A review is presented of data on solid-liquid distribution coefficients (Kd-s) of the main radiologically important radionuclides of the Chernobyl release within geological deposits at the Chernobyl ...Nuclear Power Plant (ChNPP) Site. The Kd values for Sr, Cs and Pu for Quaternary sandy deposits that form sedimentary cover at Chernobyl fall within the range of parameters reported in international sorption databases. In agreement with general knowledge on radionuclide geochemical behavior and affinity to soils, Kd-s increase in the sequence: Sr < Cs < Pu. Alluvial and fluvioglacial sandy deposits are characterized by larger Kd values then deposits of eolian genesis due to higher content of clay minerals in fine fractions. For Sr, laboratory batch tests have given Kd values that are in a reasonable agreement with in situ measurements. At the same time, the 90Sr Kd-s obtained from groundwater transport model calibrations were noticeably lower than experimentally determined values, thus showing potential limitations of the Kd-approach. Monitoring data on mobility of 90Sr, 137Cs and 239,240Pu in groundwater in the Chernobyl zone on a whole are consistent with the radionuclide Kd-s summarized in this article. The highest concentrations in groundwater (based on data for 2012–2014) were observed for 90Sr, while orders of magnitude lower concentrations were observed for 137Cs and 239,240Pu. At the same time, detection of 137Cs and 239,240Pu in groundwater at sites with a relatively deep groundwater table suggests the possibility of facilitated transport of small amounts of these radionuclides in the form of non-retarded colloids or complexes.
•Sr, Cs and Pu Kd-s for deposits with different lithology in Chernobyl zone are compiled.•Methods of Kd determination are cross-compared.•The summarized Kd-s are generally consistent with international sorption databases.•Groundwater monitoring data are generally consistent with summarized Kd-s.•There is evidence of non-retarded transport of small amounts of radionuclides.
Once deposited, radiocesium remains in the environment for a long time, and constantly enters the food chain. Over time, game species tend to accumulate 137Cs by two orders of magnitude more than ...farm animals. This occurs especially in places heavily contaminated, thus meat products made out of local game should be treated with caution. One of such areas, known as the Opole Anomaly, is located in South-Western Poland and represents one of most 137Cs contaminated regions across Europe after the Chernobyl accident. The aim of the study was to find out the 137Cs activity in soil and local game, the value of the soil-to-game aggregated transfer factor and to assess the effective dose of the ionising radiation (Eeff) received by consumers of local game meat in years 2012–2019. We examined meat of three common game species: red deer, roe deer and wild boar for 137Cs activity. 137Cs activity in meat samples ranged from 0.14 to 592 Bq kg−1. The aggregated transfer factor (Tag) in game ranged from 0.006 to 0.01 m2 kg−1 f.w. for wild boar, 0.005–0.008 m2 kg−1 f.w. for roe deer, and 0.003–0.004 m2 kg−1 f.w. for red deer. The effective dose received by people who regularly consume local game meat ranged from less than 14.2 µSv y−1 to 134 µSv y−1, depending on the amount of differently contaminated game meat consumed annually. Even those for whom game is the only source of meat, consumption of wild boar along with local mushrooms and bilberries will, since 2012, not exceed the regulation limit of 137Cs at the level of 1 mSv y−1. By the best of our knowledge this is the first study regarding 137Cs activity in game and risk assessment from the most contaminated “post-Chernobyl” area in Poland.
•137Cs activity in three game species from the Opole Anomaly was studied in detail.•The highest mean activity of 137Cs in the years 2012–2019 was in wild boars.•The aggregated transfer factor values were similar to other studies from Europe.•Effective doses that hunters receive when consuming game are less than 200 µSv y−1.
