Zakeri F.,Iranian Nuclear Regulatory Authority |
Zakeri F.,Nuclear Science and Technology Research Institute, Iran |
Rajabpour M.R.,Iranian Nuclear Regulatory Authority |
Haeri S.A.,Iranian Nuclear Regulatory Authority |
And 6 more authors.
Radiation and Environmental Biophysics | Year: 2011
In order to investigate the biological effects of exposure to low-dose radiation and to assess the dose-effect relationship in residents of high background radiation areas (HBRAs) of Ramsar, cytogenetic investigation of unstable-type aberrations was performed in 15 healthy elderly women in a HBRA of Ramsar, Talesh mahalle, and in 10 elderly women living in a nearby control area with normal background radiation. In total, 77,714 cells were analyzed; 48,819 cells in HBRA residents and 28,895 cells in controls. On average, 3,108 cells per subject were analyzed (range 1,475-5,007 cells). Significant differences were found in the frequency of dicentric plus centric rings in 100 cells (0.207 ± 0.103 vs. 0.047 ± 0.027, p < 0.0005), total chromosome-type aberrations per 100 cells (0.86 ± 0.44 vs. 0.23 ± 0.17, p < 0.0005), and chromatid-type aberrations per 100 cells (3.31 ± 2.01 vs. 1.66 ± 0.63, p = 0.01) by the Mann-Whitney U test between HBRA and the control, respectively. Using chromosomal aberrations as the main endpoint to assess the dose-effect relationship in residents of HBRAs in Ramsar, no positive correlation was found between the frequency of dicentric plus centric ring aberrations and the cumulative dose of the inhabitants estimated by direct individual dosimetry; however, obvious trends of increase with age appeared in the control group. Based on these results, individuals residing in HBRAs of Ramsar have an increased frequency of detectable abnormalities in unstable aberrations. © 2011 Springer-Verlag.
PubMed | Noor Eye Hospital, Tehran University of Medical Sciences, Shahid Beheshti University of Medical Sciences and Iranian Nuclear Regulatory Authority
Type: Journal Article | Journal: Research in cardiovascular medicine | Year: 2015
The use of ionizing radiation has led to advances in medical diagnosis and treatment.The purpose of this study was to determine the risk of radiation cataractogenesis in the interventionists and staff performing various procedures in different interventional laboratories.This cohort study included 81 interventional cardiology staff. According to the working site, they were classified into 5 groups. The control group comprised 14 professional nurses who did not work in the interventional sites. Participants were assigned for lens assessment by two independent trained ophthalmologists blinded to the study.The electrophysiology laboratory staff received higher doses of ionizing radiation (17.2 11.9 mSv; P < 0.001). There was a significant positive correlation between the years of working experience and effective dose in the lens (P < 0.001). In general, our findings showed that the incidence of lens opacity was 79% (95% CI, 69.9-88.1) in participants with exposure (the case group) and our findings showed that the incidence of lenses opacity was 7.1% (95% CI:2.3-22.6) with the relative risk (RR) of 11.06 (P < 0.001).We believe that the risk of radiation-induced cataract in cardiology interventionists and staff depends on their work site. As the radiation dose increases, the prevalence of posterior eye changes increases.
PubMed | State Office for Radiological and Nuclear Safety, Syrian Atomic Energy Commission, Ministry of Health, Radiologist Ministry of Health and 28 more.
Type: Journal Article | Journal: Radiation protection dosimetry | Year: 2015
The article reports results from the largest international dose survey in paediatric computed tomography (CT) in 32 countries and proposes international diagnostic reference levels (DRLs) in terms of computed tomography dose index (CTDI vol) and dose length product (DLP). It also assesses whether mean or median values of individual facilities should be used. A total of 6115 individual patient data were recorded among four age groups: <1 y, >1-5 y, >5-10 y and >10-15 y. CTDIw, CTDI vol and DLP from the CT console were recorded in dedicated forms together with patient data and technical parameters. Statistical analysis was performed, and international DRLs were established at rounded 75th percentile values of distribution of median values from all CT facilities. The study presents evidence in favour of using median rather than mean of patient dose indices as the representative of typical local dose in a facility, and for establishing DRLs as third quartile of median values. International DRLs were established for paediatric CT examinations for routine head, chest and abdomen in the four age groups. DRLs for CTDI vol are similar to the reference values from other published reports, with some differences for chest and abdomen CT. Higher variations were observed between DLP values, based on a survey of whole multi-phase exams. It may be noted that other studies in literature were based on single phase only. DRLs reported in this article can be used in countries without sufficient medical physics support to identify non-optimised practice. Recommendations to improve the accuracy and importance of future surveys are provided.
Mianji F.A.,Nuclear Science and Technology Research Institute, Iran |
Diba J.K.,Iranian Nuclear Regulatory Authority |
Kardan M.R.,Nuclear Science and Technology Research Institute, Iran
Nuclear Technology and Radiation Protection | Year: 2013
A method for exploiting human's internal contamination data for radioactive release estimation in nuclear power plant accidents is proposed. Nevertheless, such data is often very rough and uncertain; it is accessible even in toughest situations when most of the active and passive monitors are damaged by the accident. These data can be used in combination with other collectable data for estimating the event scale in severe nuclear power plan accidents. The rationale behind the method is that nuclear power plant accidents are often associated with internal contamination of radiation workers involved in the early stages of emergency response activities mainly due to the release of 131I in atmosphere. The proposed inverse analytical approach uses the 131I intake of contaminated workers, their working conditions, chronology of events, and applied personal safety measures during the first hours or days of the emergency response activities to estimate the magnitude of 131I concentration in the air.