Radiation Protection Advice Research Articles

Operationalising an ensemble approach in the description of uncertainty in atmospheric dispersion modelling and an emergency response

Uncertainties were propagated through the chain of atmospheric dispersion and radiological assessment models based on an ensemble approach for a range of scenarios. It was apparent that the time taken to complete model runs, ranging from several hours to a few tens of hours, was not appropriate for an emergency response. Thus, for an operational method, there was a requirement to reduce the number of ensemble members and/or reduce model run time for a single ensemble member, such that a measure of uncertainty may be obtained within the timeframe of one hour, but without significant detriment to the model endpoints derived, the uncertainty estimated and the radiation protection advice inferred. This study proposes recommendations for operationalising an ensemble approach used in the description of uncertainty in atmospheric dispersion modelling and an emergency response.

Radiation Protection advice for hospital laboratory staff dealing with samples from diagnostic nuclear medicine patients

Radiation Protection advice for hospital laboratory staff dealing with samples from diagnostic nuclear medicine patients

Education and training for radiation protection experts working in the medical field

Introduction A course has been developed to provide the Knowledge, Skills and Attitudes (KSAs) for Radiation Protection Experts (RPEs) working in the medical field as part of the ENETRAP III ( http://enetrap3.sckcen.be/ ) EC funded project. Purpose The training is designed to ensure that successful course participants are able to provide competent radiation protection advice to employers, staff and members of the public in the medical field. Materials and methods The course contains a one week face-to-face module with lectures and workshops designed to ensure the KSA requirements are satisfied. Nine months prior to the face-to-face module, registered course participants are tasked to understand the Knowledge required of RPEs and provide portfolios evidencing the required Skills and Attitudes. Detailed guidance and formative assessments are provided using an IAEA e-learning platform ( http://clp4net-nkm.iaea.org/ ). Draft portfolios are sent to the faculty for comment and are then discussed in an open forum during the face-to-face module to provide opportunities for further improvements and reflection. Results Candidates that have successfully completed the course will have fulfilled the required content for the portfolios and passed both an oral assessment on their portfolio and a multiple choice examination at the end of the face-to-face module. Conclusion Successful course participants will be able to provide evidence to an authorised body to seek accreditation as an RPE in the medical field under Council Directive 2013/59/Euratom (BSS). Disclosure The authors declare that they have no conflict of interest.

The provision of emergency RPA/MPE services following a major disaster in an acute hospital setting.

Due to a catastrophic flooding event that occurred in July 2013, up to 40% of Letterkenny General Hospital’s services were taken out of clinical use. This included all of the Diagnostic Radiology Department's services excluding Mammography. The loss of the Radiology Department had a severe impact on the Hospital’s capability to function as an Acute Centre. The role of the Diagnostic Imaging section of the Department of Medical Physics and Bioengineering, Galway University Hospitals in the aftermath of the disaster shall be outlined in this talk. The main duties included the provision of radiation protection advice “on the fly” due to the dynamic nature of the reinstatement of services; the generation of new shielding designs as required and the commissioning of replacement CT and X-ray equipment. All duties had to be carried as expeditiously as possible to enable imaging services to resume in a timely manner. As a consequence of this event, it may be an opportune time to reflect on the disaster preparedness of all hospitals and perhaps learn some lessons for the future.

Radiation protection in dental X-ray surgeries – still rooms for improvement

To illustrate the authors' experience in the provision of radiation protection adviser (RPA)/medical physics expert (MPE) services and critical examination/radiation quality assurance (QA) testing, to demonstrate any continuing variability of the compliance of X-ray sets with existing guidance and of compliance of dental practices with existing legislation. Data was collected from a series of critical examination and routine three-yearly radiation QA tests on 915 intra-oral X-ray sets and 124 panoramic sets. Data are the result of direct measurements on the sets, made using a traceably calibrated Unfors Xi meter. The testing covered the measurement of peak kilovoltage (kVp); filtration; timer accuracy and consistency; X-ray beam size; and radiation output, measured as the entrance surface dose in milliGray (mGy) for intra-oral sets and dose-area product (DAP), measured in mGy.cm(2) for panoramic sets. Physical checks, including mechanical stability, were also included as part of the testing process. The Health and Safety Executive has expressed concern about the poor standards of compliance with the regulations during inspections at dental practices. Thirty-five percent of intra-oral sets exceeded the UK adult diagnostic reference level on at least one setting, as did 61% of those with child dose settings. There is a clear advantage of digital radiography and rectangular collimation in dose terms, with the mean dose from digital sets 59% that of film-based sets and a rectangular collimator 76% that of circular collimators. The data shows the unrealised potential for dose saving in many digital sets and also marked differences in dose between sets. Provision of radiation protection advice to over 150 general dental practitioners raised a number of issues on the design of surgeries with X-ray equipment and critical examination testing. There is also considerable variation in advice given on the need (or lack of need) for room shielding. Where no radiation protection adviser (RPA) or medical physics expert (MPE) appointment has been made, there is often a very low level of compliance with legislative requirements. The active involvement of an RPA/MPE and continuing education on radiation protection issues has the potential to reduce radiation doses significantly further in many dental practices.

