Summaries of articles

2002-2005 · 2006

JRP volume 25, issue 4 (December 2005)
 

Development and comparison of five site-specific biosphere models for safety assessment of radioactive waste disposal
G Pröhl et al (343--373)
This paper describes the development and application of biosphere models that might be used for performance assessment studies of nuclear waste disposals. The models have been developed for five European sites assuming a release of radionuclides to waters that are used as drinking water for humans and cattle and as irrigation water. Normalised annual individual doses were calculated, and uncertainties were estimated for ³⁶Cl, ⁷⁹Se, ⁹⁹Tc, ¹²⁹I, ¹³⁵Cs, ²²⁶Ra, ²³¹Pa, ²³⁰Th, 237Np, 239Pu, and 238U. The results indicate the spectrum of exposures in different environments and specify the interaction of environmental conditions, human habits and potential exposure.

A comparative radiological assessment of five European biosphere systems in the context of potential contamination of well water from the hypothetical disposal of radioactive waste
G Olyslaegers et al (375--391)
In the frame of the BioMoSA project, the Reference Biosphere Methodology developed in the IAEA programme BIOMASS was applied to five different European locations. The hypothetical contamination of a biosphere and the dose to individuals was assessed by using mathematical models. The calculations revealed that ingestion of drinking water, fruit and vegetables were the most important exposure pathways. Consumption habits, transfer factors, irrigation rates, distribution coefficients and inclusion of daughter products were important parameters that influence the end results. Variations in the confidence intervals were found to be higher for sorbing than for mobile elements.

Age-at-exposure effects on risk estimates for non-cancer mortality in the Japanese atomic bomb survivors
W Zhang et al (393--404)
This paper considers age and time patterns in excess risks of non-cancer disease mortality in the A-bomb survivors.  The results suggest that the excess relative risk might be highest for exposure at ages 30--49 years, and that those exposed at ages 0--29 years might have a low excess relative risk compared with those exposed at older ages. The differences in excess relative risk for different age-at-exposure groups imply that the dose response relationships for non-cancer disease mortality need to be modelled with adjustment for age-at-exposure.

A respiratory model for uranium aluminide based on occupational data
R W Leggett et al (405--416)
Doses were reconstructed for a group of workers exposed in the 1960s to airborne uranium aluminide (UAl_x) during the fabrication of reactor fuel plates.  Early in the fuel fabrication programme, intakes of UAl_x were underestimated by site health physicists due to an unusual pattern of delayed dissolution of UAl_x in the lungs resulting in initially low urinary U. Elevated intakes were recognised after a few months when urinary U began to rise sharply, even in workers removed from exposure. This paper summarises findings on the behaviour of UAl_x in these workers and describes a respiratory model for inhaled UAl_x.

Action levels for automatic gamma-measurements based on probabilistic radionuclide transport calculations
B Lauritzen and P Hedemann-Jensen (417--434)
In a nuclear or radiological emergency situation gamma measurements from distributed, automatic monitoring stations may provide a first assessment of exposures resulting from airborne and deposited activity. A methodology is presented for calculation of gamma radiation action levels for the introduction of specific countermeasures, based on probabilistic modelling of the dispersion of radionuclides and the radiation exposure. In a case study of long-range atmospheric dispersion of radionuclides, dose rate action levels are estimated for sheltering and foodstuff restrictions. It is concluded that the methodology is applicable to all emergency countermeasures following a nuclear accident, but measurable quantities other than ambient dose equivalent rate are needed for decisions on foodstuff countermeasures.

Determination of the baseline for radiological health practices
A T Ramli et al (435--450)
Environmental terrestrial gamma radiation dose-rates were measured throughout Melaka, Malaysia, with the objective of establishing baseline data. Results obtained are shown in tabular, graphic and cartographic form. The values of terrestrial gamma radiation dose-rate vary significantly over different soil types and for different underlying geological characteristics. An isodose map of gamma dose-rate was drawn. The population-weighted mean dose-rate for Melaka state is 172 ± 17 nGy h^-1. The mean annual effective dose to the population from outdoor terrestrial gamma radiation was estimated to be 0.21 mSv. This value is higher than the world average of 0.07 mSv.

Thorium lung burdens and health effects in miners in China
X-A Chen (451--460)
From 2390 male miners exposed to dust in a rare earth and iron mine in China, 136 men (64 with higher dust exposures and 72 with lower exposures) were selected for physical measurements and health examinations.  The measured average thorium lung burden for the higher exposed miners was significantly greater than that for the lower exposed miners, and the incidence of severe breathlessness and pneumoconiosis of stage 0⁺ was also significantly raised in the former group.  A study of lung cancer at the mine found significantly elevated levels among both the dust-exposed miners and those not exposed, when compared with the rate for China.  This is attributed to higher levels of smoking in the workforce, combined with exposure to silica- and thorium-bearing dusts and thoron progeny.

Radiation doses to workers and members of the public from the Irish peat-fired power generation
C Organo et al (461--474)
Regulatory control of Irish peat-fired power generation according to the Irish legislation was found unnecessary as the results from an investigation of the radiation exposures to workers at the largest Irish peat-fired power plant indicated that the radiation dose received by any worker involved in the processing and handling of the peat and peat ash did not exceed 150 µSv per annum. The potential use of peat fly ash as a by-product in the building industry was also found to have a negligible radiological impact for construction workers and for members of the public.

A short history of radon
G M Kendall et al (475--492)
Uranium is born in the catastrophic collapse of massive stars.  When uranium decays it produces the natural radioactive gas, radon.  We now know that radon is responsible for the largest component of the radiation dose received by the average UK citizen.  However, radiological protection was originally focused on controlling the risks associated with man-made nuclear fission and recognition of the importance of radon exposures in buildings was slow to emerge.  This paper describes how our understanding of radon has developed and how policies to control the risks have been developed both for homes and for workplaces.

Ionising radiation exposure of the UK population: 2005 review
J S Hughes et al (493--496)
Since 1974 the National Radiological Protection Board (now the Radiation Protection Division of the Health Protection Agency) has produced reviews of the levels of exposure to ionising radiation in the UK, from sources of natural and artificial origin.  The latest review in the series gives estimates of annual doses based predominantly on data collected for the years 2001 to 2003. The overall average annual dose is rounded to 2.7 mSv, and the average annual dose from natural radiation is found to be 2.2 mSv. The overall average annual dose is slightly increased over that found in the previous, 1999, review.  This increase is mainly due to a larger contribution from medical irradiation.

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JRP volume 25, issue 3 (September 2005)
 

Childhood cancer mortality in relation to the St Lucie nuclear power station
J D Boice Jr et al (229--240)
Radioactive releases from the St Lucie nuclear power station have been suggested as a possible cause for an unusual county-wide excess of childhood cancers of brain and other nervous tissue in St Lucie County, Florida.  A geographical correlation study was conducted contrasting the county mortality patterns over a 50 year period with those in two neighbouring counties.  No different patterns were seen in overall childhood cancer mortality or in childhood cancers of the brain and other nervous tissue, suggesting that the power plant operation has not influenced mortality rates.  The ecological nature of the study, however, is recognised.

Should we worry about children and radon?
G M Kendall and T J Smith (241--256)
Epidemiological studies have demonstrated that elevated levels of radon are associated with increased risks of lung cancer.  More detailed investigations show that the risk comes from the radon decay products rather than from radon gas itself.  There is no such body of evidence to demonstrate that radon or its decay products present a risk to children, or the unborn child.  Nevertheless, any exposure to radiation potentially carries some risk.  We have carried out calculations to investigate the magnitude of any such risk by comparing radiation doses to adults with those to children aged 1 and 10 years.

Practical procedures for a radon etched track dosimetry service
J C H Miles et al (257--276)
The natural radioactive gas radon presents the largest and best documented risk of all sources of radiation.  While general predictions about the likelihood of high radon levels in any area can be made, the only way to discover whether a particular house has high levels is to measure it.  Etched track detectors are widely used for the detection of radon and its decay products.  They have many desirable attributes but stringent Quality Assurance is required.  This paper describes the practical procedures necessary to allow the use of etched track detectors in large scale surveys of radon in houses.

Disaggregation and valuation of collective dose and global circulation dose
K Charles and S R Jones (277--288)
Collective dose is used as a measure of the overall detriment of practices involving the use of ionising radiation. Its application to environmental discharges is complicated by the extended time periods and geographical areas over which the resulting dose may be accumulated. This paper shows that the collective dose resulting from the global circulation of released radionuclides is accumulated at exceedingly low individual dose rates. The paper explores the possible implications for cost--benefit analyses of combining collective dose disaggregation with a valuation of the person-Sv which varies according to the levels of individual dose at which collective dose is accumulated.

