Radioecology: Why Bother?

The importance of radioecology to the discussion of radioactive contamination is discussed here. This paper discusses the history of radioecology, alongside the most recent developments in the science. It describes the need for more environmental data, and explains where the gaps in current knowledge lie. The calculation of radiation dose to wildlife along with the complications in performing such calculations is discussed. The paper also tackles the difficult question of the implications of radioecology on nuclear waste management and site decommissioning policies. From the beginnings of the science to today, radioecology is poised to be an important field of study as humans continue to rely on ionizing radiation to improve their lives.

Estimation of Annual Effective Dose Due to Ingestion of Natural Radionuclides in Cattle in Tin Mining Areas of Jos Plateau, Nigeria: Are Large Mammals Really Affected?

We have read with great interest the paper which was published in Natural Science, 2014 issue number 6 titled “Estimation of annual effective dose due to ingestion of natural radionuclides in cattle in tin mining area of Jos Plateau, Nigeria” [1]. The paper motivated us to use state-of-the-art computational technique to investigate the risks of the tin mining activity in Jos-Plateau, Nigeria on large mammals (e.g. cattle). The Tier 2 Erica Tool assessment was used to estimate the total dose rate and risk quotients of these reference terrestrial animals. Our investigation revealed that the expected and conservative risk quotients of large mammals due to internal and external exposure to enhanced level of radioactivity are 0.05 and 0.16, respectively. Since the risk quotients are less than unity, this indicates that there is less than 5% probability that the screen dose rate (10 μGy•h–1) is exceeded. The estimated total dose rate to large mammals is 0.52 μGy•h–1 which is not statistically significant. A critical analysis of [1] is presented in the introductory part of this paper.

The Problem of Natural Radioactive Elements

The article presents two opposing views on the origin of natural radioactive elements. According to a view based on the Big Bang Theory, the elements found on Earth were formed by the process of primary nucleosyntase 13.8 billion years ago, with the exception of uranium and other heavy elements that were formed billions of years later under stellar conditions. It follows from this view that throughout the existence of the earth, the global amount of uranium and other primary radionuclides is reduced as a result of natural decay. The reasoning of the proponents of the BB theory is as follows: if the global radioactivity decreases, the problem of the threat decreases and one only needs to get used to the newly discovered natural phenomenon. There are even official regulations that exclude ionizing radiation from radon in the calculation of the limit dose. The Primary Forces of Nature theory presents a completely different view. Considering the analogous influence of gravity on the formation of the globs of the solar system, the logical explanation of the phenomena of geological activity are thermonuclear processes, such as on the sun. Hence the conclusion that the elements chemical are now created in the core of the Earth in the process of thermonuclear synthesis. The problem is serious because there is an accelerated growth of new igneous matter containing the created elements, and the ionizing radiation of natural radionuclides is the main factor responsible for the radioactivity level of the human environment.

Radioactive Elements in Phosphorous Fertilizer —Basalt Flour-Recommended Mineral Fertilizer

The article presents the concept of using powdered basalt as a mineral fertilizer and replacing radioactive phosphate rock with it. In addition to the characteristics of phosphate rock deposits and the ecological effects of the use of phosphorus fertilizers, the issue of the genesis of phosphate deposits was discussed. Phosphate rock contains natural radioactive elements whose origin is debatable. It is generally accepted that all elements are formed in a thermonuclear fusion reaction. The natural radioactivity of the elements results only from the instability of atomic nuclei, with a large advantage of neutrons over protons. The view of the cosmic origin of elements in the primary nucleosynthesis of the Big Bang is opposed to the view of the generation of elements in the present-day core of the Earth. Depending on the adopted view, extremely different conclusions can be drawn. If it is assumed that natural radioactive elements were formed in space billions of years ago, their number decreases as they decay. Conversely, if these elements form in the Earth’s core and appear as a component of basalt magma, their amount increases exponentially. Referring to publications on the theory of natural forces of nature, the article explains the phenomenon of spontaneous formation of fusion reactors. At the same time, the phenomenon of the expansion of the globe was explained, manifested by a tenfold increase in the volume of the globe over the last 200 million years. Growing basalt magma has a stabilized mineral composition and contains traces of uranium. Therefore, in the basalt rock the uranium concentration is low (<1 ppm), while in the phosphate rock uranium precipitates from concentrated igneous solutions and its concentration increases to 600 ppm.

