A calculational method of photon dose equivalent based on the revised technical standards of radiological protection law. (No. 2).

The historical change of radon dose evaluation is reviewed based on the United Nations Scientific Committee on the Effects of Atomic Radiation (UNSCEAR) reports. Since 1955, radon has been recognized as one of the important sources of exposure of the general public. However, it was not really understood that radon is the largest dose contributor until 1977 when a new concept of effective dose equivalent was introduced by International Commission on Radiological Protection. In 1982, the dose concept was also adapted by UNSCEAR and evaluated per caput dose from natural radiation. Many researches have been carried out since then. However, lots of questions have remained open in radon problems, such as the radiation weighting factor of 20 for alpha rays and the large discrepancy of risk estimation among dosimetric and epidemiological approaches.

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ESTIMATION OF UNCERTAINTY IN MEASUREMENT OF DOSE EQUIVALENT AT LABORATORY LEVEL USING CASO4 :Dy-BASED TLD BADGE SYSTEM IN INDIA

Radiation Protection Dosimetry ◽

10.1093/rpd/ncz268 ◽

2019 ◽

Vol 188 (2) ◽

pp. 135-147 ◽

Cited By ~ 1

Author(s):

S M Pradhan ◽

D Datta ◽

Munir S Pathan ◽

Kshama Srivastava ◽

T Palani Selvam

Keyword(s):

Coefficient Of Variation ◽

Whole Body ◽

Dose Equivalent ◽

Radiation Quality ◽

Variance Model ◽

Factors Affecting ◽

Uncertainty In Measurement ◽

Photon Dose ◽

Combined Uncertainty ◽

Quality Coefficient

Abstract The objective of this paper is to estimate the combined uncertainty in the measurement of dose equivalent at laboratory level using CaSO4:Dy-based thermoluminescent dosemeter badge system by including variations in the components of the system. The variability of performance of the system is analysed using random effects one way analysis of variance model. The model enables estimation of the overall variance of the performance of the sampled population. The population in the study comprises all possible indicated dose equivalents on irradiation of dosemeters to a specific dose equivalent and radiation quality. Coefficient of variation and combined uncertainty at 95% level of confidence in the measurement of Hp(10) due to S-Cs radiation quality are found to be 6.6 and 14.3%, respectively, at the dose level of 5.31 mSv. The above parameters in the measurement of in-use quantity, i.e. whole body dose or photon dose equivalent are found to be 7.4 and 16.4%, respectively. The performance of the monitoring system on relative response has been observed to be satisfactory. Various factors affecting the variability of performance of the system are identified for further improvement in coefficient of variation.

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UNCERTAINTY EVALUATION IN MEASUREMENT OF THE PERSONAL DOSE EQUIVALENT AT NINE INDIVIDUAL MONITORING SERVICES IN ASIA AND THE PACIFIC REGION

Radiation Protection Dosimetry ◽

10.1093/rpd/ncaa093 ◽

2020 ◽

Vol 190 (2) ◽

pp. 217-225

Author(s):

Chadia Rizk ◽

Panagiotis Askounis ◽

H Burçin Okyar ◽

John Konsoh Sangau ◽

Samaneh Baradaran ◽

...

Keyword(s):

Uncertainty Evaluation ◽

Radiological Protection ◽

International Electrotechnical Commission ◽

Pacific Region ◽

Dose Equivalent ◽

Annual Dose ◽

Uncertainty In Measurement ◽

The Pacific ◽

Dose Limits ◽

Relevant Dose

Abstract This paper presents the results of the evaluation of the uncertainty in measurement of the personal dose equivalent, Hp(10), at nine individual monitoring services (IMSs) in Asia and the Pacific region. Different types of passive dosemeters were type-tested according to the International Electrotechnical Commission 62387 requirements. The uncertainty in measurement was calculated using the Guide to the Expression of Uncertainty in Measurement approach. Expanded uncertainties ranged between 24 and 86% (average = 38%) for Hp(10) values around 1 mSv and between 14 and 40% (average = 27%) for doses around the annual dose limit, Hp(10) = 20 mSv. The expanded uncertainties were lower than the 1.5 factor in either direction proposed by the International Commission on Radiological Protection for doses near the relevant dose limits. This indicates an acceptable level of uncertainty for all participating IMSs. Uncertainty evaluation will help the IMSs to acknowledge the accuracy of their measurements.

