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In animals, migration is an evolutionary adaptation to manage seasonally varying habitats. Often driven by climatic changes or resource availability, amphibians then migrate from their hibernation sites to their breeding grounds. This research focused on the migratory habits of the Great crested newt (Triturus cristatus). The study explored factors like gender, body size, and environmental determinants, noting that immigration and emigration events proved distinct during the year. Results unveiled that males typically reached ponds first, with temperature being pivotal: males preferred up to 5 °C, females around 10 °C, while juveniles moved as temperatures increase. Wind velocity affected larger newts, around 120 mm, prompting them to migrate with stronger winds. Notably, heavy rainfall favored migration of newts of roughly 60 mm size. Humidity displayed gender-based trends: males associated positively with average levels, females showed aversion above 50%, and juveniles leaned towards drier conditions. Emigration patterns mirrored these findings, emphasizing roles of temperature, wind, and humidity. The effect of moonlight is not statistically significant. These findings provide valuable insights into the environmental factors influencing the migration of T. cristatus, which may guide future conservation efforts.

Small waterbodies like floodplain ponds are considered to be an important component of the global carbon budget. Although they are found in large numbers worldwide and their numbers are increasing every year due to the creation of new ponds, we do not have sufficient data on direct estimates of emission fluxes from these waterbodies yet. Herein, we present results from a set of 24 ponds located in the Morava River floodplain, Czech Republic. The ponds varied in their origin (man-made vs. natural), size, depth, sediment organic matter content, and macrophyte growth. Water chemistry parameters, concentrations, and exchange of CO2 and CH4 with the atmosphere were directly measured during the day and night from spring to summer 2020. The ponds emitted more CO2 and CH4 during nighttime, and both CO2 and, in particular, CH4 emissions tend to increase with the duration of pond inundation. Total diffusive fluxes of CO2 and CH4 into the atmosphere ranged from −37072.9 to 432683.3 μmol m−2 d−1, and −11485.3 to 95,889.6 μmol m−2 day−1, respectively. Generally, all ponds were found to be a net source of CO2 and CH4 to the atmosphere. In average, ponds emitted 7.64 g CO2-equivalent m−2 d−1. Thus, our results indicate that floodplain ponds are an important source of both CO2 and CH4 to the atmosphere and they should not be omitted in a regional carbon budget.

A crucial aspect of conservation management for endangered newt species is the establishment of a monitoring methodology and the evaluation of trap efficacy to ensure the accuracy of data collection. In this study, we assessed three funnel trap types (prism shape, umbrella shape, and Ortmann's trap) to capture great crested newts (Triturus cristatus). We also tested three baits (chicken liver, chemical lights in glow sticks, and control traps without bait) and determined the optimal trap control time within a 12 h period. Our findings showed that the umbrella shape trap was most effective, catching five times more newts than the Ortmann's and prism shape traps. Surprisingly, the commonly used prism shape trap performed poorly. Bait type did not significantly impact newt captures compared to control traps. During the 12 h experiment, newts spent the longest time in the chicken liver-baited Ortmann's trap (averaging 4.5 h), while the umbrella shape trap with chicken liver bait had the highest turnover of individuals. We observed no behavioural response from “trap-shy” individuals. This study emphasizes the importance of selecting appropriate traps, considering bait choice, and trap control time for effective monitoring of endangered newt populations.

Abstract Reproductive isolation barriers maintain the integrity of species by preventing interspecific gene flow. They involve temporal, habitat or behavioral isolation acting before fertilization, and postzygotic isolation manifested as hybrid mortality or sterility. One of the approaches of how to study reproductive isolation barriers is through the analysis of hybrid zones. In this paper, we describe the structure of a hybrid zone between two crested newt species (Triturus cristatus and T. carnifex) in the southern part of the Czech Republic using morphological, microsatellite, and mitochondrial (mtDNA) markers. Specifically, we tested the hypothesis that the structure of the hybrid zone is maintained by species‐specific habitat preferences. Comparing the genetic structure of populations with geographical and ecological parameters, we found that the hybrid zone was structured primarily geographically, with T. cristatus‐like populations occurring in the northeast and T. carnifex‐like populations in the southwest. Despite T. cristatus tending to occur in deeper ponds and T. carnifex on localities with more shading, the effect of both ecological parameters on the structure of the zone was minimal. Next, we corroborated that T. carnifex individuals and some hybrids possess mtDNA of T. dobrogicus, whose nuclear background was not detected in the studied hybrid zone. Hybridization between T. carnifex and T. dobrogicus (resulting in unidirectional mtDNA introgression) had to predate subsequent formation of the hybrid zone between T. cristatus and T. carnifex. Populations of crested newts in the southern part of the Czech Republic thus represent a genetic mosaic of nuclear and mitochondrial genomes of three species.

