Analysis of noise levels in the neonatal intensive care unit: the impact of clinical microsystems.

Reorganization of neonatal intensive care by introducing clinical microsystems may help to allocate nursing time more appropriately to the needs of patients. However, there is concern that cohorting infants according to acuity may enhance noise levels. This single-center study investigated the impact of reorganization of neonatal intensive care unit by implementing clinical microsystems in a Level III NICU on environmental noise. This prospective study measured 24-h noise levels over a period of 6 months during pre- and post-implementation of microsystems cohorting infants of similar acuity. Comparative analyses of the mixed acuity (i.e., before) and the cohorting (i.e., after) model were performed by creating daily profiles from continuous noise level measurements and calculating the length of exposure to predefined noise levels. Compared to baseline daytime measurements, noise levels were 3-6 dBA higher during physician handover. Noise levels were 2-3 dBA lower on weekends and 3-4 dBA lower at night, independent of the organizational model. The introduction of clinical microsystems slightly increased average noise levels for high-acuity pods (A and B) but produced a much more substantial decrease for low-acuity pods (E), leading to an overall reduction in unit-wide noise levels.    Conclusion: Our data show that noise levels are more driven by human behavior than by technical devices. Implementation of microsystems may help to reduce noise exposure in the lower acuity pods in a NICU. What is Known: • Excessive noise levels can lead to adverse effects on the health and development of premature infants and other critically ill newborns. • The reorganization of the neonatal intensive care unit following the clinical microsystems principles might improve quality of care but also affect noise exposure of staff and patients. What is New: • The transition from a mixed -acuity to cohorting model is associated with an overall reduction in noise levels, particularly in low-acuity pods requiring less nursing care. • Nevertheless, baseline noise levels in both models exceeded the standard permissible limits.

Association between occupational noise and obesity: a retrospective cohort study in China.

OBJECTIVES: To determine the relationship between occupational noise, and obesity and body mass index (BMI) changes. METHODS: Baseline data were collected from participants (n = 1264) who were followed for 6 years in a retrospective study. The noise exposure level (LAeq,8h) was determined by equivalent continuous weighted sound pressure levels using the fixed-point surveillance method for noise monitoring. The cumulative noise exposure (CNE) level was determined using the equal energy formula, which is based on exposure history and level. RESULTS: The incidence of obesity at low (RR = 2.364, 95% CI 1.123-4.739]), medium (RR = 3.921, 95% CI 1.946-7.347]), high (RR = 5.242, 95% CI 2.642-9.208]), and severe noise levels (RR = 9.322, 95% CI 5.341-14.428]) was higher risk than the LAeq,8h control level. The risk of obesity among participants exposed to low (RR = 2.957, 95% CI 1.441-6.068]) and high cumulative noise levels (RR = 7.226, 95% CI 3.623-14.415]) was greater than the CNE control level. For every 1 dB(A) increase in LAeq,8h, the BMI increased by 0.063 kg/m2 (95% CI 0.055-0.071], SE = 0.004). For every 1 dB(A) increase in the CNE, the BMI increased by 0.102 kg/m2 (95% CI 0.090-0.113], SE = 0.006). CONCLUSIONS: Occupational noise is related to the incidence of obesity. The occupational noise level and occupational noise cumulative level were shown to be positively correlated with an increase in BMI.

The influence of occupational noise exposure on blood pressure and hearing loss among female workers of childbearing age.

OBJECTIVES: Women exposed to occupational noise experience adverse pregnancy outcomes. Therefore, we initiated a large, population-based, cross-sectional study to further investigate the effects of occupational noise on hearing and blood pressure among female workers of childbearing age. STUDY DESIGN AND SETTING: A total of 6981 childbearing-aged female workers were selected for this cross-sectional study. Basic characteristics of participants were analyzed by comparing the exposed and control groups. Logistic regression models were employed to calculate the odds ratios (ORs) and 95% confidences intervals (CIs) for the associations of occupational noise with levels of hearing loss and blood pressure. The associations were further explored through stratification by age and duration of noise exposure. RESULTS: Compared with participants not exposed to occupational noise, increasing years of occupational noise exposure were independently associated with an elevated risk of hypertension after adjustment of age, industry classification, enterprise size and economic type. Compared to participants not exposed to occupational noise, only the prevalence of bilateral hearing loss was significantly higher after adjustments for age, industry classification, enterprise size and economic type. Compared with those with normal hearing, the ORs and 95% CIs were 1.97 (0.95-4.07), 2.22 (1.05-4.68) and 1.29 (1.06-1.57) for bilateral, unilateral and any ear hearing loss, respectively. CONCLUSIONS: Occupational noise exposure is positively associated with both hypertension and bilateral hearing loss among female workers of childbearing age. Those exposed to occupational noise show an increased risk of hypertension after adjusting for potential confounders.