30 years after the Chernobyl Nuclear Power Plant (CNPP) accident, its radioactive releases still remain of great interest mainly due to the long half-lives of many radionuclides emitted. Observations ...from the terrestrial environment, which hosts radionuclides for many years after initial deposition, are important for health and environmental assessments. Furthermore, such measurements are the basis for validation of atmospheric transport models and can be used for constraining the still not accurately known source terms. However, although the “Atlas of cesium deposition on Europe after the Chernobyl accident” (hereafter referred to as “Atlas”) has been published since 1998, less than 1% of the direct observations of 137Cs deposition has been made publicly available. The remaining ones are neither accessible nor traceable to specific data providers and a large fraction of these data might have been lost entirely. The present paper is an effort to rescue some of the data collected over the years following the CNPP accident and make them publicly available. The database includes surface air activity concentrations and deposition observations for 131I, 134Cs and 137Cs measured and provided by Former Soviet Union authorities the years that followed the accident. Using the same interpolation tool as the official authorities, we have reconstructed a deposition map of 137Cs based on about 3% of the data used to create the Atlas map. The reconstructed deposition map is very similar to the official one, but it has the advantage that it is based exclusively on documented data sources, which are all made available within this publication. In contrast to the official map, our deposition map is therefore reproducible and all underlying data can be used also for other purposes. The efficacy of the database was proved using simulated activity concentrations and deposition of 137Cs from a Langrangian and a Euleurian transport model.
Gridded map of the updated 137Cs deposition database for the Chernobyl accident. The resolution was set to 0.1° over Europe and 0.01° inside the Exclusion Zone of Chernobyl (25E-40E and 47N-55N). Display omitted
•A Chernobyl dataset is presented emphasising to the Former Soviet Union countries.•Deposition data of 137Cs have been improved significantly.•A gridded database of 0.1° × 0.1° resolution over Europe is directly available.•Using the same tools we have created a deposition map similar to Atlas.•Deposition of 137Cs, 90Sr, 238−240Pu and 241Am from 2015 are included.
An extended dataset of Chernobyl observations is made publicly available with emphasis in the Former Soviet Union countries, where about half of the radioactive pollution occurred.
The assessment of the fluctuating asymmetry based on measurement of the parameters of left and right parts of silver birch (Betula pendula (L.) Roth.) leaves and relative sizes of pairs of Scots pine ...(Pinus sylvestris L.) needles from the Chernobyl Exclusion Zone (ChEZ) was carried out. Twelve samples of both birch leaves and pairs of needles were collected from 10 trees at 5 sites in the Chernobyl Exclusion Zone and also at one control site located outside the ChEZ. Values of gamma dose rate in the air varied between the sites from 0.1 to 40 μGy h−1. Activity concentrations of 90Sr and 137Cs in the birch leaves varied over the range of 0.9÷2460 kBq kg−1 and 0.1÷339 kBq·kg−1 (DW), respectively. In addition to the above, in the Scots pine needles, these ranges were 0.7 ÷1970 kBq kg−1f for 90Sr and 0.1÷78 kBq kg−1 (DW) for 137Cs. From the values of the radionuclides activity concentrations in the plants, the internal dose rate is estimated to be in the range of 0.1 ÷ 274 μGy h−1. The main sources of the internal dose rate were radiation of 90Sr and 90Y. Indices of fluctuating asymmetry of silver birch leaves and Scots pine needles varied over the range of 0.048 ± 0.007 ÷ 0.060 ± 0.009 and 0.014 ± 0.002 ÷ 0.018 ± 0.002, respectively, and did not statistically differ for all experimental sites. The indices also did not depend on the external or internal dose rate of ionizing radiation for plants. The above findings seem to be consistent with other research effort in terms of understanding the response of organisms to chronic pollutant exposure and the long-term effects of large scale nuclear accidents.
Display omitted
•30-year impact of Chernobyl on plant species development.•Fluctuating asymmetry (FA) used as a measure of developmental stability.•No changes in developmental stability along gradient of a dose rate.•FA of leaves and needles remains unchanged in the face of the ionizing radiation.
Este artículo se acerca a la catástrofe nuclear ocurrida en Chernóbil el 26 de abril del año 1986, analizando, desde un punto de vista ideológico y cultural, la manera en que ha sido trabajada la ...memoria de la tragedia en el teatro iberoamericano contemporáneo. Atendiendo a este último adjetivo, conviene señalar que el intervalo temporal del estudio quedará ceñido exclusivamente a las obras y montajes realizados durante el presente siglo. Una vez establecidas estas premisas iniciales, será identificado un corpus de estudio concreto sobre el que trabajar y, a partir de aquí, se formularán tanto los elementos comunes como los códigos diferenciales y específicos de cada uno de los productos culturales seleccionados. Este análisis permitirá extraer claves pertinentes mediante las que elaborar una interpretación detallada en referencia a los espacios conceptuales del uso y la semántica configurados alrededor del topónimo Chernóbil. Se parte, pues, de la hipótesis de existencia de una serie de semas significativos adheridos al nombre mismo, que, a lo largo de los años, ha ido ampliando su base semántica, llegando a convertirse en un concepto con el que trabajar de forma creativa, tanto para la escritura dramática como para la puesta en escena. En este sentido, debemos tener en cuenta que la imagen de Chernóbil, la cual pasa de un ámbito puramente histórico y social a un espacio constituido por signos culturales, no mantiene una codificación única o exclusiva dirigida por institución alguna, sino que, más bien, parece responder a ingredientes psicológicos y emocionales relacionados con experiencias derivadas de realidades artísticas diversas.