Antibiotic resistance has become a global threat in which the anthropogenically influenced aquatic environment represents not only a reservoir for the spread of antibiotic resistant bacteria (ARB) among humans and animals but also an environment where resistance genes are introduced into natural microbial ecosystems. Wastewater is one of the sources of antibiotic resistance. The aim of this research was the evaluation of wastewater impact on the spread of antibiotic resistance in the water environment. In this study, qPCR was used to detect antibiotic resistance genes (ARGs)—blaCTX-M-15, blaCTX-M-32, ampC, blaTEM, sul1, tetM and mcr-1 and an integron detection primer (intl1). Detection of antibiotic resistant Escherichia coli was used as a complement to the observed qPCR results. Our results show that the process of wastewater treatment significantly reduces the abundances of ARGs and ARB. Nevertheless, treated wastewater affects the ARGs and ARB number in the receiving river.

Tracking individual animals with small-sized passive integrated transponder tags (PIT tags) has become a popular and widespread method, one which can be used for investigating life history traits, including dispersal patterns of small protected animals such as newts. In this study, we tested the applicability of PIT tag usage for individual marking with the Great crested newt (Triturus cristatus) as a model amphibian species, and to test the detection of the newts in nature using a passive telemetry system. Clove oil was used as an anaesthetic before surgery. We implanted PIT tags under the skin of 140 newts. The survival rate of newts was 98.57%. X-ray images were taken to check the exact positions of the PIT tags. Since approximately 15.71% of the newts were capable of expelling the tag from their bodies, tag loss has to be accounted for in future behavioural studies dealing with newts and other amphibians potentially capable of frequent tag expulsion. Lastly, we detected by passive telemetry 97 individuals out of 100 released into a natural breeding pond. Males had higher activity (13 detected males vs 7 females per hour) than females, thus males could be detected if present with more certainty. The result of the movement behaviour showed that e.g. the male of T. cristatus in a breeding pond can travel up to 20 m in 78 seconds. In summary, this promising method could allow the automatic data collection of marked newts in aquatic as well as in terrestrial biotopes, providing data on their dispersal, diurnal activity and movement behaviour.

Morphological abnormalities occur frequently in wild amphibian populations. We analysed malformation and injuries in the hybrid zone of three crested newt species, in the Czech Republic. In total, 274 individuals from 35 localities in South Moravia (Czech Republic) were examined during the period 2010-2014. Malformations were found in eight newts (2.9%) from seven localities. Injuries were recorded on 59 newts (21.5%). Proportions of tail crest injuries was significantly higher (P ˂ 0.1) in males than in females and the probability of being injured was significantly higher (P ˂ 0.01) for adult individuals. We discuss gene mutation, parasitism and predation as possible explanations for our observations.

Methanogenic archaea produce methane as a metabolic product under anoxic conditions and they play a crucial role in the global methane cycle. In this study molecular diversity of methanogenic archaea in the hyporheic sediment of the lowland stream Sitka (Olomouc, Czech Republic) was analyzed by PCR amplification, cloning and sequencing analysis of the methyl coenzyme M reductase alpha subunit (mcrA) gene. Sequencing analysis of 60 clones revealed 24 different mcrA phylotypes from hyporheic sedimentary layers to a depth of 50 cm. Phylotypes were affiliated with Methanomicrobiales, Methanosarcinales and Methanobacteriales orders. Only one phylotype remains unclassified. The majority of the phylotypes showed higher affiliation with uncultured methanogens than with known methanogenic species. The presence of relatively rich assemblage of methanogenic archaea confirmed that methanogens may be an important component of hyporheic microbial communities and may affect CH4 cycling in rivers.

Three experiments were conducted with a volunteer to test the kinetics of the 222Rn exhalation after a short-time exposure to an elevated 222Rn air concentration. Radon concentration in an exhaled air was measured, complemented by whole body counting of 222Rn decay products in a body. Exhaled activities are compared with the prediction of the recent ICRP biokinetic model for radon. While a rapid equilibration of the exhaled radon activity concentration with that in the air inhaled corresponded with the model, the measured 222Rn exhalation rate was significantly less than modelled. Five hours after termination of the inhalation phase, the radon concentration in the exhaled air decreased to levels expected for non-elevated indoor radon activity concentration. Whole body activities of the 222Rn decay products were found higher than expected. Inhalation of the unattached fraction or residual activity of decay products in the air inhaled may be the explanation. [ABSTRACT FROM AUTHOR]

