A Scoping Review on Occupational Noise Mitigation Strategies and Recommendations for Sustainable Ship Operations.

Environmental and occupational noise has the potential to result in health risks. The presence of high noise levels aboard ships can cause substantial hazards that affect the well-being of those employed in the maritime industry. The study and implementation of occupational noise reduction aboard ships are of the highest priority for ensuring the well-being of marine workers, compliance with regulatory standards, protection of the environment, and improvement of overall operational efficiency and safety within the maritime sector. A scoping study was conducted to collect and summarize the existing scientific literature about approaches to preventing occupational noise in vessel operations. We searched electronic databases for papers published up to June 2024. Initially, 94 articles were identified for screening, and the present research produced 16 studies, which were finally analyzed. Resultantly, noise control may begin with elimination, substitution, engineering, administrative, and hearing protection (ear plugs or muffs). Noise control innovation would be started with engineering techniques. Hearing protection devices (HPDs) could be used to reduce noise and as an instrument of communication between sailors. More research needs to be carried out in order to find the best ways for maritime vessels to reduce noise at work and to see how well they work in lowering the risks that come with noise for workers on board.

[A study on the hearing protection and intervention effects of silicone earplug usage among manufacturing workers].

Objective: To assess the efficacy of silicone earplugs in protecting workers exposed to noise in a typical manufacturing environment, and to provide training interventions for workers who do not achieve the anticipated noise reduction levels, as well as examining the spectral characteristics of earplug attenuation. Methods: From June to August 2022, a total of 294 noise-exposed workers in two manufacturing enterprises equipped with the same type of earplug were studied by cluster sampling method, by conducting questionnaire surveys, collecting data, fitting tests, and providing trainings, the current noise exposure levels of workers in the industry as well as the perception about the earplug were understood. Additionally, the attenuation before and after intervention in workplace were measured, the spectral characteristics of noise reduction were were described and compared. Results: The percentage of workers with Personal Attenuation Rating (PAR) of 0 is 32.7% (96/294), and the baseline pass rates are all below 60%. There were no significant differences in pass rates based on gender, age, noise exposure, education level, or cognition of earplug effectiveness. After adjusting the way that earplugs are worn or changing the type of earplugs, all workers were able to meet their noise reduction requirements. The median PAR improvement for both companies is above 10 dB. The noise attenuation of the earplug vary with frequency, with lower attenuation at 4 000 Hz and higher attenuation at 8 000 Hz, showing some deviation from the nominal values. Conclusion: The difference between the actual sound attenuation value of earplugs and the nominal value is related to the noise frequency. When using silicone earplugs, attention should be paid to the spectral composition of the noise in the workplace.

Effect of Noise in the Emergency Department on Occupational Burnout and Resignation Intention of Medical Staff.

OBJECTIVE: This study aims to explore the effect of noise in the emergency department on the occupational burnout and the resignation intentions of medical staff. METHODS: This retrospective study selected 42 medical staff (group A) in the emergency department of our hospital from March 2020 to March 2021 and 39 medical staff (group B) in the rehabilitation department during the same period as research subjects. Noise levels in the daily working environment of medical staff were collected. The Maslach Burnout Inventory General Survey and Intent to Leave Scale was used to evaluate occupational burnout and resignation intention. A multivariate linear regression analysis was adopted to explore the effects of noise exposure level in the emergency department on occupational burnout and resignation intention. RESULTS: The scores of emotional fatigue, work apathy and sense of achievement in group A were higher than those in group B (P < 0.05), among which reverse scoring was adopted for sense of accomplishment. Group A had significantly higher scores of resignation intention I, resignation intention II and resignation intention III than group B (P < 0.001). The department of group A had significantly higher noise level than that of group B (P < 0.001). The Multivariate linear regression analysis showed that noise level in the emergency department was correlated with the occupational burnout and resignation intention of medical staff (all P < 0.05). CONCLUSIONS: The emergency department is exposed to a high noise level, which is correlated with the occupational burnout and resignation intentions of medical staff. Therefore, hospitals should give importance to noise exposure in the emergency departments and adopt positive coping strategies to reduce the effect of noise on medical staff and the resignation rate.

A Comprehensive Review of Auditory and Non-Auditory Effects of Noise on Human Health.

