[en] This paper presents the development of the Radiation Protection Programme of the Commission of the European Communities (CEC) over a period of almost 30 years. This research Programme represents the complement to the regulatory obligations of the CEC and supports about 30% of Community research in this area by means of cost-shared contracts. It also emphasizes co-operation within the Community and with other countries. One valuable instrument for promoting co-operation are groups, such as the European Late Effect Project Group (EULEP) whose working is explained in some detail. The Chernobyl accident presented a special challenge to research in the Community, and 10 specific research actions were initiated to assess its radiological consequences and to improve preparedness against nuclear accidents

[en] During the past 25 years, the reduction of occupational radiation doses at Ontario Hydro's nuclear generating stations has been the prime radiological safety priority. It is, however, an appropriate time to consider the need for further improvements in all aspects of the radiation protection program and how such improvements can be made. In other words, time for a renewal of our commitment to excellence in all aspects of radiological safety. This paper reviews the performance of Ontario Hydro over the last 25 years, highlights some of the important elements of the present radiation protection program, and describes some initiatives underway in the search for excellence

[en] Progress in the dosimetry of internally deposited radionuclides since World War II is reviewed. The Permissible Doses Conference held at Chalk River in 1949 defined the Standard Man and a biokinetic lung model, setting maximum permissible body burdens (MPBB), maximum permissible concentrations in air (MPC_A), and maximum permissible concentrations in water (MPC_W) for selected radionuclides. ICRP publications 2, 6 and 9 followed, focusing on setting MPCs. The use of the power function to describe radionuclide retention in the human body was discussed in Publication 2, but not recommended for use until Publication 6. Publication 2 defined the term effective energy. The integration time for internal exposures became 50 years, and the committed dose was defined. ICRP publications 10, 10A and 54 provided guidance for the calculation of doses from measured activity in vivo or in excreta. In 1979 ICRP publication 30 replaced publication 2 as the handbook for internal dosimetry. There will be a major revision of Publication 30 following the release of the new ICRP recommendations. A future publication will give doses to patients who have been administered radiopharmaceuticals. New computer tools will allow the development of more realistic metabolic models, and new dosimetric models that calculate doses to cells will be developed. The availability of high resolution solid state detectors has resulted in improvement in measurements of radionuclides in vivo, and some improvement in radiochemical analyses of excreta. However, poor sensitivity to actinides leaves something to be desired in vitro measurements and air monitoring

[en] Using a novel assay to assess the radiosensitivity of lymphoblastoid cell lines developed from individual donors, we have shown that the radioresponses of lymphoblastoid cell lines derived from ostensibly normal persons may cover a wide range. By comparison to lines of known radiosensitivity, a significant proportion of these normal lines may exhibit extreme hypersensitivity. Abnormal radiosensitivity in the in vitro assay appears attributable to deficient ability to accomplish effective DNA repair of ionizing radiation-induced DNA damage, and may serve to identify a subset of the population with greater-than-expected susceptibility to 'spontaneous', and possibly radiogenic, cancer. Identification of susceptible subpopulations may affect radiation protection practices in the future

[en] The modern nuclear medicine department utilizes a diverse group of radioisotopes and an equally diverse group of radiopharmaceuticals onto which they are attached. In the clinical setting it is often too easy to minimize the radiation protection procedures that should be followed when handling these drugs. This paper describes the current menu of radiopharmaceuticals in use, followed by the methods employed to give adequate radiation protection to the staff and the patients. Work patterns of personnel may be followed more closely now than in the past with almost instantaneous TLD monitoring available. The implications of these analyses are discussed

[en] Epidemiological studies of underground miners who have been exposed to elevated levels of radon daughters form the principal basis for assessing the risk of radon daughter exposure. The reliability of exposure estimates for these miners is of prime importance as actual measurements of radon daughter concentrations are infrequent or indeed missing totally during early years of mining. This paper reviews various sources of uncertainty in exposure estimation which include temporal and spatial variability of radon sources, changing mining methods and ventilation conditions, and uncertainties concerning the miners' work history. This paper also briefly describes two statistical approaches based on Bayesian methods, which allow the examination of the effect of uncertainty on the risk estimation process. These methods are illustrated by application to data taken from the literature. Based on these analyses, we conclude the most likely ranges for absolute and relative risk coefficients are from <5 to about 15 cases per 10⁶ person year WLM and from <0.5 to about 1.5% per WLM, respectively

[en] A major goal of this workshop/symposium was to bring together a group of experts from Canada and other countries to identify changing needs in radiation protection and potential goals for future research. The 33 papers presented cover the areas of regulation, research needs, and radiation protection during operation, accident conditions and medical procedures

[en] This poster presents a few examples of measurements at CRNL over the past 35 years of tritium in the environment. The concentration of bomb tritium in precipitation, river water and groundwater illustrates the movement of a global pulse of HTO through a river basin and into a groundwater system. The movement down the Ottawa River of a pulse of reactor tritium released recently is shown. The distribution of tritium in the annual growth rings of trees growing in a waste management area gives information on the past history of tritium in the area. Results from recent studies of the behaviour in the open environment of tritium released as HT are summarized. In each case estimates of the committed dose to exposed individuals are presented

[en] The author reviews each of the topics in ICRP Publication 26 against the equivalent recommendation given by the U.S. NCRP. He shows the status of these recommendations with regard to U.S. regulatory agency activities. The topics covered include annual occupational dose equivalent limit, dose equivalent limits for members of the public, protection of the embryo/fetus, quality factor for neutrons, application of the committed dose equivalent for planning, operations and control, radon remediation in homes, and risk estimates

[en] Understanding how our present dose limits have evolved may help us to make today's situation a watershed marking the introduction of more realistic methods of dose control, instead of another step in an ongoing saga of continuing reductions in the maximum permissible dose as knowledge of the associated risks increases - a saga which has been exploited to great advantage by various anti-nuclear groups. The widely held belief that there is a need for yet another reduction in the annual maximum permissible dose for occupationally exposed workers ignores the impact of the ALARA principle on the protection of workers. This paper is intended to demonstrate that such a change is unnecessary, and could well be counterproductive in terms of risk reduction