Interaction of smoking and occupational noise exposure on hearing loss: a cross-sectional study

Music to Define a Generation: Factors Associated With Hearing Protection Use at Music Venues

OBJECTIVES

Excessive noise levels in music venues can negatively impact long-term hearing health. We investigated the prevalence, characteristics, and factors associated with hearing protection use among music event attendees.

STUDY DESIGN

Cross-sectional cohort.

METHODS

Adult participants (2,352) from online music forums completed a questionnaire assessing attendance at music events, hearing protection (HP) usage, type, and frequency, along with history of hearing-related symptoms and medical history. Primary outcome was defined as HP use at music venues. Data were characterized using descriptive statistics, paired t tests, and Pearson's chi-squared tests. Multivariable regression analysis elicited factors associated with any and regular HP use.

RESULTS

Our 2,352 respondents were primarily male (61.3%) and on average 28.7 years old (SD = 7.0). Of the respondents, 60.6% reported using HP, and 33.2% reported regular use; high-fidelity earplugs were the most used HP type (57.5%). HP use was associated with significantly fewer reports of negative hearing-related symptoms. In a multivariable regression model, factors associated with less likelihood of HP use included being female (vs male, OR = 0.74, CI = [0.55-0.98]), less concern about effects on hearing (OR = 0.53, CI = [0.45-0.61]), and pop music event attendance (vs EDM, OR = 0.40, CI = [0.22-0.72]). Increased attendance frequency in the past year was associated with higher likelihood of regular HP use (OR = 1.07, CI = [1.04-1.09]). Decreased attendance duration was associated with decreased likelihood (OR = 0.09, CI = [0.03-0.33]).

CONCLUSION

HP use prevalence was high, while frequent use remained low. HP use was significantly associated with reduced hearing-related symptoms. Demographic factors, otologic symp-tomology, and attendance-related characteristics were associated with HP use. These findings may guide interventions to increase adoption at music venues.

LEVEL OF EVIDENCE

4.

Association of Smoke and Nicotine Product Consumption With Sensorineural Hearing Loss: A Population-Level Analysis

OBJECTIVE

To test the hypothesis that use of cigarettes or other products with either cigarette-like smoke profile or high nicotine content by young populations increases the odds of developing sensorineural hearing loss (SNHL).

STUDY DESIGN

Retrospective cohort study.

SETTING

TriNetX US Collaborative Network (2003-2022).

PATIENTS

Approximately 3.6 million patients at least 18 years old.

INTERVENTION

None.

MAIN OUTCOME MEASURES

The primary outcome of interest was diagnosis of SNHL, defined using medical billing codes ( International Classification of Diseases, Tenth Revision , Current Procedural Terminology , etc.). Cohort inclusion criteria included electronic health record entry after 2003, age 18 to 54 or 55+ years at index, and status of cigarette, noncigarette nicotine, or cannabis use. Covariates were controlled via 1:1 propensity score matching for SNHL-related conditions, including diabetes mellitus and ischemic diseases. Odds for developing SNHL were calculated against control subjects aged 18 to 54 years who have no record of nicotine/cannabis use.

RESULTS

Odds for developing SNHL are higher for people 18 to 54 years old who use any nicotine product (odds ratio [95% confidence interval], 5.91 [5.71-6.13]), cigarettes only (4.00 [3.69-4.33]), chewing tobacco only (9.04 [7.09-11.63]), or cannabis only (3.99 [3.60-4.44]) compared with control. People 55+ years old who use no products also showed increased odds for SNHL (4.73 [4.63-4.85]).

CONCLUSIONS

Both nicotine and smoke exposure seem to be strongly associated with increased odds for developing SNHL, with chewing tobacco having the strongest association.

The Effect of Active and Passive Smoking on Hearing Loss in Noise-Exposed Metal Workers

Background

Many people are exposed to cigarette smoke actively or passively. We aimed to determine the effect of active and passive smoking on hearing thresholds and hearing loss noise-exposed workers.

Methods

This cross-sectional study was conducted on 929 metal workers. We divided the workers into 3 groups according to smoking status-current smokers, nonsmokers, and passive smokers. Audiometric testing was recorded for both ears. Hearing loss was defined by 3 models. The SPSS software Version 24 was used to analyze the collected data. We used an independent t test, chi-square, Fisher exact, and analysis of variance tests and logistic regression, and the significance level was set at P ˂0.05 to interpret the relationships between variables.

