Exemplifying the “wild boar paradox”: dynamics of cesium-137 contaminations in wild boars in Germany and Japan

Abstract

Wild boars (Sus scrofa) are notorious for accumulating high contamination levels of 137Cs in their meat. Publicly available data of 137Cs contamination levels in wild boars from 2011 to 2019 were used to determine some radioecological characteristics in Germany (affected by Chernobyl-fallout, 1986) and Japan (affected Fukushima, 2011). The effective half-life of 137Cs in wild boar meat was much longer in Germany (7.3 y) than in Japan (2.6 y), respectively. Wild boars in Germany thus show much more persistent contamination levels than other game or forest animals. This unusual behavior has been termed “wild boar paradox.” In German wild boars, the data sets reveal a distinct geographical and seasonal dependence with higher activity concentrations in winter than in summer. In Japan, contamination levels only exhibit a distinct decline behavior.

Disproportionately High Contributions of 60 Year Old Weapons-137Cs Explain the Persistence of Radioactive Contamination in Bavarian Wild Boars

“…This phenomenon was also reported in 137 Cs contaminations in American honey 44 as well as Japanese wild boars. 45 We therefore suggest that due to various factors, such as animal mobility, activity inventory in soil, soil type, 20 , 46 land use (e.g., agricultural soil vs forest soil), 6 , 47 animal access to agricultural areas with lower 137 Cs levels in crops than in wild plants or mushrooms growing in forests, 20 heterogeneity of deposition, season of sampling, 30 etc., 48 no simple model can correlate topsoil 137 Cs inventories and the resulting activity concentration in the animal tissue.…”

“…This phenomenon has been termed “wild boar paradox” and is generally attributed to the ingestion of 137 Cs accumulating hypogeous fungi (e.g., deer truffle, Elaphomyces) by wild boars. , Depending on the soil composition, especially clay mineral content, these underground mushrooms are a critical repository of the downward migrating 137 Cs. They are one major food item for wild boars, particularly during winter when food on the surface is scarce . However, due to the lack of convincing evidence for identifying the sources of 137 Cs, the origins of the persistent contamination in wild boars remains unclear.…”

“…They are one major food item for wild boars, particularly during winter when food on the surface is scarce. 30 However, due to the lack of convincing evidence for identifying the sources of 137 Cs, the origins of the persistent contamination in wild boars remains unclear.…”

Rare earth contamination of edible vegetation: Ce, La, and summed REE in fungi

“…Micro- and macrofungi are key components of forest ecosystems. They recycle chemical elements and other nutrients, often symbiotically benefiting plants, but they are also food for a myriad of organisms including large animals (Lepp et al 1987 ; Berendes and Steinhauser 2022 ). In addition to the physiological necessity of assimilating essential nutrients including minerals from their substrates, macromycetes inadvertently also uptake a variety of environmental pollutants, both inorganic elements, as well as a range of anthropogenic organic chemicals.…”

Research and management challenges following soil and landscape decontamination at the onset of the reopening of the Difficult-To-Return Zone, Fukushima (Japan)

“…Nevertheless, these seasonal variations were shown to be less pronounced than in wild board contaminated in Germany following the Chernobyl accident, and this observation may be due to their more diverse food sources for wild boards in Japan (Berendes and Steinhauser, 2022). Overall, as the 137 Cs contamination in wildlife 455 muscles decreases with the distance from FDNPP, the strategy may be two-fold.…”