The legislative purpose of the Law of the People′s Republic of China on the Prevention and Control of Occupational Diseases is to safeguard the health, related rights and interests of workers, and to promote economic and social development. The remarkable achievements in occupational disease prevention and control indicate the implementation effect of the legal system for prevention and control of occupational diseases. The implementation effect of laws is influenced by various factors, including legislation, law enforcement, and law compliance. This study proposes a methodology to study the relationship between the implementation effect and influencing factors of the legal system for prevention and control of occupational diseases, based on the implementation theory of the law and the actual implementation of the legal system for prevention and control of occupational diseases, so as to further improve the level of legislation, law enforcement, and law compliance, and to promote the realization of the legislative purpose. The results of this study show that the law enforcement dimension of prevention and control of occupational diseases can be examined by retrospective analysis of the incidence of occupational diseases, or the relationship between other illegal situations and the intensity of supervision and punishment. The compliance dimension can focus on the application of enforcement principles (legality principle, rationality principle, and efficiency principle) and attribution diagnosis principles for occupational diseases. The legislative dimension should prioritize the appropriateness of the legal system′s content, implementation status, and clarity and acceptability of legal expressions. In addition, research should be conducted on issues such as opportunities for violations, motivations for compliance, social atmosphere, and legal awareness campaigns. Relevant research data can be obtained by collecting management statistics, media reports and special subject design observations. Only when laws are well-established, well-enforced, well-applied, and when law-abiding becomes the conscious choice of employers and law enforcement agencies, can workers′ occupational health rights be effectively protected and the authority of the law fully realized.

Objective To explore the nephrotoxic effects of exposure to perfluorobutanoic acid (PFBA) and its mechanism in mice, with a particular focus on analyzing the changes in kidney metabolism and their potential implications. Methods The specific pathogen free C57BL/6 mice were randomly divided into control group, low-dose group, and high-dose group, with 10 mice in each group. Mice in the three groups received intragastric administration of PFBA solution at doses of 0, 35 and 350 mg/kg body weight, once per day for seven consecutive days. The histopathological changes of kidneys of mice in these three groups were evaluated. Metabolomic profiling of mouse kidneys was performed using ultra-high-performance liquid chromatography coupled with quadrupole time-of-flight mass spectrometry. Differentially accumulated metabolites (DAMs) were identified based on the Human Metabolome Database, and related metabolic pathways were analyzed through MetaboAnalyst 6.0 and Kyoto Encyclopedia of Genes and Genomes (KEGG). Results Histopathological analysis of kidneys showed that the renal pelvis mucosa of mice in the low-dose group presented focal mild inflammatory changes without marked structural damage, whereas mice in the high-dose group showed severe inflammation and partial destruction of renal structure. The kidney coefficient of mice in both low-dose group and the high-dose group decreased (both P<0.05), and the Paller scores of renal tissues increased (both P<0.05) compared with that in the control group. The Paller score of mouse renal tissue in the high-dose group was higher than that in the low-dose group (P<0.05). Metabolomic profiling identified 46 DAMs (26 upregulated, 20 downregulated) in the low-dose group and 104 DAMs (54 upregulated, 50 downregulated) in the high-dose group, with 26 shared DAMs between the two dose groups. KEGG pathway analysis revealed that DAMs were mainly involved in metabolic pathways such as glycerophospholipid metabolism, glycerolipid metabolism, sphingolipid and steroid hormone synthesis. Conclusion Acute exposure to PFBA can cause kidney injury in mice. Lipid metabolism pathways such as glycerophospholipid and sphingolipid metabolism is involved in the development of acute renal toxicity of PFBA.