Even 30 years after the accident, an association between breast cancer incidence and ionizing radiation exposure from Chernobyl fallout remains uncertain. We studied breast cancer incidence in the ...most contaminated regions of Belarus (Gomel and Mogilev) and Ukraine (Kyiv, Zhytomyr and Chernihiv) before (1978‐1986) and after (1987‐2016) the accident. Breast cancer cases and female population size data were received from the national cancer registries and the state departments of statistics. The study included 85 132 breast cancers with 150 million person‐years at risk. We estimated annual rayon (district)‐average absorbed doses to the breast from external and internal irradiation of the adult female population over the period of 1986‐2016. We studied an association between rayon‐average cumulative absorbed breast dose with 5‐year lag, that is, excluding the exposure in 5 years prior to breast cancer diagnosis, and breast cancer incidence using negative binomial regression models. Mean (median) cumulative breast dose in 2016 was 12.3 (5.0) milligray (mGy) in Belarus and 5.7 (2.3) mGy in Ukraine, with the maximum dose of 55 mGy and 54 mGy, respectively. Breast cancer incidence rates statistically significantly increased with calendar year and attained age, and were higher in urban than in rural residents. Adjusting for time, age and urbanicity effects, we found no evidence of increasing incidence with rayon‐average 5‐year lagged cumulative breast dose. Owing to ecological study design limitations, a case‐control study covering this area with individually reconstructed absorbed breast doses is needed testing for association between low‐dose protracted radiation exposure and breast cancer risk after Chernobyl.
What's new?
The Chernobyl nuclear accident in 1986 exposed various populations, including nearby residents and cleanup workers, to low‐dose ionizing radiation. Here, using national cancer data and data on radionuclide fallout, the authors investigated associations between breast cancer incidence and ionizing radiation exposure in female populations in the most contaminated regions of Belarus and Ukraine following the Chernobyl accident. Analyses indicate that over the period 1986‐2016, breast cancer incidence did not increase in relation to the average 5‐year lagged cumulative breast dose in urban and rural populations. Possible dose misclassification warrants additional investigation via a case‐control study applying individual breast doses.
Display omitted
Some of the highest 90Sr activity concentrations recorded beyond the Chornobyl Exclusion Zone occur in the Ivankiv district of Ukraine, located approximately 50 km south of the power ...plant, an area which nonetheless remains important for agricultural production. Although characterized by soils with low exchangeable calcium values, which can enhance the bioavailability of certain radionuclides, information on the transfer of 90Sr to food crops and trees in the region has remained limited to date. Analysis of 116 grain samples (wheat, rye, oat, barley or Triticale) collected from fields in 13 settlements in the region between 2011 and 2019 revealed 90Sr and 137Cs activity concentrations above Ukrainian limits in almost half of those samples, with annual averages exceeding this limit in four of those nine years (most recently in 2018) and with no clear evidence for a declining trend over time. Analysis of paired sandy soil samples from the same fields yielded concentration ratios for transfer of 90Sr from soils to grains that were on average 3 times higher than that specified by the IAEA. In addition, three quarters of wood samples collected from the trunks of trees (primarily pines) from 12 locations in the same district between 2015 and 2019 contained 90Sr activity concentrations in excess of the Ukrainian limits for firewood (60 Bq/kg), with levels more than four times that limit at one location and again no evidence for decline over time. A single sample of ash collected from a domestic wood-burning oven in the district contained 90Sr at a level 25 times higher than in the most contaminated wood sample collected in this study. Overall these results reveal additional facets of the ongoing legacy of Chornobyl contamination within the Ivankiv district, and the diversity of pathways by which local residents may be exposed to radionuclides. They also highlight the dangers associated with the current lack of routine and comprehensive environmental and food monitoring programs within the region, especially at a time in which the use of locally-sourced wood for biomass energy generation is set to expand markedly.
