A Long-Term Study Of Radionuclide Concentrations In Mushrooms In The 30-Km Zone Around The Mining-And-Chemical Combine (Russia)

Cs-137 concentrations were measured in mushrooms in an area affected by radioactive discharges of the Mining-and-Chemical Combine (MCC) (Rosatom, Russia) in 2002-2017. The sources of radionuclides in the study sites were global fallouts and waterborne and airborne radioactive discharges of the MCC. The mushroom species Suillus granulatus and S. luteus showed the highest Cs-137 concentrations (140-7100 Bq kg(-1)) for this area. Over the entire monitoring period, no significant change in Cs-137 concentration was observed in the Suillus spp. samples collected from the sites with the aerial deposition of radionuclides. In the floodplain site with the radionuclide deposition from water and air, a significant decrease in the average Cs-137 concentration was observed in the period between 2004 and 2017: a three-fold decrease in Suillus spp. and a nine-fold decrease in Lactarius deliciosus. The effective half-lives of Cs-137 in fruiting bodies of the mushrooms L. deliciosus and Suillus spp. in this site were 3.6 +/- 0.6 and 9.2 +/- 2.7 years, respectively.