Characterization and real-time optical measurements of the ionizing radiation dose response for a new radiochromic medium

2005 ◽  
Vol 32 (8) ◽  
pp. 2510-2516 ◽  
Author(s):  
Alexandra Rink ◽  
I. Alex Vitkin ◽  
David A. Jaffray
Keyword(s):  
Radiation Dose ◽  
Ionizing Radiation ◽  
Real Time ◽  
Dose Response ◽  
Optical Measurements

Suitability of radiochromic medium for real-time optical measurements of ionizing radiation dose

2005 ◽  
Vol 32 (4) ◽  
pp. 1140-1155 ◽  
Author(s):  
Alexandra Rink ◽  
I. Alex Vitkin ◽  
David A. Jaffray
Keyword(s):  
Radiation Dose ◽  
Ionizing Radiation ◽  
Real Time ◽  
Optical Measurements

scholarly journals Effects of exposure to low-dose ionizing radiation on changing platelets: a prospective cohort study

2021 ◽  
Vol 26 (1) ◽  
Author(s):  
Ning Liu ◽  
Yang Peng ◽  
Xinguang Zhong ◽  
Zheng Ma ◽  
Suiping He ◽  
...  
Keyword(s):  
Radiation Dose ◽  
Ionizing Radiation ◽  
Dose Response ◽  
Low Dose ◽  
Linear Trend ◽  
Hematological Parameters ◽  
Response Relationship ◽  
Dose Response Relationship ◽  
Spline Models ◽  
Cumulative Radiation Dose

Abstract Background Numerous studies have concentrated on high-dose radiation exposed accidentally or through therapy, and few involve low-dose occupational exposure, to investigate the correlation between low-dose ionizing radiation and changing hematological parameters among medical workers. Methods Using a prospective cohort study design, we collected health examination reports and personal dose monitoring data from medical workers and used Poisson regression and restricted cubic spline models to assess the correlation between changing hematological parameters and cumulative radiation dose and determine the dose-response relationship. Results We observed that changing platelet of 1265 medical workers followed up was statistically different among the cumulative dose groups (P = 0.010). Although the linear trend tested was not statistically significant (Ptrend = 0.258), the non-linear trend tested was statistically significant (Pnon-linear = 0.007). Overall, there was a correlation between changing platelets and cumulative radiation dose (a change of βa 0.008 × 109/L during biennially after adjusting for gender, age at baseline, service at baseline, occupation, medical level, and smoking habits; 95% confidence interval [CI] = 0.003,0.014 × 109/L). Moreover, we also found positive first and then negative dose-response relationships between cumulative radiation dose and changing platelets by restricted cubic spline models, while there were negative patterns of the baseline service not less than 10 years (− 0.015 × 109/L, 95% CI = − 0.024, − 0.007 × 109/L) and radiation nurses(− 0.033 × 109/L, 95% CI = − 0.049, − 0.016 × 109/L). Conclusion We concluded that although the exposure dose was below the limit, medical workers exposed to low-dose ionizing radiation for a short period of time might have increased first and then decreased platelets, and there was a dose-response relationship between the cumulative radiation dose and platelets changing.

Risk of Myelodysplastic Syndromes in People Exposed to Ionizing Radiation: A Retrospective Cohort Study of Nagasaki Atomic Bomb Survivors

2011 ◽  
Vol 29 (4) ◽  
pp. 428-434 ◽  
Author(s):  
Masako Iwanaga ◽  
Wan-Ling Hsu ◽  
Midori Soda ◽  
Yumi Takasaki ◽  
Masayuki Tawara ◽  
...  
Keyword(s):  
Cohort Study ◽  
Radiation Dose ◽  
Ionizing Radiation ◽  
Dose Response ◽  
Myelodysplastic Syndromes ◽  
Retrospective Cohort Study ◽  
Retrospective Cohort ◽  
Radiation Effects ◽  
Atomic Bomb ◽  
Atomic Bomb Survivors

