Measurements of radiocesium in animals, plants and fungi in Svalbard after the Fukushima Daiichi nuclear power plant disaster

Conceptualization of the comprehensive phyto-radiotoxicity incurred by radiocesium and strategies to expunge the metal using biotechnological and phytoremediative approaches

Agricultural pollution with 137Cs is an ecological threat due to its sustained half-life and radioactivity. Release of radiocesium isotopes after major nuclear power plant accidents like the Fukushima Dai-ichi and the Chernobyl nuclear power plant disasters have severely affected the surrounding growth of agricultural crops and vegetables cultivated across extensive areas. Even years after the nuclear accidents, biosafety in these agricultural fields is still questionable. Due to similarity in charge and ionic radius between radiocesium and K+, the radionuclides are promiscuously uptaken via K+ channels expressed in plants. Bioaccumulation of radiocesium reportedly promotes physiological and anatomical anomalies in crops due to radiation and also affects the rhizospheric architecture. Due to radiation hazard, the ecological balance and quality are compromised and ingestion of such contaminated food results in irreversible health hazards. Recently, strategies like exogenous supplementation of K+ or genetic engineering of K+ channels were able to reduce radiocesium bioaccumulation in plants taking the advantage of competition between radiocesium and K+ translocation. Furthermore, bioremediation strategies like phycoremediation, mycoremediation, phytoremediation and rhizofiltration have also showed promising results for removing radiocesium from polluted sites. It has been proposed that these eco-friendly ways can be adopted to de-pollute the contaminated sites prior to subsequent cultivation of crops and vegetables. Hence it is essential to: 1) understand the basic radiotoxic effects of radiocesium on agricultural crops and surrounding vegetation and, 2) design sustainable ameliorative strategies to promote radiocesium tolerance for ensuring food and social security of the affected population.

A comparison of different detection techniques for 137Cs measurements of cattle in vivo

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.

Sources, fate and distribution of inorganic contaminants in the Svalbard area, representative of a typical Arctic critical environment-a review

Global environmental changes not only contribute to the modification of global pollution transport pathways but can also alter contaminant fate within the Arctic. Recent reports underline the importance of secondary sources of pollution, e.g. melting glaciers, thawing permafrost or increased riverine run-off. This article reviews reports on the European Arctic-we concentrate on the Svalbard region-and environmental contamination by inorganic pollutants (heavy metals and artificial radionuclides), including their transport pathways, their fate in the Arctic environment and the concentrations of individual elements in the ecosystem. This review presents in detail the secondary contaminant sources and tries to identify knowledge gaps, as well as indicate needs for further research. Concentrations of heavy metals and radionuclides in Svalbard have been studied, in various environmental elements since the beginning of the twentieth century. In the last 5 years, the highest concentrations of Cd (13 mg kg^-1) and As (28 mg kg^-1) were recorded for organic-rich soils, while levels of Pb (99 mg kg^-1), Hg (1 mg kg^-1), Zn (496 mg kg^-1) and Cu (688 mg kg^-1) were recorded for marine sediments. Increased heavy metal concentrations were also recorded in some flora and fauna species. For radionuclides in the last 5 years, the highest concentrations of ¹³⁷Cs (4500 Bq kg^-1), ²³⁸Pu (2 Bq kg^-1) and ^{239 + 240}Pu (43 Bq kg^-1) were recorded for cryoconites, and the highest concentration of ²⁴¹Am (570 Bq kg^-1) was recorded in surface sediments. However, no contamination of flora and fauna with radionuclides was observed.

Radiation dose rate to Japanese cedar and plants collected from Okuma, Fukushima Prefecture

After the 2011 Fukushima Dai-ichi Nuclear Power Station (FDNPS) accident, wild populations of animals and plants living in the evacuation zone received additional ionizing radiation of both internal and external radiation doses. Morphological abnormalities of pine and fir trees near the FDNPS were reported. In order to evaluate dose-effect relationships, it is necessary to quantify the radiation doses to trees and plants. In this study, the internal and external dose rates to Japanese cedar and plants collected at three sites in Okuma, approximately 4 km southwest of FDNPS were estimated applying the ERICA Assessment Tool. The activity concentrations of ¹³⁴Cs and ¹³⁷Cs in soils, cedar trunks, and plants were determined. The total dose rates to cedar ranged from 2.2 ± 1.2 to 6.1 ± 2.2 μGy h^-1. These rates were within the derived consideration reference levels (DCRLs) reported by ICRP 108 as 4-40 μGy h^-1 for pine trees. The highest estimate for plants was 7.1 ± 2.7 μGy h^-1, much smaller than the DCRLs reported for grasses and herbs (40-400 μGy h^-1). On average, the internal radiation dose rates to cedars at the two sites accounted for 5% and 29% of the external dose rates, respectively, while the value in another site was only 0.4% for cedar. This was attributed to differences in the crown area between the three sites. The trunk diameter of cedars shows a positive correlation with the ratio of internal to external radiation dose rates. It indicates that the total dose rate to cedars is easily estimated with the soil radiocaesium inventory and trunk diameter. The internal radiation dose rate to the plant varied depending on the plant species. This variation was considerably large in plants due to the presence of two species, including Solidago altissima and Artemisia indica var. maximowiczii.