Journal of Radiological Protection

Publications in this journal

• Article: Assessment of eye and body dose for interventional radiologists, cardiologists, and other interventional staff.

  C J Martin, J S Magee
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  ABSTRACT: A dose limit for the eye of 20 mSv, as proposed by the ICRP, could be exceeded by interventional clinicians. Data on eye dose levels for interventional radiologists and cardiologists provided by medical physicists from hospitals around the UK have been collated. The results indicate that most hospitals would require one or more interventional clinicians to be classified and several would have exceeded a 20 mSv limit. Dose data in the literature have been reviewed to derive factors that might be used to predict eye dose levels based on dose per procedure or kerma-area product workload. These could be used in prior risk assessments to establish monitoring practice. An alternative approach to personnel dose monitoring in radiology applications using a collar dosimeter worn outside the lead apron as the first dosimeter is proposed. The collar dosimeter would provide an assessment of eye dose in terms of Hp(3) and body dose in terms of Hp(10), which could be divided by ten to provide an assessment of effective dose. If Hp(3) exceeded 1 mSv per month, regular monitoring with a head dosimeter would be recommended, and if Hp(10) exceeded 2 mSv per month, then an under-apron dosimeter should also be worn.
  Journal of Radiological Protection 05/2013; 33(2):445-460.
• Article: A review of the behaviour of U-238 series radionuclides in soils and plants.

  N Mitchell, D Pérez-Sánchez, M C Thorne
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  ABSTRACT: The U-238 series of radionuclides is of relevance in a variety of environmental contexts ranging from the remediation of former uranium mining and milling facilities to the deep geological disposal of solid radioactive wastes. Herein, we review what is known concerning the behaviour of radionuclides from the U-238 decay chain in soils and plants. This review is intended to provide a single comprehensive source of information to anyone involved in undertaking environmental impact assessment studies relating to this decay chain. Conclusions are drawn relating to values and ranges of distribution coefficients appropriate to uranium, thorium, radium, lead and polonium in different soil types and under various environmental conditions. Similarly, conclusions are drawn relating to plant:soil concentration ratios for these elements for different plant and soil types, and consideration is given to the distribution of these elements within plants following both root uptake and foliar application.
  Journal of Radiological Protection 04/2013; 33(2):R17-R48.
• Article: An analysis of radiation dose reduction in paediatric interventional cardiology by altering frame rate and use of the anti-scatter grid.

  S L McFadden, C M Hughes, R B Mooney, Robert J Winder
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  ABSTRACT: The purpose of this work is to investigate removal of the anti-scatter grid and alteration of the frame rate in paediatric interventional cardiology (IC) and assess the impact on radiation dose and image quality. Phantom based experimental studies were performed in a dedicated cardiac catheterisation suite to investigate variations in radiation dose and image quality, with various changes in imaging parameters. Phantom based experimental studies employing these variations in technique identified that radiation dose reductions of 28%-49% can be made to the patient with minimal loss of image quality in smaller sized patients. At present, there is no standard technique for carrying out paediatric IC in the UK or Ireland, resulting in the potential for a wide variation in radiation dose. Dose reductions to patients can be achieved with slight alterations to the imaging equipment with minimal compromise to the image quality. These simple modifications can be easily implemented in clinical practice in IC centres.
  Journal of Radiological Protection 04/2013; 33(2):433-443.
• Article: A generic biokinetic model for noble gases with application to radon.

  Rich Leggett, James Marsh, Demetrio Gregoratto, Eric Blanchardon
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  ABSTRACT: To facilitate the estimation of radiation doses from intake of radionuclides, the International Commission on Radiological Protection (ICRP) publishes dose coefficients (dose per unit intake) based on reference biokinetic and dosimetric models. The ICRP generally has not provided biokinetic models or dose coefficients for intake of noble gases, but plans to provide such information for (222)Rn and other important radioisotopes of noble gases in a forthcoming series of reports on occupational intake of radionuclides (OIR). This paper proposes a generic biokinetic model framework for noble gases and develops parameter values for radon. The framework is tailored to applications in radiation protection and is consistent with a physiologically based biokinetic modelling scheme adopted for the OIR series. Parameter values for a noble gas are based largely on a blood flow model and physical laws governing transfer of a non-reactive and soluble gas between materials. Model predictions for radon are shown to be consistent with results of controlled studies of its biokinetics in human subjects.
  Journal of Radiological Protection 04/2013; 33(2):413-432.
• Article: Skin dose rate conversion factors after contamination with radiopharmaceuticals: influence of contamination area, epidermal thickness and percutaneous absorption.

