REASSESSMENT OF INHALATION DOSES TO WORKERS IN AUSTRALIAN SHOW CAVES

Abstract Exposure to radon in show caves is an existing exposure situation. A survey of radon levels in underground show caves around Australia, carried out in 1994, found that most of the show caves located in South-Eastern Australia had yearly average radon levels exceeding the Australian radon reference level of 1000 Bq m−3. At the time of the original survey, the radiation doses from exposure to radon progeny of the tour guides in these caves were estimated using the epidemiologically based dose conversion factors and all dose were assessed to be less than 10 mSv per year. In February 2018, the International Commission for Radiological Protection (ICRP) published updated radon and radon progeny dose conversion factors (DCF) applicable to worker exposure to radon in show caves. These updated DCF values are based on dosimetric modelling and are sensitive to the radon progeny activity size distribution. The recommended DCF values are up to a factor four times higher than the previous ICRP recommendations. The ICRP has published data that allows for the estimation of site-specific radon progeny dose coefficients if required. A reassessment of the radiation doses to workers in Australian show caves has been made using these updated ICRP DCF values and the historical measurements of radon progeny activity size distributions in Australian show caves. Using the site-specific DCF values, it is estimated that 15% of the workers exceeded 10 mSv y−1 and 6% exceeded 20 mSv y−1. Although the total number of show cave workers in Australia is very small, the updated radon progeny dose estimates are a significant radiation protection issue for the affected individuals and their employers.

Download Full-text

ICRP recommendations on radon

Annals of the ICRP ◽

10.1177/0146645320931974 ◽

2020 ◽

Vol 49 (1_suppl) ◽

pp. 68-76 ◽

Cited By ~ 1

Author(s):

J.D. Harrison ◽

J.W. Marsh

Keyword(s):

Occupational Exposure ◽

Reference Level ◽

Radiological Protection ◽

Radiation Doses ◽

Site Specific ◽

Detailed Consideration ◽

Equilibrium Factor ◽

Dose Coefficient ◽

Dose Coefficients ◽

Icrp Publication

The International Commission on Radiological Protection (ICRP) publishes guidance on protection from radon in homes and workplaces, and dose coefficients for use in assessments of exposure for protection purposes. ICRP Publication 126 recommends an upper reference level for exposures in homes and workplaces of 300 Bq m−3. In general, protection can be optimised using measurements of air concentrations directly, without considering radiation doses. However, dose estimates are required for workers when radon is considered as an occupational exposure (e.g. in mines), and for higher exposures in other workplaces (e.g. offices) when the reference level is exceeded persistently. ICRP Publication 137 recommends a dose coefficient of 3 mSv per mJ h m−3 (approximately 10 mSv per working level month) for most circumstances of exposure in workplaces, equivalent to 6.7 nSv per Bq h m−3 using an equilibrium factor of 0.4. Using this dose coefficient, annual exposure of workers to 300 Bq m−3 corresponds to 4 mSv. For comparison, using the same coefficient for exposures in homes, 300 Bq m−3 corresponds to 14 mSv. If circumstances of occupational exposure warrant more detailed consideration and reliable alternative data are available, site-specific doses can be assessed using methodology provided in ICRP Publication 137.

Download Full-text

Radiation doses to individuals due to 238U, 232Th and 222Rn from the immersion in thermal waters and to radon progeny from the inhalation of air inside thermal stations

Radiation and Environmental Biophysics ◽

10.1007/s00411-012-0426-9 ◽

2012 ◽

Vol 51 (4) ◽

pp. 375-389 ◽

Cited By ~ 7

Author(s):

M. A. Misdaq ◽

M. Ghilane ◽

J. Ouguidi ◽

K. Outeqablit

Keyword(s):

Thermal Waters ◽

Radiation Doses ◽

Radon Progeny

Download Full-text

PRELIMINARY EVALUATION OF PATIENT RADIATION DOSES DURING RADIONUCLIDE DIAGNOSTIC WITH MONOCLONAL ANTIBODIES LABELED WITH 89Zr

Pharmacy Formulas ◽

10.17816/phf81118 ◽

2021 ◽

Author(s):

Larisa A. Chipiga ◽

Anna E. Petrova ◽

Artem A. Mosunov ◽

Laura T. Naurzbaeva ◽

Stanislaus M. Kushnarenko ◽

...

Keyword(s):