OBJECTIVE: Excessive noise is unpleasant and induces several physiological and psychological effects. Noise pollution is a potential threat to humans, particularly those continuously exposed for extended periods throughout the day over many years. This review aims to examine the various auditory and non-auditory outcomes associated with prolonged exposure to noise pollution. MATERIALS AND METHODS: The review utilized a combination of relevant keywords to search the electronic databases. After screening based on the applied selection criteria for title, abstract, and full text, 44 articles were finally selected for critical review. RESULTS: We identified and analyzed research findings related to noise-induced hearing loss, tinnitus, and sleep disturbances along with non-auditory issues such as annoyance, cognitive impairments, and mental stress associated with cardiovascular disorders. Furthermore, the existing studies were compared and collated to highlight the unique challenges and significance of noise pollution as a distinctive environmental concern and to explore the ongoing efforts in its research and prevention, including the early detection and potential reversal of noise-induced hearing loss. CONCLUSION: The fundamental health consequences of noise pollution underscore the need for extensive research encompassing emerging noise sources and technologies to establish a health management system tailored to address noise-related health concerns and reduce noise exposure risk among populations. Finally, further research is warranted to ensure improved measurement of noise exposure and related health outcomes, especially in the context of occupational noise.

Relationship Between Occupational Noise Exposure and Gestational Hypertension in Pregnant Women in Taizhou City: Cross-Sectional Study.

OBJECTIVE: In view of the hazards of occupational noise exposure, this study investigated the relationship between occupational noise exposure and gestational hypertension in Taizhou City, Zhejiang Province, China to provide inspiration and reference for reducing the occurrence of gestational hypertension. METHODS: This cross-sectional study analyzed the clinical data of 316 pregnant women in Taizhou City admitted to Taizhou Hospital of Zhejiang Province affiliated to Wenzhou Medical University from May 2020 to May 2023. In accordance with Acoustic Environment Quality Standards (GB3096-2008), 60 dB was used as the cut-off point. These pregnant women were divided into the low noise group (LNG, n = 161) and high noise group (HNG, n = 155) according to the noise exposure level in the working environment. This also study compared the noise exposure, blood pressure (BP), fasting blood glucose (FBG), blood lipid (BL), fetal size, and heart rate (HR), and analyzed the relationship of noise exposure with BP, FBG, BL, fetal size, HR, and occurrence of gestational hypertension. RESULTS: The HNG had higher noise exposure level (P < 0.001), BP, FBG, BL and HR (P < 0.001), larger fetal size (P < 0.001) and higher occurrence of gestational hypertension (P < 0.05) compared with the LNG. Correlation analysis showed that noise exposure level was positively correlated with BP, FBG, BL, HR, and fetal size (P < 0.001) and had the strongest association with gestational hypertension. CONCLUSION: Occupational noise exposure has adverse effects on pregnant women and fetuses. Pregnant women should pay attention to their exposure to occupational noise to prevent gestational hypertension. The results of this study must be further verified and generalized.

Association between exposure to metalworking fluid aerosols, occupational noise and chronic kidney disease: a cross-sectional study in China.

BACKGROUND: Chronic kidney disease (CKD) carries a high public health burden yet little is known about the relationship between metalworking fluid (MWF) aerosols, occupational noise and CKD. We aimed to explore the relationship between occupational MWF aerosols, occupational noise and CKD. METHODS: A total of 2,738 machinists were sampled from three machining companies in Wuxi, China, in 2022. We used the National Institute for Occupational Safety and Health (NIOSH) method 5524 to collect individual samples for MWF aerosols exposure, and the Chinese national standard (GBZ/T 189.8-2007) method to test individual occupational noise exposure. The diagnostic criteria for CKD were urinary albumin/creatinine ratio (UACR) of ≥ 30 mg/g and reduced renal function (eGFR < 60 mL.min- 1. 1.73 m- 2) lasting longer than 3 months. Smooth curve fitting was conducted to analyze the associations of MWF aerosols and occupational noise with CKD. A segmented regression model was used to analyze the threshold effects. RESULTS: Workers exposed to MWF aerosols (odds ratio [OR] = 2.03, 95% confidence interval [CI]: 1.21-3.41) and occupational noise (OR = 1.77, 95%CI: 1.06-2.96) had higher prevalence of CKD than nonexposed workers. A nonlinear and positive association was found between increasing MWF aerosols and occupational noise dose and the risk of CKD. When daily cumulative exposure dose of MWF aerosols exceeded 8.03 mg/m3, the OR was 1.24 (95%CI: 1.03-1.58), and when occupational noise exceeded 87.22 dB(A), the OR was 1.16 (95%CI: 1.04-1.20). In the interactive analysis between MWF aerosols and occupational noise, the workers exposed to both MWF aerosols (cumulative exposure ≥ 8.03 mg/m3-day) and occupational noise (LEX,8 h ≥ 87.22 dB(A)) had an increased prevalence of CKD (OR = 2.71, 95%CI: 1.48-4.96). MWF aerosols and occupational noise had a positive interaction in prevalence of CKD. CONCLUSIONS: Occupational MWF aerosols and noise were positively and nonlinearly associated with CKD, and cumulative MWF aerosols and noise exposure showed a positive interaction with CKD. These findings emphasize the importance of assessing kidney function of workers exposed to MWF aerosols and occupational noise. Prospective and longitudinal cohort studies are necessary to elucidate the causality of these associations.