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.

Is occupational noise associated with arthritis? Cross-sectional evidence from US population.

BACKGROUND: The impact of occupational noise exposure on various diseases, including ear and cardiovascular diseases, has been studied extensively. Nevertheless, the connection between osteoarthritis (OA) and rheumatoid arthritis (RA) and occupational noise exposure remains largely unexplored in real-world scenarios. This study assessed the association between occupational noise exposure and the prevalence of two types of arthritis. METHODS: This study used database data from 2005 to 2012 and 2015-March 2020 from the prepandemic National Health and Nutrition Examination Survey (NHANES) related to occupational noise exposure and arthritis. Multivariate logistic regression analysis was used to estimate the association between occupational noise exposure and RA/OA, adjusting for age, gender, race, education level, marital status, the ratio of family income to poverty, trouble sleeping, smoking status, alcohol consumption, diabetes, hypertension, body mass index (BMI), metabolic equivalents (METs), and thyroid disease. RESULTS: This study included 11,053 participants. Multivariate logistic regression analysis demonstrated that previous exposure to occupational noise was positively associated with self-reported RA (OR = 1.43, 95% CI = 1.18-1.73) and OA (OR = 1.25, 95% CI = 1.07-1.46). Compared to individuals without a history of occupational noise exposure, those with an exposure duration of 1 year or greater exhibited higher odds of prevalent RA, though there was no apparent exposure response relationship for noise exposure durations longer than 1 year. The results of our subgroup analyses showed a significant interaction between age and occupational noise exposure on the odds of self-reported prevalent OA. CONCLUSIONS: Our findings suggest an association between occupational noise exposure and the prevalence of RA and OA. Nevertheless, further clinical and basic research is warranted to better explore their associations.

Occupational noise and hypertension in Southern Chinese workers: a large occupational population-based study.

INTRODUCTION: An increasing number of original studies suggested that occupational noise exposure might be associated with the risk of hypertension, but the results remain inconsistent and inconclusive. In addition, the attributable fraction (AF) of occupational noise exposure has not been well quantified. We aimed to conduct a large-scale occupational population-based study to comprehensively investigate the relationship between occupational noise exposure and blood pressure and different hypertension subtypes and to estimate the AF for hypertension burden attributable to occupational noise exposure. METHODS: A total of 715,135 workers aged 18-60 years were included in this study based on the Key Occupational Diseases Surveillance Project of Guangdong in 2020. Multiple linear regression was performed to explore the relationships of occupational noise exposure status, the combination of occupational noise exposure and binaural high frequency threshold on average (BHFTA) with systolic and diastolic blood pressure (SBP, DBP). Multivariable logistic regression was used to examine the relationshipassociation between occupational noise exposure status, occupational noise exposure combined with BHFTA and hypertension. Furthermore, the attributable risk (AR) was calculated to estimate the hypertension burden attributed to occupational exposure to noise. RESULTS: The prevalence of hypertension among occupational noise-exposed participants was 13·7%. SBP and DBP were both significantly associated with the occupational noise exposure status and classification of occupational noise exposure combined with BHFTA in the crude and adjusted models (all P < 0·0001). Compared with workers without occupational noise exposure, the risk of hypertension was 50% greater among those exposed to occupational noise in the adjusted model (95% CI 1·42-1·58). For participants of occupational noise exposed with BHFTA normal, and occupational noise exposed with BHFTA elevated, the corresponding risks of hypertension were 48% (1·41-1·56) and 56% (1·46-1·63) greater than those of occupational noise non-exposed with BHFTA normal, respectively. A similar association was found in isolated systolic hypertension (ISH) and prehypertension. Subgroup analysis by sex and age showed that the positive associations between occupational noise exposure and hypertension remained statistically significant across all subgroups (all P < 0.001). Significant interactions between occupational noise status, classification of occupational noise exposure combined with BHFTA, and age in relation to hypertension risk were identified (all P for interaction < 0.001). The associations of occupational noise status, classification of occupational noise exposure combined with BHFTA and hypertension were most pronounced in the 18-29 age groups. The AR% of occupational noise exposure for hypertension was 28·05% in the final adjusted model. CONCLUSIONS: Occupational noise exposure was positively associated with blood pressure levels and the prevalence of hypertension, ISH, and prehypertension in a large occupational population-based study. A significantly increased risk of hypertension was found even in individuals with normal BHFTA exposed to occupational noise, with a further elevated risk observed in those with elevated BHFTA. Our findings provide epidemiological evidence for key groups associated with occupational noise exposure and hypertension, and more than one-fourth of hypertension cases would have been prevented by avoiding occupational noise exposure.