Dose reconstruction of a Brazilian industrial gamma radiography partial-body overexposure case
F C A Da Silva (289--298)
A Brazilian operator of a ⁶⁰Co industrial gamma radiography apparatus was involved in a partial-body radiological accident, which caused serious injuries to his left hand. This work presents the dose reconstruction used for assessment of the distribution of doses on the patient’s hand, which was made using two methods: physical and computational techniques. For the first technique a physical hand simulator was built. The computational method was performed using microcomputer software for external dose calculations, named 'Visual Monte-Carlo MC', together with a hand voxel simulator. The values obtained through both methods were compared. About half of them were similar within a range of uncertainty of 20%.

Fast retrospective determination of radon exposure with a sensitive alpha scintillation probe
H von Philipsborn et al (299--303)
Retrospective determination of long-term (20-year) radon exposure, as required for epidemiological studies, relies on Po-210 measurements on glass surfaces of a mirror or a picture from the room under study. Such measurements are greatly facilitated by using a novel alpha scintillation probe instead of nuclear track detectors. The essential feature of the  convenient alpha scintillation probe is an extremely low background of 4 ± 2 counts per hour for an area of 44 cm², instead of normally 60 cph. Hence, the limit of detection for a 30-min measurement is 5 Bq m^-2 Po-210, corresponding to about 200 Bq m^-3 indoor Rn-222 exposure for 20 years.

Population dose distribution due to soil radioactivity in cities across Nigeria
R I Obed et al (305--312)
Soil samples collected in major cities across Nigeria were analysed for their natural radioactivity concentration levels using gamma-ray spectrometry. The average gamma absorbed dose rate in air across the cities ranged between 19 ± 5 nGy h^-1 and 88 ± 44 nGy h^-1. Using available population data in the study areas, about 2.84% of the population is exposed to a dose rate of less than 20 nGy h^-1, 52.40% between 20 and 30 nGy h^-1 and 31% between 30 and 60 nGy h^-1. About 13.76% of the entire study area is exposed to dose rates of greater than 60 nGy h^-1.

The UK Committee on Radioactive Waste Management
K Baverstock and D J Ball (313--320)
The UK Committee on Radioactive Waste Management is charged with recommending to Government, by July 2006, options for the long term management of the UK’s radioactive waste legacy. These options should 'inspire public confidence'. Now, more than halfway into the time allotted, we, as two former members of the Committee, express our concerns at the wayward approach that has been adopted. The Committee has placed emphasis on gaining public confidence but this has been done at the expense of recruiting the best scientific expertise in the management of radioactive waste, an act which we believe will actually undermine public confidence. Furthermore, given also the immense importance of this decision to public safety, national security and the national interest, we believe urgent steps should be taken to review the Committee’s process, its management and its sponsorship.

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JRP volume 25, issue 2 (June 2005)
 

A review of the potential for radium from luminising activities to migrate in the environment
A C Baker and C Toque (127--140)
During the first half of the twentieth century radium, mixed with other components, was used to luminise many items, including watches, clocks, dials and meters. On many sites, and in particular MoD sites, luminised instruments and paint were disposed of by burning and burial. This paper presents a review of the potential for radium from such sites to migrate in the environment. The transport mechanisms considered are surface water transport, groundwater transport, wind transport, due to the action of animals or people, by plant uptake and due to landslip.

Tritium in well waters, streams and atomic lakes in the East Kazakhstan Oblast of the Semipalatinsk Nuclear Test Site
P I Mitchell et al (141--148)
The concentration of tritium has been measured in well waters, streams and atomic lakes in the SE region of the Semipalatinsk Test Site. The data reveal that levels of tritium in domestic well waters within the settlement of Sarzhal are extremely low at the present time and of no radiological significance. Levels in the neighbouring atomic lakes are up to three orders of magnitude higher, while levels in streams and test-tunnel waters sourced in the Degelen Mountains, site of 215 underground nuclear tests, are even higher. Although there is clear evidence that significant amounts of tritium are being exported in surface waters from the Degelen and Balapan test-field zones, there is no evidence that wells within Sarzhal have yet been contaminated by tritium-rich waters from either zone. This suggests that the latter are not connected hydrologically to the near-surface groundwater recharging these wells. Nevertheless, the continued monitoring of Sarzhal well waters is recommended in the medium term.

Doses from the consumption of Cardiff Bay flounder containing organically bound tritium
A Hodgson et al (149--159)
ICRP dose coefficients (Sv/Bq) for the ingestion of organically bound tritium (OBT) apply to unspecified forms in diet. To obtain information relating to the specific case of OBT in fish from Cardiff Bay, the retention of tritium in adult rats was determined after administration as either tritiated water (HTO) or dried flounder flesh. The results obtained after administration of flounder suggest that appropriate assumptions for retention of tritium in an adult male are 70% behaving as HTO with a 10 day half-time and 30% as OBT in body tissues with a 100 day half-time.  These assumptions result in an ingestion dose coefficient of 6 x 10^-11 Sv/Bq, about 40% greater than the ICRP value.

Penetration of tritium (as tritiated water vapour) into low carbon steel and remediation using abrasive cleaning
A Lewis et al (161--168)
The UKAEA Winfrith site is in a phase of accelerated decommissioning and de-licensing which will generate significant volumes of metal wastes some of which may be suitable for disposal as exempt wastes. If contamination is present, it is often confined within the surface layers of the metal. The UKAEA Winfrith site operates a shot blast facility (WACM) that removes paint and surface contamination from low carbon steel enabling surface contaminated painted metal to be processed and therefore certified as exempt. The results of sampling and analysis show that the tritium is mainly held in the paint or outer 40 µm layer of the metal and that processing through the WACM effectively removes these layers along with sufficient tritium to meet the SoLA Exemption Order criteria.

Radiological protection evaluation of Brazilian industrial installations with electron accelerators
M J M Lourenco et al (169--179)
Electron accelerators are used by eight industrial installations in Brazil, with a total of 14 machines generating electron beams. This paper describes a methodology for the evaluation of the radiological protection status of these accelerator facilities. The methodology was developed mainly based on
specific recommendations from the International Atomic Energy Agency (IAEA). Main safety items were evaluated at the installations. Several inadequacies were observed at two out of the eight installations, from the radiological safety and radioprotection points of view. Most of the non-compliances have been corrected during this work, and the rest are in the course of being corrected.

The effect of gamma irradiation on the germination and growth of certain Nigerian agricultural crops
C E Mokobia and O Anomohanran (181--188)
This study was carried out to determine the effect of gamma irradiation on the germination and growth of seeds stored using gamma irradiation. Three seeds, namely maize, okra and groundnut, were irradiated with different doses of gamma rays and were planted. Their germination and growth were then monitored for a period of 8 weeks. Results from this study indicate that the number of germinated seeds and the growth rate for the crops decrease with increase in the radiation dose. The study presented a chart of percentage germination of seeds versus exposure dose as a quick guide to farmers, policy makers and agricultural institutions.

Investigation of photon attenuation coefficients for marbles
C Basyigit et al (189--192)
As marble is one of the most important materials used in building construction, its photon absorption properties have been investigated. To this end, photon attenuation coefficients have been obtained both experimentally and theoretically for different marbles produced in different parts of Turkey. The results were compared with those for ordinary concrete, which is the most commonly used material in building construction. It was found that marble has higher attenuation coefficients than ordinary concrete, which means that marble is a better material then ordinary concrete to shield radiation.
 

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JRP volume 25, issue 1 (March 2005)
 

Personal photon dosemeter trial - Devonport Royal Dockyard
R Collison (1--32)
This paper describes a photon dosemeter trial conducted to establish an understanding of the operational responses of various personal dosemeters employed at Devonport and to assess new types of dosemeters.  The suitability of each dosemeter for use within typical relatively low doserate sites, such as Devonport, has been assessed.  Although some dosemeters responded well, some commonly used personal dosemeters were found to generally be unsuitable for sites such as Devonport.