The discrepancy between laboratory or controlled conditions ecotoxicity tests and field data on wildlife chronically exposed to ionising radiation is presented for the first time. We reviewed the ...available chronic radiotoxicity data acquired in contaminated fields and used a statistical methodology to support the comparison with knowledge on inter-species variation of sensitivity to controlled external γ irradiation. We focus on the Chernobyl Exclusion Zone and effects data on terrestrial wildlife reported in the literature corresponding to chronic dose rate exposure situations (from background∼100 nGy/h up to ∼10 mGy/h). When needed, we reconstructed the dose rate to organisms and obtained consistent unbiased data sets necessary to establish the dose rate–effect relationship for a number of different species and endpoints. Then, we compared the range of variation of radiosensitivity of species from the Chernobyl-Exclusion Zone with the statistical distribution established for terrestrial species chronically exposed to purely gamma external irradiation (or chronic Species radioSensitivity Distribution – SSD). We found that the best estimate of the median value (HDR50) of the distribution established for field conditions at Chernobyl (about 100 μGy/h) was eight times lower than the one from controlled experiments (about 850 μGy/h), suggesting that organisms in their natural environmental were more sensitive to radiation. This first comparison highlights the lack of mechanistic understanding and the potential confusion coming from sampling strategies in the field. To confirm the apparent higher sensitive of wildlife in the Chernobyl Exclusion Zone, we call for more a robust strategy in field, with adequate design to deal with confounding factors.
► Discrepancy between controlled tests and Chernobyl effects data on wildlife was examined. ► We proposed a method to correct the dosimetry used for Chernobyl wildlife. ► Wildlife from the Chernobyl zone is more radiosensitive than in controlled situations. ► Field data sets outcoming from robust strategy are still needed to validate derived from controlled tests benchmarks.
Measurements of external contaminant exposures on individual wildlife are rare because of difficulties in using contaminant monitors on free-ranging animals. Most wildlife contaminant exposure data ...are therefore simulated with computer models. Rarely are empirical exposure data available to verify model simulations, or to test fundamental assumptions inherent in exposure assessments. We used GPS-coupled contaminant monitors to quantify external exposures to individual wolves (Canis lupus) living within the Belarus portion of Chernobyl's 30-km exclusion zone. The study provided data on animal location and contaminant exposure every 35 min for 6 months, resulting in ~6600 individual locations and 137Cs external exposure readings per wolf, representing the most robust external exposure data published to date on free ranging animals. The data provided information on variation in external exposure for each animal over time, as well as variation in external exposure among the eight wolves across the landscape of Chernobyl. The exposure data were then used to test a fundamental assumption in screening-level risk assessments, espoused in guidance documents of the U.S. Environmental Protection Agency and U.S. Department of Energy, — Mean contaminant concentrations conservatively estimate individual external exposures. We tested this assumption by comparing our empirical data to a series of simulations using the ERICA modeling tool. We found that modeled simulations of mean external exposure (10.5 mGy y−1), based on various measures of central tendency, under-predicted mean exposures measured on five of the eight wolves wearing GPS-contaminant monitors (i.e., 12.3, 26.3, 28.0, 28.8 and 35.7 mGy y−1). If under-prediction of exposure occurs for some animals, then arguably the use of averaged contaminant concentrations to predict external exposure is not as conservative as proposed by current risk assessment guidance. Thus, a risk assessor's interpretation of simulated exposures in a screening-level risk analysis might be misguided if contaminant concentrations are based on measures of central tendency. We offer three suggestions for risk assessors to consider in order to reduce the probability of underestimating exposure in a screening-level risk assessment.
Display omitted
•GPS-coupled contaminant monitors worn by wolves within Chernobyl's exclusion zone.•Measured external exposure at 35-min intervals on 8 wolves for 6 months•Empirical data compared to model simulations of external exposure•Simulations using mean contaminant levels under-predicted exposure on 5 of 8 wolves.•Findings question current exposure assessment guidance of USEPA and USDOE.
PDF