Knowledge, attitude, and practices towards occupational noise among maintenance and administration workers of selected health facilities in Modimolle-Mookgopong Municipality, South Africa.

This study aimed to determine knowledge, attitude, and practices towards Noise-Induced Hearing Loss among maintenance and administration workers in selected health facilities in the Modimolle-Mookgopong Municipality. Non-probability convenient sampling was used to select 250 participants. Maintenance workers were populated within the age range of 26-35 years, being more than administrative personnel (COR 1.59, CI 0.8-3.16). Maintenance workers showed more knowledge of noise being an unwanted sound (COR 1.04, CI 0.29-3.73), an ear infection (COR 4.65, CI 1.48-14.58) and poor hearing of speech as a sign of hearing loss (AOR 0.25, CI 0.07-0.86). Thirty-four percent (34%) of maintenance workers believed that ear screening and assessments are important while 17.9% believed not to be important. Forty-eight percent (58%) of maintenance workers suggested that they could not use hearing protectors effectively without training while 13.7% suggested training is needed.

The rate of occupational noise-induced hearing loss among male workers in Israel and implication on hearing surveillance frequency.

OBJECTIVES: To investigate the annual rate of NIHL in Israel, a modern economy with relatively low industrial hazardous noise exposure. To review international protocols of hearing surveillance. To recommend an effective, efficient, hearing screening frequency protocol. METHODS: A historical cohort study was conducted. Audiometric surveillance data from the Jerusalem occupational medicine registry of male employees in various industries from 2006 to 2017 were used. Mean individual annual threshold shifts simulating 1-8 checkup interval years were calculated. Joinpoint regression analysis was used to assess the interval in which the slope of the calculated ATS variability moderates significantly. RESULTS: A total of 263 noise-exposed workers and 93 workers in the comparison group produced 1913 audiograms for analysis. Among the noise-exposed workers, using the 1-4 kHz average, threshold shifts stabilized from 3 years onwards at around 1 dB per year in all age groups and 0.83 dB in the stratum younger than 50 years. No enhanced decline was detected in the first years of exposure. CONCLUSION: Although most countries conduct annual hearing surveillance, hearing threshold shifts of noise-exposed workers become more accurate and show less variability when calculated at 3-year checkup intervals onwards than shorter intervals. Since margins of errors of the test method are much larger than the annual shift found, screening schedule that enables each subsequent test to identify a real deterioration in hearing is necessary. Triennial audiometric screening would be a better surveillance frequency for noise-exposed workers younger than 50 years of age in the category of 85-95 dBLAeq,8 h without other known risk factors.

Development of an audiological assessment and diagnostic model for high occupational noise exposure.

