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.

Background Hypertension is one of the chronic diseases with the highest prevalence in China, and a history of hypertension may potentially exacerbate hearing loss. Investigating the association between long-term blood pressure trends and hearing thresholds could contribute to hearing protection efforts for occupationally noise-exposed populations. Objective By investigating hearing thresholds and blood pressure levels among occupationally noise-exposed workers in an urban rail transit enterprise, and conducting a comprehensive analysis of the association between long-term blood pressure changes and hearing thresholds, to provide data references for health management strategies targeting occupationally noise-exposed workers. Methods Workers exposed to occupational noise at a rail transit enterprise were enrolled as study subjects and underwent pure-tone audiometry. Group-based trajectory modeling was employed to identify blood pressure trajectories. Categorical data were compared using chi-square tests, while normally distributed continuous variables were analyzed via t-tests and analysis of variance (ANOVA). Generalized linear mixed models (GLMMs) were subsequently applied toexamine associations between these trajectory groups and high-frequency hearing thresholds. Results Among 2 002 occupationally noise-exposed workers, the median (P₂₅, P₇₅) age was 32 (28, 35) years, with a median (P₂₅, P₇₅) working tenure of 7 (3, 10) years. In 2019, the positive hypertension rate was 9.04%, with a mean systolic blood pressure (SBP) of (122.97±11.60) mmHg and a mean diastolic blood pressure (DBP) of (76.37±9.02) mmHg. The hearing loss prevalence was 10.1%, showing bilateral high-frequency average hearing thresholds of (17.18±8.71) dB and speech-frequency average thresholds of (13.79±3.46) dB. Three distinct trajectory groups were identified for both SBP and DBP. Compared with other trajectory groups, the high-stable DBP group exhibited significantly higher hearing loss prevalence (χ²=6.34, P=0.042) and elevated high-frequency hearing thresholds (all Ps<0.05). Specifically, within the 30-39 age subgroup, the moderate-stable DBP group demonstrated 1.96 dB lower high-frequency thresholds than the high-stable group [β(95%CI): −1.96 (−3.61, −0.32), P=0.020]. Conclusion Among occupationally noise-exposed workers in a municipal rail transit enterprise, DBP trajectories demonstrated a positive association with high-frequency hearing thresholds. Notably, in young and middle-aged occupationally noise-exposed populations, DBP may exert a more critical influence than SBP on the progression of hearing loss.

To analyze the clinical data and imaging examination data of a patient with metallic mercury poisoning from subcutaneous injection. The abdominal B-ultrasonograph results of the patient indicated multiple scattered hyperechoic spots accompanied by "comet tail" sign in the liver and right renal sinus, the nature of which was not clear and it was considered crystal deposition. The chest X-ray revealed scattered and multiple spot-like, snowflake-like and tree-cast-like high-density shadows in both lung fields. The chest computed tomography scan revealed multiple spot and patchy high-density shadows distributed in both lungs, considering hematogenous distribution deposits, and possible mercury poisoning. Laboratory test results showed that blood mercury level was 4.16 μmol/L and urine mercury level was 6 545.5 μg/g Cr. After 28 days of mercury chelation therapy, the abdominal ultrasound examination showed that the hyperechoic spots in the liver and right renal sinus were reduced compared with the previous examination. Metallic mercury poisoning from subcutaneous injection has specific manifestations in abdominal B-ultrasound imaging, which can provide a basis for the early diagnosis of metallic mercury poisoning in clinical practice and can be used to observe the efficacy of mercury chelation therapy.