Radon is one of the main potential sources of background radiation for any rare event experiments like neutrinoless double beta decay or dark matter experiments. The Radon Trapping Facility (RTF) installed in 2004 at the Modane Underground Laboratory (LSM) has been running for nine years providing radon-purified air at a level of 10 mBq m−3 for several experiments. The radon suppression principle is based on a radon physical adsorption using cooled compressed air at −55 °C pumped through a column filled with the K48 activated charcoal. After disassembling of the RTF, the 2.6 m high charcoal column has been divided into several layers in order to study with different techniques the dynamic adsorption coefficient (the K-factor) as a function of the depth and the radon spatial trapping profile by measuring the 210Pb activity. It has been demonstrated that after almost a decade of running, the K-factor of the activated charcoal remains constant except for the first few cm of the column. Furthermore, it has been demonstrated that the mass activity of 210Pb as a function of the depth of the charcoal column exhibits an exponential decay profile. The radon mean retention time τR of (47.6 ± 1.2) days and the radon mean free path of (28.9 ± 0.4) cm have been derived and found to be consistent at 1σ with the ones obtained from the K-factor study, i.e. from a total independent measurement. The radon suppression factor of the RTF of has been also estimated with a value consistent at 2σ with the suppression factor measured during the RTF operation. Thus, this study has proven the capacity of the RTF to purify the LSM air from radon by more than three orders of magnitude during nine years of operation. [ABSTRACT FROM AUTHOR]

Po was determined in 24-h urine of seven healthy males from Prague, Czech Republic, for ten consecutive days. The results show that for each volunteer, the urinary excretion of Po changed only little from day to day in the studied time period. For two volunteers, the difference in the daily excreted Po activity for two consecutive days was not significant, given the 95 % confidence interval (two sigma) of the activity measurements. The same is valid for the excretion data of the other volunteers, except for some days where the differences were slightly higher. The range of daily urinary excretion of Po of each volunteer in the studied time period was quite narrow. Among the volunteers, the maximum daily urinary excretion value of Po was at most about a factor of 2.5 higher than the lowest excretion value. An attempt to explain the observed small inter-individual variability of Po excretion in daily urine is made. [ABSTRACT FROM AUTHOR]

Activity concentrations of 137Cs were detected in more than 400 outer spruce bark samples collected at sites variably affected by Chernobyl fallout across the Czech Republic in 1995 and 2010. The temporal changes in the 137Cs activities were found. The mean effective half-life (T EF) for 137Cs in spruce bark was 9.6 years, and the mean environmental half-life (T E) was 14 years. The effective half-lives were significantly higher in areas with higher long-term annual precipitation sums. Coefficient a in linear regression y = ax + b of half-lives on precipitation sums was 0.015 y mm−1 for T EF and 0.036 y mm−1 for T E. The aggregated transfer factor of 137Cs from soil to bark was determined and the pre-Chernobyl bark contamination related to year 2010 was estimated. [Copyright &y& Elsevier]

This paper reports on results of activity mass concentration analyses performed in various forest mushrooms in the Czech Republic within 1986 and 2011. The estimated effective half-life of 137Cs and its environmental half-life (i.e. the effective half-life minus the effect of physical decay) were found to be 5.6±0.6 and 6.9±0.7 y, respectively. Non-homogeneity in 137Cs surface contamination over the country's territory and fungus species-based 137Cs accumulation capacity then account for a span of up to 4 orders of magnitude in activity mass concentrations measured each year after the Chernobyl accident. The highest geometric activity mass concentration (Bq kg−1 of dry weight) means of 137Cs (obtained from samples between years 2004 and 2011) were measured in Suillaceae (1050 Bq kg−1) and Boletus badius (930 Bq kg−1), the lowest in Agaricus (1 Bq kg−1). The geometric mean of all mushrooms amounted to 230 Bq kg−1, being 440 Bq kg−1 in Boletales, 150 Bq kg−1 in Russulales and 21 Bq kg−1 in Agaricales. Geometric standard deviation levels were generally high. The highest Cs accumulation capacity was observed in Boletales (namely in Suillaceae), while the lowest in Agaricales, being over 3 orders of magnitude lower than in Suillaceae. [ABSTRACT FROM PUBLISHER]

