Objective To investigate the existing nuclear radiation health emergency response capacity of local health systems at nuclear power plant sites in Guangdong Province. Methods The health administrative departments of all nuclear power plants sites in Guangdong Province, along with radiation health protection institutions, designated nuclear radiation treatment hospitals, and township health centers, were selected as the study subjects using the purposive sampling method. A series of standardized questionnaires on the capacities for nuclear radiation health emergency response, developed uniformly by the National Institute for Radiological Protection, Chinese Center for Disease Control and Prevention, were adopted to separately investigate the capacities for nuclear radiation health emergency response in the study subjects. Results There were 13 health administration departments, 15 radiological health protection institutions, 18 designated hospitals for nuclear radiation medical response, and 18 township health centers located in the nuclear power plants sites in Guangdong Province. Among the 13 health administration departments, the Health Commission of Guangdong Province met all 15 criteria for nuclear radiation health emergency response capacities. All six prefecture-level health administrative departments possessed more than 10 capacities for nuclear radiation health emergency response, while only one of the six county-level departments had more than 10 such capacities. Among radiation health protection institutions, the provincial-level institution possessed all 18 capacity for nuclear radiation health emergency response; of the six prefectural-level institutions, only four had more than 10 capacities; none of the eight county-level institutions or 18 township health centers possessed more than 10 capacities. Among designated nuclear radiation treatment hospitals, provincial-level institution met all 32 capacities for nuclear radiation health emergency response; of the eight prefecture‑level hospitals, only four meet more than ten such capacities; and of the nine county‑level hospitals and 18 township health centers, none possess more than 10 capacities. Conclusion Provincial- and prefectural-level nuclear radiation emergency capacity in Guangdong Province is adequate, whereas county-level and township health centers have obvious weaknesses in organizational structure, personnel training, equipment reserves, funding, and technical reserves; emergency response capacity needs urgent enhancement.

Objective​ To analyze the current status of nuclear radiation health emergency response capacity in areas of the nuclear power plants in Guangdong Province, and to formulate a construction plan for municipal-level nuclear radiation health emergency response teams. Methods Provincial-, municipal-, and county-level administrative regions in the nuclear power plant host areas of Guangdong Province were selected as the study subjects. A series of questionnaires designed by the National Institute for Radiological Protection, Chinese Center for Disease Control and Prevention, were used to assess the capacity of nuclear radiation health emergency response. Based on the findings, a construction plan for municipal-level nuclear radiation health emergency response teams was formulated. Results A total of 13 administrative regions which host nuclear power plants were involved, including one provincial-level, six municipal-level, and six county-level regions. The availability rates of 31 capacity indicators of nuclear radiation health emergency response among 13 administrative regions ranged from 15% to 100%, with an average of 51%. Provincial-level capacity of nuclear radiation health emergency response was relatively well established, county-level radiation monitoring and protection capacity was nearly absent, municipal-level regions possessed basic capacity, but with obvious regional disparities and a general lack of specialized facilities and materials required for the treatment of nuclear radiation injuries, making them the key level for improvement in nuclear radiation health emergency response. The Construction Plan for Municipal-Level Nuclear Radiation Health Emergency Response Teams specifies that the total number of team members should be no fewer than 30 to ensure rapid response and immediate arrival at the scene. The List of Key Professional Equipment proposes the prioritized allocation of five categories of equipment: personal basic equipment, contamination detection and classification equipment, decontamination equipment, medical treatment equipment, and command and logistical support equipment. Conclusion Nuclear radiation health emergency response capacity in Guangdong Province requires further improvement, particularly in standardized development of municipal-level nuclear radiation health emergency response teams. The Construction Plan for Municipal-Level Nuclear Radiation Health Emergency Response Teams defines capacity requirements and provides a list of essential equipment, offering a practical reference for other regions.

