Long-term environmental behaviour of radioactive particles released during the Chernobyl accident and deposited in sandy topsoil in Ivankiv district of Kyiv Region (Ukraine), in radioactive trench ...waste materials from the Red forest, and in bottom sediments from the Cooling pond has been assessed. The efficiency of the models describing the dissolution/weathering rates of U fuel particles developed 15–20 years ago was tested, and their predictions for the dynamics of remobilization, mobility and plants uptake of 90Sr were confirmed.
It was found that at present in the topsoil and in radioactive trench waste material, total dissolution of fuel particles of low chemical stability (UO2+x) has occurred and about half of the non-oxidized chemically stable fuel particles (UO2) has also dissolved, indicating radiological stabilization of the environment and that the mobile fraction of radionuclides would be reduced in the future. The biological availability of 90Sr in topsoil due to fuel particles dissolution has reached maximum values and further decrease is expected.
The presence of chemically extra-stable fuel particles (U-Zry-Ox) in environments should be taken into account when the total radionuclides activity concentrations are assessed during radioactive materials management.
It was shown that nearly half of the 90Sr activity remained as part of the non-dissolved UO2 fuel particles at the time of the study. Taking into consideration that 31 ± 4% of the radionuclide activities were still associated with non-dissolved chemically extra-stable particles (U-Zry-Ox) in radioactive trench waste materials from the Red forest, increased dissolution should not be expected in the near future.
The physico-chemical form of radionuclides in air exposed sediments from the Cooling pond were determined, and results showed that about 70–80% of total 90Sr, 241Am and plutonium isotopes activity were associated with U fuel particles. The low dissolution rate of radionuclides from the pond sediments is attributed to prolonged slightly alkaline pH in the medium due to zebra mussel residues.
According to new data, the emission value of 238Pu associated with fuel particles released during the Chernobyl accident amounted to 1.8 × 1013Bq (1.2% of the activity in the reactor) and 90Sr amounted to 2.6 × 1015Bq (1.5% of the activity in the reactor).
•The presence of radioactive uranium oxide particles containing high specific activity of radionuclides is a distinctive feature of the Chernobyl accident.•The efficiency of the models describing the dissolution/weathering rates of U fuel particles in environment is confirmed.•The biological availability of 90Sr in topsoils due to fuel particles dissolution has reached maximum values and further decrease is expected.•The fuel particles' dissolution rate is an important parameter of the source term for radiation protection of the human and the environment.
April 2016 sees the 30th anniversary of the accident at the Chernobyl nuclear power plant. As a consequence of the accident populations were relocated in Belarus, Russia and Ukraine and remedial ...measures were put in place to reduce the entry of contaminants (primarily 134+137Cs) into the human food chain in a number of countries throughout Europe. Remedial measures are still today in place in a number of countries, and areas of the former Soviet Union remain abandoned.
The Chernobyl accident led to a large resurgence in radioecological studies both to aid remediation and to be able to make future predictions on the post-accident situation, but, also in recognition that more knowledge was required to cope with future accidents. In this paper we discuss, what in the authors' opinions, were the advances made in radioecology as a consequence of the Chernobyl accident.
The areas we identified as being significantly advanced following Chernobyl were: the importance of semi-natural ecosystems in human dose formation; the characterisation and environmental behaviour of ‘hot particles'; the development and application of countermeasures; the “fixation” and long term bioavailability of radiocaesium and; the effects of radiation on plants and animals.
•A review of 30 years of radioecological studies following the 1986 Chernobyl accident.•Key contributions to radioecology from post-Chernobyl research are discussed.
Abstract
Background
Ionizing radiation is a known cause of female breast cancer, but there have been few studies of the risk after prolonged radiation exposure at low dose rates.
Methods
This ...population-based case-control study estimated breast cancer risk after ∼25 years’ exposure to radiation from the Chernobyl accident. Cases (n = 468) were women ≤55 years old when first diagnosed with invasive breast cancer during October 2008 through February 2013, who lived in Bryansk Oblast, Russia at the time of the accident and their diagnoses. Controls, individually matched to cases on birth year, administrative district of residence and urban vs non-urban settlement during the accident, were women without breast cancer who lived in Bryansk Oblast at the time of the accident and on their cases’ diagnosis dates (n = 468). Subjects were interviewed regarding residence, dietary and food source histories to support individualized estimation of their radiation doses to the breast, which ranged from 0.04 − 41 centigray (cGy) (mean 1.3 cGy).
Results
In multivariable analyses, the odds ratio for breast cancer risk was 3.0 95% confidence interval (CI): 1.3, 7.0 and 2.7 (95% CI: 1.0, 7.3) in the seventh and eighth dose octiles, respectively, relative to the lowest octile. Analyses of dose effect modification suggested that radiation-related risk may have been higher in women who were younger at the time of the accident and/or at the time of diagnosis.
