Use of everyday materials in retrospective nuclear accident dosimetry

Following a large-scale nuclear event, a quantitative estimate of the radiation dose to the general population necessitates the availability of adequate procedures for the assessment of doses. The main objectives of dose reconstruction, namely retrospective dosimetry can be synoptically stated as in the following: a) To guide the provision of proper protection for the population that had been exposed to radiation, b) To provide assuring information to the worrying public and c) To provide input data for epidemiological studies. Amongst the methods used for dose estimation are the Thermoluminescence (TL) and the Optically Stimulated Luminescence (OSL). Methods based on TL and OSL have the advantage that they allow the measurement of the integrated absorbed dose. When the irradiation comes from external sources, materials found within the perimeter of the accident area such as bricks, tiles and pottery and certain household chemicals, can be used. The absorbed dose may be evaluated many years after the accident.

Download Full-text

Consider This Before Using the SARS-CoV-2 Pandemic as an Instrumental Variable in an Epidemiological Study

American Journal of Epidemiology ◽

10.1093/aje/kwab107 ◽

2021 ◽

Author(s):

Michelle C Dimitris ◽

Robert W Platt

Keyword(s):

Human Health ◽

Instrumental Variables ◽

Respiratory System ◽

Instrumental Variable ◽

Large Scale ◽

Epidemiological Studies ◽

Natural Experiments ◽

Weather Events ◽

External Sources ◽

Sources Of Variation

Abstract Epidemiologists sometimes use external sources of variation to explore highly-confounded exposure-outcome relationships or exposures that cannot be randomized. These exogenous sources of variation, or natural experiments, are sometimes proposed as instrumental variables to examine the effects of a given exposure(s) on a given outcome(s). Previous epidemiological studies have applied this technique using famines, earthquakes, weather events, and previous pandemics as exogenous sources of variation for other exposures; interest in applying this technique using the current severe acute respiratory system coronavirus 2 (SARS-CoV-2) pandemic is already documented. Yet, large-scale events like these likely have broad and complicated impacts on human health, which almost certainly violates the exclusion restriction assumption of instrumental variable analyses. We review the assumptions of instrumental variable analyses, highlight previous applications of this method with respect to natural experiments with broad impacts or “shocks”, and discuss how these relate to our current observations of the SARS-CoV-2 pandemic. While we encourage thorough investigation of the broad impacts of the SARS-CoV-2 pandemic on human health, we caution against its widespread use as an instrumental variable to study other exposures of interest.

Download Full-text

The Potential Use of Car Windscreens for Post-Accident Dose Reconstruction in the Periphery of Nuclear Installations

Applied Sciences ◽

10.3390/app10207127 ◽

2020 ◽

Vol 10 (20) ◽

pp. 7127

Author(s):

Norfadira binti Wahib ◽

Mayeen Uddin Khandaker ◽

S. F. Abdul Sani ◽

K. S. Al-mugren ◽

D. A. Bradley ◽

...

Keyword(s):

Large Scale ◽

Gamma Ray ◽

Dose Range ◽

Absorbed Dose ◽

Analytical Techniques ◽

Photoelectric Effect ◽

Dose Reconstruction ◽

Windshield Glass ◽

Signal Fading ◽

Potential Use

Cars of a variety of brands are usually parked at a fixed but increasing distance in the periphery of nuclear installations. Herein we focus on the potential use of car windscreens for post-accident dose reconstruction from unplanned nuclear events and natural disasters, also in regard to unexpected events arising during large-scale use of radioactive and nuclear materials. The situation requires identification of analytical techniques that could both readily and reliably be used to assess absorbed dose, sufficient to prompt remedial action where necessary. Samples from three widely used car brands—Honda, Toyota and Proton—are studied in respect of their thermoluminescence (TL) yield. Key TL dosimetric features in the gamma-ray dose range of 1–100 Gy are examined. An ERESCO model 200 MF4-RW X-ray machine has also been used for energy response studies; a Harshaw 3500 TLD reader equipped with WinREMS software was used for the luminescence measurements. All brands exhibit linearity of TL yield versus dose, the samples from Honda showing the greatest response followed by that of the Toyota and Proton brands. The marked energy dependence reflects the effect of the strongly Z-dependent photoelectric effect. Signal fading was investigated over a period of 28 days, the Toyota and Proton brand windshield glass showing a relatively low loss at 52.1% and 52.6% respectively compared to a 56.7% loss for that of the Honda samples. This work forms the first such demonstration of the potential of car windshield glass as a retrospective accident dosimeter.

Download Full-text

Automated Cytogenetic Biodosimetry at Population-Scale

Radiation ◽

10.3390/radiation1020008 ◽

2021 ◽

Vol 1 (2) ◽

pp. 79-94

Author(s):

Peter K. Rogan ◽

Eliseos J. Mucaki ◽

Ben C. Shirley ◽

Yanxin Li ◽

Ruth C. Wilkins ◽

...