  P Covens, D Berus, V Caveliers, L Struelens, F Vanhavere, D Verellen
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  ABSTRACT: Skin contamination with radiopharmaceuticals can occur during biomedical research and daily nuclear medicine practice as a result of accidental spills, after contact with bodily fluids of patients or by inattentively touching contaminated materials. Skin dose assessment should be carried out by repeated quantification to map the course of the contamination together with the use of appropriate skin dose rate conversion factors. Contamination is generally characterised by local spots on the palmar surface of the hand and complete decontamination is difficult as a result of percutaneous absorption. This specific issue requires special consideration as to the skin dose rate conversion factors as a measure for the absorbed dose rate to the basal layer of the epidermis. In this work we used Monte Carlo simulations to study the influence of the contamination area, the epidermal thickness and the percutaneous absorption on the absorbed skin dose rate conversion factors for a set of 39 medical radionuclides. The results show that the absorbed dose to the basal layer of the epidermis can differ by up to two orders of magnitude from the operational quantity Hp(0.07) when using an appropriate epidermal thickness in combination with the effect of percutaneous absorption.
  Journal of Radiological Protection 03/2013; 33(2):381-393.
• Article: Background in the context of land contaminated with naturally occurring radioactive material.

  D Read, G D Read, M C Thorne
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  ABSTRACT: The financial implications of choosing a particular threshold for clearance of radioactively contaminated land are substantial, particularly when one considers the volume of naturally occurring radioactive material (NORM) created each year by the production and combustion of fossil fuels and the exploitation of industrial minerals. Inevitably, a compromise needs to be reached between the level of environmental protection sought and the finite resources available for remediation. In the case of natural series radionuclides, any anthropogenic input is always superimposed on the inventory already present in the soil; this 'background' inventory is conventionally disregarded when assessing remediation targets. Unfortunately, the term is not well defined and the concept of 'background dose' is open to alternative interpretations. In this paper, we address the issue of natural background from a geochemical rather than from a solely radiological perspective, illustrating this with an example from the china clay industry. We propose a simple procedure for decision making based on activity concentrations of primordial radionuclides and their progeny. Subsequent calculations of dose need to take into account the mineralogical and chemical characteristics of the contamination, which in the case of NORM are invariably reflected in uranium series disequilibrium.
  Journal of Radiological Protection 03/2013; 33(2):367-380.
• Article: Methods used to estimate residential exposure to 50 Hz magnetic fields from overhead power lines in an epidemiological study in France.

  Jérôme Bessou, François Deschamps, Lionel Figueroa, Damien Cougnaud
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  ABSTRACT: An epidemiological study of paediatric cancers in relation with various environmental factors is currently being carried out in France. One of these factors is the proximity of children's residences to high voltage overhead lines (63-400 kV). This possible influence will be studied following three criteria, namely 'distance', 'distance-voltage' and 'calculated residential exposure' to extremely low frequency magnetic field (ELF-MF). This paper describes methods for generating and characterising these three criteria of increasing complexity and characterises the influence of the input data in terms of uncertainties in the exposure to ELF-MF assigned to subjects. The method developed for the 'calculated residential exposure' criterion is based on a limited number of configurations of overhead lines, selected to have a representative sample of the French high voltage (HV) network. The calculated exposure is then fitted to each subject and each neighbouring overhead line, taking into account the yearly mean current flowing in the line and the distance of the residence from the power line. All variability factors introduced by this simplified representation have been analysed, classified and quantified to give the best assessment and associated confidence interval of the residential ELF-MF exposure of the subjects. The overall 1σ uncertainty of the calculated residential exposure excluding geo-coding uncertainties is around 8% for subjects living close to power lines with a known current load and 17% for the others.
  Journal of Radiological Protection 03/2013; 33(2):349-365.
• Article: The selection of parameter values in studies of environmental radiological impacts.

  M C Thorne
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  ABSTRACT: The ERICA Tool has become widely accepted as an appropriate approach to assessing radiological impacts of environmental concentrations of radionuclides on wildlife. Although generally a comprehensive and state-of-the-art approach in this type of assessment, its treatment of uncertainty at Tier 2 is extremely limited and is not likely to be valid in the assessment contexts in which it will typically be employed. A more appropriate approach to the treatment of uncertainties is described. This leads to the conclusion that where data are lognormally distributed, it is appropriate to use the arithmetic mean of the distribution in reasonably cautious assessment calculations (as is done in the ERICA Tool) rather than to use the geometric mean, but that the uncertainty factor adopted should be larger than the range of 3 to 5 currently recommended at Tier 2 of the ERICA Tool.
  Journal of Radiological Protection 03/2013; 33(2):N1-N7.
• Article: Quality factor of secondary cosmic radiation at flight altitudes.