PURPOSE: To explore the diagnostic auditory indicators of high noise exposure and combine them into a diagnostic model of high noise exposure and possible development of hidden hearing loss (HHL). METHODS: We recruited 101 young adult subjects and divided them according to noise exposure history into high-risk and low-risk groups. All subjects completed demographic characteristic collection (including age, noise exposure, self-reported hearing status, and headset use) and related hearing examination. RESULTS: The 8 kHz (P = 0.039) and 10 kHz (P = 0.005) distortion product otoacoustic emission amplitudes (DPOAE) (DPs) in the high-risk group were lower than those in the low-risk group. The amplitudes of the summating potential (SP) (P = 0.017) and action potential (AP) (P = 0.012) of the electrocochleography (ECochG) in the high-risk group were smaller than those in the low-risk group. The auditory brainstem response (ABR) wave III amplitude in the high-risk group was higher than that in the low-risk group. When SNR = - 7.5 dB (P = 0.030) and - 5 dB (P = 0.000), the high-risk group had a lower speech discrimination score than that of the low-risk group. The 10 kHz DPOAE DP, ABR wave III amplitude and speech discrimination score under noise with SNR = - 5 dB were combined to construct a combination diagnostic indicator. The area under the ROC curve was 0.804 (95% CI 0.713-0.876), the sensitivity was 80.39%, and the specificity was 68.00%. CONCLUSIONS: We expect that high noise exposure can be detected early with this combined diagnostic indicator to prevent HHL or sensorineural hearing loss (SNHL). TRIAL REGISTRATION NUMBER/DATE OF REGISTRATION: ChiCTR2200057989, 2022/3/25.

Occupational noise exposure and tinnitus: the HUNT Study.

OBJECTIVE: We aimed to assess the association between occupational noise exposure and tinnitus. Further, to assess whether the association depends on hearing status. DESIGN: In this cross-sectional study, tinnitus (>1 h daily) was regressed on job exposure matrix (JEM)-based or self-reported occupational noise exposure, adjusted for confounders. STUDY SAMPLE: The 14,945 participants (42% men, 20-59 years) attended a population-based study in Norway (HUNT4, 2017-2019). RESULTS: JEM-based noise exposure, assessed as equivalent continuous sound level normalised to 8-h working days (LEX 8 h), over the working career or as minimum 5 years ≥85 dB) was not associated with tinnitus. Years of exposure ≥80 dB (minimum one) was not associated with tinnitus. Self-reported high noise exposure (>15 h weekly ≥5 years) was associated with tinnitus overall and among persons with elevated hearing thresholds (prevalence ratio (PR) 1.3, 1.0-1.7), however not statistically significantly among persons with normal thresholds (PR 1.1, 0.8-1.5). CONCLUSIONS: Our large study showed no association between JEM-based noise exposure and tinnitus. This may to some extent reflect successful use of hearing protection. High self-reported noise exposure was associated with tinnitus, but not among normal hearing persons. This supports that noise-induced tinnitus to a large extent depends on audiometric hearing loss.

A history of occupational noise exposure is associated with steep-slope audiograms and poorer self-reported hearing-aid outcomes.

OBJECTIVE: To investigate the effects of previous occupational noise exposure in older adults with hearing loss on (1) audiometric configuration and acoustic reflex (AR) thresholds and (2) self-reported hearing abilities and hearing aid (HA) effectiveness. DESIGN: A prospective observational study. STUDY SAMPLE: The study included 1176 adults (≥60 years) with bilateral sensorineural hearing loss. Pure-tone audiometry, AR thresholds, and responses to the abbreviated version of the Speech, Spatial, and Qualities of Hearing Scale (SSQ12) and the International Outcome Inventory for Hearing Aids (IOI-HA) questionnaire were obtained, along with information about previous occupational noise exposure. RESULTS: Greater occupational noise exposure was associated with a higher prevalence of steeply sloping audiograms in men and women and a 0.32 (95% CI: -0.57; -0.06) scale points lower mean SSQ12 total score among noise-exposed men. AR thresholds did not show a significant relation to noise-exposure status, but hearing thresholds at a given frequency were related to elevated AR thresholds at the same frequency. CONCLUSIONS: A noise exposure history is linked to steeper audiograms in older adults with hearing loss as well as to poorer self-reported hearing abilities in noise-exposed men. More attention to older adults with previous noise exposure is warranted in hearing rehabilitation.

Noise exposure during robot-assisted total knee arthroplasty.