Objective To analyze the problems found in the on-site quality assessment of occupational medical examination (OME) institutions in Guangdong Province. Methods A total of 150 OME institutions were selected as the research subjects from Guangdong Province in 2023 using a random number table method. The on-site quality assessment was conducted by listening to reports, meeting discussion, on-site inspection, data review and human-machine assessment. The relevant assessment results were analyzed. Results Occupational disease prevention and treatment institutes (institutes, centers) and disease control and prevention centers (hereinafter referred to as "occupational prevention institutions"), public hospitals, and private institutions accounted for 8.7%, 51.3%, and 40.0% respectively. The top three categories of registered inspections were physical factors, chemical factors and dust, accounted for 98.0%, 96.7% and 96.0%, respectively, among the 150 OME institutions. A total of 1 063 rectification items were identified, and the average number of rectification items identified per occupational prevention institutions, public hospitals and private institutions was four, six and nine, respectively. The rectification rates of the four modules of quality assessment from high to low were OME work quality control, quality management system, organizational structure, and OME information reporting, accounted for 53.2%, 23.3%, 13.7% and 9.7%, respectively. The coincidence rate from high to low of occupational reporting of noise-exposure, dust-exposure, and other hazard-exposure was 92.5%, 91.1%, and 93.4%, respectively. The on-site failure rate of quality control director, technical director, chief physician, pneumoconiosis film reader, audiometry reader and pulmonary function examination operator accounted for 15.3%, 12.7%, 8.0%, 6.7%, 6.0% and 2.7%, respectively. Institutions capable of conducting registered and partially registered OME accounted for 90.7% and 6.0%, respectively. The five institutions that were unable to conduct registered OME were private institutions. A total of five private institutions were found to be suspected of illegal and irregular activities. Conclusion The problems of OME in the on-site quality assessment of OME institutions in Guangdong Province were mainly quality control. Private institutions had more prominent problems in various aspects. It is necessary to strengthen the training of key personnel such as technical directors, quality control directors, and chief physicians.

Objective To analyze the epidemiological characteristics of occupational hand-arm vibration disease (OHAVD) in Guangdong Province from 2006 to 2022. Methods The data of newly reported OHAVD cases and suspected occupational disease cases in Guangdong Province from 2006 to 2022 was collected from the Report Card of Occupational Diseases and Report Card of Suspected Occupational Diseases using Occupational Diseases and Health Hazard Factors Monitoring Information System under China Disease Prevention and Control Information System. Epidemiological characteristics of the newly reported OHAVD cases and related suspected occupational disease reports were analyzed. Results A total of 660 newly reported OHAVD cases were reported in Guangdong Province from 2006 to 2022. The number of cases showed a periodic fluctuating trend over the years. Males accounted for 98.64% of the newly reported OHAVD cases with a median age of 38 years and a median hand-transmitted vibration exposure period of 8.7 years. These cases were predominantly distributed in the Pearl River Delta region, including Zhongshan City, Dongguan City, Guangzhou City, Shenzhen City and Foshan City, accounting for 99.25%. The manufacturing enterprises had 98.79% of the cases, investment enterprises of Hong Kong, Macao and Taiwan merchants of China had 83.18% of the cases, and large- and medium-sized enterprises had 92.73% of the cases. The 660 cases were distributed in 440 enterprises, but there were some characteristics of group outbreaks. There were 20 enterprises (4.55% of the total number of enterprises) had more than three cases involving 219 cases (33.18%). There were five enterprises which had more than 10 cases and the cases number ranged from 12 to 56. Among 382 newly reported OHAVD cases from 2014 to 2022, 44.24% were identified as suspected occupational diseases before diagnosis, of which 59.76% (101/169) were determined by occupational health inspection institutions. Conclusion Newly reported OHAVD cases in Guangdong Province were aggregated in terms of regional distribution, industry, enterprise ownership, and enterprise scale, with a risk of group outbreaks. It is suggested to enhance the OHAVD prevention and control in male workers exposed to hand-transmitted vibrations in the Pearl River Delta's manufacturing enterprises.