  O Burda, T Sato, F Wissmann
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  ABSTRACT: Dosimetry at aviation altitudes requires instruments that are able to measure the dose contributions of all field components. Tissue-equivalent proportional counters (TEPCs) are well suited for this task. From the measured lineal energy distribution, the absorbed dose and the dose equivalent can be obtained. The ratio of both quantities is named the quality factor, which is a measure of the biological effectiveness of the radiation field. The results of this work show that the mean quality factors obtained by using a TEPC are independent of the altitude, at least at altitudes between flight level (FL) 300 and FL 400, but show a significant dependence on the vertical cutoff rigidity. From a numerical simulation of the radiation field inside an aircraft, the influence of the aircraft structure can be shown.
  Journal of Radiological Protection 03/2013; 33(2):339-348.
• Article: Radiation risk of individual multifactorial diseases in offspring of the atomic-bomb survivors: a clinical health study.

  Yoshimi Tatsukawa, John B Cologne, Wan-Ling Hsu, Michiko Yamada, Waka Ohishi, Ayumi Hida, Kyoji Furukawa, Norio Takahashi, Nori Nakamura, Akihiko Suyama, Kotaro Ozasa, Masazumi Akahoshi, Saeko Fujiwara, Roy Shore
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  ABSTRACT: There is no convincing evidence regarding radiation-induced heritable risks of adult-onset multifactorial diseases in humans, although it is important from the standpoint of protection and management of populations exposed to radiation. The objective of the present study was to examine whether parental exposure to atomic-bomb (A-bomb) radiation led to an increased risk of common polygenic, multifactorial diseases-hypertension, hypercholesterolaemia, diabetes mellitus, angina pectoris, myocardial infarction or stroke-in the first-generation (F1) offspring of A-bomb survivors. A total of 11 951 F1 offspring of survivors in Hiroshima or Nagasaki, conceived after the bombing, underwent health examinations to assess disease prevalence. We found no evidence that paternal or maternal A-bomb radiation dose, or the sum of their doses, was associated with an increased risk of any multifactorial diseases in either male or female offspring. None of the 18 radiation dose-response slopes, adjusted for other risk factors for the diseases, was statistically significantly elevated. However, the study population is still in mid-life (mean age 48.6 years), and will express much of its multifactorial disease incidence in the future, so ongoing longitudinal follow-up will provide increasingly informative risk estimates regarding hereditary genetic effects for incidence of adult-onset multifactorial disease.
  Journal of Radiological Protection 03/2013; 33(2):281-293.
• Article: Artificial radionuclides in the Irish Sea from Sellafield: remobilisation revisited.

  John Hunt, Kinson Leonard, Linda Hughes
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  ABSTRACT: Measured concentrations of Cs-137, tritium, Tc-99, Pu-239+240 and Am-241 in representative materials from the Irish Sea were investigated with reference to continuing remobilisation from sediments. Long time series of monitoring data since the 1960s were employed.Cs-137 in sea water and fish shows peaks in concentrations normalised to discharge rate (NACs) from 1985 to 1989. This is consistent with the time needed for dispersion in sea water following the preceding reductions in discharges; continuing enhancements of NACs above pre-1970s levels follow, consistent with the effect of activity remobilised from sediment. It is estimated that about 300 TBq of Cs-137 was remobilised from the immediate tidal area around Sellafield from 1989 to 2009. The enhancements in concentrations continue to this day, with the effect of remobilisation at present being ∼6 TBq y-1, approximately doubling the effect of direct discharges. To provide an indication for the future, the rate of Cs-137 remobilisation is decreasing with a half-time of ∼6 years.The data for tritium and Tc-99 were examined in view of the interest in these radionuclides. The concentrations broadly reflect the levels of discharges and the need for dispersion. As expected, there is no evidence of sustained remobilisation of tritium, due to its mobility (or low Kd). The same lack of evidence was found to apply for Tc-99 despite known sorption of a small proportion of the discharged activity by Irish Sea sediments.Pu-239+240, by contrast, shows much evidence of the effect of remobilisation; concentrations in sea water near Sellafield have reduced much more slowly than discharges. At Southerness, ∼50 km away, there was no significant reduction in sea water concentrations from 1985 to 1996, and winkles showed an increase then decrease in concentrations over this period, consistent with a spreading of activity. This effect was replicated in mud at Garlieston, ∼70 km from Sellafield.For Am-241, the rate of grow-in from Pu-241 has dominated direct discharges since the late 1970s. Grow-in continues today in the Irish Sea at the rate of ∼8 TBq y-1, ∼200 times the rate of direct discharge. Winkles at Southerness show evidence of a spreading effect of Am-241, with an increase then decrease from 1985 to 1996. At Garlieston there was an increase in concentrations in mud from 1985 to 1997, and at Carlingford in Northern Ireland the concentration of Am-241 in mud appears to be increasing still. This effect of the spread of activity away from Sellafield may continue, at least in the near future.
  Journal of Radiological Protection 03/2013; 33(2):261-279.
• Article: Comparison of ionisation chamber and semiconductor detector devices for measurement of the dose-width product for panoramic dental units.