The aim of the study was to examine the noise exposure for operating theater staff during total knee arthroplasty (TKA) with three different robot systems. There is already evidence that noise exposure during TKA performed manually exceeds recommended guidelines for occupational noise. Therefore, if surgical staff is exposed to it for several years, the development of noise-inducing hearing loss (NIHL) is significantly increased. To investigate the noise exposure during robot-assisted TKA, the study measured the average noise and the peak sound pressure during TKA with MAKO robot (Stryker, Kalamazoo, Michigan, United States), NAVIO robot (Smith and Nephew, London, Great Britain), and CORI robot (Smith and Nephew, London, Great Britain) using a class 1 sound level meter. Each robot system exceeds the recommended guidelines from the national institute for occupational safety and health. While the MAKO robot had the highest average sound level (93.18 dB(A)) of the three robot systems (NAVIO: 88.88 dB(A), CORI: 89.38 dB(A)), the peak sound level was the highest with the NAVIO Robot (134.48 dB(C)) compared to the MAKO Robot (128.98 dB(C)) and CORI robot (126.48 dB(C)). Robot-assisted TKA is a risk factor for NIHL, like manually performed TKA. Further research for decreasing the noise exposure during TKA is needed to minimize the hearing loss in operating theater staff.

Hearing loss and hypertension among noise-exposed workers: a pilot study based on baseline data.

This study aimed to assess the prevalence of noise-induced hearing loss (NIHL) and hypertension, and the association between NIHL and hypertension using occupational physical examination data of 42,588 noise-exposed workers from local enterprises in Yangzhou between 2015 and 2017. The average binaural high-frequency threshold on average (BHFTA), systolic blood pressure (SBP), and diastolic blood pressure (DBP) were 23.09 ± 11.32 dB, 126.85 ± 15.94 mm Hg and 79.94 ± 11.61 mm Hg. The prevalence of NIHL and hypertension were 24.38% and 25.40%. An increased risk of NIHL and hypertension was observed in the groups of males, aged >35 years, noise exposure time >5 years, noise exposure level >85 dB(A) and smoking. 32.25% NIHL workers had hypertension. NIHL workers were at higher risk of hypertension (adjusted OR = 1.07, 95%CI = 1.02-1.13). This study shows that the noise-exposed workers have high risk of developing NIHL and hypertension.

Risk factors associated with occupational noise-induced hearing loss in the Hispanic community health study/study of Latinos: A cross-sectional epidemiologic investigation.

The purpose of this study was to estimate the prevalence of occupational noise exposure and risk factors of occupational noise-induced hearing loss (NIHL) in Hispanic/Latino adults included in the baseline wave of the Hispanic Community Health Study/Study of Latinos collected from 2008 to 2011. Sequential multiple linear regression modeled the relationship between occupational NIHL (defined as a 3-, 4-, 6-kHz pure-tone average [PTA]) and occupation type, self-reported noise exposure, cardiovascular disease (CVD) risk score, and hearing protective device (HPD) use. The final model controlled for sex, age, and recreational noise exposure. Among 12,851 included participants, approximately 40% (n = 5036) reported occupational noise exposure "Sometimes" (up to 50% of the time) or "Frequently" (75-100% of the time). In the final fitted model, longest-held occupation and CVD risk were associated with poorer hearing. Specifically, those in non-skilled, service, skilled, and military/police/other job categories had between 2.07- and 3.29-dB worse PTA than professional/office workers. Additionally, a shift in the CVD risk score category from low to medium was associated with a 2.25- and 8.20-dB worse PTA for medium and high CVD risk, respectively. Age and sex were also significantly associated with poorer hearing, such that men presented with 6.08 dB worse PTA than women, and for every one-year increase in age, PTA increased by 0.62 dB (ps < .001). No interactions were seen between noise*sometimes or frequent exposure to other ototoxic agents and PTA (ps = .33 & .92, respectively). The prevalence of occupational noise exposure was high in this cross-sectional investigation of adults from Hispanic/Latino backgrounds. Findings contribute to the extant literature by demonstrating that risk factors for occupational NIHL in adults from varying Hispanic/Latino backgrounds are consistent with those of other previously studied groups.

