Radiological Detriment Research Articles

Радиологический ущерб: применение новой метрики риска Международной комиссии по радиологической защите

Currently, the International Commission on Radiological Protection (ICRP) is discussing the practical application of a new radiation risk metric, called radiological detriment (RD). The concept of RD was first introduced by the ICRP in Publication 22 more than 30 years ago. At the same time, it was important to assess both the risk of radiation induced cancer development and the quality of the future life of patients. Of great interest is the comparison of RD and the lifetime attributable risk (LAR), which is currently widely used in assessing radiation safety. In this study, а comparison of RD and LAR estimates was made for the population living near the fabrication/refabrication module (FRM) of the Pilot Demonstration Energy Complex, that is currently under construction in the city of Seversk, Tomsk region. It is shown that during normal operation of the FRM and after a beyond design basis accident, the RD value is approximately 20% higher than the LAR value. Thus, the LAR value of mortality for residents of the city of Seversk during normal operation of the FRM is 40 times lower than the negligible risk level according to NRB-99/2009 (10Е-6 year-1), while the RD value remains 32 times lower than the negligible level. The simultaneous estimation of the RD and LAR values performed for the first time shows the possibility of their effective use for assessing the level of radiological protection of the population and workers.

Радиологическая защита населения в условиях нормальной эксплуатации Опытного демонстрационного энергокомплекса (ОДЭК) и масштабирование на Промышленный энергокомплекс (ПЭК) в рамках Проектного направления «Прорыв»

The paper presents results of research on radiological protection of the public during normal op-eration of Pilot-demonstration energy complex (PDEC) and in increased total power of reactor plants in the Industrial power complex (IPC) based on the current national radiation safety stand-ards (NRB-99/2009), UNSCEAR conclusions and ICRP recommendations. To evaluate radiologi-cal protection of the public the concepts of radiological detriment (RD) and the level of radiation protection (LRP) were used. The concepts were also used to examine the compliance of the BREST-OD-300, fabrication/refabrication module, processing module, BR-1200 and BN-1200 re-actors, collectively called nuclear objects, with safety standards. RD and LRP were estimated with the use of data of the Russian national cancer statistics and cancer statistics of the regions, wherein nuclear objects are planned to be placed – Tomsk, Sverdlovsk, Chelyabinsk. For the public residing nearby the nuclear objects the estimated LRP and RD meet NRB-99/2009 re-quirements concerning the restriction of radiation risk at the level of 10Е-5 from potential irradiation during a year. For the public of the critical group (girls younger than 5 years of age), residing nearby the PDEC and the nuclear objects the negligible risk of 10Е-6 can be achievable if annual radiation doses of 3H, for BREST-OD-300, reduce by 80%, and of annual doses of Cs-137, for the processing module reduce by 75%. The negligible risk for the public can be achieved if annual radiation doses of H-3 for BREST-OD-300 reduce by 10% and annual radiation doses of Cs-137 for processing module reduce by 5%. Projected radiation risk value for the public residing nearby BN-1200 and BR-1200 or nearby the IPC with two BR-1200 facilities will be much lower than the level of the negligible risk of 10Е-6. The RD calculated with ICRP methodology, serves as confirmation of the need to improve efficiency in cancer care in Tomsk region in order the regional RD to be at the national level. Because the high level of radiological protection of the public during the normal operation of the fabrication/refabrication module, its further operation when establishing IPC based on BR-1200 is feasible.

Оценка потенциальных радиологических рисков населения при реализации проекта «Прорыв» Госкорпорации «Росатом». Часть 1. Рекомендации МКРЗ

The concept “radiation detriment” has been debated intensively in the pages of the ICRP Publica-tion 103 (2007), new radiation epidemiological data obtained after 2007 have also been brought into discussion. For radiation detriment calculation radiation risk models based on data of the study of Japanese cohort of atomic bombings survivors were used. Models developed for esti-mating radiation risk factors take account of gender and age at exposure. Now ICRP has estimat-ed radiation detriment in specially designed standard population by averaging the estimates based on age at exposure. The concept “radiation detriment” was developed for quantification of the overall harm to health of humans and their offspring from stochastic effects of low-level radi-ation on different parts of the body, reduction in life expectancy and reduced quality of life. In ad-dition, radiation detriment is used to assess effective dose and its standardization for radiological protection. In the paper, the concept “radiation detriment” is assessed with regard to the possibility of extending the area of its application. The applicability of technique for calculation of radiation detriment is possible to be extended with account of Russian health and statistical data, lethality fraction estimates, years of life lost, gender and age. The extended “radiation detriment” will be renamed as “radiological detriment”, that will highlight the possibility of quantifying potential harm to a specific irradiated population. The magnitude of population-based radiological detri-ment may be used not only for matching sources of ionizing radiation by their impact on the standard population, but also for estimating the level of radiological protection of the specific population. The level of radiological detriment may be used for quantification of potential harm to the public health in the implementation of the Rosatom project “Proryv”.