Summary of: Radiation protection in dental X-ray surgeries – still rooms for improvement

To illustrate the authors' experience in the provision of radiation protection adviser (RPA)/medical physics expert (MPE) services and critical examination/radiation quality assurance (QA) testing, to demonstrate any continuing variability of the compliance of X-ray sets with existing guidance and of compliance of dental practices with existing legislation. Data was collected from a series of critical examination and routine three-yearly radiation QA tests on 915 intra-oral X-ray sets and 124 panoramic sets. Data are the result of direct measurements on the sets, made using a traceably calibrated Unfors Xi meter. The testing covered the measurement of peak kilovoltage (kVp); filtration; timer accuracy and consistency; X-ray beam size; and radiation output, measured as the entrance surface dose in milliGray (mGy) for intra-oral sets and dose-area product (DAP), measured in mGy.cm(2) for panoramic sets. Physical checks, including mechanical stability, were also included as part of the testing process. The Health and Safety Executive has expressed concern about the poor standards of compliance with the regulations during inspections at dental practices. Thirty-five percent of intra-oral sets exceeded the UK adult diagnostic reference level on at least one setting, as did 61% of those with child dose settings. There is a clear advantage of digital radiography and rectangular collimation in dose terms, with the mean dose from digital sets 59% that of film-based sets and a rectangular collimator 76% that of circular collimators. The data shows the unrealised potential for dose saving in many digital sets and also marked differences in dose between sets. Provision of radiation protection advice to over 150 general dental practitioners raised a number of issues on the design of surgeries with X-ray equipment and critical examination testing. There is also considerable variation in advice given on the need (or lack of need) for room shielding. Where no radiation protection adviser (RPA) or medical physics expert (MPE) appointment has been made, there is often a very low level of compliance with legislative requirements. The active involvement of an RPA/MPE and continuing education on radiation protection issues has the potential to reduce radiation doses significantly further in many dental practices.

Radiographic imaging for the dental team, 4th edition (2008)

Authors: Dale Miles, Margot Van Dis, Gail Williamson and Catherine Jensen Publisher: Saunders, Elsevier, Jordan Hill, Oxford, UK Price: £39.99 ISBN: 978-1-4160-6004-8 This textbook is now in its 4th edition and has been revised in several areas to keep it up to date in terms of new technology and current radiation protection advice. In addition, there is now supplementary online material for both students and instructors on the Evolve website. The book comprises 11 chapters, with the first being devoted to intraoral imaging. Here, the standard intraoral projections are described. Diagrams …

Applying the ionising radiation regulations to radon in the UK workplace

As a response to the identification of a health risk from workplace radon in the UK, the Ionising Radiations Regulations include the protection of workers from excessive levels of radon. Employers are required to make risk assessments, and the interpretation of the Health and Safety Executive is that the regulations apply to workplace premises in locations already designated as Radon Affected Areas for domestic purposes, with the difference that in workplaces, it is the maximum winter radon concentration rather than the annual average which is the parameter of interest. This paper discusses the rationale behind the current regulatory environment, outlines the role and duties of Accredited Radiation Protection Advisers and summarises the strategies necessary to conform to the regulations.

The radioactive autopsy: safe working practices

Autopsy cases involving individuals retaining radioactive substances are fortunately rare, but when they occur they can impose significant radiation safety and legal requirements. This review aims to improve the understanding of these issues so that appropriate precautions are implemented when necessary. This review describes the properties of ionizing radiations, natural and man-made sources of ionizing radiation and its use in healthcare. It identifies the most likely circumstances leading to radioactive substances being present during autopsy and sources of information, including radiation protection advice. It discusses precautions that may need to be implemented prior to, during and following autopsy. Despite the issue of appropriate information to patients and next of kin, it is inevitable that some cases will be identified only at autopsy and it is important that robust local procedures are maintained. Information must be communicated to assist safe management of the body and liaison between relevant professional groups may be needed to standardize methods of communication. Provided that appropriate precautions are implemented, determined through consultation with a qualified expert in radiation protection and by completion of risk assessment, the radioactive autopsy can be undertaken safely and in compliance with relevant legislative requirements.

