Ionizing radiation regulations and the dental practitioner: 1. The nature of ionizing radiation and its use in dentistry

Legislation governing the use of ionizing radiation in the workplace and in medical treatment first became law in 1985 and 1988, being superseded by the Ionizing Radiations Regulations 1999 (IRR99) and the Ionizing Radiation (Medical Exposure) Regulations 2000, (IR(ME)R 2000), respectively. This legislation ensures a safe environment in which to work and receive treatment and requires that those involved in the radiographic process must be appropriately trained for the type of radiographic practice they perform. A list of the topics required is detailed in Schedule 2 of IR(ME)R 2000 and is paraphrased in Table 1, with the extent and amount of knowledge required depending on the type of radiographic practice undertaken.

CLINICAL RELEVANCE

Virtually all dental practitioners undertake radiography as part of their clinical practice. Legislation requires that users of radiation, including dentists and members of the dental team, understand the basic principles of radiation physics, hazards and protection, and are able to undertake dental radiography safely with the production of high quality, diagnostic images.

An unrecognized occupancy change in the vicinity of a medical linear accelerator

It seems obvious that if a significant increase in occupancy occurs in the immediate vicinity of any radiation room a reexamination of the adequacy of the shielding should be performed. We discuss a facility where a new building was constructed in close proximity to an existing medical linear accelerator and no consideration was given to the consequences of that construction as it might impact the doses received by occupants of the new structure. For more than 10 years some areas in that building may have received exposures greater than the allowed regulatory limit. The situation reported here should serve as a cautionary tale for those who have the responsibility for providing radiation protection at any site where new construction or increases in occupancy might require a reanalysis of the previously designed radiation shielding.

[The main directions of improving the system of state accounting and control of radioactive substances and radioactive waste products]

This paper describes a modification of the basic directions of state accounting and control of radioactive substances and radioactive waste products, whose implementation will significantly improve the efficiency of its operation at the regional level. Selected areas are designed to improve accounting and control system for the submission of the enterprises established by the reporting forms, the quality of the information contained in them, as well as structures of information and process for collecting, analyzing and data processing concerning radioactive substances and waste products.

[Contemporary legislation and importance of psychophysiologic examination in system of medical support for workers engaged into production with radiation and nuclear danger]

In accordance with contemporary legislation, the article covers materials on specification and approbation of concept model for psychophysiologic examination in medical establishments during medical examination of workers engaged into production with raidation and nuclear danger. The authors defined methodology, examination methods and designed an order of psychophysiologic examination. The psychophysiologic examination and purpose-oriented rehabilitation appeared efficient.

Radar commentary: Use of linear no-threshold hypothesis in radiation protection regulation in the United States

Radiation protection recommendations advanced by the International Commission on Radiological Protection and National Council on Radiation Protection and Measurements, and many times adopted into regulations by the United States Nuclear Regulatory Commission, need to be based on scientifically justified assumptions and conclusions. The linear no-threshold model assigns risk to every radiation exposure above zero dose and is the current basis for setting radiation protection standards worldwide. This hypothesis is vigorously challenged by many individuals but just as vigorously defended in spite of the uncertainties surrounding health effects at low dose levels. It is clear that at radiation doses below 100 mSv, the effects, if any, are so low as to be unobservable and perhaps, therefore, unknowable. However, the linear no-threshold hypothesis is used routinely to formulate regulatory dose limits for workers and the general public and to derive stochastic radiogenic risk estimates at low doses. This note will show that while the linear no-threshold hypothesis may play a legitimate role in setting radiation protection standards and operating policies, such as establishing dose limits or as part of an operational "as low as is reasonably achievable" (ALARA) policy, it is inappropriate for use in estimating possible cancer risks associated with low-level radiation exposures. It will also demonstrate that the raising, not lowering, of current regulatory dose limits is more solidly supported by the actual observed data on radiation dose and effects. The authors submit that the misuse of the linear no-threshold model for predicting radiation effects in exposed individuals and populations should be discontinued.

Accident at the Fukushima Dai-ichi nuclear power stations of TEPCO--outline & lessons learned

The severe accident that broke out at Fukushima Dai-ichi nuclear power stations on March 11, 2011, caused seemingly infinite damage to the daily life of residents. Serious and wide-spread contamination of the environment occurred due to radioactive materials discharged from nuclear power stations (NPSs). At the same time, many issues were highlighted concerning countermeasures to severe nuclear accidents. The accident is outlined, and lessons learned are extracted with respect to the safety of NPSs, as well as radiation protection of residents under the emergency involving the accident. The materials of the current paper are those released by governmental agencies, academic societies, interim reports of committees under the government, and others.