Results

The hearing threshold levels at 4000 Hz, high frequencies, and low frequencies were significantly higher in smokers than nonsmokers (P < 0.05). Also, and hearing loss at the 4000 Hz (P = 0.002; odds ratio [OR] = 1.96; 95% CI = 1.27-3.03) and high frequencies (P = 0.001; OR = 2.15; 95% CI = 1.36-3.4) had a significant correlation with smoking. Hearing loss was significantly correlated with passive smoking at 4000 Hz (P < 0.001; OR = 5.87; 95% CI = 3.29-10.47), high frequencies (P < 0.001; OR = 7.16; 95% CI = 3.97-12.89) and low frequencies (P = 0.021; OR = 4.16; 95% CI = 1.12-15.43).

Conclusion

The findings show that active and passive smokers who work in noisy environments are at higher risk for noise-induced hearing loss. Therefore, smoking cessation in smoker workers and reduction of environmental exposure to cigarette smoke is necessary to reduce the exacerbation of hearing loss. Moreover, more attention should be paid to passive smokers and they should be given priority in the same programs.

Noise-induced hearing loss profile among Taiwan Airforce on duty pilots

PURPOSE

Noise-induced hearing loss (NIHL) often results in impaired functional hearing and accidental injuries; thus, reducing military performance and endangering flight safety. While a few studies addressing laterality (left-right ear differences) and NIHL incidence between fixed-winged (jet-fighter) and rotary-wing (helicopter) aircrafts yielded inconsistent results, little is known about the NIHL profile among different types of jet-fighter pilots. This study aims to conduct a fine-grained examination of NIHL among Airforce jet pilots, with planned comparisons of laterality and aircraft type, along with the goal to compare the sensitivity of different hearing indices in predicting military pilot NIHL.

MATERIALS AND METHODS

This cross-sectional study utilizes the health and hearing data of 1025 Taiwanese Air Force Military pilots from the 2019 Taiwanese physical examination database to assess the changes in their hearing thresholds, and evaluate their risk for NIHL.

RESULTS

Our results showed that, among available military aircraft types, the trainer aircraft and M2000-5 jet-fighter had the highest risk of NIHL, in addition to a left ear inferiority found in the overall population of military pilots. Among the three hearing indices used in this study -the International Organization for Standardization (ISO) three-point hearing index, the Occupational Safety and Health Administration (OSHA) three-point hearing index, and the American Academy of Otolaryngology-Head and Neck Surgery's (AAO-HNS) high-frequency three-point hearing index-, the OSHA the AAO-HNS were the most sensitive.

CONCLUSION

Our results suggest a better noise protection for trainer and M2000-5 pilots, especially for the left ear, is warranted.

Association of dietary factors with noise-induced hearing loss in Korean population: A 3-year national cohort study

Noise-induced hearing loss (NIHL) is a hearing impairment (HI) caused by various clinical factors. Identifying the relationship between NIHL and nutrient consumption could help in reducing the prevalence of hearing loss. The aim of this study was to analyze the relationship between NIHL and dietary factors using data of the Korea National Health and Nutrition Examination survey (KNHANES). The data were collected from The Fifth KNHANES 2010-2012. The survey was taken by a total of 10,850 participants aged 20-65 years. Air conduction audiometry was measured at 500, 1000, 2000, and 4000 Hz in both ears. Metabolic syndrome, noise exposure, alcohol consumption, smoking, income level, marital status, and nutritional intake were evaluated. The differences between non-HI and HI participants in the noise-exposed group showed statistically significant differences in age, sex, marital and smoking status, alcohol consumption, and fasting glucose and triglyceride levels (p<0.05). In a multiple regression analysis of the noise-exposed group, age showed a significant association with HI (OR: 0.604; 95% CI: 0.538-0.678) after adjusting for confounders. In multivariate analysis for dietary factors affecting HI in noise-exposed groups, retinol (OR: 1.356; 95% CI: 1.068-1.722), niacin (OR: 1.5; 95% CI: 1.022-2.201), and carbohydrates (OR: 0.692; 95% CI: 0.486-0.985) showed a significant association with NIHL. Age was identified as the only factor significantly affecting NIHL. When the dietary factors of the noise-exposed group were analyzed, high intake of niacin and retinol and low intake of carbohydrates appeared to reduce the risk of hearing loss.