Objective To analyze the monitoring data of ¹³¹I internal exposure in Guangdong Province over the past 3 years, study the thyroid ¹³¹I contamination levels among nuclear medicine staff, and provide a basis for optimizing the monitoring plan. Methods Using a convenience sampling method, 574 detections of nuclear medicine staff from 28 hospitals in Guangdong Province were included in the study. The thyroid ¹³¹I activity was measured directly in vivo. Differences in detection rates were analyzed, and committed effective doses were estimated. Results Over the past 3 years in Guangdong Province, ¹³¹I accumulation was found in the thyroids of staff from 14 hospitals for 62 (10.8%) detections, with an average activity of 154.8 (13.2-8730.6) Bq. The adjusted annual intake was 50.7 (4.5-820.6) kBq. The committed effective dose was 0.56 (0.05-9.03) mSv/a, and the values were ≥ 2 mSv for 8 persons. Among different positions, nurses showed the highest detection rate (19.6%), followed by cleaners (14.7%), with significant differences (P<0.05). Among different exposure types, the detection rate was highest for loading medication into automatic dispenser (23.3%), and the mean activity was highest for entering thyroid cancer patient ward (495.4 Bq), with significant differences (P<0.05). Conclusion Monitoring of ¹³¹I internal exposure in Guangdong Province found that the radiation doses of some staff members had exceeded the threshold specified in other investigations. Routine personal ¹³¹I internal exposure monitoring should be conducted, with increased monitoring frequency. Priority should be given to nurses and cleaners, with monitoring extended to cleaners and outsourced dispensing staff.

Objective To investigate the role of the O-6-methylguanine-DNA methyltransferase (MGMT) gene-3′ untranslated region (UTR) microRNA-associated single nucleotide polymorphism (miRSNP) (rs7896488 G>A) in affecting miR-4297-targeted modulation of MGMT in senescence of lung cells with polymorphic genotypes induced by fractionated low dose ionizing radiation (LDIR). Methods i) MiRSNPs were predicted and screened using bioinformatics, and DNA from two types of lung cells, A549 cells and human bronchial epithelioid cells (HBE cells), was extracted for target gene sequencing. After co-transfection of pGL3c-MGMT-3′UTR-rs7896488 G>A reporter gene recombinant plasmid, pRL-TK Vector with micrON mimic NC #22 or micrON hsa-miR-4297 mimic (set up as the mimic NC group and the miR-4297 mimic group) in these two types of lung cells, dual luciferase reporter gene assay was performed. The relative expression of MGMT mRNA was detected by real-time fluorescence quantitative polymerase chain reaction, and the relative expression of MGMT protein was detected by Western blotting. ii) These two types of lung cells were randomly divided into the control group and irradiation group, which received either 0 or 100 mGy X-rays irradiation seven times. After irradiation, the cells were transfected with either micrON mimic NC #22 or micrON hsa-miR-4297 mimic, resulting in mimic NC + control group, miR-4297 mimic + control group, mimic NC + irradiation group, and miR-4297 mimic + irradiation group. Cells were collected for senescence-associated-β-galactosidase (SA-β-Gal) staining, and the relative expression of matrix metalloproteinase-9 (MMP-9) and chemokine (C-X-C motif) ligand-1 (CXCL-1) proteins was detected via Western blotting. Results i) The rs7896488 G>A was the miRSNP located in the conserved binding region targeted by miR-4297 in the MGMT gene 3′UTR. A549 cells were the rs7896488 GG wild-type homozygous genotype, while HBE cells were the rs7896488 GA heterozygous mutant genotype. In the miR-4297 mimic group, A549 and HBE cells carrying the rs7896488 G allele showed significantly lower dual-luciferase activity compared with that in the mimic NC group (both P<0.01). However, there was no significant difference in dual-luciferase activity between the two groups in both A549 and HBE cells carrying the rs7896488 A allele (both P>0.05). The relative expression levels of MGMT mRNA and MGMT protein of A549 cells in the miR-4297 mimic group were lower than those in the mimic NC group (both P<0.05). However, there was no significant difference in MGMT mRNA and MGMT protein of HBE cells between these two groups (both P>0.05). ii) The relative activity of SA-β-Gal and the relative expression of MMP-9 and CXCL-1 proteins of A549 cells in the miR-4297 mimic+irradiation group were higher than those in the mimic NC + control group, the miR-4297 mimic + control group, and the mimic NC + irradiation group (all P<0.05). The relative activity of SA-β-Gal and the relative expression of MMP-9 and CXCL-1 proteins of HBE cells in the miR-4297 mimic + irradiation group were higher than those in the mimic NC + control group and the miR-4297 mimic + control group (all P<0.05), while there was no significant difference compared with those in the mimic NC + irradiation group (all P>0.05). Conclusion MGMT-3′UTR-miRSNP rs7896488 G>A plays a role in LDIR-induced senescence of lung cells with different polymorphic genotypes by affecting miR-4297-targeted regulation of MGMT.