Objective To explore the effects of combined exposure to bisphenol A (BPA) and high-fat diet on liver lipid metabolism and hepatocyte senescence in mice, and to elucidate the potential mechanisms of the onset and development of non-alcoholic fatty liver disease (NAFLD). Methods Specific pathogen free C57BL/6J mice were randomly divided into six groups, with 10 mice with equal numbers of each sex in each group. The mice in the control group and the simple BPA group were fed with regular diet, while others four groups of mice were fed with high-fat diet. At the same time, the mice in the simple BPA group were intragastric administered with BPA at a dose of 50 μg/kg body weight, while the mice in the low-, medium- and high-dose BPA+high-fat groups were intragastric administered with BPA at doses of 5, 50 and 500 μg/kg body weight respectively. The mice in the control group and the high-fat group were intragastric administered with the same volume of corn oil once per day for 90 consecutive days. Liver tissues were subjected to hematoxylin-eosin (HE) and Oil Red O staining. Liver coefficients and lipid-stained area ratios were calculated. Serum level of total cholesterol, triglycerides, high-density lipoprotein, low-density lipoprotein, and the activities of alanine aminotransferase (ALT) and aspartate aminotransferase (AST) were determined using an automatic biochemical analyzer. The hepatic tumor necrosis factor-α (TNF-α), interleukin (IL)-6, and IL-10 levels were quantified by enzyme-linked immunosorbent assay. The relative expression of cholesterol regulatory element binding protein 1 (SREBP1), CCAAT enhancer binding protein α, P16, and phosphorylated histone H2AX (γ-H2AX) in liver tissues was detected using Western blotting. The interaction effect of the combined exposure to BPA and high-fat diet was observed based on the result of mice in the control group, the simple high-fat group, the simple BPA group, and the medium-dose BPA group+high-fat group (the combined exposure group) using a 2×2 factorial design. The results of mice in the simple high-fat group and the low-, medium-, and high-dose BPA+high-fat groups were used to observe the effect of BPA exposure dose under high-fat diet conditions. Results i) The interactive effect of combined exposure to BPA and high fat. The HE and Oil Red O staining results indicated that the combined exposure to BPA and high-fat diet successfully established NAFLD in mice. The interactive effect of combined exposure to BPA and high-fat diet on serum ALT activity and the relative expression of P16 in the liver tissue of female mice, as well as the serum ALT and AST activities and the relative expression of SREBP1 in the liver tissue of male mice was significant (all P<0.05). Specifically, the serum ALT activity of male mice in the combined exposure group was higher than that in the simple high-fat group (P<0.05), while the ALT activity in the serum of female mice in the combined exposure group was lower than that in the simple BPA group (P<0.05). The relative expression of SREBP1 protein in the liver tissue of male mice in the combined exposure group was higher than that in the control group, the simple high-fat group, and the simple BPA group (all P<0.05). For the other indicators, there were no significant differences in the interactive effect of combined exposure to BPA and high-fat diet (all P>0.05). ii) Dose effects of BPA exposure. The HE and Oil Red O staining result showed that the degree of vacuolar steatosis in the liver of female and male mice of medium- and high-dose BPA + high-fat groups was aggravated, and the range of inflammatory cell infiltration was expanded when compared with same-sex mice in the simple high-fat group. The serum ALT activity and the fat stained area ratio, as well as the relative expression of P16 in liver tissue of female mice in high-dose BPA + high-fat group increased (all P<0.05), while the level of IL-10 in liver tissue decreased (P<0.05), compared with the female mice in simple high-fat group. The serum ALT activity, the TNF-α level in liver tissue, and the relative expression of SREBP1, P16 and γ-H2AX proteins in liver tissue of male mice in high-dose BPA + high-fat group increased (all P<0.05), while the IL-6 level in liver tissue decreased (P<0.05), compared with the male mice in simple high-fat group. For the female or male mice in the low- and medium-dose BPA + high-fat groups, only some of the above indicators showed significant changes (all P<0.05). Conclusion The combined exposure to BPA and high-fat diet has a synergistic effect on the onset and development of NAFLD. The mechanism may be related to inducing cellular senescence and modulation of lipid synthesis pathways, thereby affecting liver steatosis. The exposure dose of BPA may affect the synergistic effect.