Oxidative Stress Assessment of Noise Exposure in the Workers Using Hearing Protection in a Pressing Industry.

BACKGROUND AND OBJECTIVE: Exposure to noise by generation of free radicals causes oxidative stress in body. The aim of this study was the evaluation of oxidative stress in workers who have used hearing protection devices during working time. MATERIAL AND METHOD: Pressing workers (n=24) of a home appliance industry were studied using hearing protection devices to reduce noise exposure. Twenty two office staff (without exposure to noise) were considered as a control group. Two groups were matched for age, work experience and smoking. Exposure to noise was measured by dosimeter method at workstations. By obtaining 3 ml blood sample, Malondialdehyde levels, Thiol groups and total antioxidant capacity were evaluated in all subjects. RESULTS: Exposure to sound pressure level in pressing workers by considering the noise reduction factor of the earplug was observed in 77.65 dB with minimum 75.1 dB and Maximum 81.22 dB. Plasma thiol groups (0.076 (0.041-0.119) vs (0.110 (0.076-0.197), mmol/l P =0.0001) and total antioxidant capacity (361.33± 54.65 vs 414.14± 96.82, µmol/ml P = 0.026) in pressing workers significantly decreased than control group. Pearson correlation showed significant results between exposure to noise and oxidative stress parameters. CONCLUSION: Exposure to noise wave cause oxidative stress in different site of body. Oxidative stress is an intermediate way for different disease due to noise exposure. Reducing of noise exposure by earplug in pressing workers is not efficient protection for oxidative stress generation. Therefore, hearing protection devices are not a barrier to the harmful effects of noise in occupational exposure.

Cross-sectional study on the health of workers exposed to occupational noise in China.

OBJECTIVE: This study aimed to understand the health of workers exposed to occupational noise and explore the influencing factors related to workers' health, especially the impact of noise on workers' hearing. This work can provide a basis for formulating relevant measures for occupational noise prevention and control in the future. METHODS: On the basis of the key occupational disease monitoring project in Chongqing, China, in 2021, the data of 1125 workers exposed to occupational noise were analyzed. Data included demographic information, occupational history, clinical physical examination information, and noise detection information of the working environment. Chi-square test and multifactorial logistic regression were used for statistical analysis. RESULTS: The prevalence rates of abnormal electrocardiogram (ECG), blood pressure (BP), and pure tone audiometry (PTA) were 21.9% (246/1125), 27.8% (313/1125), and 18.0% (202/1125), respectively. Male workers accounted for 78.8%. Compared with male workers, female workers had a lower prevalence of abnormal PTA (OR = 0.28, 95% CI = 0.16-0.50). Workers working in medium enterprises had a lower prevalence of abnormal BP than workers in micro enterprises (OR = 0.36, 95% CI = 0.19-0.66). The prevalence of abnormal BP and PTA of workers increased with age. After adjusting for age, sex, and body mass index, the prevalence of abnormal ECG of mining workers was higher than that of manufacturing workers (OR = 1.54, 95% CI = 1.07-2.24), and the prevalence of abnormal PTA had a rising trend with the increase in noise exposure value. CONCLUSION: Noise-exposed workers have a high prevalence of abnormal ECG, BP, and PTA, and factors such as age, enterprise size, and workplace noise exposure are correlated with the aberrant health of workers. Governments, enterprises, and individuals need to attach great importance to the possible adverse effects of noise. They must also actively adopt various effective measures to protect the occupational safety and health of workers.

Occupational noise and genetic variants in stress hormone biosynthesis-based genes and rates of blood lipid changes in China: A five-year longitudinal study.

