Two stages in the accumulation of 137Cs by mushroom Suillus luteus after the Chornobyl accident

Studies of the 137Cs content in fruit bodies of Suillus luteus in the territory of the Chornobyl exclusion zone and Kyiv region outside the zone were carried out during the period 1986 - 2020. It was found that the dynamics of 137Cs activity in the mushroom can be described as a two-stage process. The first stage since 1986 was characterized by the annual increase in levels of specific activity of 137Cs for the following 10 - 12 yrs. During the second stage, there has been a gradual decrease in concentrations of 137Cs. The ecological half-life of 137Cs in the mushroom at the second stage differs for different sampling sites. Its minimum values were noted at villages Yaniv and Novo-Shepelychy sampling sites inside the exclusion zone. The maximum of 137Cs ecological half-life in Suillus luteus was observed on the Rzhyshchiv sampling site, which is the most remote from the Chornobyl Nuclear Power Plant outside the exclusion zone.