Keyword(s):

High Performance ◽

Large Scale ◽

Dicentric Chromosome ◽

Automated Assignment ◽

Simulated Population ◽

Dose Estimation ◽

Processing Times ◽

Multiple Processors ◽

Exposure Levels ◽

Population Scale

The dicentric chromosome (DC) assay accurately quantifies exposure to radiation; however, manual and semi-automated assignment of DCs has limited its use for a potential large-scale radiation incident. The Automated Dicentric Chromosome Identifier and Dose Estimator (ADCI) software automates unattended DC detection and determines radiation exposures, fulfilling IAEA criteria for triage biodosimetry. This study evaluates the throughput of high-performance ADCI (ADCI-HT) to stratify exposures of populations in 15 simulated population scale radiation exposures. ADCI-HT streamlines dose estimation using a supercomputer by optimal hierarchical scheduling of DC detection for varying numbers of samples and metaphase cell images in parallel on multiple processors. We evaluated processing times and accuracy of estimated exposures across census-defined populations. Image processing of 1744 samples on 16,384 CPUs required 1 h 11 min 23 s and radiation dose estimation based on DC frequencies required 32 sec. Processing of 40,000 samples at 10 exposures from five laboratories required 25 h and met IAEA criteria (dose estimates were within 0.5 Gy; median = 0.07). Geostatistically interpolated radiation exposure contours of simulated nuclear incidents were defined by samples exposed to clinically relevant exposure levels (1 and 2 Gy). Analysis of all exposed individuals with ADCI-HT required 0.6–7.4 days, depending on the population density of the simulation.

Download Full-text

Lack of an association between gallstone disease and bilirubin levels with risk of colorectal cancer: a Mendelian randomisation analysis

British Journal of Cancer ◽

10.1038/s41416-020-01211-x ◽

2021 ◽

Author(s):

Richard Culliford ◽

Alex J. Cornish ◽

Philip J. Law ◽

Susan M. Farrington ◽

Kimmo Palin ◽

...

Keyword(s):

Colorectal Cancer ◽

Large Scale ◽

Causal Effect ◽

Gallstone Disease ◽

Epidemiological Studies ◽

Mendelian Randomisation ◽

Linear Relationships ◽

Potential Risk Factors ◽

The Relationship ◽

Circulating Levels

Abstract Background Epidemiological studies of the relationship between gallstone disease and circulating levels of bilirubin with risk of developing colorectal cancer (CRC) have been inconsistent. To address possible confounding and reverse causation, we examine the relationship between these potential risk factors and CRC using Mendelian randomisation (MR). Methods We used two-sample MR to examine the relationship between genetic liability to gallstone disease and circulating levels of bilirubin with CRC in 26,397 patients and 41,481 controls. We calculated the odds ratio per genetically predicted SD unit increase in log bilirubin levels (ORSD) for CRC and tested for a non-zero causal effect of gallstones on CRC. Sensitivity analysis was applied to identify violations of estimator assumptions. Results No association between either gallstone disease (P value = 0.60) or circulating levels of bilirubin (ORSD = 1.00, 95% confidence interval (CI) = 0.96–1.03, P value = 0.90) with CRC was shown. Conclusions Despite the large scale of this study, we found no evidence for a causal relationship between either circulating levels of bilirubin or gallstone disease with risk of developing CRC. While the magnitude of effect suggested by some observational studies can confidently be excluded, we cannot exclude the possibility of smaller effect sizes and non-linear relationships.

Download Full-text

Multimorbidity clusters in patients with chronic obstructive airway diseases in the EpiChron Cohort

Scientific Reports ◽

10.1038/s41598-021-83964-w ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Jonás Carmona-Pírez ◽

Beatriz Poblador-Plou ◽

Ignatios Ioakeim-Skoufa ◽

Francisca González-Rubio ◽

Luis Andrés Gimeno-Feliú ◽

...

