The worksite survey of occupational disease diagnosis is a series of occupational health investigations in the workplace initiated by the occupational disease diagnosis institution or the public health administrative department in order to understand whether there is a causal relationship between the workers' diseases and the workplace in the process of occupational disease diagnosis and verification. The main purpose of the worksite survey is to find out whether there are occupational hazards that cause health damage to workers in the workplace, and to analyze whether there is a causal relationship between the exposure to occupational hazards at the corresponding concentration (intensity) and the diseases suffered by workers. In actual work, it is necessary to determine whether it is necessary to organize worksite survey according to the legal situation and actual work of occupational disease diagnosis. The mainly works of worksite survey includes three aspects: preliminary preparation, survey implementation and survey report writing. It is necessary to pay attention to the key and difficult tasks such as preparation before survey, survey plan and questionnaire, complexity and uncertainty of worksite survey and sampling and detection of occupational hazard factors in workplace. After the worksite survey,it is necessary to write a written occupational disease on-site investigation report to provide objective, reliable and scientific evidence for occupational disease diagnosis.

Objective To investigate the effects and mechanisms of silica dust on the apoptosis of alveolar epithelial cell (AEC) through in vitro and animal experiments. Methods i) In vitro experiment. A549 cells were stimulated with 100 mg/L silica suspension for 0, 12, 24 and 48 hours. The cell apoptosis rate was detected by flow cytometry. ii) Animal experiment. Specific pathogen-free male C57BL/6 mice were randomly divided into control, 14-day, 28-day, and 56-day groups, with five mice in each group. The mice in the control group were sacrificed at 56 days after being treated with 40.0 μL 0.9% sodium chloride solution, and the mice in the last three groups were sacrificed at 14, 28 and 56 days after being treated with 40.0 μL silica suspension with a mass concentration of 125 g/L via tracheal exposure method. The lung tissues of mice were collected to measure lung organ coefficients. Masson staining was used to detect the degree of pulmonary fibrosis, and Ashcroft scores were evaluated. The apoptosis of AEC in mice was observed by TUNEL immunofluorescence assay. iii) The mRNA relative expression of apoptosis-related genes in A549 cells and mouse lung tissue was detected using reverse transcription and real-time fluorescence quantitative polymerase chain reaction. Results i) In vitro experiment. The apoptosis rate of A549 cells increased with longer silica exposure (all P<0.05). The relative expression of B cell lymphoma-2 (BCL-2) mRNA in A549 cells in 24 h group and 48 h group decreased (both P<0.05), and the relative expression of BCL-2 associated X protein (BAX) mRNA increased (both P<0.05), compared with 0 h group. The mRNA relative expression of caspase (CASP) -3 and CASP-9 in A549 cells increased with longer silica exposure (all P<0.05). ii) Animal experiment. The lung organ coefficients and Ashcroft score in mice progressively increased (all P<0.05), the degree of pulmonary fibrosis was gradually aggravated, and TUNEL positive cells in lung tissue were gradually increased, while Bax, Casp-3 and Casp-9 mRNA relative expression increased with longer silica exposure (all P<0.05). Conclusion Silica dust may cause pulmonary fibrosis by inducing apoptosis of AEC, with a time-dependent effect. The mechanism may be related to the effect of silica dust on mitochondrial apoptosis through Bcl-2/Bax/Caspase-3 signaling pathway.

