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British atomic tests in Australia.

The United Kingdom and Australia have reached agreement on the British payment for cleaning up the Maralinga (South Australia) site at which the UK tested some of its atomic weapons in the 1960s. The tests were conducted amid great secrecy and only in recent years has the truth about the health hazards fully emerged. The peace movement opposed the tests and its stand has been vindicated. Also vindicated have been the claims by Aborigines that more damage was done by the tests than was earlier admitted.

Air Pollution, Radioactive↗

Post-irradiation approaches to treatment of radiation injuries in the context of radiological terrorism and radiation accidents: a review.

PURPOSE: Events of the recent past have focused attention on the possibility of radiological (nuclear) terrorism and on the implications of such terrorist threats for radiation accident preparedness. This review discusses recent advances in the knowledge about how radiation injuries from such events might be treated pharmacologically, and the practical barriers to clinical utilization of these approaches. CONCLUSIONS: A wide range of pharmacological approaches are being developed in the laboratory that could greatly expand the ability to treat acute and chronic radiation injuries. However, there are currently a variety of practical and legal barriers that would prevent the actual clinical use of most of the approaches. There are also the potential weaknesses in most of the current programmes for dealing with the consequences of radiation accidents or nuclear terrorism, including the absence of widespread radiation biodosimetry capabilities and the resulting inability to triage. If a major radiation accident or terrorist event occurs, the lack of biodosimetry and treatment capabilities will be compounded by widespread public fear of 'radiation'.

Abnormalities, Radiation-Induced↗

Environmental radiation and radioactive releases.

Today the most important anthropogenic radiation comes from atmospheric testing of nuclear weapons carried out 20-30 years ago, authorized discharges to the sea from nuclear reprocessing plants, and from the Chernobyl accident in 1986. In the past decade the International Union of Radioecologists (IUR) has contributed to improved international co-operation among radioecologists from all parts of the world through its creation of a number of working groups for specific radioecological problems. More than 30 years of radioecological studies have probably made the radioactive contamination of our environment the best-understood of all present pollution problems. This review indicates the doses to man received from the important anthropogenic sources, as well as those from natural background radiation. It appears that in a global perspective the latter is by far the most important contributor.

Background Radiation↗

The Maralinga Rehabilitation Project: final report.

Maralinga, South Australia was an important site in the United Kingdom nuclear weapons test programme. Seven bombs were exploded and a series of 'safety' tests carried out; the latter in particular disseminated appreciable amounts of uranium and plutonium over a wide area. A programme to clean up the test site over several years was instituted, with in-situ vitrification as a principal measure. The final report on the programme has now been published. However, both the programme and the Report are seriously flawed; this article provides criticisms of both.

Air Pollution, Radioactive↗

Genetic aberrations in Chernobyl-related thyroid cancers: implications for possible future nuclear accidents or nuclear attacks.

Cases of thyroid cancer among children in Belarus represent a unique model system in which the cause of the cancer is known--radiation. Although other sources of radiation-induced cancers are diminishing (survivors of Hiroshima and Nagasaki, and individuals exposed to diagnostic or therapeutic radiation) fears of radiation exposure from accidents and terrorism are increasing. Our analysis of current data reveals that Chernobyl-related cancer cases might have a specific pattern of genetic aberrations. These data strongly confirm the hypothesis that radiation-induced cancers might arise as a result of specific gene aberrations that are distinct from those in sporadic cancers, suggesting that methods of prevention and treatment of radiation-induced cancers might require a different approach. Understanding of the molecular mechanisms of Chernobyl-related papillary thyroid carcinomas will help to identify mechanisms by which radiation causes aberrations and oncogenic cell transformation. Thus, in turn, it will be important in the development of new treatments or technologies to minimize the effects of radiation damage from nuclear accidents or nuclear attacks.

Adolescent↗

Harold Knapp and the geography of normal controversy: radioiodine in the historical environment.

In 1962, after high levels of the isotope Iodine-131 were detected in Utah milk supplies, Dr. Harold Knapp, a mathematician working for the AEC's Division of Biology and Medicine, developed a new model of estimating, first, the relation between a single deposition of radioactive fallout on pasturage and the levels of Iodine-131 in fresh milk and, second, the total dose to human thyroids, resulting from daily intake of the contaminated milk. The implications of Knapp's findings were enormous. They suggested that short-living radioiodine, rather than long-living nuclides such as radiostrontium, posed the greatest hazard from nuclear test fallout and that children raised in Nevada and Utah during the 1950s had been exposed to internal radiation doses far in excess of recommended guidelines. This paper explores the explicit historical revisionism of Knapp's study, his refusal, contra normal AEC practices of knowledge production and spatial representation, to distance himself from the people and places downwind from the Nevada Test Site, and the reactions his work provoked among his AEC colleagues.

Adolescent↗

Joint EC/USNRC expert judgement driven radiological protection uncertainty analysis.