Conclusions
This study suggests that prolonged exposure to ionizing radiation at low dose rates can increase risk of breast cancer.
Embodiment is a key under-researched component of dark tourism experiences. Qualitative and experimental methods were applied in four studies to reveal the bidirectional body–mind synchronization in ...dark tourism experiences. Taking the Chernobyl zone as a case, we first prove the mind-to-body pathway in which the dark experience exerts a measurable effect on the participants' sensory expression in photographs and sketches. We then discover the body-to-mind pathway in which the expressions of darkness can be decoded by others. Furthermore, this study illustrates how the different dark levels of the product photos on a website affect the potential tourists' feelings. This study expands the understanding of embodiment theory in dark tourism with implications for product design and marketing.
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•The bidirectional body–mind synchronization is constructed in dark tourism.•Dark experience influences sensory expression in photographs and sketches.•The expressions of darkness can be decoded and correctly interpreted by others.•Different dark levels of photos affect the potential tourists' product evaluation.
•A detailed chronicle on dosimetry after the Chernobyl and Fukushima accidents.•A critical analysis of the weak points from the previous nuclear accidents.•Recommendations to improve dosimetry for ...decision making processes.•Applications of dosimetry in medical surveillance and preventive healthcare.
The experiences of the Chernobyl and Fukushima nuclear accidents showed that dosimetry was the essential tool in the emergency situation for decision making processes, such as evacuation and application of protective measures. However, at the consequent post-accidental phases, it was crucial also for medical health surveillance and in further adaptation to changed conditions with regards to radiation protection of the affected populations. This review provides an analysis of the experiences related to the role of dosimetry (dose measurements, assessment and reconstruction) regarding health preventive measures in the post-accidental periods on the examples of the major past nuclear accidents such as Chernobyl and Fukushima. Recommendations derived from the review are called to improve individual dose assessment in case of a radiological accident/incident and should be considered in advance as guidelines to follow for having better information. They are given as conclusions.
Genetic and epigenetic changes were investigated in chronically irradiated Scots pine (Pinus sylvestris L.) populations from territories that were heavily contaminated by radionuclides as result of ...the Chernobyl Nuclear Power Plant accident. In comparison to the reference site, the genetic diversity revealed by electrophoretic mobility of AFLPs was found to be significantly higher at the radioactively contaminated areas. In addition, the genome of pine trees was significantly hypermethylated at 4 of the 7 affected sites.
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•Chronic radiation exposure changes the genetic structure of plant populations.•Genomes of irradiated pines are hypermethylated.•The level of hypermethylation does not depend on annual dose.
These results indicate that even relatively low levels of chronic radiation exposure can influence on the genetic characteristics and the methylation status of natural pine populations and that it should be considered as an important ecological factor reflecting the anthropogenic impact on ecosystems.
The radioactive nuclide 137Cs that was released during the Chernobyl accident in 1986 is still present in the environment of wide parts of Middle Europe. It causes internal radiation exposure of ...people who incorporate this radionuclide when eating contaminated food, in particular boar meat and certain kinds of wild mushrooms. This study investigates the exposure of German hunters and their family members, which are supposed to consume these kinds of food more frequently than the general population. For this purpose, the body activity of 137Cs was measured in 58 hunters and their family members mostly from Southern Germany and it was compared with body activities from 1729 measurements of 251 members of the general population. Significantly higher 137Cs body activities were found in the hunters and their family members compared to the references after matching both groups for sociodemographic factors and the time of the measurement (factor of 2.4 between the geometric means, p-value ≪ 0.001). Within the hunters and their family members, an adjusted exponential regression showed significant associations of the activity and of mushroom picking (factor 2.6, 95% confidence interval 1.5–4.6) and of the frequency of having boar meat as part of the diet (factor 1.4 per meal per week, 95% confidence interval 1.1–1.8). No significant association was found for the 137Cs surface contamination at the hunting grounds. Within families, mostly similar results were found in terms of activity concentrations. For the hunter with the highest measured activity (1050 Bq), an annual contribution to the effective dose of 35 μSv was calculated, showing that also in hunters and their family members 137Cs is expected to cause only small contributions to the total effective dose from environmental exposure.
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•58 hunters and their family members were measured for their 137Cs body activities.•Higher 137Cs activities were found in hunters than in the general population.•Mushroom picking and boar meat consumption increased the activities significantly.•The highest activity was 1050 Bq, the annual committed effective dose was 35 μSv.•In all measured hunters the 137Cs caused small contributions to the effective dose.
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