Objective To investigate the protective effect and mechanisms of total alkaloids of Bulbus Fritillaria Pallidiflora (TA-BFP) on pulmonary fibrosis in silicosis mice. Methods i) Bulbus Fritillaria Pallidiflora (BFP) powder was collected by heating and refluxing twice with 70.00% ethanol, and the dried concentrated sample was purified using cation-exchange and macroporous adsorbent resins to obtain TA-BFP. The total alkaloids level was detected using ultraviolet spectrophotometry and the characteristic peaks in TA-BFP were identified using the high-performance liquid chromatography-evaporative light scattering detector (HPLC-ELSD). ii) Specific pathogen-free male C57BL/6J mice were randomly divided into the control group, model group and intervention group, with 15 mice in each group. Mice in the model group and the intervention group were treated with 80 μL silica suspension with a mass concentration of 62.5 g/L, while the control group was treated with an equal volume of 0.9% sodium chloride solution using non-exposed tracheal instillation method. On the 28th day after modeling, mice in the intervention group were given TA-BFP at a dose of 60 mg/kg body mass, and the model group and control group were given 2.00% Tween-80 solution at the same volume by gastric gavage, once per day, for 28 days. The mouse lung tissue pathology was observed, lung organ coefficient was calculated, and inflammation and fibrosis scores were assessed after the intervention period. Serum levels of mouse interleukin (IL)-1β, IL-6, and tumor necrosis factor-α (TNF-α) were measured by enzyme-linked immunosorbent assay. Results i) The total alkaloid level of TA-BFP in the BFP powder was 50.36% after elution and purification. A total of nine alkaloid components in TA-BFP were identified by HPLC-ELSD. ii) The results of lung histopathology showed that no obvious changes of inflammation and fibrosis were identified in the lungs of mice in the control group, obvious changes of inflammation and fibrosis were identified in the lungs of mice in the model group, and the intervention group showed reduced inflammation and fibrosis in the lungs of mice compared with that of the model group. The lung organ coefficient, pulmonary inflammation score, pulmonary fibrosis score, and levels of serum IL-1β, IL-6, and TNF-α were significantly higher in the model group than those in the control group (all P<0.05). The lung organ coefficient, pulmonary inflammation score, pulmonary fibrosis score, and levels of serum IL-1β, and TNF-α were significantly higher in the intervention group than those in the control group (all P<0.05), while the pulmonary inflammation score, pulmonary fibrosis score, and levels of serum IL-1β, IL-6, and TNF-α were significantly lower in the intervention group than those in the model group (all P<0.05). Conclusion TA-BFP alleviates pulmonary inflammation in silicosis mice, thereby delaying the progression of pulmonary fibrosis. The mechanism may involve in inhibiting the expression of inflammatory factors IL-1β, IL-6, and TNF-α.

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 develop the "Questionnaires on the Knowledge, Attitudes, and Practices of College Students in Response to Public Health Emergencies" and validate its reliability and validity. Methods The initial questionnaire was developed according to literature review, expert consultations, and one-on-one interviews with students and educators. A total of 43 college students were selected as the pre-test subjects using the convenience sampling method. The final version of the questionnaire was developed using item analysis and expert consultations. A total of 682 college students were selected as the validation subjects using the cluster sampling method. The exploratory factor analysis and confirmatory factor analysis were used to assess the reliability and validity of the questionnaire. Results The final version of the questionnaire consisted of three dimensions: knowledge, practice, and attitude, with 5, 10, 7 items, respectively. The KMO test value for the questionnaire was 0.804, with Bartlett′s test of sphericity showing a chi-square value of 2 000.557 (P<0.01). The content validity index for each item ranged from 0.894 to 1.000, with the overall content validity index for the questionnaire being 0.966 and 0.973. The exploratory factor analysis identified three common factors, with a cumulative variance contribution rate of 54.1%. The result of confirmatory factor analysis showed good model fit, with model fit index, comparative fit index, normed fit index, incremental fit index, Tucker-Lewis Index, root mean square error of approximation of 2.960, 0.930, 0.940, 0.930, 0.950 and 0.070, respectively. The Cronbach's α coefficient for the questionnaire was 0.772, split-half reliability was 0.604, and test-retest reliability was 0.905. Conclusion The "Questionnaires on the Knowledge, Attitudes, and Practices of College Students in Response to Public Health Emergencies" demonstrates good reliability, and it is suitable for widespread application.