Keyword(s):

Substance Use ◽

Chronic Conditions ◽

Large Scale ◽

Mental Health Problems ◽

Epidemiological Studies ◽

Chronic Obstructive ◽

High Morbidity ◽

Airway Diseases ◽

Obstructive Sleep ◽

Obstructive Airway Diseases

AbstractChronic obstructive airway diseases such as chronic obstructive pulmonary disease (COPD), asthma, rhinitis, and obstructive sleep apnea (OSA) are amongst the most common treatable and preventable chronic conditions with high morbidity burden and mortality risk. We aimed to explore the existence of multimorbidity clusters in patients with such diseases and to estimate their prevalence and impact on mortality. We conducted an observational retrospective study in the EpiChron Cohort (Aragon, Spain), selecting all patients with a diagnosis of allergic rhinitis, asthma, COPD, and/or OSA. The study population was stratified by age (i.e., 15–44, 45–64, and ≥ 65 years) and gender. We performed cluster analysis, including all chronic conditions recorded in primary care electronic health records and hospital discharge reports. More than 75% of the patients had multimorbidity (co-existence of two or more chronic conditions). We identified associations of dermatologic diseases with musculoskeletal disorders and anxiety, cardiometabolic diseases with mental health problems, and substance use disorders with neurologic diseases and neoplasms, amongst others. The number and complexity of the multimorbidity clusters increased with age in both genders. The cluster with the highest likelihood of mortality was identified in men aged 45 to 64 years and included associations between substance use disorder, neurologic conditions, and cancer. Large-scale epidemiological studies like ours could be useful when planning healthcare interventions targeting patients with chronic obstructive airway diseases and multimorbidity.

Download Full-text

Multicenter Evaluation of an ELISA for the Detection of Cryptosporidium spp. Antigen in Clinical Human Stool Samples

Microorganisms ◽

10.3390/microorganisms9020209 ◽

2021 ◽

Vol 9 (2) ◽

pp. 209

Author(s):

Romy Razakandrainibe ◽

Célia Mérat ◽

Nathalie Kapel ◽

Marc Sautour ◽

Karine Guyot ◽

...

Keyword(s):

Large Scale ◽

Cryptosporidium Oocyst ◽

Clinical Importance ◽

Epidemiological Studies ◽

Elisa Test ◽

Enzyme Linked Immunosorbent Assay ◽

Cryptosporidium Spp ◽

Stool Samples ◽

Conventional Microscopy ◽

Human Stool

Human cryptosporidiosis remains underdiagnosed, and rapid/accurate diagnosis is of clinical importance. Diagnosis of the Cryptosporidium oocyst in stool samples by conventional microscopy is labor-intensive, time-consuming, and requires skillful experience. Thus, we aimed to evaluate the usefulness of a coproantigen enzyme-linked immunosorbent assay (ELISA) test in detecting Cryptosporidium spp. from fecal specimens. For this aim, we evaluated the performances of a commercial ELISA (CoproELISA Cryptosporidium kit, Savyon Diagnostics, Israel) for the detection of Cryptosporidium spp. in random clinical stool samples through a multicenter study. The sensitivity and specificity for coproantigen ELISA were 98.86% and 94.32%, respectively. The coproantigen ELISA results indicate that the simple, rapid, reliable, and standardized immunoassay test is sensitive and specific for routine diagnosis, and may be useful for large-scale epidemiological studies of cryptosporidiosis.

Download Full-text

Whole-Genome Phylogenomic Heterogeneity of Neisseria gonorrhoeae Isolates with Decreased Cephalosporin Susceptibility Collected in Canada between 1989 and 2013

Journal of Clinical Microbiology ◽

10.1128/jcm.02589-14 ◽

2014 ◽

Vol 53 (1) ◽

pp. 191-200 ◽

Cited By ~ 78

Author(s):

Walter Demczuk ◽

Tarah Lynch ◽

Irene Martin ◽

Gary Van Domselaar ◽

Morag Graham ◽

...

Keyword(s):

Neisseria Gonorrhoeae ◽

Large Scale ◽

Epidemiological Studies ◽

23S Rrna ◽

Genome Comparison ◽

Whole Genome ◽

Content Type ◽

Genomic Epidemiology ◽

High Level ◽

Sequence Types

A large-scale, whole-genome comparison of CanadianNeisseria gonorrhoeaeisolates with high-level cephalosporin MICs was used to demonstrate a genomic epidemiology approach to investigate strain relatedness and dynamics. Although current typing methods have been very successful in tracing short-chain transmission of gonorrheal disease, investigating the temporal evolutionary relationships and geographical dissemination of highly clonal lineages requires enhanced resolution only available through whole-genome sequencing (WGS). Phylogenomic cluster analysis grouped 169 Canadian strains into 12 distinct clades. While someN. gonorrhoeaemultiantigen sequence types (NG-MAST) agreed with specific phylogenomic clades or subclades, other sequence types (ST) and closely related groups of ST were widely distributed among clades. Decreased susceptibility to extended-spectrum cephalosporins (ESC-DS) emerged among a group of diverse strains in Canada during the 1990s with a variety of nonmosaicpenAalleles, followed in 2000/2001 with thepenAmosaic X allele and then in 2007 with ST1407 strains with thepenAmosaic XXXIV allele. Five genetically distinct ESC-DS lineages were associated withpenAmosaic X, XXXV, and XXXIV alleles and nonmosaic XII and XIII alleles. ESC-DS with coresistance to azithromycin was observed in 5 strains with 23S rRNA C2599T or A2143G mutations. As the costs associated with WGS decline and analysis tools are streamlined, WGS can provide a more thorough understanding of strain dynamics, facilitate epidemiological studies to better resolve social networks, and improve surveillance to optimize treatment for gonorrheal infections.

