Objective: To investigate the characteristics of acoustic impedance test and its diagnostic role for occupational noise induced deafness, in order to provide an objective basis for the differential diagnosis of occupational noise induced deafness. Methods: A retrospective study was conducted to investigate the cases on the diagnosis of occupational noise-induced deafness in Guangdong province hospital for occupational disease prevention and treatment from January 2016 to January 2017. A total of 198 cases (396 ears) were divided into occupation disease group and non occupation disease group based on the diagnostic criteria of occupational noise deafness in 2014 edition, acoustic conductivity test results of two groups were compared including tympanograms types, external auditory canal volume, tympanic pressure, static compliance and slope. Results: In the occupational disease group, 204 ears were found to have 187 ears (91.67%) of type A, which were significantly higher than those in the non occupational disease group 143/192 (74.48%) , the difference was statistically significant (χ²=21.038, P<0.01). Detection of Ad or As type, occupation disease group in other type were 16/204 (7.84%) , 3/204 (1.47%) , were lower than Ad or As type of occupation disease group (15.63%) , other type (9.38%) , the differences were statistically significant[ (χ²=5.834, P<0.05) , (χ²=12.306, P<0.01) ]. Occupation disease group canal volume average (1.68±0.39) ml higher than that of non occupation disease group (1.57±0.47) ml, the difference was statistically significant (t=2.756, P<0.01) ; occupation disease group mean static compliance (1.06±0.82) ml higher than that of non occupation disease group (0.89±0.64) ml. The difference was statistically singificant (t=2.59, P<0.01) . Conclusion We observed that acoustic impedance test had obvious auxiliary function in the differential diagnosis of occupational noise induced deafness, More than 90% of the confirmed cases showed an A-form tympanograms, it is one of the objective examination methods which can be used in the differential diagnosis of pseudo deafness.

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.

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.

Objective: Study of the results and the degree on occupational noise-induced deafness in-to the different high frequency hearing threshold weighted value, in order to provide theoretical basis for the re-vision of diagnostic criteria on occupational noise-induced deafness. Methods: A retrospective study was con-ducted to investigate the cases on the diagnosis of occupational noise-induced deafness in Guangdong province hospital for occupational disease prevention and treatment from January 2016 to January 2017. Based on the re-sults of the 3 hearing test for each test interval greater than 3 days in the hospital, the best threshold of each frequency was obtained, and based on the diagnostic criteria of occupational noise deafness in 2007 edition, Chi square test, t test and variance analysis were used to measure SPSS21.0 data, their differences are tested among the means of speech frequency and the high frequency weighted value into different age group, noise ex-posure group, and diagnostic classification between different dimensions. Results: 1. There were totally 168 cases in accordance with the study plan, male 154 cases, female 14 cases, the average age was 41.18 ±6.07 years old. 2. The diagnosis rate was increased into the weighted value of different high frequency than the mean value of pure speech frequency, the weighted 4 kHz frequency increased by 13.69% (χ²=9.880, P=0.002) , 6 kHz increased by 15.47% (χ²=9.985, P=0.002) and 4 kHz+6 kHz increased by15.47% (χ²=9.985, P=0.002) , the difference was statistically significant. The diagnostic rate of different high threshold had no obvious differ-ence between the genders. 3. The age groups were divided into less than or equal to 40years old group (A group) and 40-50 years old group (group B) , there were higher the diagnostic rate between high frequency weighted 4 kHz (A group χ²=3.380, P=0.050; B group χ²=4.054, P=0.032) , weighted 6 kHz (A group χ²=6.362, P=0.012; B group χ²=4.054, P=0.032) , high frequency weighted 4 kHz+6 kHz (A group χ²=6.362, P=0.012; B group χ²=4.054, P=0.032) than those of speech frequency average value in the same group on oc-cupational noise-induced deafness diagnosis rate, the difference was statistically significant. There was no sig-nificant difference between age groups (χ²=2.265, P=0.944) . 4. The better ear's mean value of pure speech fre-quency and the weighted values into different high frequency of working years on each group were compared, working years more than 10 years group was significantly higher than that of average thresholds of each frequen-cy band in 3-5 group (F=2.271, P=0.001) , 6-10 group (F=1.563, P=0.046) , the difference was statistically significant. The different high frequency weighted values were higher than those of the mean value of pure speech frequency, and the high frequency weighted 4 kHz+6 kHz had the highest frequency difference, with an average increase of 2.83 dB. 5. The diagnostic rate into weighted different high frequency was higher in the mild, moderate and severe grades than in the pure speech frequency. In the comparison of diagnosis for mild occupational noise-induced deafness, in addition to the weighted 3 kHz high frequency (χ²=3.117, P=0.077) had no significant difference, the weighted 4 kHz (χ²=10.835, P=0.001) , 6 kHz (χ²=9.985, P=0.002) , 3 kHz+4 kHz (χ²=6.315, P=0.012) , 3 kHz+6 kHz (χ²=6.315, P=0.012) , 4 kHz+6 kHz (χ²=9.985, P=0.002) , 3 kHz+4 kHz+6 kHz (χ²=7.667, P=0.002) were significantly higher than the diagnosis rate of the mean value of pure speech frequency. There was no significant difference between the two groups in the moderate and se-vere grades (P>0.05) . Conclusion Bring into different high frequency hearing threshold weighted value in-creases the diagnostic rate of occupational noise-induced deafness, the weighted 4 kHz, 6 kHz and 4 kHz+ 6 kHz high frequency value affects the result greatly, and the weighted 4 kHz+6 kHz high frequency hearing threshold value is maximum the effect on occupational noise-induced deafness diagnosis.