Objective To assess the current status of occupational radiation hazards in animal diagnosis and treatment institutions in Foshan City. Methods A total of 214 animal diagnosis and treatment institutions in Foshan City in 2024 were selected as the study subjects using the judgment sampling method. The radiation protection management status was investigated. Results A total of 178 out of the 214 animal diagnosis and treatment institutions were equipped with radiation diagnostic equipment in Foshan City. Among these 178 institutions, 98 (accounting for 55.1%) obtained permits from the ecology and environmental department, 21 (accounting for 11.8%) completed occupational hazard project declarations, 53 (accounting for 29.8%) conducted workplace radiation level monitoring, 132 (accounting for 74.2%) were equipped with radiation protection equipment, 40 (accounting for 22.5%) conducted occupational health examinations for the radiation staff, 39 (accounting for 21.9%) provided radiation protection knowledge training for the radiation staff, and 52 (accounting for 29.2%) performed personal radiation dose monitoring. However, none of the institutions implemented the “Three Simultaneities (design, construct, put into operation and use simultaneously with the main body of the construction project)” system for occupational disease prevention facilities in construction projects. Conclusion sAnimal diagnostic and treatment institutions in Foshan City have low levels of radiation protection management and inadequate occupational health monitoring. The radiation staff has low awareness of radiation protection, Relevant department should strengthen supervision and management, organize radiation protection knowledge training, and standardize occupational health management to effectively safeguard workers' health rights.

Objective To understand the situation of dental cone beam computed tomography (CBCT) quality control testing phantoms in radiation health technical service institutions in Guangdong province, analyze the differences among different phantoms, and provide a reference for dental CBCT quality control testing. Methods The testing phantoms of 49 radiation health technical service institutions were used as the research objects. The designated CBCT equipment was used for scanning and imaging. The Z-score method was used to evaluate the high-contrast resolution, low-contrast resolution, and distance measurement deviation of each phantom. Results The satisfaction rates of various items for the phantoms in 49 institutions ranged from 85.7% to 100%. The distance measurement deviations of four institutions were “suspicious”, and the high-contrast resolution of four institutions and the distance measurement deviation of one institution were “unsatisfactory”. Conclusion The overall performance of dental CBCT quality control testing phantoms in radiological health technical service institutions in Guangdong province is satisfactory. However, there are still some phantoms with poor results in items such as distance measurement deviation and high-contrast resolution. The structural design, material selection, and manufacturing process of the phantom may all affect the results of quality control testing. Therefore, appropriate phantoms, optimized exposure conditions, and suitable reconstruction algorithms should be used in CBCT quality control testing to ensure accurate and reliable measurements.