Reference biospheres for post-closure performance assessment: inter-comparison of SHETRAN simulations and BIOMASS results
S J Birkinshaw et al (33--49)
In post-closure radiological assessments of deep geological repositories for radioactive wastes, a small number of poorly retarded and long-lived radionuclides (or their progeny) are typically determined to be potentially available for transport from the repository to the near-surface in groundwater.  Their radiological impact is then assessed by considering the dilution that occurs when deep groundwaters mix with recent meteoric waters and the biotic processes that lead to uptake of the radionuclides by plants and animals.  Typically, lumped parameter models have been used to represent these dilution and bioaccumulation processes.  By comparing a lumped parameter model of a surface-water catchment used in a recent IAEA study with a physically based representation of the same catchment, it is shown that use of a lumped parameter model without prior calibration against a physically based model has the potential for implying unexpected and implausible hydrological characteristics.  Thus, use of a lumped parameter model without prior calibration has the potential to detract from the confidence that can be placed in any post-closure safety assessment in which it is used.

Uncertainty and power at low levels of incurred radiation dose
M Wilson and D Jackson (51--66)
Radiation dose assessments are undertaken by nuclear licensed sites throughout the UK.  Such calculations are not complex and, often, the resultant dose is expressed as a single mean value.  However, such an approach may mask considerable uncertainty.  Current drivers are to reduce discharges, hence environmental concentrations and resultant doses, to a point where they are `close to zero’ for artificial radionuclides.  In order to demonstrate compliance with this target, it is necessary to know whether one estimate of the average differs significantly from another.  This study illustrates some effects of variability and approaches to maximising the information which can be derived from a dataset.

Field and model investigations of external gamma dose rates along the Cumbrian coast
P McDonald et al (67--82)
A survey of external dose rates from gamma-rays along the Cumbrian coast was performed to improve model predictions through the updating of fine-sediment proportions. Improvements were successfully implemented; however, unexpected field observations were made at two sites. At Drigg Barn Scar, the ⁶⁰Co contained in sessile biota significantly contributed to the external gamma dose rate. At Whitehaven Coal Sands, the mineralogy of the sands contributed to an atypically high concentration of ¹³⁷Cs in sandy material. This work highlights the key role fine-sediment proportions have on external dose rate calculations; however, contributions from biota, whenever present, can also be significant.

Chromosome intra- and inter-changes determined by G-banding in radiation workers with in vivo exposure to plutonium
E J Tawn and C A Whitehouse (83--88)
Chromosome aberration frequencies in blood lymphocytes from workers from Sellafield have been re-assessed in light of recent suggestions that high LET exposure results in a distinct profile of chromosome damage characterised by intra-chromosomal and complex aberrations. Although increases in chromosome inter-changes, i.e. translocations, were observed for both low and high LET exposure there were no significant increases in any other aberration type and no difference in aberration profiles between the two types of radiation exposure. This study has therefore failed to find evidence of a specific marker of high LET exposure associated with historical intakes of plutonium received occupationally at Sellafield.

Analysis of the RB1 gene in children with retinoblastoma having residential connections to West Cumbria, England
J K Cowell et al (89-92)
In the early 1990s attention was drawn to eight cases of retinoblastoma with residential connections to West Cumbria and this led to speculation that they may in some way be associated with the operation of the Sellafield nuclear reprocessing plant. Although only one of the fathers worked at Sellafield it was considered important to establish whether any of the cases was attributable to a germline mutation. Six of the families provided blood samples which were analysed for the presence of a constitutional RB1 mutation. No mutations were detected thus providing strong evidence against any occupational or environmental genotoxic effect causing germline mutations in the parents of these children.

Influence of gamma radiation on the electro-optical characteristics of CR-39 polymer
S E San (93-96)
The influence of gamma radiation on the electro-optical properties of CR-39 polymer has been investigated by capacitive and interferometric measurements to see the order and tendency of irradiation effects on polymer CR-39, which is commonly used in track detectors. These measurements provide additional evidence as to how electronic properties of polymers get modulated by gamma irradiation. It is believed that the study of the electronic properties of such materials gives new evidence on the real degradation mechanisms and on the relative importance of possible combinations of the proposed mechanisms. Experimental results exhibit radiation dependent degradation even at relatively low doses.

Using the sievert
P J Allisy-Roberts (97--100)
Two international recommendations for changes to the current SI brochure regarding the quantity dose equivalent H and its unit the sievert are presented and a possible extension to include the quantity effective dose is discussed. The importance of stating the radiation quantity of interest in addition to its unit is stressed.
 

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JRP volume 24, issue 4 (December 2004)
 

Leukaemia and lymphoma mortality in areas in Japan with nuclear power plants
Y Yoshimoto et al (343--368)
Superficial increases in health risks can give rise to public concern, for example the very small additional risk of cancer due to the radioactive discharges from a normally operating nuclear power plant (NPP). To address such concern, this study examined leukaemia and lymphoma mortality rates in Japanese municipalities containing a NPP compared with those in control areas without a NPP. No significant excess of deaths among young people was observed for these two causes, which often generate concern in Western countries. However, statistically significant excess relative risk (ERR) estimates, especially for leukaemia, were sometimes observed when the elderly were included. We consider that only confounding can be a plausible explanation for the pattern of results found in the study.

Measurement of radionuclides in members of the UK public
S A Hodgson et al (369--389)
This paper summarises a review of measurements of ⁹⁰Sr, ¹³⁷Cs, ¹³¹I, ²³⁹Pu, ²⁴¹Am, uranium and thorium. Emphasis is placed on people who live, or have lived, in the vicinity of nuclear sites. The measurements include those conducted at autopsy, by whole or partial body monitoring, and the assay of teeth, foetuses and urine. The data show elevated levels of some radionuclides close to some nuclear sites. However, the authors concluded that the levels were sufficiently low that any increase in  cancer risks would be small compared with those arising from intakes of naturally occurring radionuclides.

Evaluation of annual committed effective doses to members of the public in Morocco due to ²³⁸U and ²³²Th in various food materials
M A Misdaq and W Bourzik (391--399)
In this study uranium (²³⁸U) and thorium (²³²Th) concentrations have been measured inside different foodstuffs by using a new method based firstly on calculating detection efficiencies of the CR-39 and LR-115 type II solid state nuclear track detectors for the emitted alpha-particles and secondly on counting the resulting track densities. It has been shown that cereals are the largest contributors to the uranium and thorium dietary intakes for the Moroccan population. Annual committed effective doses due to uranium and thorium intakes from the ingestion of a typical food basket by of the Moroccan population have been evaluated. The influence of the uranium and thorium intakes and age of individuals on the committed effective dose was investigated.

Discharge reductions - value for money?
R G Morley et al (401--408)
The environmental impacts of discharges from UK nuclear industry operations are very small, and arguably insignificant compared to the variation in UK natural background radiation dose levels. They are well below any `safe/unsafe’ boundary. The perception of the general public in the UK, however, is that such discharges may be harmful, or at least undesirable. The paper argues that continued reductions in discharges are not value for money for the British taxpayer.

Controlling levels of radon in drinking water
G M Kendall (409--412)
We all know that inhalation of radon decay products gives the largest component of radiation dose to the average member of the UK population.  Hundreds of thousands of people are exposed to concentrations which are above the recommended Action Level.  But recently it has been recognised that radon in drinking water may also present a hazard, albeit to very many fewer people.  This note describes the legal and administrative controls on concentrations of radon in drinking water in England and Wales.

The plenary session on the ICRP recommendations for the 21st century at IRPA-11, Madrid
G Webb et al (413--422)
For the last five years the International Commission on Radiological Protection (ICRP) has been developing ideas and consulting widely in the lead up to a revision of its basic recommendations published in 1990. The IRPA Congress in Madrid in May 2004 was the first occasion on which the profession heard in detail the contents of the draft 2005 recommendations. A panel was assembled to give initial responses to the draft and their comments are brought together in this memorandum.
 

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JRP volume 24, issue 3 (September 2004)
 

Epidemiological studies of UK test veterans: I. General description
G M Kendall et al (199--217)
The atomic bombs on Hiroshima and Nagasaki redefined the weaponry which was needed by countries which aspired to be great powers. The British government was quick to decide that it must develop its own nuclear deterrent.  The test programme which ensued involved atmospheric nuclear weapons tests between 1952 and 1958.  In subsequent years there were suggestions that the health of those involved had suffered. This paper describes the setting up of epidemiological studies of mortality and cancer incidence in UK participants in the nuclear weapons test programme.

Epidemiological studies of UK test veterans:  II. Mortality and cancer incidence
C R Muirhead et al (219--241)
In order to study mortality and cancer incidence in men who took part in the UK atmospheric nuclear weapons tests, a cohort of about 22,000 participants was set up in the 1980s. So too was a closely matched comparison group of a similar size.  Three analyses of mortality and cancer incidence have been carried out over the past 15 years.  This paper describes the development of the evidence and the main findings.