The development of two probabilistic accident consequence codes sponsored by the European Commission and the United States Nuclear Regulatory Commission, COSYMA and MACCS respectively, was completed in 1990. These codes estimate the risks and other endpoints associated with accidents from hypothesised nuclear installations. In 1991, both commissions sponsored a joint project for an uncertainty analysis of these two codes. The main objective of this joint project was to systematically derive credible and traceable probability distributions for the respective code input variables. These input distributions will subsequently be used in two uncertainty analyses for each code separately. A formal expert judgement elicitation and evaluation process was used as the best available technique to accomplish that objective. This paper describes the process and some of the findings of the eight expert judgement exercises performed under the joint study.

Animals↗

Strategy for population protection and area rehabilitation in Russia in the remote period after the Chernobyl accident.

The report presents the history of the development of criteria for radiation and social protection of the Russian population residing in the areas contaminated with radionuclides after the Chernobyl accident, in the remote time periods after the accident. The tendencies for reduction of standards with time are shown, and their causes are analysed. It is noted that the optimization principle was not applied in the explicit form for population protection. The current radiation situation in the contaminated areas of Russia is described, and the future situation is forecast. Main pathways of external and internal population exposure are described. Modern possibilities for reduction of the population exposure dose are discussed. The authors propose promising criteria and methods for population protection and rehabilitation of contaminated areas in Russia.

Health Physics↗

A 3D Lagrangian particle model for direct plume gamma dose rate calculations.

A fully 3D Lagrangian particle model has been presented for calculating the direct gamma dose rates due to a radionuclide plume in the atmosphere. A continuous release of radionuclides into the atmosphere was simulated by liberating a series of puffs (each containing 100 Lagrangian particles). These puffs were released with a constant time lag between the successive puffs. The Lagrangian particle trajectories were tracked for about 25 h in a turbulent atmosphere, with a specified wind field. The atmosphere turbulent/stability characteristics like wind velocity fluctuations, eddy lifetime, etc, were obtained from the reported data in the published literature. For calculating the direct plume gamma dose rates, a point isotropic source formula has been used with appropriate attenuation and build-up factors for the air medium. Each Lagrangian particle represented a point source whose radioactive strength was calculated from the known release rate. The dose rates at ground due to the radionuclide plume were calculated by adding the contribution from each Lagrangian particle in the domain. The numerically calculated dose rates were compared with the numerical results reported in the literature. An excellent comparison was observed for downwind distances up to about 20 km. However, for distances exceeding 20 km, the numerical data were below the reported results for the Gaussian plume model. This discrepancy was due to the vertical wind shear. It is concluded that a Gaussian plume model can be used for the concentration calculations provided the lateral dispersion parameter, sigma(gamma), includes the effect of wind shear, for distances exceeding 20 km.

Air Movements↗

Descriptive epidemiology of thyroid carcinoma in Carinthia, Austria: 1984-2001. Histopathologic features and tumor classification of 734 cases under elevated general iodination of table salt since 1990: population-based age-stratified analysis on thyroid carcinoma incidence.

INTRODUCTION: The aim of the study was to investigate the current thyroid carcinoma (TC) incidence in Carinthia, a former iodine-deficient, goiter-endemic region in Austria with approximately 550,000 inhabitants from 1984 to 2001. Using age-cohort analysis we analyzed the TC incidence under the impact of two regional risk factors: the contamination of Austrian soils by the radioactive fallout in from Chernobyl 1986 and the increased iodination of table salt in a general program of goiter prophylaxis begun in 1991. To evaluate the characteristics of TC incidence, we compared the results of the periods 1984-1989, 1990-1995, and 1996-2001. RESULTS: A total of 734 TC cases were diagnosed. Papillary, follicular, medullary, oxyphilic, and anaplastic TC accounted for 76%, 18%, 3%, 1%, and 2%, respectively. The female to male ratio was 3:1. The annual incidence rate increased by 8.05% in females and 11.6% in males. TC cases younger than 40 years of age accounted for 22.6%, with a rate increase of 18% per year in young males, the female-to-male ratio decreased from 8.3, 6.1, 2.7 younger than 40 in the compared periods. Along with a further increase in papillary TC incidence and papillary thyroid carcinoma (PTC) follicular thyroid carcinoma (FTC) ratio in the adult population, the ratio tended to decrease in the younger than 40-year-old population. T4 class TC and loco-regional lymph node involvement increased significantly. INTERPRETATION: The observed changes in TC incidence, particularly in the young population, as in adults, could be linked to the abovementioned risk factors involved in the initiation and early growth of TC, and iodine may play a role in stimulating overall thyroid activity.

Age Distribution↗

Thyroid nodules, thyroid function and dietary iodine in the Marshall islands.