Objective To explore the genotoxicity of lead on DNA damage and the repair role of homologous recombination repair protein RAD51 in lead-induced DNA double-strand breaks in TK6 cells. Methods i) TK6 cells in the logarithmic growth phase were divided into five groups: blank control group, low-dose group, medium-dose group, high-dose group, and positive control group. The first four groups were treated with lead acetate at concentrations of 0, 120, 240 and 480 μmol/L, respectively. The positive control group was treated with 100 μmol/L hydrogen peroxide solution incubated on ice for 24 hours. After the positive rate of phosphorylated histone H2AX (γ-H2AX) was detected by immunofluorescence. Cell proliferation was detected by 5-ethynyl-2'-deoxyuridine (EDU) method. Cell cycle and apoptosis were detected by flow cytometry, and the relative expression of RAD51 protein was detected by Western blotting. ii) A short hairpin RNA (shRNA) silencing RAD51 model was constructed in TK6 cells, and the cells were divided into untreated group (normal TK6 cells), negative control group (sh-NC), and RAD51 silencing group (sh-RAD51). The mRNA expression of RAD51 was detected by real-time fluorescence quantitative polymerase chain reaction, and the protein expression of RAD51 was detected by Western blotting to verify the interference effect. iii) Normal TK6 cells, sh-NC, and sh-RAD51 were treated with 480 μmol/L lead acetate for 24 hours, and were divided into lead treatment group, lead+negative control group, and lead + RAD51 silencing group, respectively. Untreated normal TK6 cells was served as the control group. The positive rate of γ-H2AX and the expression of RAD51 protein in each group was detected by immunofluorescence and Western blotting, respectively. Results i) With the increase of lead acetate treatment concentration in TK6 cells, the positive rate of γ-H2AX increased (all P<0.05), the proportion of EDU positive cells decreased (all P<0.05), and the proportion of S-phase cells decreased (all P<0.05). The proportion of G1-phase cells in the high-dose group and the positive control group was higher than those in the low- and medium-dose groups (all P<0.05). The proportion of G2-phase cells in the medium-dose group, high-dose group, and positive control group increased compared with the blank control group (all P<0.05), although no significant differences were observed among these three dosing groups (all P>0.05). The apoptosis rate and the relative expression of RAD51 protein of TK6 cells in each group increased with the increase of lead acetate concentration (all P<0.05). ii) The relative expression levels of RAD51 mRNA and protein in the RAD51 silencing group were lower than those in the untreated group and the negative control group (all P<0.05) after RAD51 silencing. iii) The positive rate of γ-H2AX in the lead + RAD51 silencing group increased (all P<0.05), and the relative expression of RAD51 protein decreased (all P<0.05),compared with the control group, lead treatment group, and lead + negative control group. Conclusion Lead exposure induces DNA double-strand breaks in TK6 cells, inhibits cell proliferation, and causes cell cycle arrest and apoptosis in a dose-effect manner. Downregulation of the RAD51 gene can lead to inhibition of the homologous recombination repair pathway, thereby increasing the TK6 cell sensitivity to lead-induced DNA damage.

Objective To analyze the level of occupational health literacy (OHL) and mental health status in key populations in Jiangsu Province, and explore the impact of OHL on occupational stress, depressive symptoms, anxiety symptoms and insomnia symptoms. Methods A total of 11 181 workers from Jiangsu Province from April to December 2023 were selected as the research subjects using a combination of stratified cluster random sampling and probability proportional sampling method. The OHL levels of the workers, as well as their occupational stress, depression symptoms, anxiety symptoms and insomnia symptoms, were investigated using the Occupational Health Literacy Questionnaire of National Key Populations (including Occupational Health Literacy Scale, Core Occupational Stress Scale, Patient Health Questionaire-9, Generalized Anxiety Disorder 7-item Scale, and Self-Sleep Management Questionnaire). Results The OHL level of the research subjects was 41.7%, and the literacy levels of the four dimensions of occupational health legal knowledge, basic knowledge of occupational health protection, basic skills of occupational health protection, and healthy working style and behavior were 40.6%, 76.4%, 28.0% and 54.4%, respectively. The detection rates of occupational stress, depression symptoms, anxiety symptoms and insomnia symptoms were 21.8%, 17.7%, 26.4% and 29.6%, respectively. The result of multivariable logistic analysis showed that participants with adequate OHL had a lower risk of occupational stress, depressive symptoms, anxiety symptoms, and insomnia symptoms than those without adequate OHL (all P<0.01) after controlling individual and occupational confounding factors. The odds ratios and their 95% confidence intervals were 0.448(0.402-0.499), 0.664(0.593-0.742), 0.705(0.639-0.777) and 0.885(0.809-0.969), respectively. Conclusion OHL is an independent influencing factor for occupational stress, depressive symptoms, anxiety symptoms and insomnia symptoms in key populations from Jiangsu Province. Effective measures should be taken to improve the OHL level of workers, to reduce the risks of occupational stress, depressive symptoms, anxiety symptoms and insomnia symptoms.