Bystander effect models fitted to lung cancer data in underground miners
M P Little (243--255)
Bystander effects following exposure to alpha-particles have been observed in many experimental systems. Brenner and Sachs (2002 Int. J. Radiat. Biol. 78 593--604) have recently proposed a model of the bystander effect that they use to explain the inverse dose-rate effect observed for lung cancer in radon-exposed miners. In this paper we re-fit the Brenner and Sachs model to miner data. The fit of the original model of Brenner and Sachs is poor, although it is much improved by assuming a 5--6 year period between the development of the first pre-malignant cell and cancer. The fit of this latter model is equivalent to that of a linear relative risk model with adjustment for age at exposure and attained age, both accounting for the observed inverse dose-rate effect.

Radioactive source disposals from Scottish hospitals
R S Corrigall et al (257--264)
This paper describes the organisation of the collection and disposal of sealed radioactive sources from Scottish hospitals, funded by the Scottish Executive to address problems arising from accumulation of redundant sources. Co-ordination of uplifts from several hospitals allowed financial savings to be made as well as alleviating problems of security and source storage.  Radioactive Substances Act compliance is discussed and the use of special authorisations. The 246 sources collected originated in fourteen hospitals, but were uplifted from five pick-up points. The total activity was 16.2 TBq including one blood irradiator source. Source transport arrangements and security are considered, including emergency procedures.

Homogeneity within critical groups
G J Hunt (265--272)
This paper examines developments since the 1960s of criteria for homogeneity of habits within critical groups of the public subject to exposures near nuclear and related facilities. It is suggested that under more recent radiation protection guidelines, an important criterion for selection of the critical group is homogeneity of summed effective doses rather than that of the underlying factors such as ages and habits focusing on a particular pathway. Thus there need be less emphasis on the term `critical pathway’. However, examples of recent retrospective assessments near UK nuclear establishments are given and it is shown that, in practice, critical groups selected on the basis of summed effective doses are still fairly homogeneous in terms of detailed habits.

Thermoluminescence dosimetric properties of new GR-200F dosimeters
El-Faramawy et al (273--282)
There is an increasing need for efficient beta detectors in the field of medical physics and retrospective dosimetry. The thermoluminescence properties of a new version of thin LiF:Mg, Cu, P (GR-200F) tapes are investigated and compared with those of highly sensitive thin Al₂O₃:C beta detectors for their applicability in the detection of low energy photons and beta particles. The dosimetric properties of GR-200F are assessed for possible use at low-level beta dosimetry. The results with its flexible tape form reveal the applicability of GR-200F for the detection of ⁹⁰Sr incorporated in a biological tissue.

Thyroid cancer in Ukraine after the Chernobyl accident
W F Heidenreich et al (283--293)
The rate of incidence of childhood thyroid cancer in northern Ukraine during 1986--98 is described as a function of time-since-exposure, age-at-exposure and sex. After a minimum latent period of about three years, the excess absolute risk (EAR) coefficient (EAR/Gy) shows a linear rise with time-since-exposure for at least nine years, and is roughly constant with age-at-exposure up to 15 years. The EAR coefficient is greater for girls, by about a factor of two at very young ages, which increases to about five for ages-at-exposure of 16--18 years. In terms of absolute risk, the thyroid of young children is not more sensitive to radiation-induced cancer than the thyroid of older children. Since the background risk of thyroid cancer in increasing with attained age, a constant absolute risk implies a decreasing relative risk.

High radon exposure in a Brazilian coal mine
L H S Veiga et al (295--305)
This paper presents a preliminary radiological survey in a Brazilian underground coal mine, where workers have been exposed to high radon concentrations since 1945 without any compliance to regulatory standards since there is no national regulation regarding this exposure in non-uranium mines.  Current radon concentration was about 1.6 KBq m^-3 and average annual exposure to radon progeny was estimated to be 1.9 WLM, ranging from 0.2 to 7.0 WLM. In conclusion, these workers have not been working safely from the perspective of the health hazard related to radon and radon progeny exposure.

A computer program for the assessment of thyroid dose under accident conditions
S S Raza et al (307--314)
The thyroid dose received by members of the public during accident conditions at a nuclear research reactor in Pakistan has been calculated. Sensitivity of the dose results to different air exhaust rates and meteorological conditions was studied. A computer program (PAKRAD-M) was developed which incorporates the exponentially decreasing activity release rate for the calculation of doses. The effect of incorporating this source depletion was responsible for a significant reduction in the projected doses for a high containment air exhaust rate. For low exhaust rates, more decay time was available for the radioactivity within the containment before release to the atmosphere and the doses were low. The results indicate that the distance at which the maximum dose occurs increases if the atmosphere is stable.

No risk from low-level radiation
D J Higson (315--319)
The linear no-threshold (LNT) risk model has been a convenient tool in the practice of radiation protection but yields no demonstrable benefits to health when applied at low doses and low dose rates. Not only is it unsupported by scientific data but there is evidence of beneficial effects from low levels of radiation exposure. The assumption that such exposures are harmful has fostered an unwarranted fear of radiation. This paper concludes that the LNT model should not be applied at dose rates up to at least ten times the average of natural background radiation.
 

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JRP volume 24, issue 2 (June 2004)
 

High radon concentrations in a house near Castleisland, County Kerry (Ireland) - identification, remediation and post-remediation
C Organo et al (107--120)
In July 2003 the highest radon concentration ever recorded in a house in Ireland was detected in a house near Castleisland, County Kerry. The average radon concentration found was approximately 49,000 Bq/m³. This is almost 250 times above the national Reference Level and gives rise to an annual radiation dose of approximately 1.2 Sv to the occupants. On investigation it was learned that although he had never smoked, the householder had been diagnosed with lung cancer in March 2003 and that his wife had died of the same illness in 1998. This paper describes the identification of this house and gives information on the possible cause of both lung cancers, and reviews the levels of natural background radiation in the area.  The follow up actions taken are discussed including the efforts made to heighten awareness of the hazards from radon in the locality.

Radon exposure in Irish workplaces
P A Colgan et al (121--129)
This paper reports on experiences in Ireland in measuring radon in workplaces.  A comprehensive measurement programme has been completed in the majority of schools and where concentrations above 200 Bq/m³ have been identified, remediation has been successful in reducing significantly the concentrations present.  All underground mines and show caves have also been monitored.  Other measurement campaigns have been less successful and the response rate to legally binding direction letters has been poor with over 50% of employers ignoring multiple correspondence.  It is concluded that more and better information needs to be available before successful measurement and remediation programmes can be put in place.

Radiation and liver disease: probability of causation in the presence of hepatitis-C infection
J B Cologne et al (131--145)
In a study of joint effects of radiation and other factors on the prevalence of non-cancer liver diseases in the atomic-bomb survivors, estimating probability of causation (POC) for radiation was complicated by the presence or absence of chronic hepatitis-C virus (HCV) infection. Employing a general `mixture’ model that does not assume either additive or multiplicative joint effects, we estimated a lower bound on POC for radiation with or without HCV infection. Causation could be definitively attributed to radiation only in the absence of HCV infection, which is a much stronger risk factor.

Radiation protection control system for a tokamak fusion device
Z Chai (147--153)
A radiation protection control system has been designed to protect workers and the public against neutron and photon radiation from the HT-7U fusion experimental device, in particular to ensure that workers cannot unexpectedly enter the area of high radiation levels at any time. The multi-subsystems (radiation monitoring subsystem, access control subsystem, safety interlock subsystem, and related other facilities) integration concept is proposed for the design. This system has been implemented based on the up-to-date industrial field bus CAN, featuring simplicity and flexibility of installation and maintenance, capability of real-time long distance communication and multi-master protocol.

Performance characteristics of LiF thermoluminescent dosemeters used for individual monitoring in Tanzania
J E Ngaile and W E Muhogora (155--164)
This paper describes the performance characteristics of thermoluminescent dosemeters (TLDs) used to estimate the personal dose equivalent for external occupationally exposed workers in Tanzania. Major characteristics of TLDs, such as linearity of response, photon energy response, batch homogeneity and uniformity, calibration of TLDs and TLD systems in terms of operational quantities, fading, etc, have been studied. The results were found to be satisfactory for individual monitoring services. Based on the performance test and quality assurance results, the uncertainty in the individual doses evaluated was found to be within recommended limit, which conforms to the standard technical requirements for individual dosimetry services.

Practical procedures for a radon etched track dosimetry service
J C H Miles et al (165--171)
The natural radioactive gas radon presents the largest and best documented risk of all sources of radiation.  While general predictions about the likelihood of high radon levels in any area can be made, the only way to discover whether a particular house has high levels is to measure it.  Etched track detectors are widely used for the detection of radon and its decay products.  They have many desirable attributes but stringent Quality Assurance is required.  This paper describes the practical procedures necessary to allow the use of etched track detectors in large scale surveys of radon in houses.