Effects of Diet and Lifestyle on Audio-Vestibular Dysfunction in the Elderly: A Literature Review

BACKGROUND

The world's age-related health concerns continue to rise. Audio-vestibular disorders, such as hearing loss, tinnitus, and vertigo, are common complaints in the elderly and are associated with social and public health burdens. Various preventative measures can ease their impact, including healthy food consumption, nutritional supplementation, and lifestyle modification. We aim to provide a comprehensive summary of current possible strategies for preventing the age-related audio-vestibular dysfunction.

METHODS

A PubMed, Embase, and Cochrane review databases search was conducted to identify the relationship between diet, lifestyle, and audio-vestibular dysfunction. "Diet", "nutritional supplement", "lifestyle", "exercise", "physical activity", "tinnitus", "vertigo" and "age-related hearing loss" were used as keywords.

RESULTS

Audio-vestibular dysfunction develops and progresses as a result of age-related inflammation and oxidative stress. Diets with anti-inflammatory and antioxidant effects have been proposed to alleviate this illness. A high-fat diet may induce oxidative stress and low protein intake is associated with hearing discomfort in the elderly. Increased carbohydrate and sugar intake positively correlate with the incidence of audio-vestibular dysfunction, whereas a Mediterranean-style diet can protect against the disease. Antioxidants in the form of vitamins A, C, and E; physical activity; good sleep quality; smoking cessation; moderate alcohol consumption; and avoiding noise exposure are also beneficial.

CONCLUSIONS

Adequate diet or nutritional interventions with lifestyle modification may protect against developing audio-vestibular dysfunction in elderly individuals.

Telehealth solutions for assessing auditory outcomes related to noise and ototoxic exposures in clinic and research

Nearly 1.5 billion people globally have some decline in hearing ability throughout their lifetime. Many causes for hearing loss are preventable, such as that from exposure to noise and chemicals. According to the World Health Organization, nearly 50% of individuals 12-25 years old are at risk of hearing loss due to recreational noise exposure. In the occupational setting, an estimated 16% of disabling hearing loss is related to occupational noise exposure, highest in developing countries. Ototoxicity is another cause of acquired hearing loss. Audiologic assessment is essential for monitoring hearing health and for the diagnosis and management of hearing loss and related disorders (e.g., tinnitus). However, 44% of the world's population is considered rural and, consequently, lacks access to quality hearing healthcare. Therefore, serving individuals living in rural and under-resourced areas requires creative solutions. Conducting hearing assessments via telehealth is one such solution. Telehealth can be used in a variety of contexts, including noise and ototoxic exposure monitoring, field testing in rural and low-resource settings, and evaluating auditory outcomes in large-scale clinical trials. This overview summarizes current telehealth applications and practices for the audiometric assessment, identification, and monitoring of hearing loss.

Noise-Induced Hearing Loss in Police Officers: Systematic Review

Introduction

Noise-induced hearing loss (NIHL) is defined as the sensorineural hearing loss caused by acute acoustic trauma or chronic exposure to high-intensity noises. Exposure to noises can lead to irreversible damage to the inner ear and, consequently, to a permanent shift of the hearing threshold. Police officers are particularly at risk of acute or chronic hearing damages. The aim of this study is to evaluate the hearing loss of police officers in relation to the occupational risk factors and clinical-anamnestic characteristics by collecting and analyzing existing data and evidence available in public databases.

Materials and Methods

A systematic review was conducted according to the Preferred Reporting Items for Systematic Reviews and Meta-analyses group (PRISMA). Studies were included if they met inclusion and exclusion criteria. Study selection, data extraction, and quality assessment were conducted independently by two researchers.

Results

Our initial literature search yielded 29 peer-reviewed articles. Out of 29 papers, only 10 were included in the review, after inclusion and exclusion criteria were applied the.

Conclusions

Hypertension, smoking and alcohol intake significantly affect hearing performance. In addition, a history of acoustic trauma, use of ototoxic drugs, exposure to noise in leisure-time activities and failure to use ear protectors are often found in a fair number of subjects. NIHL is also related to the age of the subjects as well as the extent and duration of noise exposure. Furthermore, NIHL is also influenced by shooting practice sessions police officers are required to undertake as well as by the chronic exposure to traffic noise, especially in motorcycle police officers.

