Health risks from radioactive particles on Cumbrian beaches near the Sellafield nuclear site.

A monitoring programme, in place since 2006, continues to recover radioactive particles (<2 mm diameter) and larger objects from the beaches of West Cumbria. The potential risks to members of the public using the beaches are mainly related to prolonged skin contact with or the inadvertent ingestion of small particles. Most particles are classified as either 'beta-rich' or 'alpha-rich' and are detected as a result of their caesium-137 or americium-241 content. Beta-rich particles generally also contain strontium-90, with90Sr:137Cs ratios of up to about 1:1, but typically <0.1:1. Alpha-rich particles contain plutonium isotopes, with Pu:241Amαratios usually around 0.5-0.6:1. 'Beta-rich' particles have the greatest potential to cause localised skin damage if held in stationary contact with the skin for prolonged periods. However, it is concluded that only particles of >106Bq of137Cs, with high90Sr:137Cs ratios, would pose a significant risk of causing acute skin ulceration. No particles of this level of activity have been found. Inadvertent ingestion of a particle will result in the absorption to blood of a small proportion of the radionuclide content of the particle. The subsequent retention of radionuclides in body organs and tissues presents a potential risk of the development of cancer. For 'beta-rich' particles with typical activities (mean 2 × 104Bq137Cs, Sr:Cs ratio of 0.1:1), the estimated committed effective doses are about 30µSv for adults and about 40µSv for 1 year old infants, with lower values for 'alpha-rich' particles of typical activities. The corresponding estimates of lifetime cancer incidence following ingestion for both particle types are of the order of 10-6for adults and up to 10-5for infants. These estimates are subject to substantial uncertainties but provide an indication of the low risks to members of the public.

Effective doses and risks from medical diagnostic x-ray examinations for male and female patients from childhood to old age.

The consideration of risks from medical diagnostic x-ray examinations and their justification commonly relies on estimates of effective dose, although the quantity is actually a health-detriment-weighted summation of organ/tissue-absorbed doses rather than a measure of risk. In its 2007 Recommendations, the International Commission on Radiological Protection (ICRP) defines effective dose in relation to a nominal value of stochastic detriment following low-level exposure of 5.7 × 10-2Sv-1, as an average over both sexes, all ages, and two fixed composite populations (Asian and Euro-American). Effective dose represents the overall (whole-body) dose received by a person from a particular exposure, which can be used for the purposes of radiological protection as set out by ICRP, but it does not provide a measure that is specific to the characteristics of the exposed individual. However, the cancer incidence risk models used by ICRP can be used to provide estimates of risk separately for males and females, as a function of age-at-exposure, and for the two composite populations. Here, these organ/tissue-specific risk models are applied to estimates of organ/tissue-specific absorbed doses from a range of diagnostic procedures to derive lifetime excess cancer incidence risk estimates; the degree of heterogeneity in the distribution of absorbed doses between organs/tissues will depend on the procedure. Depending on the organs/tissues exposed, risks are generally higher in females and notably higher for younger ages-at-exposure. Comparing lifetime cancer incidence risks per Sv effective dose from the different procedures shows that overall risks are higher by about a factor of two to three for the youngest age-at-exposure group, 0-9 yr, than for 30-39 yr adults, and lower by a similar factor for an age-at-exposure of 60-69 yr. Taking into account these differences in risk per Sv, and noting the substantial uncertainties associated with risk estimates, effective dose as currently formulated provides a reasonable basis for assessing the potential risks from medical diagnostic examinations.

Amylase as a Diagnostic Tool for Plunging Ranula: Clinical Series and Description of the Technique.

OBJECTIVES: This study describes a technique of measurement for neck cyst amylase content and reviews the experience of a tertiary referral center for cases of suspected plunging ranula. METHODS: A retrospective study was performed at the Manukau Surgical Center in Auckland, New Zealand. Patients with a possible diagnosis of plunging ranula based on clinical presentation and diagnostic aspiration of the cyst contents were included. Demographic data, imaging and laboratory findings were collected, along with findings from surgery and histology. The technique for measuring the amylase of the aspirated cyst contents was also carefully recorded. RESULTS: The 37 cases of confirmed plunging ranula included in this study had a submandibular cystic swelling that was aspirated. Imaging features consistent with a plunging ranula were seen in 89% of the study group. All cases had detectable levels of amylase of ≥3 U/L in the ranula contents. There was large variability (range: 5-560 U/L) in the concentration of amylase, with 70% of the cases demonstrating an amylase concentration below 200 U/L. Aspirates were typically described as viscous (87.5%) and yellow or straw-colored. CONCLUSION: The combination of clinical presentation, imaging and the presence of amylase in the cyst contents is diagnostic for plunging ranula. LEVEL OF EVIDENCE: 4 Laryngoscope, 133:535-538, 2023.

