RESUMEN
Radon concentration was measured in 50 drinking water samples in Mashhad - Iran. The tap water used for drinking and other household usages can increase the indoor radon level. Drinking water samples were collected from various places and supplies of public water used in Mashhad. Then radon concentration has been measured by portable radon gas surveyor SILENA [PRASSI] system. The results showed that about 70% of water samples had radon concentration greater than 11Bq/l the level recommended USA environmental protection agency [EPA]. The arithmetic mean of radon concentration for all samples was 16.238 +/- 9.322 Bq/l. Also the annual effective dose in stomach and lung per person were estimated in this research, with the mean value of 0.040 mSv and 0.043 mSv per year for these two organs for all samples, respectively. The results indicate that radon concentrations in public drinking water samples of Mashhad are mostly low enough and below the proposed concentration limits. The mean radon level was 16.238 Bq/l for all samples; which is not much greater than 11Bq/l as EPA advised level. Further, only two samples induced the total annual effective dose greater than 0.1 mSv per year
RESUMEN
Palladium-103 [[103]Pd] is a brachytherapy source for cancer treatment. The Monte Carlo codes are usually applied for dose distribution and effect of shieldings. Monte Carlo calculation of dose distribution in water phantom due to a MED3633 [103]Pd source is presented in this work. The dose distribution around the [103]Pd Model MED3633 located in the center of 30×30×30 cm[3] water phantom cube was calculated using MCNP code by the Monte Carlo method. The percentage depth dose [PDD] variation along the different axis parallel and perpendicular to the source was also calculated. Then, the isodose curves for 100%, 75%, 50% and 25% PDD and dosimetry parameters of TG- 43 protocol were determined. The results show that the Monte Carlo Method could calculate dose deposition in high gradient region, near the source, accurately. The isodose curves and dosimetric characteristics obtained for MED3633 [103]Pd source are in good agreement with published results. The isodose curves of the MED3633 [103]Pd source have been derived form dose calculation by MCNP code. The calculated dosimetry parameters for the source agree quite well with their Monte Carlo calculated and experimental measurement values