In this study, samples of building material additives were analyzed for naturally occurring radioisotope activity such as uranium, radium, and radon. The radon exhalation and the annual effective doses, were also calculated. The activities of the samples, were determined using HPGe gamma spectrometry and ionization detector. The results were used to calculate dose values by using RESRAD BUILD code. The activity concentration of the samples ranges between 9–494 Bq/kg Ra-226, 1–119 Bq/kg Th-232 and 24–730 Bq/kg K-40. In conclusion the investigated samples can be used safely as building material additives as they do not pose a major risk to humans.

No abstract

There is little available information on the radioactivity concentrations in the thermal and drinking water sources in North Vietnam. In the current study, the gross alpha and gross beta activity concentrations were determined in 8 water sources in the area. The average activities of gross alpha and beta in the 8 sources are 38.7 mBq L− 1 and 88.0 mBq L− 1. These activity concentrations are lower than WHO recommendations for drinking water. In this study, the gross alpha and gross beta show a weak correlation.

No abstract

210Po is the main radiotoxic chemical in tobacco smoke and one of the primary causes of lung cancer. Investigating 210Po concentration in tobacco is important in estimating the annual effective dose (AED) due to smoking. In this study, the 210Po concentrations in tobacco leaves and soil in Quang Xuong, Vietnam were measured using a high-resolution passivated and implanted planar silicon detector. Based on these data the AEDs to smokers were estimated. The 210Po activity concentration in tobacco varied significantly from 28.7 to 254.0 mBq g−1, whereas its variation in soil was insignificant. The AED due to smoking fresh tobacco leaves in Vietnam (average 565 μSv y−1) was significantly higher than the values reported for other countries (36–361 μSv y−1).