The caesium contamination issue has historically reached some uniquely isolated and high levels approaching 20,000 Becquerels of caesium per kilogram in some specific tests; however, it has not been observed in the wild boar population of Fukushima after the 2011 accident. Evidence exists to suggest that the wild German and Ukrainian boar population are in a unique location were they have subsisted on a diet high in plant or fungi sources that biomagnifies or concentrates radiocaesium, with the most well known food source the consumption of the outer shell or wall of the "deer-truffle" elaphomyces which, along with magnifying radiocaesium, also magnifies or concentrates natural soil concentrations of arsenic.