Association of Cigarette Smoking Patterns Over 30 Years With Audiometric Hearing Impairment and Speech-in-Noise Perception: The Atherosclerosis Risk in Communities Study

IMPORTANCE

The implications of cigarette smoking and smoking cessation for hearing impairment remain unknown. Many studies on this topic have failed to account for attrition among smokers in their findings.

OBJECTIVE

To assess the association of cigarette smoking patterns with audiometric and speech-in-noise hearing measures among participants of the Atherosclerosis Risk in Communities Study.

DESIGN, SETTING, AND PARTICIPANTS

This cross-sectional study included participants of the Atherosclerosis Risk in Communities Study from 4 US communities. The analysis includes data from visit 1 (1987-1989) through visit 6 (2016-2017); data were analyzed from March 16 through June 25, 2021. Audiometric hearing and speech-in-noise testing was offered to all participants at visit 6. Participants with incomplete audiometric data or missing data for educational level, body mass index, drinking status, a diabetes or hypertension diagnosis, or occupational noise were excluded. In addition, individuals were excluded if they self-reported as having other than Black or White race and ethnicity, or if they self-reported as having Black race or ethnicity and lived in 2 predominantly White communities.

MAIN OUTCOMES AND MEASURES

Smoking behavior was classified from visit 1 (1987-1989) to visit 6 (2016-2017) using group-based trajectory modeling based on self-reported smoking status at each clinic visit. Hearing was assessed at visit 6. An audiometric 4-frequency (0.5, 1, 2, 4 kHz) pure-tone average (PTA) was calculated for the better-hearing ear and modeled as a continuous variable. Speech-in-noise perception was assessed via the Quick Speech-in-Noise Test (QuickSIN) and modeled continuously. Attrition during the 30 years of follow-up was addressed by inverse probability of attrition weighting.

RESULTS

A total of 3414 participants aged 72 to 94 years (median [IQR] age, 78.8 [76.0-82.9] years; 2032 [59.5%] women) when hearing was measured at visit 6 (2016-2017) were included in the cohort; 766 (22.4%) self-identified as Black and 2648 (77.6%) as White individuals. Study participants were classified into 3 smoking groups based on smoking behavior: never or former smoking at baseline (n = 2911 [85.3%]), quit smoking during the study period (n = 368 [10.8%]), and persistent smoking (n = 135 [4.0%]). In fully adjusted models, persistent smoking vs never or former smoking was associated with an average 2.69 (95% CI, 0.56-4.81) dB higher PTA (worse hearing) and 1.42 (95% CI, -2.29 to -0.56) lower QuickSIN score (worse performance). Associations were stronger when accounting for informative attrition during the study period (3.53 [95% CI, 1.14-5.93] dB higher PTA; 1.46 [95% CI, -2.52 to -0.41] lower QuickSIN scores). Smoking cessation during the study (vs never or former smoking) was not associated with changes in hearing.

CONCLUSIONS AND RELEVANCE

In this cross-sectional study, persistent smoking was associated with worse audiometric hearing and speech-in-noise perception. Hearing measures among participants who quit smoking during the study period did not differ from those for never or former smokers, indicating that smoking cessation (as opposed to persistent smoking) may have benefits for hearing health.

The Variability in Potential Biomarkers for Cochlear Synaptopathy After Recreational Noise Exposure

PURPOSE

Speech-in-noise tests and suprathreshold auditory evoked potentials are promising biomarkers to diagnose cochlear synaptopathy (CS) in humans. This study investigated whether these biomarkers changed after recreational noise exposure.

METHOD

The baseline auditory status of 19 normal-hearing young adults was analyzed using questionnaires, pure-tone audiometry, speech audiometry, and auditory evoked potentials. Nineteen subjects attended a music festival and completed the same tests again at Day 1, Day 3, and Day 5 after the music festival.

RESULTS

No significant relations were found between lifetime noise-exposure history and the hearing tests. Changes in biomarkers from the first session to the follow-up sessions were nonsignificant, except for speech audiometry, which showed a significant learning effect (performance improvement).