Optimization of Equipment and Methodology for Whole Body Activity Retention Measurements in Children Undergoing Targeted Radionuclide Therapy

Accurate measurements of whole-body activity retention of patients during radionuclide therapy are essential for two reasons: First, they enable the correct radiation protection advice to be given and second, they permit the accurate determination of the absorbed whole-body dose delivered during therapy. This, in turn, allows treatment planning to be carried out for future radionuclide therapy on an individual patient basis, and also enables the investigation of the potential correlation of absorbed dose with treatment outcome in groups of patients. There are significant difficulties associated with taking whole-body retention measurements of children, especially when they are very young and/or unwell. It is essential to carry these out in a way that minimises disturbance to the child while still providing good quality data. To accomplish this, we have aimed to optimize the following aspects of the procedure: (i) the environment in which the measurements are performed; (ii) the equipment--which includes the recent installation of a specially designed whole-body activity monitoring system for these patients; and (iii) the methodology for calculating the absorbed dose. These improvements have allowed large numbers of accurate and reproducible whole-body measurements to be collected following patient administrations. This has enabled the identification of more phases of radionuclide excretion during therapy than had previously been observed. These data have been used for radiation protection advice and treatment planning. Two (2) patients were given multiple radionuclide treatments and we were able to compare the whole-body doses delivered.

Potential third‐party radiation exposure from outpatients treated with for hyperthyroidism

Thirty-three hyperthyroid patients treated with radioiodine (mean administered activity 414 MBq, range 163-555) were studied to determine if pretreatment dosimetry could be used to give radiation protection advice that could assure compliance with the effective dose constraints suggested by the European Commission. Effective doses to travelers, co-workers, and sleeping partners were estimated by integrating the effective dose rate-versus-time curve obtained by fitting the dose rates measured several times after radioiodine administration to a biexponential function. The mean estimated effective doses to travelers, co-workers, and sleeping partners were 0.11 mSv (0.05-0.24), 0.24 mSv (0.07-0.52), and 1.8 mSv (0.6-4.1), respectively. The best correlation was found between effective dose (D) in mSv and maximum activity (AUmax) in MBq taken up in the thyroid: Dtraveler=0.0005 * (AUmax) +0.04 (r=0.88,p< 0.01); Dco-worker=0.0013 * (A Umax) +0.03 (r=0.89,p < 0.01); Dsleeping partners=0.0105 * (AUmax)+0.16 (r=0.93,p < 0.01). Private/public transports are always allowed. For the co-workers the effective dose constraint of 0.3 mSv is met without restrictions and with 3 days off work if AUmax is lower or higher than 185 MBq, respectively. For the sleeping partners the effective dose constraint of 3 mSv is met without restriction and with 4 nights separate sleeping arrangements if AUmax is lower or higher than 185 MBq, respectively. The potential for contamination by the patients was determined from perspiration samples taken from the patient's hands, forehead, and neck and in saliva at 4, 24, and 48 h after radioiodine treatment. The mean highest 131I activity levels for hands, forehead, neck, and saliva were 4.1 Bq/cm2, 1.9 Bq/cm2, 0.9 Bq/cm2, and 796 kBq/g, respectively. The results indicate that there is minimal risk of contamination from these patients.

Guidance from empirical risk assessment for patients receiving radioiodine therapy

Empirical measurements form the foundation for generic and individual risk assessments in order to give applicable and accurate radiation protection advice to radioiodine patients on discharge from hospital. The aim of this work is to produce a set of guidance applicable to as wide a range of radioiodine therapy patients as possible, and is therefore specific to the therapy modality and includes considerations of the patient's life patterns. Results present empirical dose rate measurements indicating the extent of the effective half-life variation of 131I as a function of therapy modality (thyroid ablation, mIBG, lipiodol) and the consequential effect on the necessary precautionary restrictions given to patients. Precautionary periods going beyond guidelines are suggested. Calculational methods have also been employed to assess suitable periods of restriction regarding the patient's return to work including individual patterns such as working hours and distances from colleagues. These methods have also been used to determine advice regarding prolonged journeys. Such guidance is growing more necessary in nuclear medicine. Thus, the work presented allows dedicated guidance to be given to patients on discharge that minimizes disruption, thereby improving the patient's quality of life in the weeks following therapy.