Objective To investigate the effects of fractionated low-dose ionizing radiation (LDIR) on the ferroptosis in human bronchial epithelial (HBE) cells as well as the associated differentially expressed genes (DEGs), biological processes, and signaling pathways. Methods HBE cells were exposed to different single doses of X-ray irradiation (0, 25, 50, 75, and 100 mGy) for 24, 48, and 72 h, respectively. The change in cell viability was detected by MTT assay. Cells were irradiated with 0, 25, 50, and 100 mGy X-rays 5 times, with 48 h between each irradiation and a dose rate of 50 mGy/min. Cells were harvested 24 h after irradiation for the measurement of the expression of ferroptosis-related genes SLC7A11 and GPX4 at the mRNA and protein levels, cellular iron content, and the expression of FTH1 and FTL mRNAs. High-throughput sequencing was used to screen for the DEGs in each dose group, followed by Gene Ontology-Biological Process (GO-BP) analysis, Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis, and Gene Set Enrichment Analysis (GSEA). Results Compared with the control group, single-dose LDIR significantly increased cell proliferation at 75 mGy after 24 h (P < 0.05), at 50, 75, and 100 mGy after 48 h (P < 0.05), and at 75 and 100 mGy after 72 h (P < 0.05). Compared with the control group, at the end of the fifth fractionated LDIR, SLC7A11 and GPX4 mRNAs decreased at all doses (P < 0.05), SLC7A11 protein decreased at all doses, GPX4 protein decreased at 25 and 100 mGy, iron content increased at all doses, and FTH1 and FTL mRNAs decreased at all doses (P< 0.05). Sequencing analysis identified 248, 30, and 291 DEGs and 10, 2, and 9 ferroptosis-associated genes at the three doses compared to the control. Gene Ontology-Biological Process analysis showed that DEGs were mainly enriched in biological processes such as response to lipids, cell death, and response to unfolded proteins. Kyoto Encyclopedia of Genes and Genomes analysis showed that DEGs were mainly enriched in the JAK-STAT signaling pathway, lipids and atherosclerosis, ferroptosis, protein processing in the endoplasmic reticulum, and FoxO signaling pathway. Gene set enrichment analysis showed that DEGs were mainly enriched in ferroptosis, fatty acid degradation, and glutathione metabolism. Conclusion Fractionated low-dose radiation induced ferroptosis in HBE cells, and DEGs were predominantly enriched in biological processes and signaling pathways related to inflammation, ferroptosis, and endoplasmic reticulum stress.

Objective To analyze bedside radiation dose rates for interventional surgery operators in Guangdong Province, examine dose distribution patterns, and identify potential weaknesses in radiation protection, and to provide guidance for optimizing radiation monitoring and protection measures. Methods A total of 209 digital subtraction angiography devices measured in Guangdong Province between 2017 and 2024 were used as the research objects. The first and second operator positions were set at 30 cm and 90 cm horizontally from the X-ray tube focal point, respectively. Monitoring points were set up at 155, 125, 105, 80, and 20 cm above the ground. Results The median bedside radiation dose rate for interventional surgery operators in Guangdong Province was 83.0 (3.9, 1044.0) μSv/h, indicating instances of exceeding standard limits. The overall dose rates under the old and new standards were 29.8 (3.9-346.5) μSv/h and 114.0 (4.0-1044.0) μSv/h respectively. Results for both standards showed a higher dose rate at the second than the first operator position. The dose rates at the heights of 105 cm (abdomen), 125 cm (chest), and 155 cm (head) were higher in the second operator position than in the first operator position. Additionally, 71.5% and 56.8% of the highest dose rate points under the new and old standards, respectively, were concentrated at 105 cm (abdomen), 125 cm (chest) and 155 cm (head) in the second operator position. Conclusion The principle of protection optimization should be followed, auxiliary protective facilities should be placed correctly, and attention should be paid to the protection of the second surgery operator position, especially above the abdomen. The dose rate results under the new standard were lower than those under the old standard, suggesting that the measurement method may overestimate radiation exposure at the secondary operator position.

