful for both for the assessment of public dose rate and the performance of epidemiological study, as well as to obtain reference data and to ascertain possible change in the environmental radioactivity due to nuclear, industrial and other human activities.