  S A Mitchell, C J Martin
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  ABSTRACT: Doses for panoramic dental radiography are assessed in terms of the dose-width product (DWP) or dose-area product, which gives a measure of the radiation through a whole exposure. The DWP can be measured using a pencil ionisation chamber (IC) similar to that used for computed tomography dose assessment. However, ICs are sensitive to radiation incident from all directions and so backscatter from the image receptor may increase the recorded dose. This study compares measurements performed using four options: a pencil IC mounted straight on the image receptor, the IC mounted with a steel plate to the rear to standardise scatter conditions, the IC mounted with a steel plate and lead collimators in front to minimise the effect of extra-focal radiation, and a Quart Dido employing a one square centimetre semiconductor detector (SD) designed for panoramic measurements. The results indicate that modification of the current method by incorporating a steel plate reduced the measurement dose by 7% on average, but the reduction was greater for units with semiconductor imaging plates. The measurements with the SD agree more closely with the IC with the steel plate to the rear. An IC with a backing plate to standardise scatter or a suitable SD is recommended for measurement on panoramic dental units.
  Journal of Radiological Protection 03/2013; 33(2):321-328.
• Article: Variation in radiographic protocols in paediatric interventional cardiology.

  S L McFadden, C M Hughes, R J Winder
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  ABSTRACT: The aim of this work is to determine current radiographic protocols in paediatric interventional cardiology (IC) in the UK and Ireland. To do this we investigated which imaging parameters/protocols are commonly used in IC in different hospitals, to identify if a standard technique is used and illustrate any variation in practice. A questionnaire was sent to all hospitals in the UK and Ireland which perform paediatric IC to obtain information on techniques used in each clinical department and on the range of clinical examinations performed. Ethical and research governance approval was sought from the Office for Research Ethics Committees Northern Ireland and the individual trusts. A response rate of 79% was achieved, and a wide variation in technique was found between hospitals. The main differences in technique involved variations in the use of an anti-scatter grid and the use of additional filtration to the radiation beam, frame rates for digital acquisition and pre-programmed projections/paediatric specific programming in the equipment. We conclude that there is no standard protocol for carrying out paediatric IC in the UK or Ireland. Each hospital carries out the IC procedure according to its own local protocols resulting in a wide variation in radiation dose.
  Journal of Radiological Protection 03/2013; 33(2):313-319.
• Article: Establishing a regional reference indoor radon level on the basis of radon survey data.

  I Yarmoshenko, A Onishchenko, M Zhukovsky
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  ABSTRACT: The establishment of national reference levels is a new requirement of the ICRP radiological protection system. For protection against indoor radon exposure measures based on a common national reference level tend to be less effective in regions where the probability of high indoor radon concentrations is relatively low in comparison with the national average. Therefore it makes sense to establish individual indoor radon reference levels for large sub-national regions as well as for urban agglomerations separately. Analysis of indoor radon surveys of the territory, taking into account the type of building, year of construction, building material, floor and other factors influencing indoor radon concentration, provides essential and important data for defining the reference level. For Ekaterinburg, Russia it is suggested to set the reference indoor radon concentration to a level of 70 Bq m-3 which corresponds to the 90th percentile of radon concentration in a representative group of buildings constructed in the period 1970-89, in which the lowest average indoor radon concentration was observed.
  Journal of Radiological Protection 03/2013; 33(2):329-338.
• Article: Open access publication-always a good thing?

  Richard Wakeford
  Journal of Radiological Protection 03/2013; 33(2):E9-E11.
• Article: Radionuclide Behaviour in the Natural Environment. Science, implications and lessons for the nuclear industry.

  G Smith
  Journal of Radiological Protection 03/2013; 33(1):257-8.
• Article: International Conference on Radiation Protection in Medicine: Setting the scene for the next decade.

  Robert H Corbett
  Journal of Radiological Protection 03/2013; 33(1):251-5.
• Article: Operational quantities adieu.

  Jun Ichiro Tada
  Journal of Radiological Protection 03/2013; 33(1):243-5.