Development of the ^(137)Cs,^(90)Sr and ^(3)H Concentrations in the Hydrosphere in the Vicinity of NPP Temelín(South Bohemia)

The paperfocuses on an analysis of the results of long-term monitoring of the concentrations of 137Cs, 90Sr and 3H in hydrosphere in the vicinity of Temelín Nuclear Power Plant (Temelín plant). The radionuclides were monitored in surface water, river sediments, aquatic flora and fish species. The main objective of the study was to analyze and integrate all of the knowledge on concentrations and behaviour of these radionuclides, which originate mainly from residual contamination, in order to assess the impacts of Temelín Nuclear Power Plant on hydrosphere in these indicators during its standard operation and possible accidents. The radionuclides were analyzed in terms of spatial and temporal variability in their concentrations and their inflows and outflows, mainly into and from Orlík Reservoir. The analysis included standard radioecological characteristics, which were applicable for assessing long-term development and behavior of radionuclides in the environment affected by their possible accidental releases on the territory of the Czech Republic or outside this territory. For all of the components of the environment, the concentrations of 137Cs and 90Sr which were used for calculation of their effective and ecological half-time, were decreasing. For 137Cs in surface water and fish, the rates of the decrease in the first and second monitoring period were different. The rate of the decrease in 90Sr concentration was invariable. The results of the monitoring showed that 86% of suspended solids and 62% of 137Cs inflowing into Orlík Reservoir accumulated in the reservoir while accumulation of 90Sr was not substantiated. Outflows of 137Cs and 90Sr activities were assessed in relation to their concentrations that were accumulated in individual basins until 1986 consequently to Chernobyl accident and tests of atmospheric nuclear weapons. The results for the whole area of the Vltava, Luznice and Otava River basins upstream from the Vltava River at Solenice showed that during the period 1986-2013 only 0.49% of 137Cs activity and 3.6% of 90Sr activity that accumulated in the basins were washed and flowed out from the area. Distribution coefficients derived from summary analysis of sediments and concentration factors for biota were calculated. Concentrations of 3H in river sites not affected by Temelín plant were slowly decreasing and their values were substantially below those from the sites affected by the plant.

Analysis of Radium Isotopes in Surface Waters nearby a Phosphate Mining with NORM at Santa Quiteria,Brazil

The radium isotopes 226Ra and 228Ra were analyzed in surface water at six points in the neighborhood of a mine of phosphate, associated with uranium, in the region of Santa Quitéria, state of Ceará, Brazil. Water samples were collected during twenty months, filtered and the concentrations of activity determined in the soluble and particulate phases. The results were analyzed using the Principal Component Analysis (PCA) for ordination of environmental data, and also by ANOVA, Tukey and Z tests to compare sets of data considering the radionuclides, the two analyzed phases and the six collecting points. The PCA identified four groups that included all collecting points, using aggregation features such as radionuclide and analyzed phase. The first group is composed by the samples of 226Ra in the soluble phase;the second group by samples of 226Ra in the particulate phase;the third one by 228Ra in the soluble phase, and finally, the fourth group by 228Ra in the particulate phase. This last group has two discrepant points (01 and 06). Statistical analysis identified differences between the concentrations of activity of radionuclides (228Ra higher than 226Ra) and in analyzed phases (soluble phase higher than the particulate one) but showed no differences between sampled points.

Land use in agricultural landscapes with chernozems contaminated after Chernobyl accident: Can we be confident in radioecological safety of plant foodstuff?

Agricultural land use in the area of the post-Chemobyl Plavsk radioactive hotspot (Tula region,Central Russia) has raised a problem of radioecological safety of obtained plant foodstuff.Verification of 137Cs activities and inventories in components of 'soil-plant' systems of the territory has been conducted in 2014-2017 in 10 agrosystems and 2 semi-natural meadows.It was revealed that density of 137Cs contamination of arable chernozems and alluvial calcareous soils nowadays varies in a range 140-220 kBq/m2 and exceeds radiation safety standard by^3.5-6 times.Deep plowing of the arable soils up to 30-cm in 1986-1987 resulted in decreasing of 137Cs inventories in rooting zone by ≈ 70% for crops cultivated with shallow disk plowing (wheat,barley),and by ≈ 35% for crops cultivated with middle plowing (buckwheat,amaranth,white mustard).The investigated plants and their compartments can be grouped on the basis of transfer factor values as follows:maize (stems and leaves)> amaranth> bromegrass > vegetation of dry meadow,galega,sunflower (seeds),vegetation of wet meadow > maize (grain),soybean (pods),barley (grain),buckwheat (grain),potatoes (tubers)> white mustard (seeds),wheat (grain).It is noticeable that generative plant compartments are characterized by less 137Cs activities in comparison with stems and leaves;and that 137Cs root uptake is not coincide with total flux of mineral nutrients in 'soil-plant' systems.In sum,137Cs soil-to-plant transfer in the area of the Plavsk radioactive hotspot is characterized by considerable discrimination,so 137Cs activities in plants are completely in accordance with national standards.