Monoclonal Antibodies ◽

Dose Assessment ◽

Published Data ◽

Radiation Doses ◽

Preliminary Evaluation ◽

Software Products ◽

Absorbed Doses ◽

Order Of Magnitude ◽

Effective Doses

In connection with the constantly increasing use of monoclonal antibodies labeled with 89Zr, in clinical practice, it is urgent to study their pharmacokinetics with the determination, based on the data obtained, of absorbed doses in tumor foci, as well as intact organs and tissues, and effective doses of patients. To date, there are a limited number of studies that provide patient doses for diagnostic examinations using 89Zr-labeled monoclonal antibodies. In this regard, the purpose of this work was to assess the biodistribution of various monoclonal antibodies (ramucirumab, trastuzumab, atezolizumab) labeled with 89Zr, based on published data, with subsequent calculation of absorbed doses in radiosensitive organs and tissues and effective doses of patients. Based on the analysis of experimental data on the biodistribution of monoclonal antibodies labeled with 89Zr for the diagnosis of oncological diseases from the available literature sources and our own assessments, it has been concluded that the results of the determination of absorbed in organs and tissues and effective doses are inconsistent. The absorbed doses in organs, according to different literature sources, vary up to an order of magnitude within one organ and reach 440 mGy per examination, the effective dose varies from 3 to 112 mSv per examination. This may be due to differences in study design, radiometry and dose assessment methods. Comparison with doses obtained on the basis of a general model of biodistribution of monoclonal antibodies demonstrates the possibility of using this model for a rough estimate of internal doses of patients. However, for a more accurate assessment, it is necessary to standardize approaches to the determination of internal radiation doses using the most effective methodological solutions and software products.

Download Full-text

MEASUREMENT OF EXTREMITY DOSES OF NUCLEAR ENERGY WORKER BY USING RING DOSIMETER

Radiation Protection Dosimetry ◽

10.1093/rpd/ncz283 ◽

2019 ◽

Vol 188 (3) ◽

pp. 271-275

Author(s):

M Tahidul Islam ◽

J Ferdous ◽

M M Haque

Keyword(s):

Nuclear Medicine ◽

Nuclear Energy ◽

Health Hazard ◽

Extreme Case ◽

Work Practice ◽

Middle Finger ◽

Whole Body ◽

Radiological Protection ◽

Radiation Doses ◽

Average Dose

Abstract Finger doses can serve as a guide to suggest any needed modification in work practice to minimise radiation doses to the extremities. In the present study, radiation doses at the base of the middle finger of both hands of 20 nuclear energy workers handling 99mTc-labelled compounds,125I and131I during various diagnostic and therapeutic procedures in nuclear medicine were measured. The laboratory assessments were carried out by means of thermoluminescence ring dosimetry in Health Physics Division, Atomic Energy Center, Dhaka. The recorded extremity doses were then compared to their routinely monitored whole-body doses. The average annual finger doses recorded in this study were found to be 10.7 ± 8.2 and 12.7 ± 12.9 mSv, respectively, for the left- and right-hand fingers, which are at least 12-fold higher than the average whole-body dose. There was, however, no extreme case found of health hazard to the workers’ hand, which exceeds maximum dose limit 500 mSv/year given by the International Commission on Radiological Protection. On comparing the average annual finger doses at different labs, significantly higher average dose was recorded at isotope-dispensing lab (19.6 ± 12.6 mSv/year) and then followed by gamma camera lab (13.2 ± 12.1 mSv/year) and radioimmunoassay lab (7.0 ± 5.5 mSv/year). These observations are fairly in good agreement with the reported results. The observations of the present study, therefore, may be implemented for the betterment of safety for the occupational workers in nuclear medicine facilities.

Download Full-text

Some Thought on New Dose Conversion Factors for Radon Progeny Inhalation

Japanese Journal of Health Physics ◽

10.5453/jhps.53.282 ◽

2018 ◽

Vol 53 (4) ◽

pp. 282-293 ◽

Cited By ~ 2

Author(s):

Shinji TOKONAMI

Keyword(s):

Radon Progeny ◽

Conversion Factors

Download Full-text

Estimating Radiation Dose to Major Organs in Dental X-Ray Examinations: A Phantom Study

Radiation Protection Dosimetry ◽

10.1093/rpd/ncaa196 ◽

2020 ◽

Author(s):

Yong Li ◽

Bingsheng Huang ◽

Jun Cao ◽

Tianqi Fang ◽

Guoqing Liu ◽

...

Keyword(s):

Radiation Dose ◽

Reference Level ◽

Radiation Doses ◽

Diagnostic Reference Level ◽

Effective Radiation Dose ◽

Organ Doses ◽

X Ray ◽

Absorbed Doses ◽

Males And Females ◽

Effective Radiation

Abstract The radiation doses absorbed by major organs of males and females were studied from three types of dental X-ray devices. The absorbed doses from cone-beam computed tomography (CBCT), panoramic and intraoral X-ray machines were in the range of 0.23–1314.85 μGy, and were observed to be high in organs and tissues located in or adjacent to the irradiated area, there were discrepancies in organ doses between male and female. Thyroid, salivary gland, eye lens and brain were the organs that received higher absorbed doses. The organ absorbed doses were considerably lower than the diagnostic reference level for dental radiography in China. The calculated effective radiation doses for males and females were 56.63, 8.15, 2.56 μSv and 55.18, 8.99, 2.39 μSv, respectively, when using CBCT, the panoramic X-ray machine and intraoral X-ray machine. The effective radiation dose caused by CBCT was much higher than those of panoramic and intraoral X-ray machines.