Radiation effects analysis in a group of interventional radiologists using biological and physical dosimetry methods

Interventional radiologists and staff members are frequently exposed to protracted and fractionated low doses of ionizing radiation, which extend during all their professional activities. These exposures can derive, due to the effects of direct and scattered radiation, in deterministic effects (radiodermitis, aged skin, cataracts, telangiectasia in nasal region, vasocellular epitelioms, hands depilation) and/or stochastic ones (cancer incidence). A methodology has been proposed for estimating the radiation risk or detriment from a group of six exposed interventional radiologists of the Hospital Universitario La Fe (Valencia, Spain), which had developed general exposition symptoms attributable to deterministic effects of ionizing radiation. Equivalent doses have been periodically registered using TLD’s and wrist dosimeters, H p (10) and H p (0.07), respectively, and estimated through the observation of translocations in lymphocytes of peripheral blood (biological methods), by extrapolating the yield of translocations to their respective dose–effect curves. The software RADRISK has been applied for estimating radiation risks in these occupational radiation exposures. This software is based on transport models from epidemiological studies of population exposed to external sources of ionizing radiation, such as Hiroshima and Nagasaki atomic bomb survivors [UNSCEAR, Sources and effects of ionizing radiation: 2006 report to the general assembly, with scientific annexes. New York: United Nations; 2006]. The minimum and maximum average excess ratio for skin cancer has been, using wrist physical doses, of [ 1.03 × 1 0 − 3 , 5.06 × 1 0 − 2 ], concluding that there is not an increased risk of skin cancer incidence. The minimum and maximum average excess ratio for leukemia has been, using TLD physical doses, of [ 7.84 × 1 0 − 2 , 3.36 × 1 0 − 1 ], and using biological doses, of [ 1.40 × 1 0 − 1 , 1.51], which is considerably higher than incidence rates, showing an excess radio-induced risk of leukemia in the group under study. Finally, the maximum radiological detriment in the group, evaluated as the total number of radio-induced cancers using physical dosimetry, has been of 2.18/1000 person-year (skin and leukemia), and using biological dosimetry of 9.20/1000 PY (leukemia). As a conclusion, this study has provided an assessment of the non-deterministic effects (rate of radio-induced cancer incidence) attributable to the group under study due to their professional activity.

Study of the availability of digital mammography for premenopausal women in the Valencian Breast Cancer Early Detection Program

In 1992, the Valencian Breast Cancer Screening Program (VBCSP) started in the Valencian Community. To date, 24 mammography units have been installed all over the region. There is a health risk in the studied women that has to be estimated and controlled. A methodology to calculate approximately the radiological detriment in the VBCSP has been developed based on Monte Carlo techniques. As qualitative parameters in the program, the average mean glandular doses from representative sample populations undergoing screening mammography (digital or film) from each of the 24 units in operation have been obtained. The American College of Radiology Imaging Network reached the conclusion that digital mammography performed significantly better than film for premenopausal and perimenopausal women younger than 50 years old [1]. Our group uses the software SCREENRISK [2] to estimate the induction/detection rates in order to corroborate American conclusions in a European region. The obtained results confirm the American results about the application of digital mammography in premenopausal and perimenopausal women younger than 50 years old.

Modelling of the mammographic exposure conditions for radiological detriment study in the valencian breast cancer screening programme

Breast screening programmes are the best weapon to fight against breast cancer. Nevertheless, despite the benefits, this practice supposes a radiological risk that cannot be forgotten. In order to calculate breast glandular doses, different MCNP-4C2 models have been developed, simulating the exposure conditions. Radiological detriments have been transported from the population under study in the UNSCEAR 2000 to the Valencian Community, obtaining the detection-induced cancer ratio (DICR) for this population.

Disaggregation of collective dose—a worked example based on future discharges from theSellafield nuclear fuel reprocessing site, UK

Collective dose has long been advocated as an important measure of the detrimentassociated with practices that involve the use of radioactivity. Application of collective dosein the context of worker protection is relatively straightforward, whereas its application inthe context of discharges to the environment can yield radically different conclusionsdepending upon the population groups and integration times that are considered. Thecomputer program PC-CREAM98 has been used to provide an indicative disaggregationinto individual dose bands of the collective dose due to potential future radioactivedischarges from the nuclear fuel reprocessing site at Sellafield in the UK. Two alternativedischarge scenarios are considered, which represent a ‘stop reprocessing early,minimum discharge’ scenario and a ‘reprocessing beyond current contracts’ scenario.For aerial discharges, collective dose at individual effective dose rates exceeding0.015 µSv y−1 is only incurred within the UK, and at effective dose rates exceeding1.5 µSv y−1 is only incurred within about 20 km of Sellafield. The geographical distribution ofcollective dose from liquid discharges is harder to assess, but it appears that collectivedose incurred outside the UK is at levels of individual effective dose rate below1.5 µSv y−1, with the majority being incurred at rates of0.002 µSv y−1 or less. In multi-attribute utility analyses, the view taken on the radiological detriment tobe attributed to the two discharge scenarios will depend critically on the weight ormonetary value ascribed to collective doses incurred within the differing bands of individualdose rate.

Dosimetric Methods for the Establishment of Reference Doses in Conventional and Computed Radiography

According to the recommendations of the International Commission on Radiological Protection (ICRP), the principles of radiation protection apply to the use of ionising radiation in medical diagnosis all other applications of ionisin radiation, the patient's radiation burden has to be justified and optimised. For a record of the patients radiological detriment, reference doses which can he determined by common dosimetric methods are needed. The entrance surface dose and the dose-area product (DAP) are suitable quantities for this purpose. Both dosimetric quantities can easily be determined with thermoluminescence dosemeters or by ionometric measurements. The establishment of reference dose levels for the identification of patient exposures, where the applied doses are unusually high, is both recommended and necessary.