CONCLUSIONS

Despite the individual variability in prefestival biomarkers, we did not observe changes related to the noise-exposure dose caused by the attended event. This can indicate the absence of noise exposure-driven CS in the study cohort, or reflect that biomarkers were not sensitive enough to detect mild CS. Future research should include a more diverse study cohort, dosimetry, and results from test-retest reliability studies to provide more insight into the relationship between recreational noise exposure and CS. Supplemental Material https://doi.org/10.23641/asha.16821283.

Hearing Loss and Associated Factors Among Noise-Exposed Workers in Palm Oil Mills

Introduction

Almost 90% of the reported occupational diseases in Sabah, Malaysian Borneo were due to hearing loss. The manufacturing industry was the main contributor to this problem. This study aims to identify the prevalence and associated factors for hearing loss among workers in the palm oil manufacturing industry in Sabah.

Material and Methods

A cross-sectional study was done among 312 respondents from five palm oil mills in Sabah from January to April 2019. Audiometric tests, validated questionnaires and sound level meters were used. Chi-square test and independent t-test were conducted to determine the associated factors for hearing loss.

Results

75% (n = 234) of the respondents were diagnosed with hearing loss. Most of them were male (96.2%) with a mean age of 44.4 (SD 9.8) years, mean duration of employment of 16.2 (SD 9.7) years and mean noise exposure of 96.1 (SD 4.8) dB(A). The significant factors associated with hearing loss were older age (p = 0.001), married (p = 0.001), blue-collar jobs (p = 0.003), smoking (p = 0.001), works with noisy machinery (p = 0.005), lower level of noise exposed (p = 0.015), longer duration of employment (p = 0.001), and longer overtime hours per week (p = 0.001).

Conclusion

The prevalence of hearing loss among workers in the noise-exposed palm oil industries was high. Annual audiometry testing and job rotation from noise-exposed workstations were recommended. A smoking cessation program may help but reduction of noise from the source by engineering control is still the best method.

Cumulative Risks from Stressor Exposures and Personal Risk Factors in the Workplace: Examples from a Scoping Review

Protecting worker and public health involves an understanding of multiple determinants, including exposures to biological, chemical, or physical agents or stressors in combination with other determinants including type of employment, health status, and individual behaviors. This has been illustrated during the COVID-19 pandemic by increased exposure and health risks for essential workers and those with pre-existing conditions, and mask-wearing behavior. Health risk assessment practices for environmental and occupational health typically do not incorporate multiple stressors in combination with personal risk factors. While conceptual developments in cumulative risk assessment to inform a more holistic approach to these real-life conditions have progressed, gaps remain, and practical methods and applications are rare. This scoping review characterizes existing evidence of combined stressor exposures and personal factors and risk to foster methods for occupational cumulative risk assessment. The review found examples from many workplaces, such as manufacturing, offices, and health care; exposures to chemical, physical, and psychosocial stressors combined with modifiable and unmodifiable determinants of health; and outcomes including respiratory function and disease, cancers, cardio-metabolic diseases, and hearing loss, as well as increased fertility, menstrual dysfunction and worsened mental health. To protect workers, workplace exposures and modifiable and unmodifiable characteristics should be considered in risk assessment and management. Data on combination exposures can improve assessments and risk estimates and inform protective exposure limits and management strategies.

Expression of serum proteins in noise induced hearing loss workers of mining based industry

Noise Induced Hearing Loss (NIHL) is caused by excessive noise exposure due to occupational activities thus affects communication and quality of life. Prolonged occupational and environmental exposure to loud noise damages key molecules present in the micro-machinery of the ear which are required for the mechano-electrical transduction of sound waves in cochlea. Specific proteins are known to be associated with hearing loss and related structural and functional disabilities in the human inner, outer hair cells and cochlea. Rationale of this study was to identify the cochlear proteins associated with the pathophysiology of NIHL using proteomic approaches in mining based industrial workers. Total (n = 210) samples were collected from mining based industrial workers of central India. Subjects were categorized based on audiometric analysis. Proteome changes of the host serum were investigated using one and two-dimensional electrophoresis in combination with LC-MS/MS and MALDI-TOF-MS. Up-regulated 46 cochlear proteins among confirmed NIHL cases were identified by MASCOT. Shrinkage discriminant analysis provided top 25 discriminating feature proteins namely myosin, transthyretin, SERPIN, CCDC50, enkurin, transferin etc. The identified potential proteins may be used as biomarkers for early detection and to understand the pathogenic mechanism of NIHL. Evaluation of these biomarkers in follow-up cases may further aid in improving NIHL diagnosis. SIGNIFICANCE: Human proteome study in Noise Induced Hearing Loss (NIHL) cases has not been published till date. This study represents most comprehensive proteomic analysis in NIHL cases taken from Indian mine workers. The identified key twenty-five discriminating feature proteins which are upregulated when an individual develops (or is in stage of development of) NIHL, provides insights into the potential roles of these varied proteins in disease progression. The proteins thus identified by proteomic approach may be used as early diagnostic biomarker to predict the occurrence of disease at very early stage.