EFFECTIVE DOSE COEFFICIENTS FOR RADON AND PROGENY: A REVIEW OF ICRP AND UNSCEAR VALUES.

The International Commission on Radiological Protection (ICRP) publishes guidance on protection against radon exposure in homes and workplaces. ICRP Publication 137 recommends a dose coefficient of 3 mSv per mJ h m-3 (~10 mSv WLM-1) to be used in most circumstances of radon exposure, for workers in buildings and in underground mines. Recently, United Nations Scientific Committee on the Effects of Atomic Radiation (UNSCEAR) reviewed radon epidemiology and dosimetry and concluded that its established dose coefficient of 1.6 mSv per mJ h m-3 (5.7 mSv WLM-1) should be retained for use in its comparisons of radiation exposures from different sources in a population. This paper explains and compares the reviews of the scientific evidence from UNSCEAR and ICRP. It is shown that the UNSCEAR and ICRP reviews are consistent and support the use of the ICRP reference dose coefficients for radiation protection purposes. It is concluded that the ICRP dose coefficient should be used to calculate doses to workers.

Bilateral Plunging Ranulas in South Auckland: Evidence for a Genetic Basis.

OBJECTIVES: We present a series of bilateral plunging ranula patients to examine the etiology, diagnosis, treatment, and prognosis of this condition. METHODS: A retrospective chart review was performed on all cases of plunging ranula treated at the Department of Otolaryngology-Head and Neck Surgery, Counties Manukau District Health Board, New Zealand, between 2001 and 2019. RESULTS: There were 17 patients with bilateral plunging ranulas from a total of 187 plunging ranula patients. Eight patients were of Pacific Island descent; six were Maori; and three were Asian. There were no European patients with bilateral plunging ranulas. There were three types of bilateral plunging ranula patients: 1) Metachronous plunging ranulas-Five patients presented with a unilateral plunging ranula with no evidence of a contralateral plunging ranula on initial imaging. Despite negative contralateral imaging findings, these patients developed a clinically evident contralateral plunging ranula 21 to 61 months later. 2) Synchronous plunging ranulas detected on imaging-Eight patients presented with a clinically evident unilateral plunging ranula but also had a contralateral plunging ranula detected on imaging. 3) Clinically evident synchronous plunging ranulas-Four patients presented with bilateral clinically evident plunging ranulas, which were also evident on imaging. Twelve patients underwent bilateral transoral sublingual gland excision and plunging ranula evacuation. CONCLUSION: All patients with a unilateral plunging ranula should be advised of the potential for developing contralateral disease, and this should be emphasized in patients of Pacific Island, Maori, and Asian descent. LEVEL OF EVIDENCE: 4 Laryngoscope, 131:73-77, 2021.

Effective dose from radiation exposure in medicine: Past, present, and future.

Effective dose (E) has been developed by the International Commission on Radiological Protection (ICRP) as a dose quantity with a link to risks of health detriment, mainly cancer. It is based on reference phantoms representing average individuals, but this is often forgotten in its application to medical exposures, for which its use sometimes goes beyond the intended purpose. There has been much debate about issues involved in the use of E in medicine and ICRP is preparing a publication with more information on this application. This article aims to describe the development of E and explain how it should be used in medicine. It discusses some of the issues that arise when E is applied to medical exposures and provides information on how its use might evolve in the future. The article concludes with responses to some frequently asked questions about uses of E that are in line with the forthcoming ICRP publication. The main use of E in medicine is in meaningful comparison of doses from different types of procedure not possible with measurable dose quantities. However, it can be used, with appropriate care, as a measure of possible cancer risks. When considering E to individual patients, it is important to note that the dose received will differ from that assessed for reference phantoms, and the risk per Sv is likely to be greater on average in children and less in older adults. Newer techniques allow the calculation of patient-specific E which should be distinguished from the reference quantity.

Endovascular treatment of carotid-cavernous sinus fistulas: ophthalmic and visual outcomes.

