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A variety of processes, both natural and anthropogenic, can have a negative impact on surface waters, which in turn can be detrimental to human and environmental health. Few studies have considered the ecotoxicological impacts of concurrently occurring contaminants, and that is particularly true for mixtures that include contaminants of emerging concern (CEC). Motivated by this knowledge gap, the present study considers the potential ecotoxicity of environmentally relevant contaminants in the representative aquatic plant Lemna minor (common duckweed), a model organism. More specifically, biological effects associated with exposure of L. minor to a ubiquitous radionuclide (uranium [U]) and a fluorinated organic compound (perfluorooctanoic acid [PFOA], considered a CEC), alone and in combination, were monitored under controlled laboratory conditions. Lemna minor was grown for 5 days in small, aerated containers. Each treatment consisted of four replicates with seven plants each. Treatments were 0, 0.3, and 3 ppb PFOA; 0, 0.5, and 5 ppb U; and combinations of these. Plants were observed daily for frond number and signs of chlorosis and necrosis. Other biological endpoints examined at the conclusion of the experiment were chlorophyll content and antioxidant capacity. In single‐exposure experiments, a slight stimulatory effect was observed on frond number at 0.3 ppb PFOA, whereas both concentrations of U had a detrimental effect on frond number. In the dual‐exposure experiment, the combinations with 5 ppb U also had a detrimental effect on frond number. Results for chlorophyll content and antioxidant capacity were less meaningful, suggesting that environmentally relevant concentrations of PFOA and U have only subtle effects on L. minor growth and health status. Environ Toxicol Chem 2023;42:2412–2421. © 2023 The Authors. Environmental Toxicology and Chemistry published by Wiley Periodicals LLC on behalf of SETAC. [ABSTRACT FROM AUTHOR]

This paper reviews the history of the radium dial workers in the United States, summarizes the scientific progress made since the last evaluation in the early 1990s, and discusses current progress in updating the epidemiologic cohort and applying new dosimetric models for radiation risk assessment. The discoveries of radiation and radioactivity led quickly to medical and commercial applications at the turn of the 20th century, including the development of radioluminescent paint, made by combining radium with phosphorescent material and adhesive. Workers involved with the painting of dials and instruments included painters, handlers, ancillary workers, and chemists who fabricated the paint. Dial painters were primarily women and, prior to the mid to late 1920s, would use their lips to give the brush a fine point, resulting in high intakes of radium. The tragic experience of the dial painters had a significant impact on industrial safety standards, including protection measures taken during the Manhattan Project. The dial workers study has formed the basis for radiation protection standards for intakes of radionuclides by workers and the public. The mortality experience of 3,276 radium dial painters and handlers employed between 1913 and 1949 is being determined through 2019. The last epidemiologic follow-up was 30 years ago when most of these workers were still alive. Nearly 65% were born before 1920, 37.5% were teenagers when first hired, and nearly 50% were hired before 1930 when the habit of placing brushes in mouths essentially stopped. Comprehensive dose reconstruction techniques are being applied to estimate organ doses for each worker related to the intake of 226Ra, 228Ra, and associated photon exposures. Time dependent dose-response analyses will estimate lifetime risks for specific causes of death. The study of radium dial workers is part of the Million Person Study of low-dose health effects that is designed to evaluate radiation risks among healthy American workers and veterans. Despite being one of the most important and influential radiation effects studies ever conducted, shifting programmatic responsibilities and declining funding led to the termination of the radium program of studies in the early 1990s. Renewed interest and opportunity have arisen. With scientific progress made in dosimetric methodology and models, the ability to perform a study over the entire life span, and the potential applicability to other scenarios such as medicine, environmental contamination and space exploration, the radium dial workers have once again come to the forefront. [ABSTRACT FROM AUTHOR]