[Stress and suffering from tinnitus-a psychosomatic approach]. / Stress und Leiden am Tinnitus aus psychosomatischer Sicht.

The development and processing of tinnitus is often associated with stress. There are many publications on this subject that have investigated possible connections between stress perception and tinnitus symptoms using different concepts and different test inventories. In this review, we present the development of Selye's concept of stress using the transactional stress model of Lazarus and its transfer to patients suffering from tinnitus. The literature evaluating the influence of stress on tinnitus symptoms with partly very different concepts is critically reviewed. For example, it is suggested that psychosocial stress has the same likelihood of contributing to tinnitus as noise in the workplace. However, what is striking in previous studies is that "stress" as an influencing variable could not be clearly verified with suitable psychometric test procedures or that no significant differences-to very different comparison groups-could be shown. Finally, a possible therapeutic approach to stress management is outlined.

[Analysis on the quality control of suspected occupational disease from the characteristics of applicants diagnosed with noise deafness].

Objective: To analyze the audiology and occupational health data of applicants diagnosed of occupational noise deafness, and to explore the influencing factors in the diagnosis of suspected occupational noise deafness. Methods: In May 2022, the information of patients diagnosed with occupational noise deafness in Peking University Third Hospital from January 2018 to December 2021 was collected, and the occupational health data of their working environment, clinical audiological examination results and diagnosis basis of occupational noise deafness were collected and analyzed. Multi-factor unconditional logistic regression analysis was used to analyze independent risk factors for the diagnosis of occupational noise deafness. Results: A total of 129 subjects were included, all of which were suspected cases of occupational noise deafness found in various occupational health examination institutions. Eight cases (6.20%) were diagnosed as occupational noise deafness, and 121 cases (93.80%) were non-occupational noise deafness. After hearing examination, only 27.27% (24/88) of the patients' audiological changes were consistent with the starting point of occupational noise deafness diagnosis. Further analysis of the noise intensity in the workplace showed that 16 patients were identified as non-occupational noise deafness because the noise intensity of the working environment was less than 85 dB. Logistic regression analysis showed that the working hours were more than 8 hours (OR=9.274, 95%CI: 1.388-61.950, P=0.022) and the noise intensity of the working environment (OR=1.189, 95%CI: 1.059-1.334, P=0.003) were independent risk factors for the diagnosis of occupational noise deafness. Conclusion: The exclusion rate of suspected occupational noise deafness found in occupational health examination is higher after adequate rest. The test results of working environment noise intensity provided by the employer can help to determine occupational noise deafness.

The association of noise exposure with stroke incidence and mortality: A systematic review and dose-response meta-analysis of cohort studies.

BACKGROUND AND AIMS: Noise exposure is a major public health challenge with important implications for cardiovascular health. However, the association between noise exposure and stroke risk remains controversial. Therefore, we aimed to evaluate the role of noise exposure on stroke incidence and mortality by conducting a dose-response meta-analysis of cohort studies. METHODS: The relevant publications were retrieved via PubMed, Embase, Web of Science, and Scopus up to June 26, 2022. The potential linear and curve relationship between noise and stroke were fitted using the generalized least squares method and restricted cubic spline. We estimated the pooled relative risk (RR) with 95% confidence interval (CI) by random-effect models. The Grading of Recommendations Assessment Development and Evaluation (GRADE) approach was used to evaluate the strength of the results. RESULTS: In total, 21 cohort studies with 16,075,204 participants and 311,878 cases were included in the analysis. The risk of stroke incidence increased up to 4% (95% CI:1.02-1.06) and stroke mortality increased up to 3% (95% CI:1.00-1.07), every 10 dB(A) increment in noise exposure. Moreover, each 10 dB(A) increment in noise exposure was associated with a 4% (95% CI:1.01-1.07) increase in ischemic stroke and a 2% (95% CI:1.00-1.04) increase in hemorrhagic stroke. According to GRADE criteria, the evidence level in this study was rated as moderate. CONCLUSIONS: The current findings provide further evidence of a dose-response relationship between exposure to noise and the risk of stroke incidence and mortality. Additionally, we update and fill a knowledge gap that the statistically significant increase in stroke incidence when noise decibels are >65 dB(A).

