Extremely high radon activity concentration in two adits of the abandoned uranium mine ‘Podgórze’ in Kowary (Sudety Mts., Poland)

Publication date: December 2016
Source:Journal of Environmental Radioactivity, Volume 165
Author(s): Lidia Fijałkowska–Lichwa
Measurements of radon activity concentration were conducted for a period of 6 months, from April to September 2011, in the air of two adits constituting part of the disused uranium mine 'Podgórze' in Kowary. Adits no. 19 and 19a in Kowary had been chosen owing to the occurrence within them of the highest documented radon concentrations in Poland, With levels higher than a million Bq m⁻³.The main goal of this study was to characterize the level of ²²²Rn activity concentration registered in selected workings of this underground space, investigate ²²²Rn changes and their characteristics over selected periods of time (an hour, a day, a month, six months) and determine the effective doses, which provided the basis for estimating the risk of exposure to increased ionizing radiation for employees and visitors to the mine.The highest values of ²²²Rn activity concentration inside the adits occurred at the time when visitors, guides and other members of the staff were present there. The recorded values of radon activity concentration, regardless of the time and the month when the measurement was performed, remained at an average level of 350–400 kBq m⁻³. These values were far above the limit of 1.5 kBq·m⁻³ recommended by international guidelines. The maximum values ranged from 800 to more than 1000 kBq·m⁻³.Radon activity concentration changes occurred only in periods determined by 7-h cycles of connecting and disconnecting the mechanical ventilation. For about 7 h after activating the ventilation system, between 7 a. m. and 2 p. m., and after closing the adit, between 7 p. m. and 2 a. m., ²²²Rn activity concentrations decreased to levels even as low as 100 kBq·m-3. However, as early as 3–4 h after disconnecting the ventilation system, there was a sharp rise in the values of ²²²Rn activity concentration, to the level higher than 800 kBq·m-3.The risk of receiving a radiation dose higher than the national standard of 1 mSv/year by members of the public occurred as soon as after spending 1 h inside the workings. The minimum monthly effective radiation dose received by every employee in the tourist adit no. 19 in Kowary was higher than 1/5 (4 mSv) of the annual effective dose allowed by Polish law (20 mSv/year). In the non-tourist adit no. 19, the minimum monthly radiation dose was more than 3 times as high as the allowed value of 4 mSv.Due to the highly disturbing and unfavourable, from a radiological protection point of view, conditions inside the disused uranium mine 'Podgórze' in Kowary, the mine manager decided to increase the efficiency of the designed mechanical ventilation system and launch measurements of radon activity concentration in the workplace.



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A tool for calculating concentration ratios from large environmental datasets

Publication date: December 2016
Source:Journal of Environmental Radioactivity, Volume 165
Author(s): Che Doering, Andreas Bollhöfer
This paper presents a tool for calculating concentration ratios from a large and structured environmental dataset of radionuclide activity and metal concentrations. The tool has been developed in MS Excel™ and includes a simple user interface for setting up queries. The tool is capable of matching environmental media samples to biota samples based on user-defined spatial and temporal criteria to derive a representative estimate of the environmental exposure conditions of an organism and its accumulation. Some potential benefits and uses of the tool are discussed.



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Anthropogenic and naturally occurring radionuclide content in near surface air in Cáceres (Spain)

Publication date: December 2016
Source:Journal of Environmental Radioactivity, Volume 165
Author(s): Antonio Baeza, Antonio Rodríguez-Perulero, Javier Guillén
The anthropogenic (¹³⁷Cs, ⁹⁰Sr, ^239+240Pu and ²⁴¹Am) and naturally occurring radionuclide (⁴⁰K, ^234,238U, ^228,230,232Th, ²²⁶Ra and ²¹⁰Pb) content in near surface air present seasonal variations related to natural processes, such as soil erosion, resuspension of fine particles of soil and radon exhalation from soil (²¹⁰Pb). The objective is to analyze seasonal variations of their concentrations and compare with radiological events (Fukushima fallout and wild fire) in a location without any known source of anthropogenic radionuclides. The ²¹⁰Pb, ⁴⁰K, and ¹³⁷Cs presented annual variations, with maximum activity levels in summer. Solar radiation and rainfall were correlated with ²¹⁰Pb and ⁴⁰K. The ^234,238U, ^228,230,232Th, ²²⁶Ra, ¹³⁷Cs and ⁹⁰Sr presented positive correlation with monthly mean values of temperature. The ratio ⁹⁰Sr/¹³⁷Cs was within the range of those reported for soils in Spain. Finally, the maximal effective dose rate was estimated to be 37 and 88 μSv/y for infants and adults, respectively, well below 1 mSv/y reference level. The main contributor to effective dose was ²¹⁰Pb, about 92%, followed by:²¹⁰Pb ≫ ^228,230,232Th > ²²⁶Ra, ^234,238U > ⁷Be, ^239+240Pu > ⁴⁰K, ⁹⁰Sr > ¹³⁷Cs > ²²Na