Lipid profiles are influenced by both noise and genetic variants. However, little is known about the associations of occupational noise and genetic variants with age-related changes in blood lipids, a crucial event in the initiation and evolution of atherosclerotic cardiovascular diseases. We aimed to evaluate the associations of blood lipid change rates with occupational noise and genetic variants in stress hormone biosynthesis-based genes. This cohort was established in 2012 and 2013 and was followed up until 2017. A total of 952 participants were included in the final analysis and all of them were categorized to two groups, the exposed group and control group, according to the exposed noise levels in their working area. Single nucleotide polymorphisms (SNPs) in stress hormone biosynthesis-based genes were genotyped. Five physical examinations were conducted from 2012 to 2017 and lipid measurements were repeated five times. The estimated annual changes (EACs) of blood lipid were calculated as the difference in blood lipid levels between any 2 adjacent examinations divided by their time interval (year). The generalized estimating equations for repeated measures analyses with exchangeable correlation structures were used to evaluate the influence of exposing to noise (versus being a control) and the SNPs mentioned above on the EACs of blood lipids. We found that the participants experienced accelerated age-related decline in high-density lipoprotein cholesterol (HDL-C) levels as they were exposed to noise (ß = -0.38, 95% confidence interval (CI), -0.66 to -0.10, P = 0.007), after adjusting for work duration, gender, smoking, alcohol consumption, and pack-years. This trend was only found in participants with COMT-rs165815 TT genotype (ß = -1.19, 95% CI, -1.80 to -0.58, P < 0.001), but not in those with the CC or CT genotypes. The interaction of noise exposure and rs165815 was marginally significant (Pinteraction = 0.010) after multiple adjustments. Compared with DDC-rs11978267 AA genotype carriers, participants carrying rs11978267 GG genotype had decreased EAC of triglycerides (TG) (ß = -5.06, 95% CI, -9.07 to -1.05, P = 0.013). Participants carrying DBH-rs4740203 CC genotype had increased EAC of total cholesterol (TC) (ß = 1.19, 95% CI, 0.06 to 2.33, P = 0.039). However, these findings were not statistically significant after multiple adjustments. These results indicated that Occupational noise exposure was associated with accelerated age-related decreases in HDL-C levels, and the COMT-rs165815 genotype appeared to modify the effect of noise exposure on HDL-C changes among the occupational population.

Relationship Between Work-Related Noise Exposure and Cognitive Impairment: A Cross-Sectional Study in China.

Background: Noise exposure and the risk of cognitive impairment are currently major public health issues. Objective: This study aimed to analyze the relationship between noise exposure and early impairment of cognitive function from the perspective of occupational epidemiology and to provide evidence for the long-term prevention and treatment of dementia in the context of aging. Methods: This study was conducted in China between May and August 2021. The independent variables were the type of hazardous factors, duration of noise exposure, perceived noise intensity, and cumulative noise exposure (CNE). The dependent variable was cognitive function, which was measured using the Mini-Mental State Examination (MMSE) and Montreal Cognitive Assessment (MoCA). Multiple linear and logistic regression were used to analyze the relationship between noise exposure and cognitive function and to establish an effect curve. Results: The detection rates of cognitive dysfunction using the MMSE and MoCA were 1.1% and 36.2%, respectively. The predicted MMSE and MoCA scores showed a downward trend within the CNE value ranging from 90-140 dB.time. Each unit increase in CNE decreased cognitive function scores by 0.025 (0.037, 0.013) and 0.020 (0.037, 0.003) points,respectively. Conclusions: From the perspective of occupational epidemiology, these findings reveal a potential link between long-term noise exposure and early cognitive impairment.

Advancing noise management in aviation: Strategic approaches for preventing noise-induced hearing loss.

As urbanization and population growth escalate, the challenge of noise pollution intensifies, particularly within the aviation industry. This review examines current insights into noise-induced hearing loss (NIHL) in aviation, highlighting the risks to pilots, cabin crew, aircraft maintenance engineers, and ground staff from continuous exposure to high-level noise. It evaluates existing noise management and hearing conservation strategies, identifying key obstacles and exploring new technological solutions. While progress in developing protective devices and noise control technologies is evident, gaps in their widespread implementation persist. The study underscores the need for an integrated strategy combining regulatory compliance, technological advances, and targeted educational efforts. It advocates for global collaboration and policy development to safeguard the auditory health of aviation workers and proposes a strategic framework to enhance hearing conservation practices within the unique challenges of the aviation sector.