[Problems of safety regulation under radioactive waste management in Russia]

Analysis of the requirements of Federal Law N 190 "About radioactive waste management and incorporation of changes into some legislative acts of the Russian Federation", as well as normative-legislative documents actual and planned to be published related to provision of radiation protection of the workers and the public have been done. Problems of safety regulation raised due to different approaches of Rospotrebnadzor, FMBA of Russia, Rostekhnadzor and Minprirody with respect to classification and categorization of the radioactive wastes, disposal, exemption from regulatory control, etc. have been discussed in the paper. Proposals regarding improvement of the system of safety regulation under radioactive waste management and of cooperation of various regulatory bodies have been formulated.

Crafting interactivity for stakeholder engagement: transforming assumptions about communication in science and policy

The International Radiation Protection Association's guiding principles for stakeholder engagement focus on fostering, facilitating, and enabling interaction among stakeholders that is inclusive and fosters competent decision making. Implicit in these standards is a call to cultivate knowledge and competence in designing communication for stakeholder engagement among radiation protection professionals. Communication as design is an approach to risk communication in science and policy that differs from, yet complements, the more well-known communication practices of informing and persuading. Design focuses on the recurring practical problem faced by professionals in making communication possible among stakeholders where it has otherwise been difficult, impossible, or even unimagined. The knowledge and competence associated with design involves principles for crafting interactivity across a variety of mediated and non-mediated encounters among stakeholders. Risk communication can be improved by cultivating expertise in scalable communication design that embraces the demands of involvement without abandoning the need for competence in science and policy communication.

Using the IRPA Guiding Principles on Stakeholder Engagement: putting theory into practice

The International Radiation Protection Association (IRPA) published their Guiding Principles for Radiation Protection Professionals on Stakeholder Engagement in February 2009. The publication of this document is the culmination of four years of work by the Spanish Society for Radiological Protection, the French Society of Radioprotection, the United Kingdom Society of Radiological Protection, and the IRPA organization, with full participation by the Italian Associate Society and the Nuclear Energy Agency's Committee on Radiation Protection and Public Health. The Guiding Principles provide field-tested and sound counsel to the radiation protection profession to aid it in successfully engaging with stakeholders in decision-making processes that result in mutually agreeable and sustainable decisions. Stakeholders in the radiation protection decision making process are now being recognized as a spectrum of individuals and organizations specific to the situation. It is also important to note that stakeholder engagement is not needed or advised in all decision making situations, although it has been shown to be a tool of first choice in dealing with such topics as intervention and chronic exposure situations, as well as situations that have reached an impasse using traditional approaches to decision-making. To enhance the contribution of the radiation protection profession, it is important for radiation protection professionals and their national professional societies to embrace and implement the IRPA Guiding Principles in a sustainable way by making them a cornerstone of their operations and an integral part of day-to-day activities.

Lauriston S. Taylor lecture: Radiation Protection and Public Policy in an Uncertain World

Ionizing radiation is a known, well-documented, and reasonably well-quantified human cancer risk factor based on a remarkably consistent body of dose-response information from epidemiological studies of exposed populations supported by experimental studies using animal and cellular models. This fact is largely ascribable to the relative ease, compared to other carcinogens, of estimating radiation dose to organs and local tissues. Statistical models for radiation-related cancer risk are increasingly relevant to both radiation protection policy and the adjudication of compensation claims for cancers diagnosed following occupational and environmental exposures to ionizing radiation, as discussed in a number of expert committee reports of national and international organizations concerned with radiation-related risks. These and other publications increasingly emphasize the relevance of well-quantified uncertainties in radiation-related risk projections, including upper and lower confidence or uncertainty bounds, for radiation protection. Finally, the wealth of detailed information provided by such quantitative uncertainty analysis approaches is highly relevant to radiation protection, which might be viewed as a political process that involves a diverse group of stakeholders who, individually, may be primarily concerned with avoiding possible radiation-related risks or with avoiding possibly unnecessary costs of risk reduction or unnecessary denial of benefits that require some radiation exposure, or with balancing both considerations to some degree.