Objective To analyze the incidence of lens opacity in radiation workers. Methods A total of 46 733 radiation on-the-job workers who underwent occupational medical examinations from 2017 to 2023 were selected as the radiation group, and 19 944 non-ionizing radiation exposed workers in same period were selected as the control group using a convenient sampling method. The lens opacity of workers was compared between these two groups. Results The incidence of lens opacity in workers of the radiation group was higher than that in the control group (6.27% vs 3.95%, P<0.01). The annual incidence of lens opacity among female radiation workers was higher than that of male workers in 2017 and 2021 to 2023(9.36% vs 6.76%, 8.06% vs 6.58%, 8.12% vs 6.96%, 5.32% vs 4.37%, all P<0.05). In 2017 and 2018, the incidence of lens opacity in workers of radiation group increased with age (all P<0.01). From 2019 to 2023, the annual incidence of lens opacity in the radiation group increased with both age and length of radiation work experience (all P<0.01). In 2017, 2019, 2020, and 2022, the incidence of lens opacity was higher among the medical group compared with other groups (all P<0.05). Conclusion There is a dose-effect relationship between the incidence of lens opacity and both age and length of service in radiation among radiation workers. The incidence of lens opacity is relatively higher among female workers and those engaged in medical radiation.

ObjectiveTo establish a managing mode for illegal and irregular acts of occupational medical examination (OME) institutions to the requirements of the new situation. Methods The OME institutions from the “Guangdong Province Key Occupational Disease Monitoring and Management Platform” were selected as the study subjects using the judgment sampling method. The clues of suspected illegal and irregular acts of OME institutions were found and submitted to the local health commission for investigation and managed according to the case information monitoring and on-site quality assessment. The OME institutions found to have illegal and irregular acts were filed and investigated according to the national law after investigation and verification. A “follow-up inspection” was conducted on five OME institutions for closed loop management. Results A total of 12 OME institutions were found to have suspected illegal and irregular acts, including seven institutions that did not meet the filing requirements for effective personnel, five institutions that conducted projects beyond the scope without filing to the provincial health authorities within 15 work days from the start of the project, and two institutions that failed to fulfill the obligation of informing and reporting to the health authorities, employers, and workers as required. After submitting relevant clues and evidence to the local health commission for investigation and management, seven institutions were not given penalty, and five institutions were given administrative penalties including two institutions were fined and warned, and three institutions were warned. No illegal or irregular acts were found in the five institutions inspected during the “follow-up inspection”. Conclusion It is beneficial to explore the managing mode of “clue discovery, clue submission, investigation and disposal, follow-up inspection” for OME institutions suspected of illegal and irregular acts, which helps urge OME institutions to work in accordance with laws and regulations and effectively protect the legitimate rights and interests of workers' occupational health.

As the management system of Occupational Medical Examination (OME) institutions is moving to a record-filing model, the traditional management approach might not fulfill the current policy requirements. There is a pressing need for development of high-quality occupational health management system. In this context, the Guangdong Provincial Occupational Health Examination Quality Control Center (hereinafter referred to as the "Provincial Quality Control Center") pioneered the integration of the Performance Excellence Model (PEM) framework into the macro-quality management of OME institutions in Guangdong Province. In light of the current research gaps in the field of macro-quality management for OME institutions, the Provincial Quality Control Center, based on the core principles and standards of PEM, has closely aligned with the professional characteristics of occupational health examinations. The established macro-quality management innovation in OME institutions in Guangdong Province consists of seven dimensions: strategic direction, leadership development, identification of key management subjects, data analysis and management, human resources allocation, process optimization, and the application of quality control outcomes. This system has provided a robust impetus for the ongoing improvement of quality control efforts. The initial implementation of PEM demonstrated notable improvements in macro-quality management for OME institutions. Moving forward, the Provincial Quality Control Center will continue to strengthen the development of key technical personnel, innovate training models, harness the advantages of big data technology, restate and upgrade the system continuously, and refine the macro-quality management mechanisms of OME institutions to ensure that the health rights and interests of workers and employers are effectively safeguarded and enhanced.