Abstract: The 137Cs specific activities (mean 32Bqkg−1) were determined in spruce bark samples that had been collected at 192 sampling plots throughout the Czech Republic in 1995, and were related to the sampling year. The 137Cs specific activities in spruce bark correlated significantly with the 137Cs depositions in areas affected by different precipitation sums operating at the time of the Chernobyl fallout in 1986. The ratio of the 137Cs specific activities in bark and of the 137Cs deposition levels yielded bark aggregated transfer factor Tag about 10.5×10−3 m−2 kg−1. Taking into account the residual specific activities of 137Cs in bark 20Bqkg−1 and the available pre-Chernobyl data on the 137Cs deposition loads on the soil surface in the Czech Republic, the real aggregated transfer factor after and before the Chernobyl fallout proved to be T*ag =3.3×10−3 m−2 kg−1 and T**ag =4.0×10−3 m−2 kg−1, respectively. The aggregated transfer factors T*ag for 137Cs and spruce bark did not differ significantly in areas unequally affected by the 137Cs fallout in the Czech Republic in 1986, and the figures for these aggregated transfer factors were very similar to the mean bark Tag values published from the extensively affected areas near Chernobyl. The magnitude of the 137Cs aggregated transfer factors for spruce bark for the pre-Chernobyl and post-Chernobyl period in the Czech Republic was also very similar. The variability in spruce bark acidity caused by the operation of local anthropogenic air pollution sources did not significantly influence the accumulation and retention of 137Cs in spruce bark. Increasing elevation of the bark sampling plots had a significant effect on raising the remaining 137Cs specific activities in bark in areas affected by precipitation at the time when the plumes crossed, because the sums of this precipitation increased with elevation (covariable). [Copyright &y& Elsevier]

Carbon-14 is a radionuclide with global occurrence and partly natural origin. The main anthropogenic sources of the 14C were the nuclear weapon tests, namely at the beginning of the 1960s, nowadays the nuclear energy facilities are the main sources. Maximum in the atmospheric 14C activity was observed in 1963. In the following years the considerable 14C activity decrease was due to intensive carbon deposition into oceanic water and sediments particularly. At present the 14C activity approximates the level before nuclear age, corresponding to ∼0 ‰ Δ14C. Another actual type of anthropogenic influence is the Suess effect, i.e., the dilution of 14C by fossil carbon (fuel combustion). This effect causes a decrease of the 14C activity on a global, regional and local scale. Thus, monitoring of actual reference level of 14C activity gives a possibility to indicate local or global anthropogenic influences. This paper reporting data from the atmospheric 14CO2 monitoring in the Czech Republic and Hungary compares the actual results with other European countries. The observed effects connected with local and regional CO2 releases from fossil fuel combustion are discussed. [ABSTRACT FROM AUTHOR]

Methane (CH 4) is an important atmospheric trace gas mostly released from wet anoxic soils and sediments. While many studies have focused on relatively homogenous environments like rice fields and lake sediments, the changing contribution of heterogeneous sediments e.g. along the longitudinal profile of a rivers has not been covered very frequently. Here we investigated sediment samples from 11 locations of the Elbe River. Sediments were incubated to measure methanogenic/methanotrophic potentials and contribution of individual methanogenic pathways using isotope analysis of δ13C. Additionally, we determined the diversity of the methanogenic communities (analysis of T-RFLP targeting the mcr-A gene in the sediment samples), while abundances of archaea, methanogens and methanotrophs were determined by qPCR. The CH 4 production was detected in six samples (out of 11 examined) and ranged from 0.12 to 644.72 nmol gDW−1 d−1. Methanotrophy was found in all examined sediment samples and ranged from 654 to 10,875 nmol gDW−1 d−1. Abundance of methanogens and methanotrophs (Mcr-A and pmo-A gene copy numbers) was not significantly different and quite stable around 106 to 107 copies gDW−1. The group specific qPCR showed high fluctuations, while the highest counts were reported for Methanomicrobiales and Methanosarcinales (105 to 108 copies per gram dry sediment), followed by Methanobacteriales (103 to 105 copies per gram dry sediment). A significant proportion of unidentified methanogens was found in almost every locality. Isotope analysis of δ13C showed that (CH 4) is produced mainly by hydrogenotrophic methanogens. We see no trend in the studied parameters along the Elbe River. The molecular data showed no spatial characteristics, while we found hotspots of the measured CH 4 processes (CH 4 production and oxidation) due to other local driving factors (e.g. carbon content). Thus, out results indicate that the observed variability of the CH 4 production and oxidation rates is only indirectly linked to the presence or quantities of different microbial guilds. [ABSTRACT FROM AUTHOR]

Abstract: This work presents the results of 137Cs content long-term monitoring (1986–2007) in selected groups of foodstuffs. The data in the period of 1992–2007 were roughly log-normally distributed (beef, pork, milk). The more detailed statistical evaluation in this period of time was performed. Maximum likelihood method was used for estimation of the mean values. Several methods for decreasing the detection limits of 137Cs (detector efficiency, sample preparation, counting containers) are listed and compared. [Copyright &y& Elsevier]

Agricultural lands with farm animals (e.g. cattle) can be significantly affected by radioactive contamination following nuclear or radiation accidents. In order to optimise the techniques for measuring 137Cs in contaminated cattle, selected radiation detectors have been tested and calibrated using volumetric radiation sources. In addition, a mathematical phantom of a cow was created within Monte Carlo simulations. The main aim of the research was to propose a method for making rapid measurements of 137Cs in cattle in vivo/in situ and to select the most suitable measurement set-up. Measurements of contaminated cattle in vivo were carried out in Belarus with one selected detector, and were then compared with measurements of meat in a laboratory and with measurements of a control group of cows. The proposed measurement method was also tested on measurements of 137Cs in wild boars in Czechia with higher levels of the 137Cs activity., (© The Author(s) 2023. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.)

