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.

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.

Abstract As a rapid analytical method for both the types and activities of γ radionuclides, the γ-ray spectrometry method is widely used in the measurement of γ radionuclides in environmental and biological samples. The Gamma-ray Spectrometry Method for the Determination of Radionuclides in Environmental and Biological Samples (GB/T 16145—2022）was implemented  on  July  1,  2023,  replacing  the Determination of Radionuclides in Soil by Gamma Spectrometry (GB/T 11743—2013), Determination of Radionuclides in Water by Gamma Spectrometry (GB/T 16140—2018), Gamma Spectrometry Method of Analyzing Radionuclides in Biological Samples (GB/T 16145—2020), and Determination of Radionuclides in Air by Gamma Spectrometry (WS/T 184—2017). The background of the revised standard, the content and basis of the main revisions, and some issues that need to be discussed are briefly explained in this paper, in order to provide a useful reference for the detection of radioactivity in soil, water, biological, and air samples, as well as samples of similar matrices.

This paper briefly introduces the main content of IAEA Safety Reports Series No. 114. The aim is to further understand the status and development of exposure due to radionuclides in food other than during a nuclear or radiological emergency, as well as to provide references for the revision and improvement of the limited concentration standard of radioactive substances in food in China.

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 recommend reference composition for sourceless efficiency calibration of food gamma spectrometry by analyzing the composition of common foods based on a combination of sourceless efficiency calibration and active validation.Methods:Thirty common types of food samples in countrywide monitoring of radioactively contaminated foods were analyzed to statistically determine the reference composition of grains and vegetables. Combined with the parameters provided for white quinoa standard source, LabSOCS was applied to carry out the simulation of sourceless efficiency for its different compositions, and to calculate its measured activity, and analyzing its relative deviation to the those given in the certificate.Results:The analytical result of these 30 types of food samples showed that the five elements C, H, O, N and S accounted for 77.0%-93.7% of the food composition, being the main component of these samples. By applying white quinoa′s components and grain-based reference components to the simulation of the sourceless efficiency of white quinoa standard sources, the relative deviations of activity calculations to their certificated activities were in the range of 0.37%-5.86% and 0.38%-5.87% in absolute value, respectively.Conclusions:The white quinoa′s composition and the grain reference composition were applied to the sourceless efficiency simulation of the white quinoa standard source, and the relative deviation of the calculated measured activity to the activity of the standard source certificate was basically identical, so that if the gamma spectrometry-based sourceless efficiency simulation is used to measure the unknown composition of the food samples and it is inconvenient to carry out the analysis of the food samples′ compositions, especially in the case of emergency, it can be referred to the use of the reference compositions obtained in the present study.

Objective To develop a large-volume sample cassette in the shape of a formalin cup suitable for portable HPGe γ spectrometer, to determine the detection limits of the cassette at different detection times through fresh sample measurements, and to provide a reference for responding to and monitoring of nuclear and radiation emergencies. Methods According to the formula for calculation of detection limit described in the GB/T 16145—2022, ¹³¹I and ¹³⁷Cs were measured using the sourceless efficiency calibration software Angle and the portable HPGe γ spectrometer for the optimization of the large-volume sample cassette. Fresh salmon samples were measured using a formalin cup-shaped large-volume sample cassette. The detection times were 2, 4, 6, 8, 10, 19, 19, 22, and 24 hours. The relationship between detection time and detection limit was assessed. Results Using sample cassettes with 15 cm radius and 10 L volume, the simulated detection efficiency of the formalin cup-shaped large-volume sample cassette was 30%-46% higher and the detection limit was lower as compared with the cake-shaped large-volume sample cassette. The detection limit obtained by measuring fresh salmon samples decreased with the extension of the detection time. These results provided a reference for the detection limits of measuring fresh samples for nuclides of concern in nuclear contaminated water with different detection times. Conclusion The formalin cup-shaped large-volume sample cassette developed by combining the optimization of detection limit provides a geometry for quantitative analysis in on-site monitoring of γ nuclides in the case of emergencies. Measurement of fresh samples using the cassette with different detection times showed that 8-10 hours of detection was optimal in balancing the detection limit and the detection time.

Objective To correct the counting loss of ³⁷Ar below the activity threshold during the measurement of the absolute activity of the inert radioactive gas ³⁷Ar using the proportional counter filled with gas. Methods Monte Carlo simulation with Geant4 was performed to establish a proportional counter model and output the energy deposition spectrum of ³⁷Ar, which were used to simulate and analyze the causes and correction of counting loss. Results The photon detection efficiency was only 38.7% at 60 kPa. The counting loss was mainly caused by the wall effect produced by the photons, which could be reduced by increasing the gas pressure and corrected by extrapolation. The influence of wall effect at 100 kPa was 4.4%, and the deviation between simulation and experiment was < 0.6%. Conclusion A factor could be calculated by Geant4 simulation for the correction of counting loss, thus achieving the accurate measurement of ³⁷Ar activity by proportional counter.