Annealing and fading of LiF:Mg,Cu,P thermoluminescence dosimeters
M Hosseini-Pooya (173--178)
Both standard annealing (240 °C in an oven for 10 minutes) and reader annealing are applied in the field of personal and environmental dosimetry by means of LiF:Mg,Cu,P thermoluminescence dosimeters. In this note, the consequent effects of using the above two annealing methods on the glow curve structure and fading of the phosphor are investigated. The results show that, due to growth in low temperature peaks after using oven annealing, the fading value is higher than that for reader annealing. Also, the effects of some different preheat temperatures on the main dosimetric peaks and the optimized preheat temperature are specified and discussed.

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JRP volume 24, issue 1 (March 2004)
 

Trivial risks and the new radiation protection system
P Wikman (3--11)
This paper examines ethical perspectives on the proposal from the ICRP that doses below a certain level should be excluded from the system of protection. The principle `if the risk of harm to the health of the most exposed individual is trivial, then the total risk is trivial---irrespective of how many people are exposed’ is analysed, and found to equivocate on the meaning of the word trivial and to ignore the total risk. It is also argued that the new proposal is not justified by a change from a utilitarian ethic to an ethic based on individual rights.

The disaggregation of collective dose
S R Jones et al (13--27)
Collective dose is evaluated as the sum of all the individual radiation doses resulting from a practice, to a defined population group over a defined period of time, and is used as a measure of the detriment associated with the practice. However, when the concept is applied to effluent discharges and waste disposal widely varying values of the quantity are evaluated depending on the population groups considered and the integration period (from hundreds to tens of thousands of years) over which the evaluation is made. This paper describes a method by which collective dose may be disaggregated into the bands of individual dose rate within which it is delivered. A case study based on discharges from nuclear fuel reprocessing at Sellafield, UK, indicates that the bulk of the collective dose is accumulated at exceedingly low individual dose rates, which raises the question of how exceedingly low levels of individual risk should best be treated in multi-attribute utility analyses.

BPM and ALARP in action at Sellafield
B Morley (29--40)
Operators within the UK nuclear industry are required to employ best practicable means (BPM) to control and minimise radioactive discharges. The requirement for the use of BPM is in order to ensure that doses from discharges are as low as reasonably Practicable (ALARP). Scientific assessments to date indicate that there are no expectations of environmental harm from discharges at Sellafield, even where those discharges have historically been up to two orders of magnitude higher than current levels. Current discharges result in doses which are a small fraction of those received by the UK population due to natural background radiation. There is also no evidence to indicate that foreseeable future discharges from Sellafield will make any contribution to environmental harm. Arguably, BNFL has already gone considerably beyond the requirements of BPM with respect to discharges from the Sellafield site, and the resources invested to reach the current very low levels of discharges have been clearly disproportionate to any benefits gained. Despite this, the nuclear industry is under intense pressure from the regulatory bodies to reduce its already small discharges still further. The consequences of such socio-political primacy in decision making has been a significant contributory factor in driving the costs of nuclear generation and waste management to levels where nuclear generation in the UK is now uneconomic.

Risk related value of spend for saving a statistical life
D Jackson et al (41--59)
Decision making requires judgment and cannot be reduced to a set of rules.  Nonetheless, it can be aided by tools which quantify checks and balances.  This study sets out a value of spend for saving a statistical life (VSSSL) for use in cost--benefit studies.  This value is then linked to the risks encountered by an individual.  As the risk reduces so does the VSSSL.  At some point it is assumed that the value of further risk reduction approaches zero.  The implication of adopting this approach to determine spend on radiation dose reduction measures is illustrated.

Radioactive waste disposal implications of extending the contaminated land regime to cover radioactively contaminated land
D J Nancarrow and M M White (61--73)
Extension of the Part IIA contaminated land regime to radioactively contaminated land inevitably raises waste disposal issues.  There is likely to be a landfill availability problem for low level waste; and disposal as very low level waste is limited by the likely alpha activity.  Disposal at BNFL’s Drigg facility is limited to wastes for which there are no practical alternatives.  The Government’s decision-making programme for managing solid radioactive wastes is, however, unlikely to lead to any new national facility during the first decade of the new regime.  Hence, despite the difficulties, it appears that Drigg will play an important role for some years to come.

Remote Selective Optical Detection of Alpha Particle Sources
S M Baschenko (75--82)
Spectral investigations of the atmospheric air alpha-radioluminescence phenomenon in the spectral region 190--800 nm have ascertained that 95% of the total luminescence intensity is composed of a few lines within the narrow spectral range 310--400 nm. The lines belong to the 2⁺ system of nitrogen molecule transitions. The results obtained have enabled a simple optical receiving system to be designed.  This was proven to be able to detect, separately, a clean alpha particle source (²³⁹Pu) placed close to a higher activity gamma ray source (⁶⁰Co), from a distance of 30 m. Natural light intensity always far exceeds the radioluminescence signal, restricting the potential application of the technique to within buildings.

Using the European Community Radon Software
A R Denman et al (83--89)
Radon is present in some domestic properties at levels sufficient to pose a health risk. Such levels can usually be reduced by simple means.  Studies on a group of remediated homes in Northamptonshire, a radon affected area, estimated health benefits of remediation, confirming that remediation can be
justified.  Although previous assessments addressed collective population-average risk, the European Community Radon Software, incorporating individual smoking habits, permits individual risk evaluation. This note describes application of the software to the Northamptonshire study group, and shows that those remediating are not representative of the general population, and are among those at lower risk.

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JRP volume 23, issue 4 (December 2003)
 

The evolution of the international system of radiological protection: stakeholder views
T Lazo (363--368)
The Nuclear Energy Agency's (NEA's) Committee on Radiological Protection and Public Health (CRPPH) has collaborated closely with the ICRP in its efforts to develop new recommendations for radiological protection at the start of the 21st century.  As part of this effort, the NEA organised, in collaboration with the ICRP, two fora to discuss the radiological protection of the environment (Taormina, February 2002), and the future policy for radiological protection (Lanzarote, April 2003).  Both these meetings were attended by a broad representation of stakeholders.  The CRPPH and other stakeholders universally appreciated the opportunity to speak directly with the ICRP on these important subjects. This report summarises the main conclusions made during these two meetings to advance the deliberations of the ICRP to create a new set of recommendations responsive to stakeholder needs, firmly rooted in science, and that can be implemented in a timely, efficient and cost effective manner.

The children of atomic bomb survivors
W J Schull (369--384)
When the atomic bombing of Hiroshima and Nagasaki occurred in the summer of 1945, most members of the public presumed that many of the children conceived by the survivors would be grossly deformed or seriously damaged in other ways as a consequence of radiation-induced mutations.  Although the experimental data then available, largely limited to studies of Drosophila melanogaster, the common fruit fly, did not support this perception, the limitations of the data and the depth of public concern warranted a careful follow-up of the children born to the survivors.  To this end a surveillance was begun in 1947 of all pregnancies terminating after 20 weeks of gestation in these two cities.   Over the half century subsequent to the initiation of this surveillance, some 80-odd thousand pregnancy outcomes have been studied and a variety of potential indicators of mutational damage measured.  This report summarizes the findings of these studies and offers an estimate of the genetic risk based on these findings.

Subtle differences in study design can materially affect the outcome of epidemiological studies
H O Dickinson et al (385--403)
This paper considers methodologic differences which led two apparently similar studies of leukaemia and non-Hodgkin's lymphoma (LNHL) in the offspring of Sellafield radiation workers to reach distinct conclusions. The first, by the HSE, reported a significant association between LNHL and a father's preconceptional radiation exposure (PPI) exclusive to Seascale born children. The second, from Newcastle University, found the risk of LNHL increased less steeply with PPI and was not confined to Seascale. While the Newcastle study included all children, the HSE study relied on a 5% sample and by chance this underestimated the number associated with high dose in Seascale (so exaggerating this dose-response) and overestimated the number associated with dose outside Seascale - hence underestimating this dose-response. Even subtle differences in study design can materially affect the outcome of epidemiological studies.