Aggregated transfer factors (T ag ) were identified for three common vegetables grown in six common European soils freshly contaminated by 134 Cs and 85 Sr. The experiment was carried out as a mesocosm experiment in pots with an average soil weight of 15.8 kg per pot. The vegetables were grown one after the other during one vegetation season, in the order lettuce, onion, and radish (the order usually applied in private gardens and small farms). Despite the fact that lettuce was grown in the most contaminated soil, it had the lowest T ag (in m 2 /kg) of both radionuclides (3.6E-4 for Cs, 2.0E-2 for Sr), while onion had 6.4E-3 for Cs and 3.2E-2 for Sr and radish had 1.9E-3 for Cs and 8.1E-2 for Sr. Potassium supply did not show any statistically significant effect on Cs T ag ; there was a significant impact of K on the decrease in Sr T ag . The experiments indicated that T ag is more affected by plant species than by soil type; therefore, selection of plants with a lower capacity to uptake radionuclides may be an important measure to reduce food contamination and thus minimize the committed effective dose., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 Elsevier Ltd. All rights reserved.)

The study aims to provide a basis for measures reducing the consequences of a nuclear accident in its late phase, when plant contamination occurs mainly through the root system. Samples of the above-ground biomass of crops and soil were taken in 2020 in the vicinity of the Temelín and Dukovany nuclear power plants (Czech Republic). The 137Cs activities were determined using gamma spectrometry, and the 90Sr activities were measured through beta radiation. From the obtained values, the radionuclide transfer factors (TFs) from soil to crop biomass were calculated. The average area activity of 137Cs in the soil around Dukovany and Temelín was 1700 and 2400 Bq m-2, respectively. The average area activity of 90Sr around Dukovany and Temelín was 211 and 184 Bq m-2, respectively. The TF 137Cs ranged from < 6.3 × 10-6 to 7.9 × 10-3, with a mean of 3.5 × 10-4 m2 kg-1, and the TF 90Sr ranged from 2.7 × 10-4 to 6 × 10-2, with a mean of 1.7 × 10-2 m2 kg-1., (© The Author(s) 2022. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.)

High-volume aerosol samplers combined with laboratory analysis using high-resolution gamma ray spectrometry allow determining artificial radionuclides in the atmosphere at sub μBq/m3 levels. A major drawback of this procedure is a significant delay of the analysis result after any potential radioactive contamination deposition on the aerosol filter. Within the scope of the HAMRAD project, an autonomous device was developed in order to increase the sampling and measuring frequency. This approach yields higher detection limits (minimum detectable activity concentration [MDAC]) due to the deposited activity of radon decay products on the filter. In order to quantify the radon effect, a simple mathematical model was developed to predict MDAC for the particular radionuclide of interest for the given background conditions. It was found that MDAC can vary by a factor of ~2 for typical 'radon' conditions (~10 Bq/m3) at SÚRO Prague and by a factor up to 5 for high radon concentration (100 Bq/m3)., (© The Author(s) 2019. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.)

Currently, the territorial Radiation Monitoring Network (RMN) of the Czech Republic consists of seven laboratories equipped with gamma spectrometry High Purity Germanium (HPGe) detectors. From 2007 to 2018, five emergency exercises were carried out to test the sample throughput of these facilities and their staff. The main objective was to identify weaknesses and problem areas in the whole process from the moment of obtaining the samples to logging the results into the central RMN database. The long-term aim of these exercises is to optimize emergency response procedures. The most important factor limiting laboratory capacity is the lack of qualified personnel. The exercises showed that in the current state, these laboratories would be able to operate in 12-hour shifts for 14 days and analyze 1700 samples per day. Emergency exercises have highlighted the fact that this type of exercise should be repeated periodically in order to monitor the performance and analytical capabilities of RMN., (© The Author(s) 2019. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.)