Download Full-text

Chemical fertility of krasnozems - a review

Soil Research ◽

10.1071/sr9941015 ◽

1994 ◽

Vol 32 (5) ◽

pp. 1015

Author(s):

PW Moody

Keyword(s):

Organic Matter ◽

Cation Exchange ◽

Anion Exchange ◽

Cation Exchange Capacity ◽

Clay Fraction ◽

Exchange Capacity ◽

Published Data ◽

Total N ◽

Eastern Australia ◽

Ph Buffer

Krasnozems (Ferrosols) characteristically have high contents of citrate-dithionite extractable Fe and moderate to high contents of clay throughout the profile. They typically have low cation exchange capacity (2-20 cmolc kg-1), high P sorbing ability, and a significant anion exchange capacity at depth. The chemistry of krasnozems is dominated by the variable charge characteristics of the organic matter and the oxy-hydroxides of Fe and Al which occur in the predominantly kaolinitic clay fraction. The effects of surface charge characteristics, organic matter, and extractable iron and aluminium on the cation and anion exchange capacities, P sorbing abilities and pH buffer capacities of Australian krasnozems are reviewed. A selection of reports of nutrient deficiencies and toxicities in these soils is presented and briefly discussed. Published data on the chemical composition of the soil solutions of krasnozems are reviewed. Data from a suite of paired (undeveloped and developed) krasnozem profiles from eastern Australia indicate that exchangeable Ca and Mg, effective cation exchange capacity (ECEC), pH buffer capacity (pHBC) and total N decrease significantly (P < 0.05) in the A horizon following development, while exchangeable K, ECEC and pHBC decrease (P < 0-05) in the B horizon. The decreases in the A horizon are shown to be a direct consequence of the decline in organic matter which occurs following development. Because of the crucial role that organic matter plays in the chemical fertility of krasnozems, they are less likely to maintain their fertility under exploitative conditions than other productive clay soils such as Vertosols. It is concluded that the sustainable use of krasnozems will depend on maintenance or enhancement of organic matter levels, maintenance of surface and subsoil pH by regular application of amendments, minimization of erosion, and replacement of nutrients removed in harvested products.

Download Full-text

EVALUATION OF DOSE IN SLEEP BY MATTRESS CONTAINING MONAZITE

Radiation Protection Dosimetry ◽

10.1093/rpd/ncz163 ◽

2019 ◽

Vol 187 (3) ◽

pp. 286-299

Author(s):

Bong-Gi Kim ◽

Kyu-Hwan Jeong ◽

Hyeong-Ki Shin

Keyword(s):

Age Groups ◽

Decay Chain ◽

Dose Assessment ◽

Internal Exposure ◽

External Exposure ◽

Radon Progeny ◽

Conversion Factors ◽

Assessment Program ◽

Radioactive Concentration ◽

Effective Doses

Abstract Some companies in Korea have sold beds which contain a processed product containing monazite powder. Consumers may receive external exposure by radiation emitted by progeny radionuclides in uranium and thorium, and internal exposure through the breathing of radon progeny radionuclides produced in the decay chain. Thus, in this study, age specific dose conversion factors (mSv y−1 Bq−1) by external exposure and dose conversion factors by internal exposure (mSv y−1 per Bq m−3) were derived. Besides, a dose assessment program were developed to calculate dose by taking into account real conditions. And the age specific dose was evaluated using the radioactive concentration measured by the NSSC. As a results, external exposure was assessed to get effective doses in the range of 0.00086 to 0.0015 mSv y−1 by external exposure and a committed effective doses in the range of 1.3 to 12.26 mSv y−1 by internal exposure for all age groups.

Download Full-text

Estimation of indoor radon, thoron and their decay products’ concentrations along with annual inhalation dose in dwellings of Punjab, India

Indoor and Built Environment ◽

10.1177/1420326x16676305 ◽

2016 ◽

Vol 27 (3) ◽

pp. 380-389 ◽

Cited By ~ 5

Author(s):

Komal Saini ◽

B. K. Sahoo ◽

Bikramjit Singh Bajwa

Keyword(s):

Indoor Radon ◽

Research Centre ◽

Reference Level ◽

Radiological Protection ◽

Inhalation Dose ◽

Study Region ◽

Average Value ◽

Decay Products ◽

Single Entry ◽

Annual Inhalation Dose

In the present study, indoor radon and thoron concentrations were assessed using a newly developed pin hole-based twin cup dosimeter with a single-entry face in some areas of Punjab state, India. The equilibrium equivalent concentrations of radon and thoron were estimated directly by using the newly developed progeny (decay products) sensors designed by Bhabha Atomic Research Centre, Mumbai, India. The average radon and thoron concentrations in the study region were found to be 61.6 ± 18.6 Bq/m3 and 68.0 ± 30.8 Bq/m3, respectively, while the average equilibrium equivalent concentrations of radon and thoron were 25.9 ± 7.7 Bq/m3 and 2.2 ± 0.7 Bq/m3, respectively. Calculated average equilibrium factor for radon and thoron was 0.45 and 0.04, respectively, in the present study. The annual inhalation dose that was calculated from the present observed concentrations varied from 1.1 to 4.1 mSv/year with an average value of 2.4 mSv/year, which is well within the reference level of 10mSv/year recommended by International Commission on Radiological Protection. The study shows that thoron is a significant contributor to the inhalation dose, which is about 29% of the total inhalation dose.

Download Full-text