{L-End}Objective To analyze the characteristics of hearing loss and the influencing factors of high-frequency hearing loss (HFHL) among noise-exposed workers in an urban rail transit enterprise over five consecutive years. {L-End}Methods A total of 1 268 noise-exposed workers, who exposed to the average noise intensity of <85.0 dB(A), in an urban rail transit enterprise was selected as the research subjects using a judgment sampling method. The pure-tone audiometry results from 2019 to 2023 were collected to analyze the result of hearing loss. The influencing factors of HFHL (average hearing threshold ≥40.0 dB at high frequencies in both ears) were analyzed using the generalized estimating equations (GEE). {L-End}Results The detection rates of threshold elevations at frequencies of 0.5-6.0 kHz increased with increasing frequency from 2019 to 2023 (all P<0.01), with the highest detection rate at 6.0 kHz. The detection rate of speech frequency hearing loss (hearing threshold weighted value≥26.0 dB in the better ear) was 0.1%, 0.0%, 0.4%, 0.2%, and 0.2%, respectively. The detection rate of HFHL from 2019 to 2023 was 2.4%, 2.8%, 2.8%, 2.1%, and 2.8%, respectively. The GEE analysis results showed that the risk of HFHL of the workers in 2022 and 2023 was lower than that in 2019 (all P<0.01), with the odds ratios and 95% confidence intervals ［OR (95%CI)］ of 0.57 (0.41-0.81) and 0.65 (0.48-0.87), respectively. The risk of HFHL was higher among vehicle maintenance worker than train drivers (P<0.05), with OR (95%CI) of 2.37 (1.18-4.77). The risk of HFHL increased with age and length of service among the workers (all P<0.05), with the OR (95%CI) of 2.05 (1.22-3.46) and 1.69 (1.12-2.54), respectively. No interaction was found between type of job and age, type of job and length of service, or age and length of service in the risk of HFHL among the research subjects(all P<0.05). {L-End}Conclusion Noise exposure below the national occupational exposure limits can lead to hearing loss in noise-exposed workers of urban rail transit enterprises, possibly affecting the hearing threshold at 6.0 kHz first. The influencing factors for HFHL in workers of rail transit are age, length of service, and type of job. There is a dose-effect relationship with age and length of service.

Objective:To explore the effect of different diagnostic criteria on occupational noise-induced deafness (Onid) , and to provide theoretical basis for the revision of ONID diagnostic criteria.Methods:From January 2016 to January 2018, the physical examination results of noise-exposed workers during occupational health examination in Qingyuan Occupational Disease Prevention and Treatment Hospital were retrospectively investigated in September 2019, with Gbz 49-2014《diagnosis of occupational noise deafness》as the study object, 471 workers suspected of Onid were weighted with different combinations of high frequency hearing threshold, and the better ear weight was calculated, compared with the diagnostic criteria of 2007 and 2014, the degree of hearing loss was evaluated. SPSS 22.0 was used for statistical analysis, χ 2 test was used for counting data, and non-parametric test was used for measuring bias data. Results:The average age of 471 subjects was (40.32±7.01) years, and the average age of exposure to noise was (7.11±3.44) years. On the basis of the 2007 edition diagnostic standard, the suspected ONID diagnostic rate of different high frequency auditory threshold was increased by 16.35% and 30.15% at 3.0 kHz, 6.0 kHz increased by 20.17%, 3.0 kHz+4.0 kHz increased by 22.29%, 3.0 kHz+6.0 kHz increased by 17.20%, 4.0 kHz+6.0 kHz increased by 25.27%, the differences were statistically significant ( P<0.05) , the frequency of 3.0 kHz+4.0 kHz+6.0 kHz increased by 22.29%. Using the 2014 edition diagnostic standard, the diagnostic rate of Onid was reduced by 30.15% and 13.80%, 6 kHz is 9.98% lower, 3.0 kHz+4.0 kHz is 7.86% lower, 3.0 kHz+6.0 kHz is 12.95% lower, 4.0 kHz+6.0 is 4.88% lower, the high frequency of 3.0 kHz+4.0 kHz+6.0 kHz decreased by 7.86%, the differences were statistically significant ( P<0.05) . Conclusion:The diagnosis rate of suspected Onid is increased by weighting different high frequency hearing threshold, in which the weighted 4kHz high frequency has the greatest influence on the result, and the weighted 3 kHz high frequency has the least.