Traces of particulate radioactive iodine ( 131 I) were detected in the European atmosphere in January/February 2017. Concentrations of this nuclear fission product were very low, ranging 0.1 to 10 μBq m -3 except at one location in western Russia where they reached up to several mBq m -3 . Detections have been reported continuously over an 8-week period by about 30 monitoring stations. We examine possible emission source apportionments and rank them considering their expected contribution in terms of orders of magnitude from typical routine releases: radiopharmaceutical production units > sewage sludge incinerators > nuclear power plants > spontaneous fission of uranium in soil. Inverse modeling simulations indicate that the widespread detections of 131 I resulted from the combination of multiple source releases. Among them, those from radiopharmaceutical production units remain the most likely. One of them is located in Western Russia and its estimated source term complies with authorized limits. Other existing sources related to 131 I use (medical purposes or sewage sludge incineration) can explain detections on a rather local scale. As an enhancing factor, the prevailing wintertime meteorological situations marked by strong temperature inversions led to poor dispersion conditions that resulted in higher concentrations exceeding usual detection limits in use within the informal Ring of Five (Ro5) monitoring network.

The activity concentration of 137 Cs in samples of coniferous forest humus collected across the territory of the Czech Republic in 1995 and 2005 was analysed, and it was found significantly correlated with the surface deposition caused by the Chernobyl accident. The effective (12.8 y) and environmental (22.3 y) half-lives of radiocaesium in humus were calculated and compared with those in spruce bark. The impact of important forest stand factors, that is, precipitation, content of organic matter, age of trees and pH, on the behaviour of 137 Cs in humus was studied. It was observed that humus samples with a higher proportion of organic matter, higher pH(H2O) and pH(CaCl2) contained higher amounts of 137 Cs. Conversely, with the age of trees, the activity concentration of 137 Cs in humus is decreasing. Higher precipitation and humus acidity decrease the reduction rate of the 137 Cs in humus. These stand factors increase bioavailability of 137 Cs in humus. The transfer and retention of available 137 Cs in biomass of organisms living in humus for a long time can satisfactorily explain the longer residence time of 137 Cs in humus affected by the studied factors., (Copyright © 2017 Elsevier B.V. All rights reserved.)

In order to increase the early warning ability of the radiation monitoring network of the Czech republic, a high-volume aerosol sampler was upgraded with a NaI(Tl) probe placed directly above the aerosol filter. The paper demonstrates the possibility of using a method based on principal component regression to accurately subtract the complicated natural background caused by radon decay products. This approach yielded minimum detectable activities of 8mBq/m 3 , 3mBq/m 3 and 7mBq/m 3 for 131 I, 134 Cs and 137 Cs, respectively, after 24h of sampling., (Copyright © 2016 Elsevier Ltd. All rights reserved.)

Current (137)Cs activity concentrations were studied at three localities in individual soil horizons of Stagnosol, Arenic Podzol and Haplic Cambisol soil units in soil blocks with dimensions of 20 × 20 × 40 cm situated below pine canopies (n = 3) and spruce canopies (n = 3), and below small canopy gaps, at least 15 × 15 m in area (n = 3 + 3), which have probably endured since 1986. The main zone of (137)Cs accumulation in all the localities was found to be in the organic horizons (H and F). No significant transport and accumulation of (137)Cs into illuvial soil horizons (Bm, Bs or Bhs, Bv and Bv/IIC) was found. The estimated current total (137)Cs activity concentrations in the soil blocks 40 cm in depth were only slightly higher below the coniferous canopy than they were below nearby canopy gaps. The inventory of (137)Cs in the soils was found to be in accordance with the estimated (137)Cs inputs from the Chernobyl fallout and from global fallout. The low amounts of (137)Cs found accumulated in the aboveground biomass (mosses, grasses, needles) did not substantially bias the studied radiocaesium balance in the soils. The vertical migration rate of (137)Cs in soils (cm/year) had a tendency to be higher below canopies than below canopy gaps and below pine canopies than below spruce canopies. We expected the current (137)Cs activity concentrations in the individual soil horizons to be related to the studied soil parameters: pH (H2O), pH (CaCl2), content of organic matter and mineral portion and portion of humic and fulvic acid contents (Q4/6). However, this was not confirmed. Similarly, we observed a weak tendency toward higher (137)Cs activity in soils below the canopy than in soils below canopy gaps. The available gaps used in our study may have been too small, and they may have been affected by an accumulation of litter and humus containing (137)Cs from the surrounding plots situated below neighbouring canopies., (Copyright © 2016 Elsevier Ltd. All rights reserved.)

This paper presents the results of atmospheric radioactivity monitoring over the Czech Republic, as obtained by the Radiation Monitoring Network, following the Fukushima Dai-Ichi Nuclear Power Plant accident. Maximum values for (131)I were 5.6 mBq m(-3) in aerosol form and 13 mBq m(-3) in gaseous form. The maximum values for (134)Cs and (137)Cs were 0.64 and 0.72 mBq m(-3), respectively. The estimated effective half-time for removing the activity from the atmosphere was 6-7 d and 3.5 d for caesium and iodine, respectively. The gaseous-to-total activity ratios of (131)I ranged between 0.3 and 0.9, with an arithmetic mean value of 0.77. The mean value for the (134)Cs/(137)Cs ratios was close to 1.0. The effective inhalation dose due to the accident for an adult living in the Czech Republic was estimated at <4 × 10(-5) mSv, out of which the proportion of (131)I was 88%., (© The Author 2014. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.)