Background In recent years, the increasingly widespread application of nuclear and medical radiation technologies has resulted in a large number of occupational populations exposed to low-dose ionizing radiation (LDIR). At present, there is no consistent conclusion on the effects of long-term exposure to LDIR on the metabolic health of the occupational population. Objective To explore the association between long-term exposure to LDIR and metabolic syndrome (MetS) among medical radiologists. Methods A cross-sectional study was conducted to enroll 6431 medical radiologists who ordered occupational health checkups from January 2022 to December 2023, and basic information such as demographic characteristics, occupational characteristics, lifestyles, and dietary habits was collected through questionnaires. Physical examinations were conducted using a standardized protocol. Individual dose equivalents of occupational external exposure were monitored by dosimeters worn by medical radiologists. Logistic regression model was used for identifying influencing factors of MetS and sensitivity analysis, and restricted cubic spline model was used to explore the dose-response relationship between cumulative effective dose and MetS. Two-stage linear regression was used to evaluate threshold effect of association between cumulative effective dose and MetS. Results The positive rate of MetS was 13.6% (877/6431) among the enrolled 6431 study participants. The logistic regression showed that gender, age, monthly income, body mass index (BMI), cumulative effective dose, and smoking were influencing factors for MetS. The risk of MetS was higher in males (OR=1.511, 95%CI: 1.209, 1.888); using the < 30 years old group as reference, the risk of MetS was higher in the 30-39 years old (OR=1.509, 95%CI: 1.095, 2.079), 40-49 years old (OR=2.214, 95%CI: 1.551, 3.161), and ≥50 years old (OR=3.480, 95%CI: 2.338, 5.181) groups; using the <10000 yuan group as reference, the risk of MetS was lower in the group with a monthly income of 10000-14999 yuan (OR=0.715, 95%CI: 0.582, 0.878); the risk of MetS was higher in the BMI ≥ 24 kg·m⁻² group (OR=7.548, 95%CI: 6.223, 9.156); using the < 0.76 mSv group as reference, the risk of MetS was higher in the cumulative effective dose of 0.76-2.73 mSv group (OR=1.270, 95%CI: 1.017, 1.586); the risk of MetS was higher in the smoking group (OR=1.734, 95%CI: 1.428, 2.107). The results of restricted cubic spline showed that the cumulative effective dose was nonlinearly correlated with MetS (P _{non-linearity}=0.028), with an inflection point of 1.25 mSv. The risk of developing MetS increased by 34.1% for each unit increase in cumulative effective dose up to 1.25 mSv, whereas above 1.25 mSv, the statistical association was not significant. The sensitivity analysis results showed that after excluding the self-reported hypertensive and diabetic patients, the cumulative effective dose 0.76-2.73 mSv group still had an increased risk of developing MetS compared with the < 0.76 mSv group (P < 0.05), and the results were robust. Conclusion Among medical radiologists, male, age, BMI, and smoking are positively correlated with MetS, and monthly income is negatively correlated with MetS; cumulative effective dose is non-linearly correlated with MetS among medical radiologists.

Objective To track and evaluate the implementation and application of the occupational health standard Radiation shielding requirements for radiotherapy room—Part 4: Radiotherapy room of ²⁵²Cf neutron afterloading (GBZ/T 201.4-2015) by radiation health technical service agencies, medical institutions, health supervision agencies, and radiotherapy facility design units, and to provide a scientific basis for the further revision and implementation of this standard. Methods Following the Guideline for health standards tracking evaluation (WS/T 536-2017) and the project implementation plan, relevant practitioners were randomly selected for a questionnaire survey. The survey primarily focused on their awareness, standard training, application, and revision suggestions of GBZ/T 201.4-2015. The results were summarized and analyzed. Results A total of 168 evaluation questionnaires were collected from relevant practitioners in 28 provinces. Only 31.6% of the respondents reported being “well familiar” or “ familiar” with the standard, 27.4% of the respondents believed that the standard was widely used, and 45.2% of the respondents believed that the standard could meet the needs of their work. Only 14.9% of the respondents had received relevant training on the standard, more than half of the respondents had not applied the standard within the past 10 years, and 45.2% of the respondents believed that the standard "needs to be revised". Conclusion Due to the small number of californium-252 neutron afterloading radiotherapy devices in operation on the market, the overall awareness of the standard is low, suggesting that relevant authorities need to strengthen training and publicity of the standard, and that certain sections of the standard need to be revised or merged.