The Ionising Radiations Advisory Committee Open Meeting 10 October 2001

The Ionising Radiations Advisory Committee (IRAC) held itsfirst open meeting on 10 October 2001 in response to a request from the Health and Safety Commission (HSC) that all its advisory committees should follow the Commission's example and hold such meetings. Some of the other advisory committees have already held open meetings and others are planning to do so shortly.The aim of the meeting was to enable members of the public to meet IRAC members and to find out more about the Committee - how it worked and the type of issues it dealt with.The first two sessions were devoted to short presentations describing IRAC's work and influences, now and in the future, on radiation protection generally. The third session was a discussion forum. The agenda for the meeting and the presentations are posted on the web at: www.hse.gov.uk/foi/iracopen.htm.Each session of presentations was followed by questions of clarification and the third session of the meeting comprised an open forum. Many of the questions raised were not directly relevant to IRAC but, nevertheless, members provided brief responses and referred questions on to others as appropriate. One question had been notified in advance, asking whether members of IRAC agreed that it is now (regrettably) reasonably foreseeable that a loss of containment of radioactive material may occur at a nuclear facility as a result of impact by an aeroplane or by other hostile acts, and that this should be made clear in published guidance on REPPIR. This question was not within IRAC's remit. The Chairman of the Nuclear Safety Advisory Committee offered to take the question to the Committee's next meeting.Issues discussed included:Concerns that exposure to ionising radiation at low levels is more dangerous than is currently reflected in risk estimates. The European Parliament has adopted a resolution calling on the main international bodies, including the International Commission on Radiological Protection (ICRP), the International Atomic Energy Agency (IAEA), the United Nations Scientific Committee on Effects of Atomic Radiation (UNSCEAR), the World Health Organisation (WHO) and the European Commission, to re-examine the risk model.How to communicate relative risk to the public, to put exposure to radiation in context.Whether there are different thresholds for different types of exposure, which was agreed to be a complicated issue.The new use of x-ray units at docks to screen vehicles for illegal immigrants. This had been the subject of a Home Office consultation exercise, see: www.ind.homeoffice.gov.uk.Evaluation of the impact of radiation protection legislation, which provisions had had greatest effect and how areas still needing attention, such as industrial radiography, were being tackled.The perceived complexity of the system for obtaining HSE recognition for RPA bodies. The comments received during the review of the HSE Statement on radiation protection advisers, and HSE's proposed response, would be discussed by an advisory focus group - all the papers for this group are on the Society for Radiological Protection's web-site: www.srp-uk.org.The need for a database showing where to apply for authorisations in other European Union countries.

A generic approach to risk assessment for the Ionising Radiations Regulations 1999.

The Ionising Radiations Regulations 1999 (IRR99) require that an explicit risk assessment be carried out to control properly the risks associated with the use of ionising radiation. Prior to IRR99, risk was controlled implicitly via mechanisms such as Local Rules and staff monitoring, which were initiated by the Radiation Protection Adviser using professional judgement. To enable a consistent approach across our Trust's radiation users, a generic model of risk assessment was employed. This had been developed previously by the Trust in response to a national initiative within the NHS to manage risk. The methodology involves the generation, by a multidisciplinary staff brain-storming session, of a complete list of all possible risks. This is followed by a risk stratification process based upon severity of consequence and frequency of risk. Auditable controls are then applied and quantifiable outcome measures are monitored for continued compliance. Template risk assessments are presented to aid others in this process. It is estimated that even in a large teaching hospital with a full complement of medical radiation applications, the time resource necessary for this approach is of the order of a few days.

Radiation exposure of the families of outpatients treated with radioiodine (iodine-131) for hyperthyroidism.

Patients who receive radioiodine (iodine-131) treatment for hyperthyroidism (195-800 MBq) emit radiation and represent a potential hazard to other individuals. Critical groups amongst the public are fellow travellers on the patient's journey home from hospital and members of the patient's family, particularly young children. The dose which members of the public are allowed to receive as a result of a patient's treatment has been reduced in Europe following recently revised recommendations from ICRP. The annual public dose limit is 1 mSv, though adult members of the patient's family are allowed to receive higher doses, with the proviso that a limit of 5 mSv should not be exceeded over 5 years. Unless the doses received during out-patient administration of radioiodine can be demonstrated to comply with these new limits, hospitalisation of patients will be necessary. The radiation doses received by family members (35 adults and 87 children) of patients treated with radioiodine at five UK hospitals were measured using thermoluminescent dosimeters mounted in wrist bands. Families were given advice (according to current practice) from their treatment centre about limiting close contact with the patient for a period of time after treatment. Doses measured over 3-6 weeks were adjusted to give an estimate of values which might have been expected if the dosimeters had been worn indefinitely. Thirty-five passengers accompanying patients home after treatment also recorded the dose received during the journey using electronic (digital) personal dosimeters. For the "adjusted" doses to infinity, 97% of adults complied with a 5-mSv dose limit (range:0.2-5.8 mSv) and 89% of children with a 1-mSv limit (range: 0.2-7.2 mSv). However 6 of 17 children aged 3 years or less had an adjusted dose which exceeded this 1 mSv limit. The dose received by adults during travel was small in comparison with the total dose received. The median travel dose was 0.03 mSv for 1 h travel (range: 2 microSv-0.52 mSv for 1 h of travel time). These data suggest that hyperthyroid patients can continue to be treated with radioiodine on an out-patient basis, if given appropriate radiation protection advice. However, particular consideration needs to be given to children aged 3 years or younger. Admission to hospital is not warranted on radiation protection grounds.