Purpose: The main objective was to report the epidemiology, clinical manifestations, angiography features, treatment modality and post-treatment outcomes in patients diagnosed with carotid cavernous fistulas (CCF). Methods: A retrospective review of the medical imaging database in conjunction with medical records from 2004 to 2017 at the Royal Brisbane and Women's Hospital (RBWH) was conducted.We identified 39 patients with CCF (16 direct, 23 indirect). A total of 37 diagnoses were confirmed by direct catheter angiography. The remaining two cases were diagnosed using magnetic resonance imaging/magnetic resonance angiography. Results: Coils were deployed in 100% of direct and 83% of treated indirect fistulas that were treated. Other embolic agents were deployed alone or in combination with coils. Successful angiographic closure was achieved in 93% of direct and 92% of indirect fistulas. Multiple treatments were required in 33% of direct and 16% of indirect fistulas. Visual acuity improved in patients with direct fistulae(p = 0.02) and was preserved in those with indirect fistulae. Post-treatment diplopia persisted in six patients with direct fistulas and three patients with indirect fistulas. Four patients with indirect fistulas experienced persistent ocular hypertension post-treatment compared to two patients with direct fistulas. Conclusions: Endovascular coils are the most commonly deployed treatment for CCF. Both indirect and direct fistulas achieved high rates of closure; however, indirect fistulas were less likely to require multiple treatments. Good post-procedural vision was achieved for both groups.

Polonium-210 poisoning: a first-hand account.

BACKGROUND: Polonium-210 ((210)Po) gained widespread notoriety after the poisoning and subsequent death of Mr Alexander Litvinenko in London, UK, in 2006. Exposure to (210)Po resulted initially in a clinical course that was indistinguishable from infection or exposure to chemical toxins, such as thallium. METHODS: A 43-year-old man presented to his local hospital with acute abdominal pain, diarrhoea, and vomiting, and was admitted to the hospital because of dehydration and persistent gastrointestinal symptoms. He was initially diagnosed with gastroenteritis and treated with antibiotics. Clostridium difficile toxin was subsequently detected in his stools, which is when he first raised the possibility of being poisoned and revealed his background and former identity, having been admitted under a new identity with which he had been provided on being granted asylum in the UK. Within 6 days, the patient had developed thrombocytopenia and neutropenia, which was initially thought to be drug induced. By 2 weeks, in addition to bone marrow failure, he had evidence of alopecia and mucositis. Thallium poisoning was suspected and investigated but ultimately dismissed because blood levels of thallium, although raised, were lower than toxic concentrations. The patient continued to deteriorate and within 3 weeks had developed multiple organ failure requiring ventilation, haemofiltration, and cardiac support, associated with a drop in consciousness. On the 23rd day after he first became ill, he suffered a pulseless electrical activity cardiorespiratory arrest from which he could not be resuscitated and was pronounced dead. FINDINGS: Urine analysis using gamma-ray spectroscopy on day 22 showed a characteristic 803 keV photon emission, raising the possibility of (210)Po poisoning. Results of confirmatory analysis that became available after the patient's death established the presence of (210)Po at concentrations about 10(9)-times higher than normal background levels. Post-mortem tissue analyses showed autolysis and retention of (210)Po at lethal doses in several organs. On the basis of the measured amounts and tissue distribution of (210)Po, it was estimated that the patient had ingested several 1000 million becquerels (a few GBq), probably as a soluble salt (eg, chloride), which delivered very high and fatal radiation doses over a period of a few days. INTERPRETATION: Early symptoms of (210)Po poisoning are indistinguishable from those of a wide range of chemical toxins. Hence, the diagnosis can be delayed and even missed without a high degree of suspicion. Although body surface scanning with a standard Geiger counter was unable to detect the radiation emitted by (210)Po, an atypical clinical course prompted active consideration of poisoning with radioactive material, with the diagnosis ultimately being made with gamma-ray spectroscopy of a urine sample. FUNDING: UK NHS, Public Health England, and the UK Department of Health.

Updated estimates of typical effective doses for common CT examinations in the UK following the 2011 national review.