Objective To analyze the influencing factors of hospitalization costs in patients with occupational noise-induced deafness (ONID), and provide evidence for health policy development. Methods A total of 109 ONID patients in a hospital for occupational disease prevention and treatment in Guangdong Province were collected from 2018 to 2022 as the study subjects using a retrospective analysis method. Hospitalization information was collected, and influencing factors of hospitalization costs were analyzed. Results The average hospitalization cost per admission from 2018 to 2022 was 26 948.1, 27 805.0, 25 291.1,20 741.2 and 18 865.1 yuan, respectively, showing a downward trend. Grey relational analysis showed that the top three cost components most closely associated with the average hospitalization cost per admission were treatment expenses, medical service fees, and other expenses, with correlation coefficients of 0.786 1, 0.720 4, and 0.654 3, respectively. Univariate logistic regression analysis indicated that length of hospital stay was the primary influencing factor for average hospitalization cost per admission (P<0.01). Conclusion It is recommended to optimize clinical care pathways, improve diagnostic and treatment techniques, and reduce hospital stay duration, to lower the hospitalization costs of ONID patients.

Objective To analyze the status and influencing factors of carpal tunnel syndrome (CTS) among sonographers. Methods A total of 449 sonographers from 33 hospitals across five regions in Heilongjiang Province were selected as the study subjects using the judgment sampling method. A self-designed Musculoskeletal Disorders Questionnaire was used in the survey. Hand and wrist examinations, neuro electrophysiological testing, and high-frequency ultrasonography were conducted. Results The detection rate of CTS among the participants was 23.8% (107/449). Result of multivariable logistic regression analysis showed that sonographers with ≥20 years of work experience had a higher risk of CTS compared with those with <5 years, with an odds ratio (OR) and 95% confidence interval (CI) of 3.408 (1.535-8.407) (P<0.01). Sonographers with a proportion of obese patients ≥60% had a higher risk of CTS than those with <50% obese patients, with an OR and 95% CI of 3.083 (1.170~8.229) (P<0.05). Conclusion The detection rate of CTS among sonographers is relatively high. Work experience and proportion of obese patient are independent influencing factors of CTS. It is recommended to strengthen health monitoring for high-risk sonographer groups and adopt comprehensive preventive measures, such as optimizing work approaches and improving equipment to reduce the risk of CTS.

Objective To estimate the biological dose in a patient who developed radiation dermatitis after a local X-ray exposure incident. Methods Peripheral blood samples, which were used to performed lymphocyte chromosome aberration analysis, were collected from the patient at 54 and 102 days after the last exposure. Biological dose in the patient was estimated using four published X-ray dose-effect calibration curves for chromosomal aberrations. The absorbed dose in the patient was reconstructed using Dolphin′s model and time correction factors. Results The abnormal rates of chromosome aberration at 54 and 102 days after exposure were 1.00% and 0.40%, respectively. Based on the four calibration curves, the estimated local exposure dose at 54 day ranged from 3.59 to 10.51 Gy, and the time-corrected whole-body equivalent dose ranged from 0.27 to 0.87 Gy. The local dose estimated at 102 days ranged from 2.24 to 6.64 Gy, with a time-corrected whole-body equivalent dose of 0.12 to 0.60 Gy, which differed from the day-54 estimates. The biological doses estimated by both methods were lower than the physical dose (29.43 Gy). Conclusion The estimation of local biological dose of patient various in four dose-effect curves selected in this study. Delayed blood sampling will lead to underestimate biological dose. Early blood collection after radiation incidents is critical to ensure accuracy and reliability. Moreover, biological dose reconstruction methods for complex exposure scenarios require further research to improve the accracy of emergency response in radiation accidents.