Health study of 11,800 workers under occupational noise in Xinjiang.

BACKGROUND: We investigated the health status of some workers exposed to occupational noise in Xinjiang, and explored the influencing factors of their health level. We aimed to determine the key protection groups of occupational noise hazards, which might provide the basis for the development of targeted noise prevention measures. METHODS: We used descriptive analysis to investigate a total of 11,800 participants who underwent occupational health examination in Xinjiang Occupational Disease Prevention Hospital. RESULTS: The hearing abnormality rate of noise exposure participants was 8.03%, which was higher in males than females (χ2 = 54.507, p < 0.05). The abnormal rate of high-frequency hearing threshold in Xinjiang minorities was lower than in Han nationality (χ2 = 11.780, p < 0.05), while the results of the electrocardiogram were reversed (χ2 = 9.128, p < 0.05). Differences in abnormal rates of blood pressure (χ2 = 149.734, p < 0.05), hearing (χ2 = 231.203, p < 0.05), and physical examination (χ2 = 360.609, p < 0.05) are statistically significant in different industries. The abnormal rates of blood pressure (χ2 = 67.416, p < 0.05) and hearing (χ2 = 49.535, p < 0.05) gradually decrease with the expansion of the enterprise scale. Logistic regression analysis showed that gender, nationality, age, enterprise size, and industry were closely related to pure tone audiometry examination abnormal rate. CONCLUSION: Workers of male, elder, in mine and small/medium enterprises should be the key populations to prevent occupational noise hazard. It is necessary to standardize occupational health management in enterprises, which helps to improve workers' self-protection awareness and quality of life.

Occupational noise exposure and the prevalence of dyslipidemia in a cross-sectional study.

BACKGROUND: Occupational noise exposure was related to cardiovascular disease, of which dyslipidemia was an important inducement. This study investigated the relationship between occupational noise exposure and dyslipidemia. METHODS: Four hundred ninety-two occupational noise-exposed workers and 664 non-exposed workers were recruited to conduct environmental noise tests and personal occupational physical examinations. A lasso-logistic regression model was used to estimate the relative risk of dyslipidemia. A restricted cubic spline was used to estimate the association between noise exposure years and dyslipidemia after adjusting for potential confounding factors. RESULTS: A crude association was observed between the occupational noise exposure (75-85 dB(A)) and dyslipidemia. After adjusting for confounding factors, there was a non-linear relationship between noise exposure years and dyslipidemia (P for non-linearity =0.01). Workers exposed to 75-85 dB(A) for 11 to 24.5 years had a higher risk of dyslipidemia than non-exposed workers. CONCLUSIONS: A positive and non-linear exposure-response relationship was found in workers exposed to 75-85 dB(A) whose exposure years were between 11 and 24.5. Workers had the highest risk of dyslipidemia when exposed for 13.5 years.

Explaining better hearing in Norway: a comparison of two cohorts 20 years apart - the HUNT study.

BACKGROUND: The hearing function at a given age seems to have improved in more recent born cohorts in industrialized countries. But the reasons for the improvement have not yet been explained. METHODS: We investigated the extent to which better hearing in Norway is attributed to modifiable risk factors by using representative demographic and audiometric data from two cohorts of the Trøndelag Health Study, HUNT2 (1996-1998) and HUNT4 (2017-2019). We estimated natural indirect effects using causal inference methods in order to assess whether cohort improvement in hearing thresholds (HTs) was mediated by occupational noise exposure, recurrent ear infections, smoking and education. RESULTS: The improvement in HTs from HUNT2 to HUNT4 was 2.8 and 3.0 dB at low respectively high frequencies. Together all risk factors mediated this improvement by 0.8 dB (95% CI 0.7-0.9) and 0.8 dB (95% CI 0.7-0.9) respectively, corresponding to mediated proportions of 27 and 28%. Substantial mediation was specifically found for occupational noise in men and recurrent ear infections in women (mediated proportions of 11 and 17% at high frequencies, respectively). CONCLUSIONS: Increased education, less occupational noise exposure, ear infections and smoking contributed considerably to better hearing in Norway the last two decades.