Purpose The risk of myelodysplastic syndromes (MDS) has not been fully investigated among people exposed to ionizing radiation. We investigate MDS risk and radiation dose-response in Japanese atomic bomb survivors. Patients and Methods We conducted a retrospective cohort study by using two databases of Nagasaki atomic bomb survivors: 64,026 people with known exposure distance in the database of Nagasaki University Atomic-Bomb Disease Institute (ABDI) and 22,245 people with estimated radiation dose in the Radiation Effects Research Foundation Life Span Study (LSS). Patients with MDS diagnosed from 1985 to 2004 were identified by record linkage between the cohorts and the Nagasaki Prefecture Cancer Registry. Cox and Poisson regression models were used to estimate relationships between exposure distance or dose and MDS risk. Results There were 151 patients with MDS in the ABDI cohort and 47 patients with MDS in the LSS cohort. MDS rate increased inversely with exposure distance, with an excess relative risk (ERR) decay per km of 1.2 (95% CI, 0.4 to 3.0; P < .001) for ABDI. MDS risk also showed a significant linear response to exposure dose level (P < .001) with an ERR per Gy of 4.3 (95% CI, 1.6 to 9.5; P < .001). After adjustment for sex, attained age, and birth year, the MDS risk was significantly greater in those exposed when young. Conclusion A significant linear radiation dose-response for MDS exists in atomic bomb survivors 40 to 60 years after radiation exposure. Clinicians should perform careful long-term follow-up of irradiated people to detect MDS as early as possible.

scholarly journals A Dose-Response Model and D10-Value for Mycobacterium tuberculosis Exposed to Dosimetrically Verified Ionizing Radiation

2021 ◽  
Author(s):  
Jackson V Watkins ◽  
Justin Bell ◽  
Phillip Knabenbauer ◽  
Alexander Brandl ◽  
Karen M Dobos
Keyword(s):  
Mycobacterium Tuberculosis ◽  
Radiation Dose ◽  
Ionizing Radiation ◽  
Dose Rate ◽  
Dose Response ◽  
Large Scale ◽  
Pathogen Inactivation ◽  
Ion Chamber ◽  
A Value ◽  
Sample Chamber

AbstractTechniques for pathogen inactivation have been employed by laboratories to help ease the financial, physical, and health strains associated with (A)BSL-3 work. Exposure to radiation is the most common and useful of these methods to inactivate pathogens grown in large-scale culture. While robust protocols exist for radiation exposure techniques, there are variances in methods used to determine the radiation dose and dose rate required to inactivate pathogens. Furthermore, previous studies often do not include radiation dosimetry verification or address corresponding dosimetry uncertainties for dose response-assays. Accordingly, this study was conducted with the purpose of completing a dosimetry assessment of the radiation field within the sample chamber of a sealed source irradiator, to subsequently determine the radiation dose required to inactivate pathogenic cultures. Physical dosimetry techniques (Fricke dosimetry, ion chamber measurements, and measurements with thermoluminescent dosimeters) were used to measure dose rate and rate variances within the sample chamber. By comparing the variances between the dosimetry methodologies and measurements, an estimated dose rate within the sample chamber was determined. The results of the dosimetry evaluation were used to determine the radiation dose samples of Mycobacterium tuberculosis received, to accurately associate biological markers of inactivation to specific doses of ionizing radiation. A D10 value and dose-response curve were developed to describe the inactivation of Mtb from increasing doses of ionizing radiation. The D10 value is experimentally relevant for comparative analysis and potentially provides a biological baseline for inactivation verification. This methodology can also easily be translated to other pathogen models.ImportanceThis work set out to give us a better understanding of how much radiation is required to inactivate Mycobacterium tuberculosis, the bacteria that causes tuberculosis disease. Radiation dose from a source is not something that can just be inputted, it must be calculated, so we also determined the approximate dose from the source to address ambiguities that had previously existed while inactivating microbes. We were able to generate an accurate description of inactivation of Mycobacterium tuberculosis by correlating it with a value representing 90% death of the treated cells. We also unexpectedly discovered that very low levels of radiation increase certain activity within the cell. This is important because it allows us to better understand how radiation kills Mycobacterium tuberculosis, and gives us a value to compare to other organisms. It also offers other researchers a method to use under their own specific conditions.

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