Cortinarius caperatus found to be infested with maggots when picked. Mycologist David Arora recommends discarding the tough stipes. The popularity of "C. caperatus" across Europe has led to safety concerns related to its propensity to accumulate contaminants. Fungi are very efficient at absorbing radioactive isotopes of caesium from the soil and naturally have trace amounts of the element. Caesium may take the place of potassium, which exists in high concentrations in mushrooms. "C. caperatus" bioaccumulates radioactive caesium Cs—a product of nuclear testing—much more than many other mushroom species. Levels dramatically rose after the 1986 Chernobyl disaster. This is a potential health issue
Isotopes of caesium only long after the nuclear explosion is over. The combined yield of Cs and Cs is given as 6.7896%. The proportion between the two will change with continued neutron irradiation. Cs also captures neutrons with a cross section of 140 barns, becoming long-lived radioactive Cs. Caesium-134 undergoes beta decay (β), producing Ba 134 directly and emitting on average 2.23 gamma ray photons (mean energy 0.698 MeV). Caesium-135 is a mildly radioactive isotope of caesium with a half-life of 2.3 million years, decaying, via emission of a low-energy beta particle, into the stable isotope barium-135. Caesium-135 is one of the 7