OBJECTIVE: To investigate the impact of evolving International Commission on Radiological Protection (ICRP) recommendations concerning calculation of effective dose (E) and compare updated typical UK values for common CT examinations with previous data. METHODS: Monte Carlo simulations have provided normalized organ doses relating to 15 CT scanner models and 5 virtual reference adults. Series of representative E/dose-length product (DLP) coefficients were derived for common examinations on the separate bases of not only older stylized mathematical phantoms and voxel phantoms presently recommended by ICRP, but also the 1977, 1990 and 2007 formulations for E. Updated E/DLP coefficients were applied to typical values of DLP from the 2011 UK survey. RESULTS: Changes in ICRP recommendations that have arisen from improving evidence on stochastic risk, influence values of E by up to a factor two for CT examinations of the head and neck, although differences for the trunk typically amount to ±10%. Adoption of the voxel rather than the mathematical phantoms used previously can lead to further changes in E by a few tens of percent. Updated typical values of E for UK CT examinations range from 2 to 20 mSv. Increases by 20-400% since 2003 arise not only from increases by 30-160% in typical values of DLP, but also increases by 30-90% in relation to E/DLP coefficients for examinations of the trunk. CONCLUSION: Values of E, including updated typical data for UK CT, should be compared with caution in relation to their purpose and underlying factors concerning their calculation. ADVANCES IN KNOWLEDGE: Updated E/DLP coefficients and typical values of E for UK CT, and an appreciation of factors influencing these data.

Doses and lung cancer risks from exposure to radon and plutonium.

PURPOSE: Epidemiological studies of the French uranium miners and the plutonium workers at the Mayak nuclear facility have provided excess relative risk (ERR) estimates per unit absorbed lung dose from alpha radiation. The aim of this paper was to review these two studies and to derive values of the relative biological effectiveness (RBE) of alpha particles for the induction of lung cancer. MATERIALS AND METHODS: We examined and compared the dosimetry assumptions and methodology used in the epidemiological studies of uranium miners and the plutonium workers. Values of RBE were obtained by comparing risk coefficients including comparison of lifetime risks for a given population. To do this, preliminary calculations of lifetime risks following inhalation of plutonium were carried out. RESULTS AND CONCLUSIONS: Published values of risk per unit dose following inhalation of radon progeny and plutonium were in agreement despite the very different dose distributions within the lungs and the different ways the doses were calculated. Values of RBE around 10-20 were obtained by comparing ERR values, but with wide uncertainty ranges. Comparing lifetime risks gave similar values (10, 19 and 21). This supports the use of a radiation weighting factor of 20 for alpha particles for radiation protection purposes.

Bilateral optic disc oedema and associated optic neuropathy in the setting of FOLFOX chemotherapy.

BACKGROUND: To report a case of bilateral optic disc oedema and associated optic neuropathy in the setting of FOLFOX chemotherapy. CASE PRESENTATION: A case of a 57-year-old male being treated with FOLFOX chemotherapy for stage 3B colorectal cancer, who developed bilateral optic disc oedema and associated left sided optic neuropathy is described. The patient presented following cycles 7, 8 and 9 of chemotherapy with a history of bilateral simultaneous intermittent inferior altitudinal field defects. These episodes progressed to bilateral optic nerve oedema and a subsequent left sided optic neuropathy. The patient's symptoms and oedema regressed with discontinuation of chemotherapy. CONCLUSION: This is the first report suggesting a vasospastic role of 5-fluoruracil in 5-FU associated optic neuropathy. It highlights that 5-FU may have the potential to cause arterial vasospasm outside the cardiac vasculature, resulting in end-organ optic nerve ischaemia.

IgG4-related sialadenitis is rare: histopathological investigation of 129 cases of chronic submandibular sialadenitis.

AIMS: The incidence of IgG4-related sialadenitis among cases of chronic sialadenitis is unknown, and so we investigated the presence of IgG4 plasma cells in 129 specimens from an archival collection of consecutive cases of chronic submandibular sialadenitis collected from 1969 to 1989 that had been previously extensively characterized. METHODS AND RESULTS: Immunohistology revealed that only three of the 129 specimens contained areas over the threshold for IgG4-related sialadenitis of 50 IgG4 plasma cells per high-power field, and these cells were part of a non-specific chronic inflammatory infiltrate associated with ducts that had contained sialoliths. The infiltrate of IgG4 plasma cells in the series was significantly positively related to the total infiltrate of inflammatory cells, fibrosis, atrophy, lymphoid germinal centres and sialoliths. CONCLUSIONS: IgG4-related sialadenitis is rare and was not found in the present series. The IgG4 plasma cells that were present in the glands were part of a non-specific chronic inflammatory infiltrate.