Perfil das doenças metabólicas na perda auditiva ocupacional / Profile of metabolic damages in occupational hearing loss / Perfil de enfermedades metabólicas en la pérdida auditiva ocupacional

Introdução: O diagnóstico precoce quanto às perdas auditivas é essencial para minimização do impacto social em relação à rotina laboral e na qualidade de vida. Objetivo: Caracterizar a associação entre a perda auditiva em trabalhadores com doenças metabólicas. Método: Estudo transversal retrospectivo de dados secundários de prontuário com o tratamento das doenças metabólicas, os dados foram coletados em duas clínicas de saúde ocupacional (C1 e C2) em Florianópolis - Santa Catarina (Brasil), no período de janeiro de 2020 a dezembro de 2022, considerando exames referenciais a partir do ano de 2005. Os dados foram organizados em planilhas do programa Microsoft Excel® e, posteriormente, exportados e analisados no software MedCalc® Statistical Software versão 22.006. Resultados: Foram analisados dados de 97 pacientes (71 homens e 26 mulheres), expostos ao ruído ocupacional (p = 0,0047), com diagnóstico de ao menos uma doença metabólica (41,20%) e prevalência de medicamentos da classe ATC H (p = 0,0465) e Losartana® (OR = 1,6976). Conclusão: O ruído ocupacional é o principal fator de risco auditivo nas empresas analisadas, e a presença de doença metabólica poderá influenciar em alterações dos limiares auditivos. Para reduzir a vulnerabilidade dessa população, é necessário a promoção, educação e conscientização dos trabalhadores nos aspectos de saúde. (AU)

Introduction: Early diagnosis of hearing loss is essential to minimize the social impact in relation to work routine and quality of life. Objective: Analyze the association between hearing loss in workers and metabolic diseases. Method: Retrospective cross-sectional study of secondary data on the use of medications in metabolic diseases, the data were collected in two occupational health clinics (C1 and C2) in Florianópolis - Santa Catarina (Brazil), from January 2020 to December 2022, considering references from exams from the year 2005. The data were organized in Microsoft Excel® spreadsheets and subsequently exported and analyzed using the MedCalc® statistical software version 22.006. Results: The data of 97 patients (71 men and 26 women) exposed to occupational noise (p = 0.0047), diagnosed with at least one metabolic disease (41.20%) and prevalence of ATC H class medications (p = 0.0465) and Losartan® (OR = 1.6976). Discussion andConclusion: Occupational noise is the main auditory risk factor, and the presence of metabolic disease can influence hearing thresholds. To reduce the vulnerability of this population, it is necessary to promote, raise awareness and educate, using approaches related to health aspects at work. (AU)

Introducción: El diagnóstico precoz de la pérdida auditiva es fundamental para minimizar el impacto social en la rutina laboral y la calidad de vida. Propósito: Analizar la asociación entre pérdida auditiva en trabajadores y enfermedades metabólicas. Metodología: Estudio transversal retrospectivo de datos secundarios sobre el uso de medicamentos en enfermedades metabólicas; Los datos fueron recolectados en dos clínicas de salud ocupacional (C1 y C2) en en Florianópolis - Santa Catarina (Brasil), de enero de 2020 a diciembre de 2022, considerando referencias de exámenes del año 2005. Los datos fueron organizados en hojas de cálculo Microsoft Excel®. y posteriormente exportados y analizados. utilizando el software estadístico MedCalc® versión 22.006. Resultados: Se analizaron los datos de 97 pacientes (71 hombres y 26 mujeres) expuestos a ruido ocupacional (p = 0,0047), diagnosticados con al menos una enfermedad metabólica (41,20%) y prevalencia de medicamentos clase ATC H (p = 0,0465). y Losartan® (OR = 1,6976). Discusión y Conclusión: El ruido ocupacional es el principal factor de riesgo auditivo y la presencia de enfermedad metabólica puede influir en los umbrales auditivos. Para reducir la vulnerabilidad de esta población es necesario promover, sensibilizar y educar utilizando enfoques relacionados con aspectos de salud en el trabajo. (AU)

Sources of noise exposure across Australian workplaces: cross-sectional analysis and modelling the impact of a targeted noise-source reduction initiative.

CONTEXT: Workplace noise regulations and guidance follow the hierarchy of control model that prioritizes eliminating or reducing noise at its source. OBJECTIVES: To determine the main sources of workplace noise exposure in the Australian working population and estimate the reduction of workers exposed over the noise limit (LAeq,8h > 85 dB) if noise levels of specific tools or equipment were reduced by 10 dB. METHODS: Information on the tools used and tasks performed during each participant's last working shift was collected from 4,977 workers via telephone survey. Using a predetermined database of task-based noise levels, partial noise exposures (Pa2h) were determined for each noisy activity performed by the workers and their daily noise exposure level (LAeq,8h) was estimated. Partial exposures were categorized into 15 tool/task groups and the tally, average, and sum (Pa2h) for each group were calculated. The impacts of 5 different scenarios that simulated a reduction of 10 dB in noise emissions for specific tool groups were modelled. RESULTS: Powered tools and equipment were responsible for 59.3% of all noise exposure (Pa2h); vehicles for 10.6%; mining, refineries, and plant equipment for 5.1%; and manufacturing and food processing for 4.2%. Modelling demonstrated that a 10 dBA noise-level reduction of all powered tools and equipment would lead to a 26.4% (95% confidence interval: 22.7% to 30.3%) reduction of workers with an LAeq,8h > 85 dB. This could represent over 350,000 Australian workers no longer exposed above the workplace limit daily. CONCLUSIONS: A universal reduction of 10 dB to power tools and equipment would substantially reduce the future burden of hearing loss, tinnitus, workplace injuries, and other health effects. Initiatives to reduce the noise emissions of specific powered tool groups are warranted.

