Retrospective radon measurements based on implanted 210Po in glass objects using polycarbonate detectors

In the present investigation, a surface-deposited polonium was measured in 37 houses in Rasht and Ramsar cities of Iran with the aim of evaluating the retrospective radon concentration. The CR-LR technique is widely used in this regard, but for the first time, Lexan polycarbonate detectors were used to measure the activity of 210Po planted in glassy objects. These detectors were placed on glassy surfaces for 153 to 365 days. A passive cylindrical diffusion chamber was used for the contemporary radon concentration measurements. The diffusion chamber consists of the Lexan polycarbonate films as a solid state nuclear track detectors and filter. The surface-deposited 210Po activity concentration was found to vary from 0.26 to 11.96 mBqcm-2 with average of 2.62 mBqcm-2. The sensitivity of 210Po to polycarbonate was determined to be 0.06456 track per cm2 per mBqhcm-2. Thus, the radon concentration was found to vary from 122 to 4840 Bqm-3 with an average value 1243 Bqm-3 and the contemporary radon concentration in the area was found to vary from 15 to 2420 Bqm-3 with an average 513 Bqm-3. The results indicate that there is a significant correlation between the concentration of the retrospective radon and the concentration of the contemporary radon gas in the indicated areas with a coefficient of 0.80672

Patients doses Estimation in Common Diagnostic X-Ray Examinations and Local DRLs Determination for All Types of Patients

Objective: Nowadays medical imaging is essential in any medical diagnosis. In 1990, the International commission on radiological protection recommended diagnostic reference level (DRL)  to optimize the X-ray examinations according to the principle of optimization assisting the patient radiation dose in diagnostic imaging centres not being ignored. Material and Method: 12 common radiography examinations have been conducted for all type of patients in all of Ilam hospitals and imaging centres. The quality control check was performed on the equipment and it used the solid state dosimeters for estimating the Entrance Surface Air Kerma. Then Entrance Skin Dose of patient was estimated. Finally, its third quartile (75%) was presented as DRL. Result: The range of Entrance Skin Dose (ESD) is from 18 mGy to 0.001 mGy in lumbosacral lateral (LAT) in fat adult and Chest of an infant, respectively. Also the range of DRL is from 4.62 mGy is as low as 0.07 mGy in lumbosacral of an adult and infant’s chest, respectively. Conclusion: All DRLs obtained in this study are compared with other reference, countries and other cities in Iran. Almost DRLs in Ilam are less than them. One of the reasons may due to the execution of QA program. Establishing DRL in a province and encouraging radiographers to follow these values; carry out QA program regularly in all radiology departments will causes more effective radiation protection in population and patient dose