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Impacts on the terrestrial environment in case of a hypothetical accident involving the recovery of the dumped Russian submarine K-27

Publication date: December 2016
Source:Journal of Environmental Radioactivity, Volume 165
Author(s): J.E. Brown, I. Amundsen, J. Bartnicki, M. Dowdall, J.E. Dyve, A. Hosseini, H. Klein, W. Standring
Objects containing radioactivity have been routinely dumped in Arctic waters near NW Russia up until the 1990s. One of the most radioactive objects in this region, the nuclear submarine K-27, was dumped in Stepogovo Fjord and contained spent nuclear fuel (SNF). Although the two K-27 submarine reactors were mothballed before dumping, concerns about the potential long term risks of contamination remain and plans to retrieve and decommission K-27 exist. In this article, human dose and environmental impact aseessments are presented for two possible future scenarios involving: (1) an ingress of water into a reactor in situ leading to a spontaneous chain reaction (SCR) and (2) an on-board fire when SNF is being removed at the mainland decommissiong site at Gremhika Bay on the Kola Peninsula. Assessments have been completed using conservative assumptions, focusing on possible effects to Norwegian territory. Atmospheric transport and deposition of radioactivity was modelled near field and regionally, using appropriate models, whilst human doses and environmental exposures were modelled using a standard IAEA approach and the ERICA tool, respectively. Results indicate that large areas of Norwegian territory could be affected by fallout from the Gremhika scenario, especially in the north, though at levels two orders of magnitude lower than those observed after the Chernobyl accident. Potential doses, primarily due to ground shine, to a critical group of personnel on-site at Stepogovo resulting from a SCR could require preventative measures based on ICRP recommendations (20–100 mSv). Doses to non-human biota in Norway for the Gremhika scenario would be negligible, typical of background dose rates for terrestrial organisms.



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A novel familial autosomal dominant mutation in ARID1B causing neurodevelopmental delays, short stature, and dysmorphic features

Recent studies have identified mutations in the ARID1B gene responsible for neurodevelopmental delays, intellectual disability, growth delay, and dysmorphic features. ARID1B encodes a subunit of the BAF chromatin-remodeling complex, and mutations in multiple components of the BAF complex have been implicated as causes of Coffin–Siris syndrome, Nicolaides–Baraitser syndrome, and non-syndromic intellectual disability. The majority of documented pathogenic ARID1B mutations to date have arisen in a sporadic, de novo manner with no reports of inheritance of a pathogenic mutation from an affected parent. We describe here two patients (a 21-year-old female and her 21-month-old son) with a novel frameshift mutation in ARID1B inherited in an autosomal dominant fashion in the affected offspring. Both patients presented with neurodevelopmental delays, growth delay, and dysmorphic features including prominent nose with full nasal tip, long philtrum, and high-arched palate. Exome sequencing analysis in the female patient demonstrated a heterozygous deletion of nucleotide 1259 of the ARID1B gene (c.1259delA) resulting in a frameshift and creation of a premature stop codon. Further family testing by targeted Sanger sequencing confirmed that this arose as a de novo mutation in the mother and was passed on to her affected son. The clinical features of both patients are felt to be consistent with an ARID1B-related disorder. To our knowledge, this is the first report of a pathogenic mutation in ARID1B being passed from an affected parent to their offspring. © 2016 Wiley Periodicals, Inc.

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Maternal hypertension and risk for hypospadias in offspring

Hypospadias is one of the most common birth defects in male infants. Maternal hypertension is a suspected risk factor; however, few previous studies have addressed the possibility of reporting bias, and several previous studies have not accounted for hypospadias severity. We analyzed data from the Texas Birth Defects Registry for 10,924 nonsyndromic cases and statewide vital records for deliveries during 1999–2009, using Poisson regression. After adjustment for potential confounders, hypospadias was associated with maternal hypertension (adjusted prevalence ratio: 1.5, 95% confidence interval: 1.4–1.7). Similar associations were observed with gestational and pregestational hypertension, including separate analyses restricted to the subset of cases with severe (second- or third-degree) hypospadias. All of these associations were also similar among the subset of cases with isolated hypospadias (without additional birth defects). To evaluate the potential for bias due to potential hypertension misclassification, we repeated our analyses using logistic regression, comparing the cases to controls with other birth defects. In these analyses, the associations with gestational hypertension were similar, but adjusted associations with pregestational hypertension were no longer observed. Our findings support an association between gestational hypertension and hypospadias in offspring, but also suggest that previously observed associations with pregestational hypertension may have been inflated due to differential misclassification of hypertension (e.g., reporting bias). As gestational hypertension is recognized after hypospadias development, more research is needed to determine if this association reflects an increase in gestational hypertension risk secondary to hypospadias or if both conditions have shared risk factors (e.g., precursors of gestational hypertension). © 2016 Wiley Periodicals, Inc.

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Jacobsen syndrome, Braddock–Carey syndrome, and Beyond: Reflections on intellectual disability accompanied with thrombocytopenia

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