Nuclear weapon tests and nuclear leakage accidents have resulted in worldwide contamination by radionuclides, and ¹³⁷Cs persists in the environment because of its long half-life. Due to their radionuclide-enrichment properties, wild edible mushrooms take up ¹³⁷Cs from the surrounding matrix and store it in their fruiting bodies, thus becoming an indicator medium for radionuclide contamination and can be used to evaluate soil contamination with radionuclides. However, there are large variations in ¹³⁷Cs activity concentrations in different wild edible mushrooms depending on regions, species, and lifestyles. Therefore, it is important to carry out the detection of ¹³⁷Cs in wild edible mushrooms to understand the mechanisms of ¹³⁷Cs transfer distribution and enrichment and to monitor the environment. This paper reviews the studies on ¹³⁷Cs in wild edible mushrooms in recent years both in China and other countries. This article analyses the content of ¹³⁷Cs in wild edible mushrooms in different regions, the transfer process from soil to wild edible mushroom fruiting bodies, and the distribution of ¹³⁷Cs in wild edible mushrooms. These results provide theoretical support for the future monitoring of radionuclides in wild edible mushrooms on a nationwide scale, the establishment of relevant databases, and in-depth research on the mechanism of radionuclide transfer.

Objective To further extend the application of coincidence summing correction factor transfer experiments through the analysis of relevant measurements. Methods The passive efficiency was simulated using BE5030 high-purity germanium (HPGe) γ-energy spectrometer equipped with LabSOCS, and the total efficiency was simulated using LabSOCS in GENIE 2000 spectrum analysis software, which was used for calculating the coincidence summing correction factor. The coincidence summing correction factor transfer experiments were performed using the measurements with the point source containing ¹³⁴Cs, ⁶⁰Co, and ¹³⁷Cs as well as the body source to obtain the coincidence summing correction factors of other HPGe γ-energy spectrometers. Results The coincidence summing correction factors for ¹³⁴Cs and ⁶⁰Co were obtained using the BE5030 γ-energy spectrum. In verification by certificate activity, the absolute value of the maximum deviation was within 3.53%. Using coincidence summing correction factor transfer experiments, these factors were transferred to other high-purity germanium γ spectrometers. In verification by certificate activity, the absolute value of the maximum deviation was within 5.86%. Conclusion The coincidence summing correction factors calculated using simulated total efficiency by calling LabSOCS in the GENIE 2000 spectrum analysis software are effective in correction, and can be used as correction factors in standard laboratories. Through coincidence summing correction factor transfer experiments, the coincidence summing correction of other high-purity germanium γ-energy spectrometers can be achieved, which broadens the application of coincidence summing correction method.

Objective To determine the content and distribution characteristics of the artificial radionuclide ¹³⁷Cs and the natural radionuclides ²¹⁰Pb, ²²⁶Ra, ²²⁸Ra, and ⁴⁰K in wild edible fungi, and calculate the committed effective dose due to ¹³⁷Cs and ²¹⁰Pb in wild edible fungi. Methods Thirty samples of wild edible fungi were collected and their caps and stems were separated. A total of 60 samples were measured for ¹³⁷Cs, ²¹⁰Pb, ²²⁶Ra, ²²⁸Ra, and ⁴⁰K using a BE5030 wide-energy, low-background, high-purity germanium γ spectrometer. The paired analysis of the four radionuclides ²²⁶Ra, ²¹⁰Pb, ¹³⁷Cs, and ⁴⁰K was performed using SPSS 11.5. Results Among the 60 samples, the detection rates and dry weight specific activity ranges of ¹³⁷Cs, ²¹⁰Pb, ²²⁶Ra, ²²⁸Ra, and ⁴⁰K were 97% and 0.62-384 Bq/kg, 73% and 6.4-159 Bq/kg, 52% and 0.7-28.8 Bq/kg, 5% and 0.43-2.18 Bq/kg and 100% and （77.4-264) × 10 Bq/kg, respectively. Conclusion Based on the analysis of the 60 samples, the detection rate of radionuclides is in the order of ⁴⁰K, ¹³⁷Cs, ²¹⁰Pb, ²²⁶Ra, and ²²⁸Ra. In terms of the specific activity, the distribution of ⁴⁰K and ²²⁶Ra in wild edible fungi in the same region is basically uniform, while the content of ²¹⁰Pb and ¹³⁷Cs fluctuates in different samples. Although ¹³⁷Cs and ²¹⁰Pb can be detected in most of the wild edible fungi, the annual committed effective dose due to ingestion of wild edible fungi is negligible.