Communication of radiation benefits and risks in decision making: some lessons learned

This paper is focused on summarizing the "lessons learned" from discussions at the 2010 NCRP Annual Meeting on effective communications on the subject of radiation benefits and risks in public exposures. Five main lessons learned are discussed in regard to effective methods of public communication: the use of new social media communication tools such as Facebook and Twitter, emergency situations that require rapid societal and personal messaging, medical radiological procedures where benefits must be described in comparison to long-term health risks of radiation exposures, and information that should be provided to stakeholders in situations such as environmental radionuclide contamination to which members of the public may be exposed. It is concluded that effective communications in which radiation benefits are contrasted with health risks of exposure are an important aspect of making and implementing decisions on employing radiation health protection procedures.

Level of compliance with the radiation protection regulation--a survey among Norwegian hospitals and X-ray institutes

To identify the level of compliance with the new radiation protection regulation among Norwegian health care enterprises (HCEs). Totally, 41 HCEs were authorised to use advanced X-ray equipment for medical purposes during 2005-07. Follow-up inspections with 14 HCEs were carried out during 2007-09. Main topics for the inspections were those requirements identified as most challenging to implement in the authorisation process. Totally, 192 non-conformities with the regulation were revealed during the authorisation process. The inspections revealed that 93 % of the inspected HCEs had non-conformities with the regulation. Most common non-conformities dealt with skills in radiation protection, establishment of local diagnostic reference levels, access to medical physicists and performance of quality control of X-ray equipment. Inspections are an effective tool for implementation of regulation the requirements at the HCEs, thus improving radiation protection awareness.

Regulation of radiation protection of the patient: how and how much, the current Belgian situation

Regulation of radiation protection has always been a cornerstone to protect the patient when exposed to ionising radiation. However, large differences exist between the implementation of international approved recommendations. Even when a well-established supra-national legislative format exists, further translation is always adapted to a suitable level of the medical sector in a country. Actual trends are given for the Belgian situation, where the legislation on radiation protection in medicine is currently under revision.

The radioprotection management of a PET department with a cyclotron and radiopharmacy laboratory, in accordance with Italian legislation

The possibility of setting up a positron emission tomography (PET) facility with a cyclotron and radiopharmaceutical laboratory in situ, at a feasible price and in a very restricted space, has led to a steady increase both in the use of the PET technique in diagnostic clinical routine imaging and in the number of cyclotrons for drug production. Owing to the progress made in the PET procedures, it is now possible to have not only a highly innovative system of diagnostic examination, with a remarkable improvement in the diagnostic quality and patient care, but also a considerable increase in the number of daily examinations. In this paper, the authors show how the acquired know-how, with respect to radioprotection, has applied to the planning, running and management of the PET/CT unit, installed in the Imaging Diagnostic Department of the Policlinico Tor Vergata (PTV), at Tor Vergata University, Rome.

FDA-sunlamp recommended Maximum Timer Interval And Exposure Schedule: consensus ISO/CIE dose equivalence

The authors compared calculations of sunlamp maximum exposure times following current USFDA Guidance Policy on the Maximum Timer Interval and Exposure Schedule, with USFDA/CDRH proposals revising these to equivalent erythemal exposures of ISO/CIE Standard Erythema Dose (SED). In 2003, [USFDA/CDRH proposed replacing their unique CDRH/Lytle] erythema action spectrum with the ISO/CIE erythema action spectrum and revising the sunlamp maximum exposure timer to 600 J m(-2) ISO/CIE effective dose, presented as being biologically equivalent. Preliminary analysis failed to confirm said equivalence, indicating instead ∼38% increased exposure when applying these proposed revisions. To confirm and refine this finding, a collaboration of tanning bed and UV lamp manufacturers compiled 89 UV spectra representing a broad sampling of U.S. indoor tanning equipment. USFDA maximum recommended exposure time (Te) per current sunlamp guidance and CIE erythemal effectiveness per ISO/CIE standard were calculated. The CIE effective dose delivered per Te averaged 456 J(CIE) m(-2) (SD = 0.17) or ∼4.5 SED. The authors found that CDRH's proposed 600 J(CIE) m(-2) recommended maximum sunlamp exposure exceeds current Te erythemal dose by ∼33%. The current USFDA 0.75 MED initial exposure was ∼0.9 SED, consistent with 1.0 SED initial dose in existing international sunlamp standards. As no sunlamps analyzed exceeded 5 SED, a revised maximum exposure of 500 J(CIE) m(-2) (∼80% of CDRH's proposal) should be compatible with existing tanning equipment. A tanning acclimatization schedule is proposed beginning at 1 SED thrice-weekly, increasing uniformly stepwise over 4 wk to a 5 SED maximum exposure in conjunction with a tan maintenance schedule of twice-weekly 5 SED sessions, as biologically equivalent to current USFDA sunlamp policy.

