S. Mirzaei

Bio: S. Mirzaei is an academic researcher. The author has contributed to research in topics: Effective dose (radiation) & Absorbed dose. The author has an hindex of 1, co-authored 1 publications receiving 29 citations.

Gamma background radiation measurement in Lorestan province, Iran

Abstract: Background: The exposure of human being to ionize radiation from natural sources is a continuing, inescapable feature of life on earth. Direct measurement of absorbed dose rates in air has been carried out in many countries of the world during the last few decades. Such investigations can be useful for assessment of public dose rates, the performance of epidemiological studies, and keeping reference-data records to ascertain possible changes in the environmental radioactivity duo to nuclear, industrial, and other human activities. Materials and Methods: The measurements of the outdoor and indoor- environmental exposures including cosmic and terrestrial components were accomplished by a portable Geiger Muller detector (RDS -110). The measurements were made during daylight from September to October 2009, in five areas within nine big cities of Lorestan province. In each area, one building was randomly selected for indoor and outdoor measurements. Measurements were made for each region and an average value was used to calculate the exposure rate from gamma background radiation. Results: The results showed the Maximum and minimum outdoor dose rates as 166±44 and 65±8 nSvh-1 in Borujerd and Pol-e- dokhtar, respectively. The average of outdoor dose rates was determined 113±26 nSvh-1. Also the maximum and minimum values of indoor dose were 157±52 and 74±14 nSvh-1 in Borujerd and Pol-e-dokhtar, respectively. The average indoor dose rates were determined as 119±27 nSvh-1. Conclusion: The average annual effective dose for gamma background radiation in Lorestan province has been 0.72 mSv, with the range of 0.3– 0.6 mSv which was more than the global value (0.48 mSv). A poor correlation coefficient between was observed altitude and absorbed dose rates. Iran. J. Radiat. Res., 2011; 9(2): 89­93

Annual effective dose from environmental gamma radiation in Bushehr city.

Abstract: Background Present study was an attempt to measure outdoor and indoor gamma dose rates in Bushehr city to determine corresponding annual effective dose and, to assess effect of active nuclear power plant located in Bushehr city on background radiation level of this city.

Effective dose from natural background radiation in Keffi and Akwanga towns, central Nigeria

Abstract: Background: Human is exposed to radiaƟ on in their environment with or without their consent; and the exposure to natural background radiaƟ on is an unpreventable event on earth. Materials and Methods: An in situ assessment of the indoor and outdoor background radiaƟ on in Akwanga and Keffi towns of Nasarawa state Nigeria was carried out using a halogen-quenched Geiger Muller (GM) detector (Inspector alert Nuclear radiaƟ on monitor SN: 3544). Each of these towns was divided into at least 20 sampling areas where at least ten readings were taken in order to have a reliable data. Results: The mean indoor and outdoor annual effecƟ ve dose of Akwanga were 1.29± 0.13mSv/yr and 0.31±0.04 mSv/yr respecƟ vely; and that of Keffi were 1.08± 0.15mSv/yr and 0.25±0.04 mSv/yr respecƟ vely. The radiaƟ on levels in both highly populated towns were found to be within the safe limit for areas of normal background set by UNSCEAR (2.4 mSv/yr). Conclusion: These results would serve as a baseline upon which other exposures would be assessed and in the future, serve as reference for dosimetry and decontaminaƟ on in situaƟ ons of radiaƟ on poisoning of these towns.

Indoor and outdoor gamma radiation exposure levels in selected residential buildings across Ondo state, Nigeria

Abstract: Background: Indoor and outdoor gamma radiation exposure levels were measured in a total of 360 randomly selected dwellings categorized as local, semimodern and modern buildings across Ondo State, Nigeria to determine the annual effective doses. Materials and Methods: All radiation measurements were taken using a calibrated Kindenoo PG-15 Geiger Muller detector and a GPS for geographical coordinates of sample points. Equal number (360) sample point measurements were carried out for indoor and outdoor measurements. Measurements at each location point were performed holding the survey meter at 1 m above ground surface or floor to avoid unwanted effects of radiation from soil or building floor. The detector was also held at least six to seven meters away from buildings nearby in order to avoid unwanted effects of the building materials on outdoor measurements. Each measurement was repeated six times and the average was taken to represent the value for a sample point. Results: The average outdoor and indoor dose rates were determined as 263 ± 32 μSvh-1 and 213 ± 64 μSvh-1 respectively. The highest contribution to the total indoor dose was from the local buildings followed by semi modern buildings and the modern buildings contributed the least dose. The average annual effective dose was calculated as 1.56 ± 0.33 mSv, which is higher than the world average value (0.48 mSv). Conclusion: In view of the potential radiation resulting from building materials, comprehensive assessment of natural radiations in such materials is required.

Natural radioactivity assessment in soil samples from Kirkuk city of Iraq using HPGe detector

Abstract: Background: Inspection of the level of radioactivity from radionuclides in soil is important for the assessment of the exposure to natural radiation. Materials and Methods: Ten samples from soil were collected from different sites of Kirkuk-IRAQ and the level of natural radioactivity was measured using gamma-ray spectrometry based on a high purity germanium (HPGe) detector. Results: It was found that the specific activity ranged from 27.4 to 57.0 Bq kg for Ra, from 11.0 to 25.4 Bq kg for Th, and from 207.4 to 516.0 Bq kg for K. The results have been compared with the average values worldwide. The hazard indices have also been calculated. In general certain average values were found to be lower than the world average values; these included the average value of the radium equivalent activity (Raeq), the absorbed gamma dose rate (D), the external and internal hazard Hex and Hin, the gamma radiation representative level Index (Iγ) and the outdoor and indoor annual effective dose rate (AEDE) Conclusion: In general there are no harmful radiations effects posed to the population who live in the study area; however there are some spots which have values higher than the internationally allowable values.