BACKGROUND: Thyroid nodules have been found to be common in the population of the Marshall Islands. This has been attributed to potential exposure of radioiodines from the nuclear weapons tests on Bikini and Eniwetok between 1946 and 1958. METHODS: In order to get a full picture of thyroid pathology in the Marshallese population potentially exposed to radioactive fallout we performed a large thyroid screening programme using palpation, high resolution ultrasound and fine needle biopsies of palpable nodules. In addition, various parameters of thyroid function (free T3, free T4, thyroid stimulating hormone [TSH]) and anti-thyroid antibodies were examined in large proportions of the total population at risk. Since dietary iodine deficiency is an established risk factor for thyroid nodules, iodine concentration in urine samples of 362 adults and 119 children was measured as well as the iodine content of selected staple food products. RESULTS: The expected high prevalence of thyroid nodules was confirmed. There was no indication of an increased rate of impaired thyroid function in the Marshallese population. A moderate degree of iodine deficiency was found which may be responsible for some of the increased prevalence of thyroid nodules in the Marshallese population. CONCLUSIONS: Studies on the relationship between exposure to radioiodines and thyroid nodules need to take dietary iodine deficiency into account in the interpretation of findings.

Adult↗

Retrospective dose assessment: the measurement of the dose in quartz in dating and accident dosimetry.

In retrospective dosimetry using luminescence it is never possible to obtain a sample of the unaltered phosphor as it was at somc time in the past and before radiation exposure. This prevents direct calibration using conventional personnel dosimetry techniques, and so measurement protocols must be devised which allow accurate estimation of the dose using only the exposed phosphor. This has led to the use of complex protocols, requiring many tens of notionally identical subsamples, to obtain one estimate of the unknown dose. More recently, considerable effort has gone into devising protocols which provide an estimate of the unknown dose from only one subsample. These avoid the need to assume homogeneity in the sample. These protocols also allow faster measurement, which for the first time makes it practical to obtain multiple estimates of the unknown dose and thus externally calculated random errors. This paper discusses the development of single-aliquot protocols, with particular reference to those devised for use with quartz, and finally reviews some of their applications in the retrospective assessment of dose.

Calibration↗

Optically stimulated luminescence in retrospective dosimetry.

Since the beginning of the 1990s the exploration of optically stimulated luminescence (OSL) in retrospective accident dosimetry has driven an intensive investigation and development programme at Risø into measurement facilities and techniques. This paper reviews some of the outcomes of this programme, including the evaluation of the single-aliquot regenerative-dose (SAR) measurement protocol with brick quartz and the determination of dose-depth profiles in building materials as a guide to determining the mean energy of the incident radiation. Investigations into heated materials are most advanced, and a lower detection limit for quartz extracted from Chernobyl bricks was determined to be <10 mGy. The first results from the measurement of doses in unheated building materials such as mortar and concrete are also discussed. Both small-aliquot and single-grain techniques have been used to assess accident doses in these cement based building materials more commonly found in workplaces. Finally some results of a preliminary investigation of the OSL properties of household chemicals are discussed with reference to their potential as accident dosemeters.

Cesium Radioisotopes↗

Lessons learnt from an international intercomparison of national network systems used to provide early warning of a nuclear accident.

As part of the European Research Council's Fourth Framework Programme, the EURADOS Action Group on Monitoring of External Exposures held an intercomparison of national network systems. This took place during May/June 1999 at the Risø Natural Enviromental Radiation Measurement Station in Denmark and at the Underground Laboratory for Dosimetry and Spectrometry (UDO) of the Physikalisch-Technische Bundesanstalt (PTB) in Germany. The network systems are used continuously to monitor radiation levels throughout a country in order to give early warning of nuclear accidents having transboundary implications. The radiation levels measured are used to estimate the radiation risks to people arising from the accident. Seven European countries participated in the intercomparison with detector systems used in their national network systems as well as with detectors being developed for future use. Since different radiation quantities were measured by the systems (namely exposure, air kerma and ambient dose equivalent), the initial analysis of the intercomparison results was made in terms of the quantity air kerma rate. This report completes the analysis of the results and these are given in terms of air kerma rate in order to be consistent with the preliminary report. In addition, in some cases the results are also given in terms of the quantity measured by each national network system. The experience gained from this intercomparison is used to help organise a follow-up intercomparison to be held at the PTB Braunschweig in September 2002 and in which a further seven or eight countries from Europe will participate.

Air Pollution, Radioactive↗

131I content in the human thyroid estimated from direct measurements of the inhabitants of Russian areas contaminated due to the Chernobyl accident.

The method of processing and the results of measurements of 131I content in the thyroids of Russian people performed in May-June 1986 are presented. The contribution of radiation from Cs radionuclides in the human body was taken into account in the processing of measurement data with an SRP-68-01 device. The greatest individual 131I content was found in the thyroids of inhabitants of the Bryansk region, up to 250-350 kBq, and in the Tula and Orel regions, up to 100 kBq. The average 131I thyroid activity in the middle of May 1986 reached 80 kBq for inhabitants of some settlements in the Bryansk region, 5-8 kBq in the Tula region and 5 kBq in the Orel region.

Adolescent↗