Radiation protection in pediatric interventional cardiology: An IAEA PILOT program in Latin America

The aim of this work is to present a methodology and some initial results for a pilot program on radiation protection (RP) in pediatric interventional cardiology under the auspices of the International Atomic Energy Agency. The starting point of the program was a workshop involving several pediatric cardiologists leading this specialty in 11 Latin American countries. The workshop included a pilot RP training course and additional sessions during which the objectives of the program and the methodology to collect and process data on patient and staff radiation doses were discussed. Special attention was dedicated to agree on a common quality control (QC) protocol for the x-ray and imaging systems used in the different catheterization laboratories. The preliminary data showed that only 64% of the cardiologists used their personal dosimeters regularly and that only 36% were aware of their personal dose values. The data on pediatric interventional activity were collected from 10 centers from nine different countries. A total of 2,429 procedures (50% diagnostic and 50% therapeutic) were carried out during 2009 in these centers. Patient dose data were available in only a few centers and were not analyzed on a regular basis in any of the catheterization laboratories involved. Plans were developed for a basic QC protocol of the x-ray systems and construction of a Latin American database on pediatric cardiology with patient and staff dose values with the idea in mind of obtaining distributions of these dose values before promoting several optimization strategies.

[Diagnostic imaging in cases of suspected child abuse--focus craniocerebral trauma divergent guidelines and resulting problems]

For the clinical diagnosis of non-accidental craniocerebral trauma in children there are different recommendations and guidelines, which are not completely consistent. Depending on the examiner, the focus may be on therapeutic relevance, minimization of the exposure to radiation or potential conclusions as to the course of events. Under certain circumstances it may be difficult for the responsible institution to deal with all three perspectives, as is shown by the presented case. From the authors' point of view it would be desirable to work out a common guideline taking into account paediatric radiological and medicolegal aspects.

Independent regulatory examination of radiation situation in the areas of spent nuclear fuel and radioactive wastes storage in the Russian far east

This paper describes the findings of the radiation situation analysis on-site near Sysoeva and Razbojnik Bays. The results of radiation monitoring performed by radiological laboratory of DalRAO and studies performed by the experts from the Burnasyan Federal Medical Biophysical Centre have been used in the course of analysis. On the industrial sites, gamma dose rate reaches 60 µSv h(-1), and the specific activities of man-made radionuclides in soil reach 2.5 × 10(4) Bq kg(-1) for (137)Cs, 7.6 × 10(3) Bq kg(-1) for (90)Sr and 2.0 × 10(3) Bq kg(-1) for (60)Co. Beyond the industrial sites, there are three local parts of the area on the coast and in the off-shore water area, contaminated with man-made radionuclides. Gamma dose rate reaches 8 µSv h(-1). The radionuclide contents in soil at this area reach 3.6 × 10(3), 2.8 × 10(3) and 19 Bq kg(-1) for (137)Сs, (90)Sr and (60)Со, respectively. At the remaining part of the area nearby Sysoeva Bay, the radiation situation complies with natural background.

[Regulation and duties for the radiation protection physician in medical surveillance of exposed to AOR]

This work illustrates the duties of the physician responsible of medical surveillance of workers exposed to artificial optical radiation (AOR), (Chapter V of Title VIII of D.lgs 81/2008, in force in Italy since 2010-Directive 2006/25/EC). Emphasizes the lack of regulation regarding exposure to solar radiation, however, suggests guidelines for the management of the medical surveillance of workers exposed to this risk. With regard to the duties of the physician, it is emphasized its role in the process of risk assessment. It also presented an approach to health checks aimed, under conditions of controlled risk, to the identification, among exposed, of the workers defined by the low as "at particular risk," on which operate with periodic medical control for the determination of fitness.

An overview of Ireland's National Radon Policy

In Ireland radon is a significant public health issue and is linked to 150-200 lung cancer deaths each year. Irish National Radon Policy aims to reduce individual risk by identifying and remediating buildings with high radon concentrations and also to reduce collective dose through radon prevention as required by revised building regulations. Achievements to date are significant and include the completion of the National Radon Survey, the testing of every school in Ireland, the on-going testing of social housing, collaboration between the public health and radiation protection authorities and the inclusion of radon in inspections of workplaces. However, this work now needs to be drawn together centrally to comprehensively address the radon problem. The RPII and the relevant central governing department, the Department of Environment, Heritage and Local Government are currently working to constitute a group of key experts from relevant public authorities to drive the development of a National Radon Control Strategy.