Development of revised Ionising Radiations Regulations

New standards in ICRP60 led to the revision of the 1980 European Basic Safety Standards Directive, which in turn has created the necessity to revise the Ionising Radiations Regulations 1985. Proposals from the Health and Safety Commission (HSC) for revised regulations are currently out for public consultation in a formal Consultative Document. This article describes some of the background to the proposals in the Consultative Document, key influences on the revision process and the methods used to develop the proposals so that they are broadly acceptable to stakeholders. Some of the changes proposed are structural in nature, such as integration of the provisions of the Outside Workers Regulations. Others are of a legal nature and include: new proposals for justification, prior authorisation and risk assessment; two options for the dose limitation system; and significant changes to the means of recognising the competence of the Radiation Protection Adviser. Following the current public consultation, final proposals need to be drawn up, approved by HSC and cleared through the European Commission under procedures required by the Euratom Treaty. If all goes according to plan, the revised regulations should be on the Statute Book about the middle of next year, with most provisions coming into force on 1 January 2000.

Exposures at work to ionising radiation due to the use of naturally occurring radioactive materials in industrial processes

In its role as specialist radiation protection adviser to industries in the United Kingdom, the National Radiological Protection Board has had extensive involvement with industrial users of raw materials with low activity concentrations of naturally occurring radionuclides. The magnitude of the exposure to ionising radiation in these establishments has been investigated. This paper reviews the pathways of exposure and gives estimates of worker dose in the light of revised dose coefficients. It concludes that doses are lower than previously reported and are generally in the order of a few millisieverts per year or less.

Optimization of patient radiation dose through development of specifications for purchase of X-ray equipment.

X-ray equipment characteristics and performance have an important influence on radiation doses to patients. In order that these factors can be taken into consideration when X-ray equipment is purchased, dose related requirements need to be included in specifications and additional dose information requested from manufacturers. Dose factors include techniques that directly reduce exposure; use of low attenuation materials; provision of flexibility in choice of exposure parameters; and availability of data for dose assessment. If a standard format can be developed, this should enable manufacturers to supply this information. Specifications for different types of X-ray equipment and lists of dose information to be requested from manufacturers have been prepared by the Scottish Radiation Protection Advisers' Group for use in hospitals throughout Scotland. It is hoped that this will allow patient dose to be taken into account when X-ray equipment is purchased.

BOOK REVIEWS

BOOK REVIEWS Get access Contract Research Report No. 59/1993. By C. M. H. DRISCOLL. National Radiological Protection Board. HSE Books, London, 1993. (ISBN 07176 0407 1.) iii + 26 pp. Price £20.00. D. HUGHES D. HUGHES University Radiation Protection Adviser and Head of the Radiation Protection Service, University of LeedsLeeds LS2 9JT, U.K. Search for other works by this author on: Oxford Academic PubMed Google Scholar The Annals of Occupational Hygiene, Volume 38, Issue 2, April 1994, Pages 236–237, https://doi.org/10.1093/annhyg/38.2.236 Published: 01 April 1994

BOOK REVIEWS

BOOK REVIEWS Get access Publications of the International Commission on Radiological Protection. No. 62, Radiological Protection in Biomedical Research. Ann. ICRP22, No. 3, 1991 (ISBN 0 08 042203 9); No. 63, Principles for Intervention for Protection of the Public in a Radiological Emergency. Ann. ICRP22, No.4, 1991 (ISBN 0 08 042204 7); and No. 64, Protection from Potential Exposure: A Conceptual Framework. Ann. ICRP23, No. 1, 1993 (ISBN 0 08 042205 5). D. HUGHES D. HUGHES University Radiation Protection Adviser and Head of the Radiation Protection Service, University of LeedsLeeds LS2 9JT, U.K. Search for other works by this author on: Oxford Academic PubMed Google Scholar The Annals of Occupational Hygiene, Volume 38, Issue 2, April 1994, Pages 235–236, https://doi.org/10.1093/annhyg/38.2.235 Published: 01 April 1994