Noise exposure assessment of workers inspecting construction machinery vehicles in the Republic of Korea.

Previous studies have investigated the health hazards caused by exposure to the noise of heavy equipment used at construction sites. Korea's Ministry of Land, Infrastructure, and Transport operates a registration system for construction machinery, and regular safety inspections are mandatory. Although workers inspecting construction machinery vehicles are exposed to unwanted noise, no noise exposure assessment has been made regarding these workers in Korea. The time-weighted average (TWA) daily average noise exposure level among construction machinery inspectors at 18 inspection centers was 75.3 dB(A). Among the inspection steps, the exhaust gas inspection step was found to exhibit the highest noise exposure level, up to 100 dB(A). In Korea, if the noise level of a workplace exceeds 85 dB(A) as a TWA, workers are required to undergo special medical examinations. This study found that special medical examinations were required for two of the 18 target inspection centers (approximately 115 workers) as the 8-hour TWA noise level exceeded 85 dB(A). Therefore, regular noise exposure assessment and special medical examinations for noise are required to prevent inspectors from developing hearing disorders due to noise exposure.

Face the (unamplified) music: Key findings for musicians.

Music is complex. There are risks to hearing health associated with playing due to excessive sound exposure. Face the Music is an on-going cross-sectional project to assess the risks to unamplified classical musicians. Key findings over the first fifteen years are presented based on the research undertaken with a leading conservatoire on more than 5000 classical music students. The work covers hearing health surveillance, education and awareness, sound exposure, and new technology. The future of the research programme is discussed along with opportunities in objective hearing health assessment and new acoustic solutions. A lot has changed in fifteen years, but the research was driven by a change in United Kingdom legislation. It is hoped that the research results can inform future regulation.

Prevalence and associated factors of noise-induced hearing loss among workers in Bishoftu Central Air Base of Ethiopia.

Excessive occupational exposure to noise results in a well-recognized occupational hearing loss which is prevalent in many workplaces and now it is taken as a global problem. Therefore, this study aims to assess the prevalence of noise-induced hearing loss and associated factors among workers in the Bishoftu Central Air Base in Ethiopia. An institutional-based cross-sectional study was conducted among 260 central air base workers through face-to-face interviews, an environment noise survey, and an audiometric test for data collection. Data were entered by Epi-data version 3.1 and SPSS was used to analyze the data. Finally, a statistical analysis such as descriptive and binary logistic regression analysis was applied. A P-value < 0.05 at 95% CI was considered statistically significant. The overall prevalence of noise-induced hearing loss and hearing impairments was 24.6 and 30.9%, respectively. The highest prevalence of noise-induced hearing loss was recorded for workers who were exposed to noise levels greater than 90 dBA. Out of 132 workers exposed to the average noise level of 75 dB A, only 5% of workers were affected with noise-induced hearing loss, while 128 workers exposed to an average noise level equal to or greater than 90 dB A, 19.6% of workers were identified with noise-induced hearing loss. Regarding sex, around 21.9% of male workers were identified with noise-induced hearing loss. Workers who were exposed to a high noise level workplace previously or before the Central Air Base workplace were five times (AOR = 5.0, 95% CI 1.74-14.36) more likely affected by noise-induced hearing loss than those workers not previously exposed. Those workers who were exposed to greater or equal to 90dBA noise level were 4.98 times (AOR = 4.98, 95% CI 2.59-9.58) more likely to be exposed to noise-induced levels than those who were exposed to less than 90dBA noise level. Moreover, male air base workers were 3.5 times more likely exposed to hearing impairment than female workers (AOR = 3.5, 95% CI 1.01-12.0). This study identified that the prevalence of noise-induced hearing loss and hearing impairments was significantly high. So implementation of a hearing conservation program, giving noise education, and supplying adequate hearing protective devices (HPDs) are essentials.