Objective To analyze the effect of residual cholesterol (RC) on hearing loss in noise-exposed workers. Methods A total of 3 412 workers engaged in noise operation work in an underground railway enterprise were selected as the research subjects using the judgment sampling method. Their occupational health examination data were collected to analyze the relationship between RC and hearing loss. Results The noise intensity of workplace in the underground rail enterprise was 80.0-85.0 (81.4±3.2) dB(A). The detection rate of hearing loss was 20.2% (691/3 412). The rates of abnormal total cholesterol, triacylglycerol, high density lipoprotein cholesterol (HDL-C) and low density lipoprotein cholesterol were 35.6%, 25.7%, 9.5% and 42.4%, respectively. The median and the 25th and 75th percentiles [M(P₂₅,P₇₅)] of RC level were 0.24 (0.15, 0.37) mmol/L. The levels of total cholesterol, triacylglycerol and RC of workers in hearing loss group were higher than those in normal hearing group [M(P₂₅,P₇₅): 4.91(4.37, 5.58) vs 4.84(4.30, 5.46) mmol/L, 1.29(0.91, 1.93) vs 1.16(0.82, 1.67) mmol/L, 0.26(0.16, 0.41) vs 0.24(0.14, 0.37) mmol/L, all P<0.05]. The detection rate of hearing loss in abnormal triglyceride group was higher than that in normal triglyceride group (24.8% vs 18.7%, P<0.01), and the detection rate of hearing loss in abnormal HDL-C group was higher than that in normal HDL-C group (25.0% vs 19.8%, P<0.05). The higher the serum RC level, the higher the detection rate of hearing loss (P<0.01). Multivariate logistic regression result showed that individual with older age, longer work time and higher serum RC level had higher risk of hearing abnormality (all P<0.05), and the risk of hearing abnormality was higher in patients with abnormal fasting blood glucose than patients with normal faseing blood glucose (P<0.05) after controlling for confounding factors such as gender, alcohol consumption, body mass index, and elevated blood pressure. However, abnormal triacylglycerol and HDL-C levels were not significantly related to the risk of hearing abnormality (both P>0.05). Conclusion Serum RC levels are an independent risk factor for hearing loss among noise-exposed workers exposed to noise level of 80.0-85.0 dB(A) in the workplace.

Objective To analyze the distribution characteristics of the single nucleotide polymorphism (SNP) site rs76206423 in the promoter region of the interleukin-2 receptor (IL-2R) β gene among Han males in a high radiation background area (HBRA) in Yangjiang City. Methods A total of 48 male participants from Tangkou Town, Yangxi County, Yangjiang City (HBRA group), and 51 male participants from Hengpo Town, Enping City (control group) were selected as the research subjects using the random number table method. Peripheral venous blood samples of participants from both groups were collected, and genomic DNA was extracted. The genotyping and allele frequency distribution of the rs76206423 (A/G) site in the IL-2R β promoter region was detected among the participants in both groups using the SNP detection method. The difference of allele frequencies between population in HBRA group and five area of East Asia, South Asia, Africa, Europe, and the Americas published in the Human Genome Project database from National Center for Biotechnology Information were analyzed. Results The allele frequencies of rs76206423 of population in both groups conformed to Hardy-Weinberg equilibrium (P>0.05). In the HBRA group, the AA genotype was predominant (64.6%), while the AG genotype was the most common in the control group (51.0%), with a significant difference (P<0.05). Population in both groups showed a predominance of the variant allele A (78.1% and 72.5%, respectively), with no significant difference (P>0.05). The frequency of the G allele of rs76206423 in the population in HBRA group was higher than those in South Asian, African, European, and American populations (all P<0.01), but showed no significant difference compared with East Asian populations (P>0.05). Conclusion In the Han male population from the HBRA in Yangjiang City, the rs76206423 site in the IL-2R β gene promoter region is predominantly composed of the wild-type A allele and AA genotype, indicating genetic stability and a relatively high degree of variation at this locus.