This study considers whether a relationship exists between response to lithium (Li) exposure and select vegetation indices (VI) determined from reflectance spectra in each of four plant species: Arabidopsis thaliana, Helianthus annuus (sunflower), Brassica napus (rape), and Zea mays (corn). Reflectance spectra were collected every week for three weeks using an ASD FieldSpec Pro spectroradiometer with both a contact probe (CP) and a field of view probe (FOV) for plants treated twice weekly in a laboratory setting with 0 mM (control) or 15 mM of lithium chloride (LiCl) solution. Plants were harvested each week after spectra collection for determination of relevant physical endpoints such as relative water content and chlorophyll content. Mixed effects analyses were conducted on selected endpoints and vegetation indices (VI) to determine the significance of the effects of treatment level and length of treatment as well as to determine which VI would be appropriate predictors of treatment-dependent endpoints. Of the species considered, A. thaliana exhibited the most significant effects and corresponding shifts in reflectance spectra. Depending on the species and endpoint, the most relevant VIs in this study were NDVI, PSND, YI, R1676/R1933, R750/R550, and R950/R750. [ABSTRACT FROM AUTHOR]

The occupational external radiation dose to human medical personnel from positron emission tomography ( PET) radiopharmaceuticals has been documented, but to date no corresponding veterinary staff dose data are available. Electronic personal dosimeters ( EPDs) were used in this study to measure the per-patient external radiation doses to veterinary staff using a PET/ CT ( PET combined with computed tomography) protocol in which the patient radiopharmaceutical dose was injected after anesthetic induction. Radiation doses were recorded for the nuclear medicine technologists, the on-duty anesthesiology technologist, and an occasional observer from 19 veterinary 18 F-fluorodeoxyglucose PET/ CT studies. Patient mass range was 2.8 to 61.0 kg (22.3 kg mean) and injected activity averaged 6 MBq kg−1. The dose range received by nuclear medicine technologists per procedure was 0-30 μ Sv (9.1 μ Sv mean), by anesthetists 1-22 μ Sv (8.2 μ Sv mean), and by the observer 0-2 μ Sv (0.5 μ Sv mean). In both feline and canine studies, placement of the EPD on staff was a significant predictor of radiation dose. Additional significant predictors of staff radiation dose from canine studies included job position and injected activity. The per-patient occupational radiation doses to veterinary PET/ CT technologists were slightly greater than those reported for human nuclear medicine PET/ CT technologists, but were comparable to estimated radiation doses for nurses caring for nonambulatory human PET/ CT patients. Efforts toward maintaining staff radiation doses as low as reasonably achievable ( ALARA) will be important as veterinary PET/ CT caseload increases. [ABSTRACT FROM AUTHOR]

In 2018, the International Commission on Radiological Protection (ICRP) released Publication 138, which highlights the ethical values foundational to the system of radiological protection. Additional work, both within and beyond the ICRP, has proposed or recommended ethical values associated with applications of the system in different areas, perhaps most notably in medical, veterinary, and environmental radiological protection. There are also existing ethical frameworks not specifically related to radiological protection that are nonetheless relevant to its practice; for example, the Beauchamp and Childress principles of biomedical ethics are of particular significance when it comes to medical uses of radiation and radioactivity. At first glance, it may seem as if there are unique or isolated sets of ethical values that need to be applied depending on the circumstance. Yet while each area of application will indeed have its own unique aspects and associated value judgements, there are consistent and complementary relationships between these ethical values. This paper reviews the work of the ICRP related to ethics, including brief historical context, and highlights the similarities and differences between sets of ethical values with emphasis on medical, veterinary, and environmental applications of radiological protection., (Creative Commons Attribution license.)

Life cycle assessment (LCA) is a modelling technique used to determine the cradle-to-grave environmental and human health impacts from the production of a good or the provision of a service. Radiological protection may benefit from employing tools like LCA to obtain a broader perspective and enable comparison with analyses of non-radiological systems. Despite structural similarities to other well-established decision-aiding techniques (DATs), the impact assessment within LCA (i.e. LCIA) is not commonly used in the optimisation of radiological protection process. This paper provides a brief review of LCA, including LCIA, along with more traditional DATs (such as multi-attribute utility analysis) used in the optimisation process for comparison. Basic concrete shielding was considered as a simple, illustrative example; concrete attenuates emissions from a radiation source but is also associated with a financial cost as well as costs with respect to energy, material, and water use. LCA offers quantification of these and other key resources (termed 'impact categories'). Ultimately, we offer that, depending on the circumstance, LCA can be a useful tool in radiological protection decision-making, complementing existing techniques., (Creative Commons Attribution license.)