Risk analysis of noise-induced hearing loss of workers in the automobile manufacturing industries based on back-propagation neural network model: a cross-sectional study in Han Chinese population.

OBJECTIVES: This study aims to predict the risk of noise-induced hearing loss (NIHL) through a back-propagation neural network (BPNN) model. It provides an early, simple and accurate prediction method for NIHL. DESIGN: Population based, a cross sectional study. SETTING: Han, China. PARTICIPANTS: This study selected 3266 Han male workers from three automobile manufacturing industries. PRIMARY OUTCOME MEASURES: Information including personal life habits, occupational health test information and occupational exposure history were collected and predictive factors of NIHL were screened from these workers. BPNN and logistic regression models were constructed using these predictors. RESULTS: The input variables of BPNN model were 20, 16 and 21 important factors screened by univariate, stepwise and lasso-logistic regression. When the BPNN model was applied to the test set, it was found to have a sensitivity (TPR) of 83.33%, a specificity (TNR) of 85.92%, an accuracy (ACC) of 85.51%, a positive predictive value (PPV) of 52.85%, a negative predictive value of 96.46% and area under the receiver operating curve (AUC) is: 0.926 (95% CI: 0.891 to 0.961), which demonstrated the better overall properties than univariate-logistic regression modelling (AUC: 0.715) (95% CI: 0.652 to 0.777). The BPNN model has better predictive performance against NIHL than the stepwise-logistic and lasso-logistic regression model in terms of TPR, TNR, ACC, PPV and NPV (p<0.05); the area under the receiver operating characteristics curve of NIHL is also higher than that of the stepwise and lasso-logistic regression model (p<0.05). It was a relatively important factor in NIHL to find cumulative noise exposure, auditory system symptoms, age, listening to music or watching video with headphones, exposure to high temperature and noise exposure time in the trained BPNN model. CONCLUSIONS: The BPNN model was a valuable tool in dealing with the occupational risk prediction problem of NIHL. It can be used to predict the risk of an individual NIHL.

Hearing protection field attenuation estimation systems and associated training for reducing workers' exposure to noise.

BACKGROUND: Global Burden of Disease studies identify hearing loss as the third leading cause of years lived with a disability. Their estimates point to large societal and individual costs from unaddressed hearing difficulties. Workplace noise is an important modifiable risk factor; if addressed, it could significantly reduce the global burden of disease. In practice, providing hearing protection devices (HPDs) is the most common intervention to reduce noise exposure at work. However, lack of fit of HPDs, especially earplugs, can greatly limit their effectiveness. This may be the case for 40% of users. Testing the fit and providing instructions to improve noise attenuation might be effective. In the past two decades, hearing protection fit-test systems have been developed and evaluated in the field. They are called field attenuation estimation systems. They measure the noise attenuation obtained by individual workers using HPDs. If there is a lack of fit, instruction for better fit is provided, and may lead to better noise attenuation obtained by HPDs. OBJECTIVES: To assess: (1) the effects of field attenuation estimation systems and associated training on the noise attenuation obtained by HPDs compared to no instruction or to less instruction in workers exposed to noise; and (2) whether these interventions promote adherence to HPD use. SEARCH METHODS: We used CENTRAL, MEDLINE, five other databases, and two trial registers, together with reference checking, citation searching, and contact with study authors to identify studies. We imposed no language or date restrictions. The latest search date was February 2024. SELECTION CRITERIA: We included randomised controlled trials (RCTs), cluster-RCTs, controlled before-after studies (CBAs), and interrupted time-series studies (ITSs) exploring HPD fit testing in workers exposed to noise levels of more than 80 A-weighted decibels (or dBA) who use hearing protection devices. The unit 'dBA' reports on the use of a frequency-weighting filter to adjust sound measurement results to better reflect how human ears process sound. The outcome noise attenuation had to be measured either as a personal attenuation rating (PAR), PAR pass rate, or both. PAR pass rate is the percentage of workers who passed a pre-established level of sufficient attenuation from their HPDs, identified on the basis of their individual noise exposure. DATA COLLECTION AND ANALYSIS: Two review authors independently assessed study eligibility, risk of bias, and extracted data. We categorised interventions as fit testing of HPDs with instructions at different levels (no instructions, simple instructions, and extensive instructions). MAIN RESULTS: We included three RCTs (756 participants). We did not find any studies that examined whether fit testing and training contributed to hearing protector use, nor any studies that examined whether age, gender, or HPD experience influenced attenuation. We would have included any adverse effects if mentioned by the trial authors, but none reported them. None of the included studies blinded participants; two studies blinded those who delivered the intervention. Effects of fit testing of HPDs with instructions (simple or extensive) versus fit testing of HPDs without instructions Testing the fit of foam and premoulded earplugs accompanied by simple instructions probably does not improve their noise attenuation in the short term after the test (1-month follow-up: mean difference (MD) 1.62 decibels (dB), 95% confidence interval (CI) -0.93 to 4.17; 1 study, 209 participants; 4-month follow-up: MD 0.40 dB, 95% CI -2.28 to 3.08; 1 study, 197 participants; both moderate-certainty evidence). The intervention probably does not improve noise attenuation in the long term (MD 0.15 dB, 95% CI -3.44 to 3.74; 1 study, 103 participants; moderate-certainty evidence). Fit testing of premoulded earplugs with extensive instructions on the fit of the earplugs may improve their noise attenuation at the immediate retest when compared to fit testing without instructions (MD 8.34 dB, 95% CI 7.32 to 9.36; 1 study, 100 participants; low-certainty evidence). Effects of fit testing of HPDs with extensive instructions versus fit testing of HPDs with simple instructions Fit testing of foam earplugs with extensive instructions probably improves their attenuation (MD 8.62 dB, 95% CI 6.31 to 10.93; 1 study, 321 participants; moderate-certainty evidence) and also the pass rate of sufficient attenuation (risk ratio (RR) 1.75, 95% CI 1.44 to 2.11; 1 study, 321 participants; moderate-certainty evidence) when compared to fit testing with simple instructions immediately after the test. This is significant because every 3 dB decrease in noise exposure level halves the sound energy entering the ear. No RCTs reported on the long-term effectiveness of the HPD fit testing with extensive instructions. AUTHORS' CONCLUSIONS: HPD fit testing accompanied by simple instructions probably does not improve noise attenuation from foam and premoulded earplugs. Testing the fit of foam and premoulded earplugs with extensive instructions probably improves attenuation and PAR pass rate immediately after the test. The effects of fit testing associated with training to improve attenuation may vary with types of HPDs and training methods. Better-designed trials with larger sample sizes are required to increase the certainty of the evidence.