OBJECTIVE: To analyze the impact of GBZ 49-2014 Diagnosis of Occupational Noise-induced Deafness and GBZ49-2007 Diagnostic Criteria of Occupational Noise-induced Deafness on the diagnosis of occupational noise-induced deafness( ONID). METHODS: A total of 84 individuals,who were workers exposed to noise and diagnosed as observation subjects by GBZ 49-2007 were selected as the subjects of study by judgment sampling. They were diagnosed based on the criteria of GBZ 49-2014 and GBZ 49-2007. The impact of different diagnostic audiometry,different age and gender correction methods and the inclusion of a weighting of 0. 1 high-frequency 4. 0 k Hz hearing threshold of GBZ 49-2014 on the diagnosis of ONID was analyzed. RESULTS: The binaural high frequency threshold average( BHFTA) calculated by GBZ 49-2014 were lower than that of GBZ 49-2007 [( 52. 1 ± 10. 3) vs( 52. 8 ± 10. 1) d B,P < 0. 05 ],but monaural threshold of weighted value( MTWV) of the good ear calculated by GBZ 49-2014 were higher than speech frequency threshold average( SPTA) of the good ear of GBZ 49-2007 [( 23. 2 ± 4. 1) vs( 19. 3 ± 4. 8) d B,P < 0. 01]. All of the 84 patients had BHFTA ≥40 d B and SPTA < 26 d B when diagnosed by GBZ 49-2007,and could not be diagnosed as ONID. A total of33. 3% patients had BHFTA ≥40 d B and MTWV ≥26 d B when diagnosed by GBZ 49-2014 which could be diagnosed as mild ONID. The detection rate of ONID was 21. 4% to 34. 5%( P < 0. 01) when the threshold of 4. 0 k Hz was used as the weighting diagnostic threshold of hearing in the case of using different diagnostic audiograms and different age and sex correction methods. CONCLUSION: A high-frequency hearing threshold of 4. 0 k Hz with a weighting of 0. 1 was included in GBZ 49-2014 as a diagnostic threshold,which reduced the diagnostic threshold of ONID.

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.

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.

{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.