Application of ALARP to extremity doses for hospital workers
C J Martin and M Whitby (405--421)
Guidance is presented on application of the ALARP principle for protection of the extremities of hospital workers. Recommendations are made on the dose levels at which risk assessments should be performed, protective devices should be provided by employers and dose monitoring should be carried out. Interventional radiologists may receive high doses to their hands and legs. It is suggested that lead/rubber shields should be provided where leg doses are in the range 10--50 mSv. Doses to the hands of staff handling radionuclides depend on local practices. Recommendations relate to use of syringe shields wherever practicable and review of technique.

Chromosome aberrations and retrospective biodosimetry
E Janet Tawn and C A Whitehouse (423--430)
Chromosome translocation analysis for radiation biodosmetry relies on the assumption that frequencies remain constant in the years after exposure. Sequential sampling of radiotherapy patients revealed that whilst total translocation frequencies declined, this could be attributed to the loss of cells which, in addition to translocations, also contained dicentrics which made them unstable. Restricting the analysis to stable cells revealed no such decline. Thus extrapolating translocation frequencies obtained some years after exposure to total initial yield, and using this to equate to dose, is not possible in cases where the exposure has been high and non-homogeneous.  In practice, retrospective dosimetry is more often required in cases of historical, usually protracted, exposures which will have been essentially uniform and not of a sufficiently high dose for many cells to have acquired more than one aberration.  In such cases the frequency of translocations observed some years after the exposure can be assumed to reflect induced frequencies and be used for dose estimation.

Outdoor and indoor dose assessment with environmental thermoluminescence dosimeters (TLDs) in Costa Rica
P Mora (431--437)
Natural radiation measurements utilising environmental CaF2:Dy TLDs were used for the first time in Costa Rica, a Central American country. Other national efforts have been made with gamma spectroscopy but with no attempt to correlate to population doses. Population weighted averages gave 82 nGy/h for outdoors and 130 nGy/h for indoors, for 8 and 4 sampling sites throughout the country respectively. A preliminary population weighted value of 0.74 mSv/year for the effective dose is calculated for natural terrestrial gamma radiation in Costa Rica. Future studies should include a much larger number of sites in order to generalise the findings.

Radon concentration in Jordanian water and hot springs
A Al-Kazwini and M A Hasan (439--448)
This paper examines the Radon concentration in Jordanian drinking water and hot springs. We have found that 60% of the drinking water wells surveyed have radon concentration above the USEPA limit, mainly in rural areas. Tap water in Amman (the capital) has a very low radon concentration. This paper shows that Jordanian drinking water is safe as far as radon concentration is concerned with the exception of a few isolated local drinking water wells. However studying the pattern of the Jordanian statistical data of lung and stomach cancer incidence, we suspect some radon contribution; therefore further epidemiological investigations are needed to completely discount radon as a possible causal contributor.

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JRP volume 23, issue 3 (September 2003)

The evolution of the international system of radiological protection: food for thought from the NEA CRPPH
T Lazo (241--246)
The Committee on Radiation Protection and Public Health (CRPPH) of the Nuclear Energy Agency brings together top radiological protection regulators and experts from its 28 member countries, and works to help countries improve their radiological protection of the public, workers and the environment.  Currently, the internationally accepted system of radiological protection, on which virtually all national regulations are based, is being reviewed and updated.  The CRPPH has analysed the current system, and has suggested specific improvements to evolve the current system towards one that is more adapted to the modern needs of policy makers, regulators and radiological protection practitioners.

Cancer mortality in a Texas county with prior uranium mining and milling activities, 1950-2001
J D Boice Jr et al (247--262)
Three uranium mills and over 40 surface and in situ uranium mines operated as early as 1954 in a rural county in south Texas, USA.  Potential exposure to county residents was from possible environmental releases into the air and groundwater.  A descriptive correlation study was conducted contrasting the county mortality patterns over a 50 year period with those in four neighbouring counties similar in demographic characteristics.  No differences were observed in overall cancer mortality or in cancers of the lung, bone, liver and kidney, suggesting that the uranium mining and milling operations had not adversely affected the health of the population.  The ecological nature of the comparison, however, is recognised.

Cancer risk assessment and the linear no threshold (LNT) hypothesis
R J Preston (263--268)
There is an ongoing debate on the shape of the cancer dose-response at low doses of ionising radiation, namely, is it linear, nonlinear with a threshold, or greater than linear. The issue takes on considerable importance for the setting of protective dose limits. In this paper the case is presented for the continued use of the LNT approach based on the most current information from the fields of epidemiology, animal carcinogenesis, and cellular radiobiology. However, he emphasises that this is the case today, and that new approaches to risk assessments and new data will require continual reassessment of the LNT hypothesis.

Chromosome aberrations in radiation workers
E J Tawn and C A Whitehouse (269--278)
The study of stable chromosome aberration frequencies in occupationally exposed radiation workers with well documented dosimetry allows an evaluation of the dose-response relationship for a biological marker which may be directly related to cancer risk. Comparisons can be made with similar high dose studies for the establishment of dose and dose-rate effectiveness factors. Preliminary data presented in this paper indicate an increased frequency of translocations in a group of retired workers with cumulative lifetime doses >500 mSv compared with a control group with doses <50 mSv. Other factors which appear to be influential in determining chromosome aberration levels are smoking and increasing age.

Historical magnetic-field exposure assessment for electricity workers
D C Renew et al (279--303)
Epidemiological studies looking at health outcomes in relation to occupational magnetic-field exposures need reliable methods for assessment of the exposures.  A new method that has been used for studies involving a cohort of electricity generation and transmission workers in England and Wales is described.  Separate exposure values are provided for eleven job categories at each power station represented in the cohort for each year of its operation.  The exposure values are derived from engineering and operational data for the power stations rather than from recent measurements thus making it possible to provide realistic, individual, historical exposure values.

Radiation risk in the context of liability for injury
P Riley (305--315)
It is perceived by the man in the street that low-level radiation from a nuclear facility is more dangerous than from other practices.  The radiation protection system, in particular the ALARA principle, leads to concerns that even the smallest exposure to radiation is abnormal and dangerous.  Public perception of the radiation risk leads to fear in the minds of the public.  A consequence of this fear itself may be the damage to health in the form of psychological damage or nervous shock.  The paper draws attention to the liability for damages by radiation, in particular under the common law of the UK and US, and how liability, determined by the court, is not necessarily influenced by scientific rationality.  A natural conclusion may be that a claimant suffering injury of the type caused by radiation and who had been exposed to radiation, no matter how small a dose, that could be shown to come from a nuclear installation would be awarded damages against the licensee of the site of the installation unless it could be shown that the injury was predominantly caused by another source (radioactive or otherwise).

A more palatable approach to reduce skeletal burden of radiostrontium
V S Jagtap et al (317--326)
This study demonstrates the use of common physiologically acceptable calcium
salts for decorporating radiostrontium (*Sr) from the body in place of calcium alginate which is viscous and unpalatable. These salts have a long shelf life and can be administered as tablets. Calcium gluconate can be administered intravenously for faster clearance of *Sr. It is also noted that the direct entry of *Sr into the blood leads to rapid uptake by bone compared to the oral route.

Radiation safety concerns during cerebral interventions
R S Livingstone et al (327--336)
During radiological interventions, the dose imparted to patients is of the order such that both stochastic and deterministic effects are possible. During this study, radiation risk and contribution to this risk from work practices were evaluated on 39 patients. The effective dose for patients undergoing a single cerebral intervention varied from 1.55 mSv to 15.9 mSv and for multiple cerebral interventions varied from 16.52 mSv to 43.52 mSv. Two patients had alopecia of the radiated scalp. Proper selection of field size based on exposure factors and image magnification required to obtain the necessary clinical information could reduce radiation dose imparted to the patient significantly.

International radiation safety standards
G A M Webb and I F Robinson (337--344)
The system of international safety standards of the International Atomic Energy Agency (IAEA) is described with explanations as to the purpose of each level of the hierarchy. There is a system of committees that advise the IAEA and approve the safety standards, and one of these committees is the Radiation Safety Standards Committee (RASSC). The Committee meets twice a year and this article outlines the current situation with respect to published safety standards documents at the fundamentals, requirements and guides levels and the status of documents under development. Guidance on how to find more information and to keep up to date on the development of documents is provided. The forward plans of the IAEA in this area are discussed briefly.

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JRP volume 23, issue 2 (June 2003)

The evolution of the system of radiological protection: the justification for new ICRP recommendations
International Commission on Radiological Protection (129--142)
The International Commission on Radiological Protection (ICRP) has published two previous papers in this journal, in June 1999 and June 2001, to stimulate discussion on the best way of expressing radiological protection philosophy in the future. The Commission has now summarised the totality of the numerical values that it has recommended in some ten reports over the last twelve years. From these, a way forward is indicated to produce a simplified and more coherent statement of protection philosophy for the start of the 21st century, which it plans to publish in 2005.