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Occupational Radiation Exposure of Anesthesia Providers: A Summary of Key Learning Points and Resident-Led Radiation Safety Projects

Seminars in Cardiothoracic and Vascular Anesthesia ◽

10.1177/1089253217692110 ◽

2017 ◽

Vol 21 (2) ◽

pp. 165-171 ◽

Cited By ~ 7

Author(s):

Rachel R. Wang ◽

Amanda H. Kumar ◽

Pedro Tanaka ◽

Alex Macario

Keyword(s):

Occupational Exposure ◽

Ionizing Radiation ◽

Radiation Exposure ◽

Radiation Safety ◽

Radiological Protection ◽

Dose Equivalent ◽

Occupational Radiation Exposure ◽

Anesthesia Providers ◽

Occupational Radiation ◽

Learning Points

Anesthesia providers are frequently exposed to radiation during routine patient care in the operating room and remote anesthetizing locations. Eighty-two percent of anesthesiology residents (n = 57 responders) at our institution had a “high” or “very high” concern about the level of ionizing radiation exposure, and 94% indicated interest in educational materials about radiation safety. This article highlights key learning points related to basic physical principles, effects of ionizing radiation, radiation exposure measurement, occupational dose limits, considerations during pregnancy, sources of exposure, factors affecting occupational exposure such as positioning and shielding, and monitoring. The principle source of exposure is through scattered radiation as opposed to direct exposure from the X-ray beam, with the patient serving as the primary source of scatter. As a result, maximizing the distance between the provider and the patient is of great importance to minimize occupational exposure. Our dosimeter monitoring project found that anesthesiology residents (n = 41) had low overall mean measured occupational radiation exposure. The highest deep dose equivalent value for a resident was 0.50 mSv over a 3-month period, less than 10% of the International Commission on Radiological Protection occupational limit, with the eye dose equivalent being 0.52 mSv, approximately 4% of the International Commission on Radiological Protection recommended limit. Continued education and awareness of the risks of ionizing radiation and protective strategies will reduce exposure and potential for associated sequelae.

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Measurement of Environmental Radioactivity within Dangote Cement Escavation Site Gboko, Benue State.

NIGERIAN ANNALS OF PURE AND APPLIED SCIENCES ◽

10.46912/napas.23 ◽

2015 ◽

Vol 6 ◽

pp. 168-172

Author(s):

A A Tyovenda ◽

A A Akombor ◽

S T Tamaugee

Keyword(s):

Environmental Radioactivity ◽

Radiological Protection ◽

Limit Set ◽

Exposure Rate ◽

Dose Equivalent ◽

Background Count ◽

Equivalent Rate ◽

The Mean ◽

Excavation Site ◽

Safety Limit

The radioactivity of rocks from Dangote Cement excavation site in Gboko, Benue State were monitored and measured using the radiation meter inspector 06250 and dose meter 6150AD 2/4/6. The meters measure the dose rate, exposure rate and the activity. The meters were held 1 meter above the surface of the soil at the excavation site. Each reading was taken 10 times at varying distances between zero and 100 meters from the excavation site after which the mean readings for each of the distance were then found. Finally, the background count was taken 200 meters away from the excavation point. The highest value of dose equivalent rate of 0.428±0.006 mSv/yr, exposure rate of 0.206±0.003 mR/hr and activity of 6.8±0.4kBq were measured at zero distance from the excavation point while the least value of dose equivalent rate of 0.212±0.002 mSv/yr, exposure rate of 0.081±0.001 mR/hr and activity of 3.2±0.8kBq were obtained at 100 meters away from the excavation point. The result shows that the excavation site is within the safety limit set by the international commission on Radiological protection (ICRP) (1990).

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NOVEL ‘PHOTONEUTRON VOLUME DOSE EQUIVALENT’ HYPOTHESIS AND METHODOLOGY FOR SECOND PRIMARY CANCER RISK ESTIMATION IN HIGH-ENERGY X-RAY MEDICAL ACCELERATORS

Radiation Protection Dosimetry ◽

10.1093/rpd/ncz303 ◽

2020 ◽

Vol 188 (4) ◽

pp. 432-443 ◽

Cited By ~ 1

Author(s):

Mehdi Sohrabi ◽

Amir Hakimi

Keyword(s):

Risk Estimation ◽

High Energy ◽

Second Primary ◽

Radiological Protection ◽

Primary Cancer ◽

Second Primary Cancer ◽

Dose Equivalent ◽

X Ray ◽

Risk Estimates ◽

First Time

Abstract A novel ‘photoneutron (PN) volume dose equivalent’ methodology was hypothesized and applied for the first time for estimating PN second primary cancer (PN-SPC) risks in high-energy X-ray medical accelerators. Novel position-sensitive mega-size polycarbonate dosimeters with 10B converter (with or without cadmium covers) were applied for determining fast, epithermal and thermal PN dose equivalents at positions on phantom surface and depths. The methodology was applied to sites of tumors such as brain, stomach and prostate in 47 patients. The PN-SPC risks were estimated for specific organs/tissues using linear International Commission on Radiological Protection cancer risks and were compared with some available data. The corresponding PN-SPC risk estimates ranged from 1.450 × 10−3 to 1.901 cases per 10 000 persons per Gray. The method was applied to 47 patients for estimating PN-SPC risks in patients undergoing radiotherapy. The PN-SPC risk estimates well match those calculated by simulation but are comparatively different from those estimated by ‘PN point dose equivalent’ methods, as expected.

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