[Quantitative analysis of the characteristics and influencing factors of hearing loss among workers exposed to noise in Tianjin].

Objective: To analyze the characteristics of high-frequency average hearing loss in both ears of noise exposed workers in Tianjin in 2020, and quantitatively analyze the influencing factors of high-frequency hearing loss in both ears of workers. Methods: In March 2023, Collect and organize basic information about noise-hazardous enterprises and personal information of workers exposed to noise. Data from the Tianjin Occupational Disease and Health Hazard Factors Information Monitoring System from January 2020 to December 2020, and analyze the impact of basic information of employees, enterprise size, regional distribution, industry category, and economic type on the high-frequency average hearing loss of workers during work. Apply logistic regression to quantitatively analyze the influencing factors of abnormal high-frequency average hearing threshold of noise exposed workers. Results: The size, economic type, industry category, and regional distribution of enterprises, as well as the gender, age, length of service of workers, have an impact on the abnormal high-frequency average hearing threshold of noise exposed workers (χ(2)=733.56、3 497、27、1352.84、1197.62、2570.59、22.30、506.60, P<0.001) . Quantitative analysis using a logistic regression model showed that in the basic information of workers, noise exposed workers were male (OR=2.500, P<0.001) and aged 30-39, 40-49, and 50-59 years (OR=1.33, P<0.001; OR=1.68, P<0.001; OR=1.52, P< 0.001) , with a length of service of 4 to<10 years and≥10 years (OR=1.08, P<0.001; OR=1.615, P<0.001) being the influencing factors for high-frequency hearing loss in both ears of noise exposed workers; In terms of enterprise characteristics, medium-sized, small and micro enterprises (OR=1.12, P<0.001; OR=1.75, P<0.001; OR=2.09, P<0.001) , enterprises located in the fourth district around the city (OR=1.268, P<0.001) , and enterprises with economic types of collective economy, other economy, private economy, Hong Kong, Macao and Taiwan investment, shareholding system, and other industry economies (OR are all >1, P<0.001) are all factors affecting high-frequency hearing loss in noise exposed personnel. Conclusion: Noise is a common occupational hazard factor in Tianjin's enterprises, especially for workers in micro enterprises who face a high risk of hearing abnormalities. Therefore, enterprises need to strengthen the management and intervention of noise operations to prevent the occurrence of hearing loss in workers.