Objective To construct and validate a competency model for mental health professionals. Methods The literature analysis method, semi-structured expert interview method and Delphi method were used to construct the job competency model of mental health professionals. The hierarchical analysis method was used to construct the judgment matrix of each index and determine its weight coefficient. A total of 23 psychiatrists were selected as the validation subjects using the convenience sampling method to validate the model's effectiveness. Results The recovery rate of the valid correspondence questionnaire in this study was 100%, with an expert authority degree of 0.823, a coefficient of variation ranging from 0.070 to 0.101, and Kendall's W of 0.627-0.763 (all P<0.001). The constructed job competency model includes five primary indicators and 38 secondary indicators. The results of the consistency test (CR) showed that the CR value of the primary indicators was 0.028, and the CR values of the secondary indicators were 0.041, 0.034, 0.015, 0.020, and 0.032. The results of the hierarchical analysis showed that the weight ranking, in descending order, for primary indicators was knowledge, skills, ethical quality, intrinsic motivation, and personal traits. The top five secondary indicator combinations with the highest weights were basic clinical medicine knowledge, mental health professional knowledge, clinical diagnosis and treatment ability, medical ethics knowledge, and dedication to the job. The results of the validation analysis showed that the model scores for the 23 psychiatrists were consistent with their annual unit assessment results. Conclusion The constructed job competency model for mental health professionals can provide a reference for training and evaluation in mental health workforce development.

Objective To analyze the current situation of the knowledge-attitude-practice among noise-exposed workers at an airport apron. Methods A total of 494 noise-exposed workers from an airport apron were selected as the study subjects using the judgmental sampling method. A self-designed "Occupational Protection Knowledge, Attitudes, and Practices Questionnaire" was used to assess the current situation of knowledge-attitude-practice on occupational protection. Results Regarding the awareness of noise hazards among the study subjects, the awareness rates of noise-induced impairment on digestive function and reproductive system were the lowest (44.9% and 37.7%, respectively). The awareness rate of noise-induced negative emotions increased with length of service (P<0.01). Regarding the occupational protection knowledge for noise, the awareness rate of occupational noise-induced deafness was “incurable” was the lowest (39.1%). The support rate for five kinds of occupational protection attitudes for noise was generally >85.0%, while only 58.3% of the study subjects consistently or frequently wearing earplugs during work. The most common source of noise hazard and protection knowledge was pre-employment training (76.9%), followed by occupational disease prevention and control campaigns (76.1%). Conclusion Noise-exposed workers in this airport apron have incomplete awareness of non-auditory system hazards caused by noise, and the awareness of knowledge of some occupational protection is relatively low. Although their attitudes toward occupational protection are positive, many workers still fail to consistently wear personal protective equipment at work.

Objective To explore the influence of radiation protection knowledge-attitude-practice (RP-KAP) on occupational stress of radiation workers. Methods A total of 314 radiation workers from five hospitals in Shijiazhuang City were selected as the study subjects using the convenient sampling method. The Chinese version of the "Effort-Reward Imbalance (ERI) Questionnaire" and the "Radiation Protection Knowledge, Attitude, and Practice Questionnaire" were used for investigation. Results The detection rate of occupational stress in ERI model among the radiation workers was 74.5% (234/314). The RP-KAP practice dimension score of the population in the occupational stress group was lower than that in the non-occupational stress group (P<0.05). The results of binary logistic regression analysis showed that radiation workers with lower RP-KAP practice dimension score had a higher risk of occupational stress (P<0.01), and the risks of occupational stress among population of interventional radiology group and radiotherapy group were higher than that of X-ray diagnosis group and nuclear medicine group (both P<0.05), after controlling for confounding factors such as gender, age, type of work, professional title, daily working hours, weekly working hours and regular vacation. Conclusion RP-KAP is the influencing factor of occupational stress in the radiation workers. To improve the radiation workers' knowledge of radiation protection, protection awareness and compliance with protective behavior can effectively reduce or even eliminate occupational stress.