Objective To analyze the epidemiological characteristics of newly diagnosed occupational diseases in Guangdong Province from 2019 to 2023. Methods Data on newly diagnosed occupational diseases reported in Guangdong Province from 2019 to 2023 were collected from the national occupational disease network reporting system. The spectrum of occupational diseases and their distribution by region, industry, and population were analyzed. Results A total of 4 136 newly diagnosed occupational disease cases were reported in Guangdong Province from 2019 to 2023, showing an overall downward trend. Newly diagnosed cases were classified into eight categories and 53 types of occupational diseases. In terms of the number of cases, the top five categories were occupational diseases of the ear, nose, throat and oral cavity;occupational pneumoconiosis and other respiratory diseases; occupational diseases caused by physical factors; occupational chemical poisoning; and occupational tumors, accounting for 98.62% of all cases. The top ten specific disease types were occupational noise-induced deafness, occupational silicosis, occupational other pneumoconiosis, occupational chronic benzene poisoning, occupational heatstroke, occupational hand-arm vibration disease, occupational coal workers′ pneumoconiosis, occupational welders′ pneumoconiosis, occupational tumor (leukemia caused by benzene exposure), and occupational chronic n-hexane poisoning, accounting for 94.85% of all cases. Most of the cases were distributed in the Pearl River Delta region, accounting for 89.19%; as well as manufacturing industry, accounting for 84.89%. Male cases accounted for 87.02%. Most diagnoses occurred in individuals aged >40-60 years, accounting for 74.73%. Conclusion Newly diagnosed occupational diseases in Guangdong Province from 2019 to 2023 showed the following characteristics: concentration of categories and disease types, polarization of regional distribution, industry clustering, and population difference. The disease spectrum is evolving from a dual-disease predominance toward a multi-disease predominance.

Objective To investigate the technical capacity and service quality of occupational health technical service institutions (hereinafter referred to as "occupational health institutions") in Guangdong Province. Methods All occupational health institutions in Guangdong Province that had valid occupational health service qualifications and within the validity period were included for analysis. Data on basic information, employed personnel, and results of professional technical capacity assessments across occupational health institutions were obtained through the Guangdong Provincial Occupational Health Technical Quality Control Center. Results A total of 99 institutions with 2 732 technical staff were included in this study. Occupational health institutions in Guangdong Province were mainly distributed in the Pearl River Delta region, accounting for 87.9% (87/99) of the total. The number of public and private health institutions was 23 and 76, accounted for 23.2% and 76.8% respectively. In terms of technical personnel, the percentage of individuals worked in public or private health institutions was 24.1% and 75.9%, respectively. Personnel titles were predominantly intermediate level and no title, accounting for 38.7% and 26.4%, respectively. Individuals with a bachelor′s degree or above accounted for 67.4%. Engineering and other professionals accounted for 35.4% and 30.5%, respectively. Private institutions undertook 97.3% of testing and evaluation workload related to occupational hazard in the province. The number of occupational health institutes acquiring category Ⅰ and Ⅱ service license were 97 and 13. Among institutions participating in inter-laboratory comparisons, the overall pass rates for quantitative items were 95.5% in public and 70.3% in private institutions, while the pass rates for qualitative items were 100.0% and 94.5%, respectively. Conclusion Occupational health institutions in Guangdong Province face issues such as imbalanced regional distribution, uneven development, and insufficient technical competence and testing capacity of professional personnel. Health authorities at all levels should continue to strengthen supervision and quality control to solidify the technical foundation and comprehensively enhance service capacity and quality.