The Society for Radiological Protection - 40 years on from 1963
H J Dunster (143--156)
The Society for Radiological Protection was created in 1963 at a time when the international structure of radiological protection was already well established. The policies of these national and regional agencies were still being developed. Most of the features of these developments were guided by the recommendations of the International Commission on Radiological Protection. This review of the development of radiological protection has been produced to celebrate the forty years of the Society's support of radiological protection, both in the United Kingdom and internationally.

Forty years on: how radiological protection has evolved internationally
D Sowby and J Valentin (157--171)
In the 40 years since the Society for Radiological Protection (SRP) was founded, the international scene has changed considerably. The United Nations bodies primarily involved, the United Nations Scientific Committee on the Effects of Atomic Radiation and the International Atomic Energy Agency, have evolved from fledgling organisations to indispensable major resources. A similar development characterises regional entities such as Euratom and the OECD Nuclear Energy Agency. The International Commission on Radiological Protection (ICRP), once interested in occupational health in the practice of medicine only, has shifted its emphasis towards protection of members of the public and of patients exposed to ionising radiations and is currently looking at protection of non-human species. The International Radiation Protection Association, the federation that is now the 'mother society' of SRP, had not even been launched formally when SRP started. At that time, non-ionising radiation was on nobody's mind, and the forerunner of today's International Commission on Non-Ionizing Radiation Protection (ICNIRP) was not formed until 1977. Here we review the developments during this period, which must be described as a great success story.

Radiation-induced genomic instability and cancer
J B Little (173--181)
Genomic instability is a hallmark of cancer cells.  There is now evidence that transmissible instability can be induced in normal cells by exposure to ionising radiation, leading to a persistent enhancement in the rate at which mutations arise in their descendants over many generations of replication.  If such induced instability is involved in radiation carcinogenesis, it would imply that the initial carcinogenic event may not be a rare mutation occurring in a specific gene or set of genes.  However, radiation could act at any stage in the development of cancer by facilitating the accumulation of the remaining genetic events required to produce a fully malignant tumour.

Software for the estimation of foetal radiation dose in diagnostic radiology
E K Osei et al (183--194)
The determination of absorbed dose to the foetus in diagnostic radiology is of interest as a basis for risk estimates.
This paper describes a simple computer program, FetDose, which calculates the dose to the foetus (taking into account both the foetal depth and gestational age) from both medical and occupational exposures of the pregnant woman. It also calculates the risks of in utero exposure, compares calculated doses to published data in the literature, and provides information on the natural spontaneous risks. FetDose will be a useful tool for the medical and paramedical personnel involved with foetal dose and hence risks calculations.

A forward-looking study of ICRP protection policy
U Swarén (195--200)
Prompted by the discussion opened up by the ICRP with the prospect of a new set of general recommendations, a special project was set up in Sweden in which a small group of independent experts analysed, in particular, the new ideas floated by the ICRP in recent times including `road testing' some case studies. The paper gives a presentation of this study that is now finished. A conclusion is that there are possibilities in those ideas but that a number of issues need to be addressed and their implementation will require time.

Whole-body doses of occupationally exposed female workers in Nigeria (1999--2001)
F O Ogundare and F A Balogun (201--208)
This study has investigated the occupational doses of female radiation workers in Nigeria.  The analysis was based on the national dose registry kept by the
Federal Radiation Protection Service, University of Ibadan, Ibadan for 1999, 2000 and 2001.  The results of the study showed that in proportion to their male counterparts, there are fewer female radiation workers in the industrial sector than in the medical sector. Except in 2000 and in medical sector, the highest individual doses in both sectors were received by female workers in each of the three years.

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JRP volume 23, issue 1 (March 2003)

Carcinogenic risk of hot particle exposures
M W Charles and A J Mill (5-28)
It has been suggested that spatially non-uniform radiation exposures, such as those from small radioactive particles (‘hot particles’), may be very much more carcinogenic than when the same amount of energy is deposited uniformly throughout a tissue volume.  This review provides a brief summary of in-vivo and in-vitro experimental findings, and human epidemiology data, which can be used to evaluate the veracity of this suggestion.  Overall, this supports the contrary view and indicates that average dose, as advocated by the ICRP, is likely to provide a reasonable estimate of carcinogenic risk (within a factor of ~ ±3).

Background radiation: natural and man-made
M C Thorne (29-42)
An overview and comparison is given of dose rates arising from natural background radiation and the fallout from atmospheric testing of nuclear weapons.  Natural background radiation is distinguished into exposures from cosmic rays secondaries, cosmogenic radionuclides, and primordial radionuclides and their progeny, including radon.  Dose rates from weapons fallout peaked at about 5% of natural background in 1963 and have since fallen to about 0.2% of natural background.  These values emphasise that even gross insults to the natural environment from anthropogenic releases of
radioactive materials are likely to be of limited significance when set in the context of ambient levels of ionising radiation exposure.

Past, present and future of radioactive waste management in Nigeria
F O Ogundare (43-51)
Considering the importance of a good radioactive waste management system in any country, the waste management system in Nigeria from the early 1960s is reviewed in this work in order to see how effective it has been.  The review shows that the management of radioactive waste has not been very effective in the country.  The factors responsible for this have been identified to include: (1) ineffectiveness in the enforcement of the decree on nuclear safety; (2) inadequate manpower; and (3) insufficient funding.   The future of the system has also been looked into.  Possible ways of addressing the ineffectiveness of waste management in developing countries have also been suggested in this work.

A contribution to the linear no-threshold (LNT) discussion
K H Chadwick, H P Leenhouts and M J P Brugmans (53-77)
The paper takes the discussion about radiation risk at low doses from interpretations of measured data to a consideration of mechanisms of radiation action.  The DNA double-strand break is related to mutations, aberrations and cell killing.  A multi-step cancer model links the cellular effects to cancer.  It is concluded that the mechanism supports the LNT hypothesis although the slope of the relationship will not necessarily coincide with a linear extrapolation through all the data points.

Investigation using AEGIS of options for shielding the hand during the preparation and injection of radiopharmaceuticals
M Whitby and C J Martin (79-96)
Doses to the hands of hospital staff working with radiopharmaceuticals have been studied. The dose reduction afforded by different shielding options has been assessed. The index finger of the dominant hand of staff dispensing and injecting radiopharmaceuticals was found to receive the highest dose.  The use of a syringe shield alone in the radionuclide dispensary, where staff dispense several patients’ doses, reduced doses by approximately 75-80%.  A large range of doses received by staff dispensing and injecting radiopharmaceuticals for individual patients in the nuclear medicine department was observed.  This was dependent upon the level of shielding used and individual technique.

Prediction of the dose from marine fish consumption in Hong Kong
C B Poon and S M Au (97-104)
Based on a mathematical model for estimating the ¹³⁷Cs ingestion dose from consumption of marine fish in Hong Kong, doses due to an accidental release from the Guangdong Nuclear Power Station are predicted.  Using a probable accident scenario and pessimistic assumptions, results show that the cumulative dose, which is dominated by the contribution from fish cultured in Hong Kong waters, rises rapidly during the first five years and then gradually levels off.  Apart from a small number of critical group members whose doses may need some monitoring, the doses to the population at large are considered small when compared with that from ingestion of natural radionuclides in food and drinks in Hong Kong.

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JRP volume 22, issue 4 (December 2002)

Discrepancy between DS86 calculated and measured neutron activation data in Hiroshima
N Hunter and M W Charles (345--356)
The thermal neutron activation measurements carried out over many years in Hiroshima and Nagasaki have been the subject of ongoing debate in recent years because they indicate that current DS86 neutron doses may have been significantly underestimated in Hiroshima. In this article we show that this discrepancy appears to be reinforced by using the latest thermal neutron activation data. However, some very recent fast neutron activation data suggest that the discrepancy may not be so great as that indicated by the majority of previous thermal neutron data.  The extent of the revision needed to the DS86 neutron component remains subject to ongoing neutron activation measurements and re-analysis of existing published measurements.

The impact of possible revisions to the DS86 dosimetry on neutron risk and relative biological effectiveness
N Hunter and M W Charles (357--370)
The current DS86 dosimetry system for the Japanese bomb survivors indicates that neutron doses were too low to directly derive useful neutron risk estimates. We have investigated the impact on neutron risks of increasing neutron doses in Hiroshima in line with the majority of thermal-neutron activation measurements. These increases, if substantiated, would have no significant impact on gamma radiation risk estimates but would allow useful neutron risk estimates to be made for solid cancers and leukaemia. Whether the Japanese bomb survivors can indeed form the basis for useful, directly determined, neutron risks depends on the reliability of existing thermal and fast neutron activation data.  This is the subject of current research and debate.