The paper summarizes results of monitoring of (137)Cs activities in game species roaming in the woods over the territory of the Czech Republic for the time interval of 1986-2012. Geometric means and other statistical characteristics were estimated from the data sets on the assumption of log-normal distribution of the data from the time interval 2004-2012 where the character of data distribution had displayed no significant change. Geometric means (in Bq/kg) in meat were: wild boar 5.1, red deer 1.9, roe deer 0.77 and feathered game 0.14. The mean value in the less frequent game amounted to 0.36 Bq/kg. The geometrical standard deviation (GSD) widely varied from 1.6 to 21 for the studied species. Based on mass activity dependence on time, we assessed the effective and environmental half-lives of activity decline. For red deer and roe deer, the effective (137)Cs half-life was 2.9 and 3.2 years, and environmental half-life 3.2 and 3.6 years respectively. The effective half-life of (137)Cs in wild boar of 38 years was determined with large uncertainty and it shows constant influx of (137)Cs activity to the digestive tract of wild boars. A statistically significant season-based (137)Cs level was found in red deer and wild boar. Higher winter and spring activities of (137)Cs in wild boar are linked with decreasing access to naturally occurring food with lower (137)Cs content (chestnuts, acorns, and beech nuts), making boar grub around for ground-deposited food (often for mushrooms with higher activity). Higher winter activities of (137)Cs in red deer meat, most probably, are due to lower access to green diet in winter. The average annual committed effective dose for Czech population based on estimates of game species meat consumption between 2004 and 2012 was insignificant, only 0.03 μSv., (Copyright © 2014 Elsevier Ltd. All rights reserved.)

Activity concentrations of (137)Cs were detected in more than 400 outer spruce bark samples collected at sites variably affected by Chernobyl fallout across the Czech Republic in 1995 and 2010. The temporal changes in the (137)Cs activities were found. The mean effective half-life (TEF) for (137)Cs in spruce bark was 9.6 years, and the mean environmental half-life (TE) was 14 years. The effective half-lives were significantly higher in areas with higher long-term annual precipitation sums. Coefficient a in linear regression y = ax + b of half-lives on precipitation sums was 0.015 y mm(-1) for TEF and 0.036 y mm(-1) for TE. The aggregated transfer factor of (137)Cs from soil to bark was determined and the pre-Chernobyl bark contamination related to year 2010 was estimated., (Copyright © 2013 Elsevier Ltd. All rights reserved.)

This paper reports on results of activity mass concentration analyses performed in various forest mushrooms in the Czech Republic within 1986 and 2011. The estimated effective half-life of (137)Cs and its environmental half-life (i.e. the effective half-life minus the effect of physical decay) were found to be 5.6 ± 0.6 and 6.9 ± 0.7 y, respectively. Non-homogeneity in (137)Cs surface contamination over the country's territory and fungus species-based (137)Cs accumulation capacity then account for a span of up to 4 orders of magnitude in activity mass concentrations measured each year after the Chernobyl accident. The highest geometric activity mass concentration (Bq kg(-1) of dry weight) means of (137)Cs (obtained from samples between years 2004 and 2011) were measured in Suillaceae (1050 Bq kg(-1)) and Boletus badius (930 Bq kg(-1)), the lowest in Agaricus (1 Bq kg(-1)). The geometric mean of all mushrooms amounted to 230 Bq kg(-1), being 440 Bq kg(-1) in Boletales, 150 Bq kg(-1) in Russulales and 21 Bq kg(-1) in Agaricales. Geometric standard deviation levels were generally high. The highest Cs accumulation capacity was observed in Boletales (namely in Suillaceae), while the lowest in Agaricales, being over 3 orders of magnitude lower than in Suillaceae.