Objective:To compare the clinical effectiveness between arthroscopic hollow screws combined with a suture anchor, hollow screws and proximal humerus internal locking system (PHILOS) in the treatment of split-type fractures of humeral greater tuberosity.Methods:A retrospective study was conducted to analyze the 54 patients with split-type fracture of humeral greater tuberosity who had been admitted to Department of Joint Surgery, Hospital of Traditional Chinese Medicine, Affiliated to Southwest Medical University from May 2015 to August 2020. There were 17 males and 37 females with an age of (58.4±12.1) years. According to different treatment methods, they were divided into 3 groups. Group A of 18 cases was treated with arthroscopic hollow screws combined with a suture anchor, group B of 18 cases with hollow screws, and group C of 18 cases with PHILOS. The length of surgical incision, and range of shoulder motion, visual analogue scale (VAS), and American Shoulder and Elbow Surgeons (ASES) score at the last follow-up were recorded and compared between the 3 groups.Results:There was no statistically significant difference in the preoperative general information between the 3 groups, indicating the 3 groups were comparable ( P>0.05). The surgical incision in group A [(0.7±0.1) cm] was the shortest, followed by (5.0±1.4) cm in group B, and (12.8±2.1) cm in group C, showing statistically significant differences in pairwise comparison ( P<0.05). In the 3 groups at the last follow-up, respectively, the shoulder forward flexion was 159.7°±13.4°, 154.9°±16.2°, and 160.5°±12.9°, and the shoulder abduction 149.6°±11.3°, 142.4°±12.0°, and 145.1°±10.4°, showing no statistically significant difference among the 3 groups ( P>0.05); the external rotation was 41.1°±8.1°, 38.1°±7.8° and 43.7°±6.2°, showing a statistically significant difference between groups B and C ( P<0.05); the dorsal extension was T 12 (L 5 to T 6), T 12 (L 5 to T 7), and T 12 (L 3 to T 6), showing no statistically significant difference among the 3 groups ( P>0.05). There was no statistically significant difference among the 3 groups in the VAS score or ASES score at the last follow-up ( P>0.05). Respectively, there were 2, 6, and 4 patients in groups A, B and C who developed complications, showing statistically significant differences between the 3 groups ( P<0.05). Conclusions:In the treatment of split fractures of humeral greater tuberosity, arthroscopic hollow screws combined with a suture anchor, hollow screws and PHILOS can all relieve pain and restore joint function of the shoulder. However, arthroscopic hollow screws combined with a suture anchor are the most recommendable due to their advantages in minimally invasiveness and reduction in complications.

Objective:To measure the influencing factors associated with the analysis of 226Ra gamma spectra in order to obtain more acurate and precise measuring result on a basis of further optimizing the gamma spectrometry method for 226Ra activity. Methods:A laboratory-based HPGe gamma spectrometer was used to carry out the studies on tracking measurement of sample sealing time, measurement of background fluctuation with lead shielding, analytical method, and selection of characteristic gamma ray energy peak of its daughter nuclides in 226Ra measurement. Results:After the sample was sealed for 12 d, the decay products of 226Ra- 222Rn basically reached equilibrium. The day and night fluctuations of 222Rn in the shielded lead room were obvious but had no obvious regularity. The way of filling nitrogen into the shielded lead room could reduce or avoid the influence of background fluctuations. For 31 soil samples measured after 23 days of sealing, the result of using the efficiency curve method showed that the 226Ra result calculated from the 351.9 keV energy peak were generally higher than the 609.3 keV energy peak, and the higher ratio ranged from 8.0% to 20.7%. The result of relative comparison method showed that the deviation ratio of the two peaks ranged from -4.1 % to 10.3 %. Conclusions:It is recommended to consider the uncertainty attributed from decay equilibrium about 4 % of measured at 12 d after the sample is sealed. When filling nitrogen through the shielded lead chamber to avoid background fluctuations, attention must be paid to the matching relationship between the volume of the lead chamber and the nitrogen filling flow. When the efficiency curve method is used to analyze the activity of 226Ra, the 214Bi ( 609.3 keV ) energy peak has the effect of cascade coincidence addition, so 214Bi(609.3 keV) energy peak should be avoided. When the relative comparison method is used to analyze the activity of 226Ra, both two energy peaks of 214Pb ( 351.9 keV ) and 214Bi ( 609.3 keV ) can be used.