Analysis of gene expression has become an important tool in understanding low-dose effect mechanisms of ionizing radiation at the cellular level. Metal binding to nucleic acids needs to be considered when interpreting these results, as some radioactive metals, particularly actinides, may produce free radicals and cause oxidative stress damage via chemical means at rates much higher than free radical formation related to their radiological properties. Bacteria exposed in situ to low dose rates of plutonium-239 ( 239 Pu) and iron-55 ( 55 Fe) were previously analysed for gene expression. The work herein was motivated by an interest in more precisely identifying the distribution of radionuclides in these bacteria as well as the practical need to ensure appropriate transport and handling of the associated ribonucleic acid (RNA) extractions. RNA extractions were performed on bacteria growth media with and without bacteria cells (i.e. with and without RNA) at several different concentrations of 239 Pu and 55 Fe to inform the level of specificity of the extraction membrane as well as provide insight into internal (uptake) vs external (sorption) accumulation of these radionuclides in bacteria cells. Results of the study suggest that 239 Pu and 55 Fe detected in RNA extraction samples during long term cell studies is the result of binding to RNA prior to the time of extraction, as opposed to flow through or binding after cell lysis, and it highlights the practical importance of nucleic acid sample characterization to radiation protection more generally., (© 2023 Society for Radiological Protection. Published on behalf of SRP by IOP Publishing Limited. All rights reserved.)

Central to applying the principle of optimisation in the system of radiological protection is the evaluation of what level of radiation exposure should be considered 'as low as reasonably achievable' (ALARA), after taking into account the prevailing circumstances. Determining what is 'reasonable' is an abstract, although somewhat intuitive concept with many potential interpretations depending on both the situation and those involved, whether individuals or organisations. There are common themes in the types of considerations that need to be addressed to determine 'reasonableness' regardless of the exposure situation. However, despite the consistent and agreeable nature of these themes, there remains a gap in how to apply them in real situations. For example, without measurable goalposts (or a clear process for setting such goalposts) for determining what constitutes ALARA, we can find ourselves misinterpreting the optimisation process as keeping exposures 'as low as possible'. We propose herein, by consolidating and building on existing ideas, an easily understandable and actionable 'reasonableness' framework. This simple, yet broadly applicable tool is intended to help radiation protection experts in the systematic, deliberative, and collaborative reflection on all of the factors that make up 'reasonable' before making a decision-whether it be a proposed medical treatment or clean-up of a contaminated site. Each process execution and decision itself will necessarily retain the complexity of the prevailing circumstance. The proposed 'Rs' of Reasonable represent Relationships (stakeholders, empathy, and trust), Rationale (contextual, technical, and ethical), and Resources (technological, financial, and time)., (© 2022 Society for Radiological Protection. Published on behalf of SRP by IOP Publishing Limited. All rights reserved.)

The occupational external radiation dose to human medical personnel from positron emission tomography (PET) radiopharmaceuticals has been documented, but to date no corresponding veterinary staff dose data are available. Electronic personal dosimeters (EPDs) were used in this study to measure the per-patient external radiation doses to veterinary staff using a PET/CT (PET combined with computed tomography) protocol in which the patient radiopharmaceutical dose was injected after anesthetic induction. Radiation doses were recorded for the nuclear medicine technologists, the on-duty anesthesiology technologist, and an occasional observer from 19 veterinary (18) F-fluorodeoxyglucose PET/CT studies. Patient mass range was 2.8 to 61.0 kg (22.3 kg mean) and injected activity averaged 6 MBq kg(-1) . The dose range received by nuclear medicine technologists per procedure was 0-30 μSv (9.1 μSv mean), by anesthetists 1-22 μSv (8.2 μSv mean), and by the observer 0-2 μSv (0.5 μSv mean). In both feline and canine studies, placement of the EPD on staff was a significant predictor of radiation dose. Additional significant predictors of staff radiation dose from canine studies included job position and injected activity. The per-patient occupational radiation doses to veterinary PET/CT technologists were slightly greater than those reported for human nuclear medicine PET/CT technologists, but were comparable to estimated radiation doses for nurses caring for nonambulatory human PET/CT patients. Efforts toward maintaining staff radiation doses as low as reasonably achievable (ALARA) will be important as veterinary PET/CT caseload increases., (© 2012 Veterinary Radiology & Ultrasound.)