Following the Fukushima accident, a series of aerosol samples were taken between 24th March and 13th April 2011 by cascade impactors in the Czech Republic to obtain the size distribution of (131)I, (134)Cs, (137)Cs, and (7)Be aerosols. All distributions could be considered monomodal. The arithmetic means of the activity median aerodynamic diameters (AMADs) for artificial radionuclides and for (7)Be were 0.43 and 0.41 μm with GDSs 3.6 and 3.0, respectively. The time course of the AMADs of (134)Cs, (137)Cs and (7)Be in the sampled period showed a slight decrease at a significance level of 0.05, whereas the AMAD pertaining to (131)I increased at a significance level of 0.1. Results obtained after the Fukushima accident were compared with results obtained after the Chernobyl accident. The radionuclides released during the Chernobyl accident for which we determined the AMAD fell into two categories: refractory radionuclides ((140)Ba, (140)La (141)Ce, (144)Ce, (95)Zr and (95)Nb) and volatile radionuclides ((134)Cs, (137)Cs, (103)Ru, (106)Ru, (131)I, and (132)Te). The AMAD of the refractory radionuclides was approximately 3 times higher than the AMAD of the volatile radionuclides; nevertheless, the size distributions for volatile radionuclides having a mean AMAD value of 0.51 μm were very close to the distributions after the Fukushima accident., (Copyright © 2013 Elsevier Ltd. All rights reserved.)

The determination of low level activities of natural radionuclides from the uranium and thorium series by gamma-spectrometry faces the problem of proper natural background subtraction. Background fluctuation can cause differences in activity determination. Also the minimum detectable activity (MDA) of natural and artificial radionuclides can be influenced by background fluctuation. In this paper, results of the background fluctuation of shielded HPGe detectors with relative efficiency of 50-150% are presented together with the assessment of its influence on the determination of natural and artificial radionuclides., (© 2013 Elsevier Ltd. All rights reserved.)

Radioactive emissions into the atmosphere from the damaged reactors of the Fukushima Dai-ichi nuclear power plant (NPP) started on March 12th, 2011. Among the various radionuclides released, iodine-131 ((131)I) and cesium isotopes ((137)Cs and (134)Cs) were transported across the Pacific toward the North American continent and reached Europe despite dispersion and washout along the route of the contaminated air masses. In Europe, the first signs of the releases were detected 7 days later while the first peak of activity level was observed between March 28th and March 30th. Time variations over a 20-day period and spatial variations across more than 150 sampling locations in Europe made it possible to characterize the contaminated air masses. After the Chernobyl accident, only a few measurements of the gaseous (131)I fraction were conducted compared to the number of measurements for the particulate fraction. Several studies had already pointed out the importance of the gaseous (131)I and the large underestimation of the total (131)I airborne activity level, and subsequent calculations of inhalation dose, if neglected. The measurements made across Europe following the releases from the Fukushima NPP reactors have provided a significant amount of new data on the ratio of the gaseous (131)I fraction to total (131)I, both on a spatial scale and its temporal variation. It can be pointed out that during the Fukushima event, the (134)Cs to (137)Cs ratio proved to be different from that observed after the Chernobyl accident. The data set provided in this paper is the most comprehensive survey of the main relevant airborne radionuclides from the Fukushima reactors, measured across Europe. A rough estimate of the total (131)I inventory that has passed over Europe during this period was <1% of the released amount. According to the measurements, airborne activity levels remain of no concern for public health in Europe.

The (137)Cs specific activities (mean 32Bq kg(-1)) were determined in spruce bark samples that had been collected at 192 sampling plots throughout the Czech Republic in 1995, and were related to the sampling year. The (137)Cs specific activities in spruce bark correlated significantly with the (137)Cs depositions in areas affected by different precipitation sums operating at the time of the Chernobyl fallout in 1986. The ratio of the (137)Cs specific activities in bark and of the (137)Cs deposition levels yielded bark aggregated transfer factor T(ag) about 10.5×10(-3)m(-2)kg(-1). Taking into account the residual specific activities of (137)Cs in bark 20Bq kg(-1) and the available pre-Chernobyl data on the (137)Cs deposition loads on the soil surface in the Czech Republic, the real aggregated transfer factor after and before the Chernobyl fallout proved to be T*(ag)=3.3×10(-3)m(-2)kg(-1) and T**(ag)=4.0×10(-3)m(-2)kg(-1), respectively. The aggregated transfer factors T*(ag) for (137)Cs and spruce bark did not differ significantly in areas unequally affected by the (137)Cs fallout in the Czech Republic in 1986, and the figures for these aggregated transfer factors were very similar to the mean bark T(ag) values published from the extensively affected areas near Chernobyl. The magnitude of the (137)Cs aggregated transfer factors for spruce bark for the pre-Chernobyl and post-Chernobyl period in the Czech Republic was also very similar. The variability in spruce bark acidity caused by the operation of local anthropogenic air pollution sources did not significantly influence the accumulation and retention of (137)Cs in spruce bark. Increasing elevation of the bark sampling plots had a significant effect on raising the remaining (137)Cs specific activities in bark in areas affected by precipitation at the time when the plumes crossed, because the sums of this precipitation increased with elevation (covariable)., (Copyright © 2011 Elsevier B.V. All rights reserved.)