New methods for addition of doses from different environmental pathways
W C Camplin et al (371--388)
A new method for estimating radiation doses to UK critical groups is proposed for discussion. Results of surveillance at nuclear sites by the Food Standards Agency and the Scottish Environment Protection Agency are published in the Radioactivity in Food and the Environment (RIFE) report series. In these reports, doses to critical groups are normally estimated separately for gaseous and liquid discharge pathways. Simple summation of these doses would tend to overestimate doses actually received. Three different methods of combining the effects of both types of discharge in an integrated assessment are considered and ranked according to their ease of application, transparency, scientific rigour and presentational issues. The best method is then further developed using surveillance data for the calendar year 2000.

Doses to organs and tissues from radon and its decay products
G M Kendall and T J Smith (389--406)
It is generally accepted that inhalation of radon decay products leads to a risk of lung cancer.  But are there also risks to other organs or tissues?  Is it justifiable to ignore the contribution from radon gas?  While attention is usually concentrated on inhalation, is there a potential risk from ingestion of water containing radon or from deposition of decay products on the skin?   This paper considers these questions, both by comparing the doses calculated for different tissues under different circumstances and also by examining the evidence from epidemiology.

Radiological assessment of the level of safety in logging operations in the petroleum industry
A A Abison (407--415)
A study was initiated in 1993 in the Niger delta area to examine the radiological issues arising from the use of radioactive materials during hydrocarbon exploration and production activities spanning over forty years. The study was aimed at determining the level of radiological safety among various industrial establishments, but it could not make much progress without an assessment protocol. This paper describes such a protocol and the numerical result of its application to establishments involved in logging operations. The individual elements chosen for inclusion in the protocol are common sense and compatible with approaches such as loss prevention philosophy.

Ge-doped optical fibre as a thermoluminescent dosimeter
Y A Abdulla et al (417-421)
This article describes the use of Ge-doped optical fibre as a thermoluminescent dosimeter for measuring the percentage depth dose of 6 and 10 MV x-rays. The results indicate that the GE-doped optical fibre is in good agreement with the results obtained from a cylindrical ionisation chamber and TLD-100.

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JRP volume 22, issue 3 (September 2002)

Review: Radiological protection of the environment from the Swedish point of view
L-E Holm et al (235-247)
This is a review of the Swedish regulatory experiences of protecting the environment against harmful effects of ionising radiation. The Swedish radiation legislation aims at protecting both humans and the environment. The Swedish Parliament has established national environmental quality objectives with the purpose to hand over to the next generation a sustainable society.  The Swedish Radiation Protection Society (SSI) has the responsibility for the objective of “A Safe Radiation Environment”. In its regulations concerning the final management of spent nuclear fuel and waste and releases of radioactive substances from nuclear facilities, SSI has formulated environmental aims that focus on protection of biodiversity and biological resources.

Radiological impacts on organisms other than man of long-lived radionuclides
M C Thorne et al (249-277)
A case study is presented in which an assessment is made of the radiological impacts on organisms other than man of various long-lived radionuclides of importance in solid radioactive waste disposal.  Threshold dose rates for the induction of significant deleterious effects on communities are estimated and it is shown that compliance with radiological protection standards appropriate to man will ensure that such thresholds are not exceeded.  These results apply only to the radionuclides and assessment context considered, and the authors identify the need to build up a dossier of such case studies in support of the ICRP contention that the standard of environmental control needed to protect man from the effects of ionising radiations would ensure that other species were not put at risk.

The proportion of thyroid cancers in the Japanese atomic bomb survivors associated with natural background gamma radiation
M P Little (279-291)
Absolute and relative risk models are fitted to the Japanese atomic bomb survivor thyroid cancer incidence data followed up over the period 1958--1987, taking account of natural background radiation. Over 50% of the excess cases associated with either the atomic bomb radiation or natural background radiation are linked to exposures under the age of 20, irrespective of the assumed risk model or natural background dose rate (in the range 0.5-2.0 mSv/year). The excess risk is overwhelmingly concentrated among females, again irrespective of the assumed model or natural background dose rate. Depending on the assumed natural background dose rate and risk model between 4% and 32% of the thyroid cancers in this cohort may be associated with natural background radiation. The proportion of the thyroid tumours attributed to the atomic bomb radiation is between 19% and 22%, dependent on the assumed background radiation dose and risk model.

Choice of alpha-probe operating voltage to suit a wide range of conditions
R B Bosley and J A Simpson (293-303)
Scintillation probes are used throughout the nuclear industry to monitor for alpha radiation.  The ability to detect alpha radiation is dependent on a number of factors including the efficiency of the probe, and the surface being monitored.  In the past, it has been assumed that maximising the operating voltage and therefore the probe efficiency will improve the ability to detect alpha radiation.  However, the work presented here suggests the characteristics of the surface being monitored have far more effect on the results of alpha monitoring than the choice of operating voltage.

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JRP volume 22, issue 2 (June 2002)

Health effects of depleted uranium munitions
The Royal Society (131-139)
The Royal Society of London set up an independent expert working group to examine the health effects of exposure to depleted uranium (DU) munitions. The assessment covered both the radiological and chemical toxicity of DU and the results of the study are now available. Apart from in exceptional circumstances, the additional risk of developing fatal cancers due to exposure to DU is unlikely to be detectable above the general risk of dying from cancer over a normal lifetime. A small number of soldiers and civilians might suffer kidney damage from DU if substantial amounts are breathed in, or swallowed in contaminated soil and water.  The majority of soldiers will be exposed to levels of DU from armour-piercing penetrators that are unlikely to cause heavy metal poisoning. However, the kidneys of a few soldiers may be damaged if they inhale large quantities of DU. The soil around penetrator impact sites may be contaminated by DU. Although only a small number of civilians will be at risk, heavily contaminated soil should be removed if battlefields are re-populated.

The potential for bias in Cohen's ecological analysis of lung cancer and radon in US homes
J H Lubin (141--148)
Ecological analyses by Cohen show decreasing lung cancer rates with increasing mean radon concentrations for US counties. Cohen thus asserts that the linear-no-threshold model should be rejected for radon, and that his analysis eliminates confounding by using large numbers of adjustment variables.  This paper demonstrates both assertions are erroneous.  County-level, linear-no-threshold models are valid only when risk models for individuals are linear.  However, lung cancer risk is not linear in radon concentration, and thus Cohen's rejection of the linear-no-threshold model is based on a false premise.  We further demonstrate that county-level adjustment cannot eliminate within-county confounding.

Ethical, logical and scientific problems with the new ICRP proposals
K Shrader-Frechette and L Persson (149--161)
In 2001 the ICRP proposed, in a memorandum published in this journal, a new system of radiation protection designed to be simpler, more oriented toward individual protection, and reflective of important ethical standards. The authors argue that the proposal violates important norms of scientific simplicity, is in fact less protective of individuals than the current system, and makes a number of ethical errors. After outlining 12 ethical errors, five logical errors, and two scientific problems with the new ICRP proposal, the authors suggest possible ways to remedy these deficiencies.

The need for changes in ICRP policy: some examples based on the Chernobyl experience in Ukraine
I Likhtarev and L Kovgan (163-173)
Current ICRP recommendations are based on the independent restriction of exposure and sources for practices and interventions.  This paper shows that in Ukraine, after the Chernobyl accident, a number of problems and contradictions have arisen as the result of the strictly separated limitation of sources and exposures.  A number of examples are given which include the resettlement of inhabitants from territories radioactively contaminated after the Chernobyl accident to areas with higher levels of exposure due to very high radon levels.  The authors argue that the concept of controllable dose as presented recently by Roger Clarke on behalf of the ICRP can resolve such paradoxes.

Energy response of LiF dosemeters to ISO 4037 and diagnostic x-rays
W E Muhogora et al (175--184)
The relative response of three types of LiF dosemeter to standard ISO 4037 (series 407) x-ray qualities and diagnostic x-rays was investigated in Tanzania. It was hypothesised that the inherent mismatch between these x-ray qualities could compromise the accuracy of personal dose in diagnostic radiology practices. The results revealed a maximum over-response of 52% for diagnostic x-rays relative to ISO 4037 x-rays, which should be considered during dose assessment. Based on the acceptable uncertainty for radiation levels well below the dose limits, the over-response, however, does not significantly compromise the accuracy of the personal doses.