Download Full-text

Following the discovery of anti-MDA5 Ab, the clinical understanding of dermatomyositis has been improved

10.31219/osf.io/j2t5f ◽

2021 ◽

Author(s):

Moataz Dowaidar

Keyword(s):

Large Scale ◽

Early Stage ◽

Total Mortality ◽

Epidemiological Studies ◽

Respiratory Physiology ◽

Prognostic Indicators ◽

Current Standard ◽

Incurable Disease ◽

Triple Treatment ◽

Risk Categorization

Knowledge about clinically amyopathic dermatomyositis has exploded in the last two decades, especially after the discovery of anti-MDA5 Ab. The disease's likely genesis and pathophysiological processes have been studied in a number of scientific and epidemiological studies. Thanks to a slew of new large-scale cohort studies, the clinical characteristics of MDA5+ DM may be better identified. In addition, several prognostic indicators have been discovered, such as respiratory physiology measures and serum biomarkers, which have helped to enhance risk categorization in clinical practice and restrict the design of future clinical studies. Quantitative evaluation of pulmonary HRCT data may be the trend of imaging testing in MDA5+ DM-ILD. The current standard of treatment for MDA5+ DM-ILD is "triple treatment" with JAK inhibitors, which has been proven in recent trials to significantly improve the survival of early-stage patients. Total mortality in this incurable disease, however, is still shockingly high, especially in advanced-stage patients. There is still a pressing need for a more effective and well-evidenced treatment approach for MDA5+ DM-ILD.

Download Full-text

Trust, efficacy and ethicacy when testing prisoners for COVID-19

International Journal of Prisoner Health ◽

10.1108/ijph-10-2020-0084 ◽

2021 ◽

Vol ahead-of-print (ahead-of-print) ◽

Author(s):

Steve Lambert ◽

Dean Wilkinson

Keyword(s):

Large Scale ◽

Current System ◽

Epidemiological Studies ◽

Careful Consideration ◽

Power Relationships ◽

England And Wales ◽

Content Type ◽

Large Scale Testing ◽

The Uk ◽

The Impact

Purpose The outbreak of the severe acute respiratory syndrome coronavirus 2 virus and subsequent COVID-19 illness has had a major impact on all levels of society internationally. The extent of the impact of COVID-19 on prison staff and prisoners in England and Wales is unknown. Testing for COVID-19 both asymptomatic and symptomatic, as well as for antibodies, to date, has been minimal. The purpose of this paper is to explore the widespread testing of COVID-19 in prisons poses philosophical and ethical questions around trust, efficacy and ethicacy. Design/methodology/approach This paper is both descriptive, providing an overview of the widespread testing of COVID-19 in prisoners in England and Wales, and conceptual in that it discusses and argues the issues associated with large-scale testing. This paper provides a discussion, using comparative studies, of the issues associated with large-scale testing of prisoners across the prison estate in England and Wales (120 prisons). The issues identified in this paper are contextualised through the lens of COVID-19, but they are equally transferrable to epidemiological studies of any pandemic. Given the prevalence of COVID-19 globally and the lack of information about its spread in prisons, at the time of writing this paper, there is a programme of asymptomatic testing of prisoners. However, there remains a paucity of data on the spread of COVID-19 in prisons because of the progress with the ongoing testing programme. Findings The authors argue that the widespread testing of prisoners requires careful consideration of the details regarding who is included in testing, how consent is gained and how tests are administered. This paper outlines and argues the importance of considering the complex nuance of power relationships within the prison system, among prisoner officers, medical staff and prisoners and the detrimental consequences. Practical implications The widespread testing of COVID-19 presents ethical and practical challenges. Careful planning is required when considering the ethics of who should be included in COVID-19 testing, how consent will be gained, who and how tests will be administered and very practical challenges around the recording and assigning of COVID-19 test kits inside the prison. The current system for the general population requires scanning of barcodes and registration using a mobile number; these facilities are not permitted inside a prison. Originality/value This paper looks at the issues associated with mass testing of prisoners for COVID-19. According to the authors’ knowledge, there has not been any research that looks at the issues of testing either in the UK or internationally. The literature available details countries’ responses to the pandemic rather and scientific papers on the development of vaccines. Therefore, this paper is an original review of some of the practicalities that need to be addressed to ensure that testing can be as successful as possible.

Download Full-text