Association between Smoking and Noise-Induced Hearing Loss: A Meta-Analysis of Observational Studies

The purpose of this study was to synthesize the results of previously published observational studies through meta-analysis to clarify the association between smoking and noise-induced hearing loss (NIHL). We searched several databases as of October 2019. Based on the results of heterogeneity analysis (Q statistic and I² statistic), a fixed effect model (for no heterogeneity; Q test P > 0.1 and I² ≤ 50%) or a random effects model (for heterogeneity) was used to calculate the pooled odds ratios (ORs). We explored the potential dose-response relationship between smoking and NIHL as well. In total, 27 studies involving 30,465 participants were included. Compared with non-smokers, the pooled OR of current smokers was 2.05 (95% Confidence interval (CI): 1.71–2.46), and of former smokers was 1.11 (95% CI: 1.05–1.18). We found a curve linear association between an increasing number of pack-years (packages/day × smoking years) and risk of NIHL. The dose-response meta-analysis suggested that when the number of pack-years was less than fifteen, the risk of NIHL was increasing, and the highest combined OR was 5.25 (95% CI: 2.30–11.96) for pack-years of fifteen. After fifteen pack-years, the pooled OR had a slow decline. Our study indicated that smoking is a risk factor for NIHL. Current smokers have a higher risk than former smokers, and there is a positive dose-response relationship between smoking and NIHL.

Prevalence hearing loss of truck and bus drivers in a cross-sectional study of 65533 subjects

Background

Noise pollution is one of the most important occupational pollutants in heavy-vehicle drivers. Therefore, this epidemiological research was conducted with the aim of determining the prevalence of hearing loss in heavy-vehicle drivers in Iran.

Methods

This cross-sectional research was conducted on 65,533 heavy-vehicle drivers including truck and intercity bus drivers from February 2006 to March 2016. The air and bone threshold of pure tone was measured for each ear at 0.5, 1, 2, 3, 4, 6, and 8 kHz by a skillful radiology expert. The obtained data from this research was analyzed in SPSS software using statistical tests such as descriptive analysis and paired t test.

Results

Mean (standard deviation) of hearing loss in left and right ears of all people was 23.02 (8.25) and 22.48 (7.86), respectively. Paired t test showed that hearing loss difference in left and right ears was significant (P < 0.001). Mean and standard deviation of paired t test showed that hearing loss difference in left and right ears was significant in all frequencies except 1000 Hz (P < 0.001).

Conclusion

The findings of this research generally showed that 26.8% of the studied drivers have hearing loss. Hearing loss in the left ear was more than right ear.

Association of Behavior With Noise-Induced Hearing Loss Among Attendees of an Outdoor Music Festival: A Secondary Analysis of a Randomized Clinical Trial

Importance

To date, factors associated with noise-induced hearing loss at music festivals have not yet been analyzed in a single comprehensive data set. In addition, little is known about the hearing loss-associated behavior of music festival attendees.

Objectives

To assess which factors are associated with the occurrence of a temporary threshold shift (TTS) after music exposure and to investigate the behavior of music festival attendees.

Design, Setting, and Participants

This prospective post hoc analysis gathered data from a randomized, single-blind clinical trial conducted on September 5, 2015, at an outdoor music festival in Amsterdam, the Netherlands. Adult volunteers with normal hearing were recruited via social media from August 26 through September 3, 2015. Intention to use earplugs was an exclusion criterion. Of 86 volunteers assessed, 51 were included. This post hoc analysis was performed from October 3, 2016, through February 27, 2017.

Interventions

Music festival visit for 4.5 hours.

Main Outcomes and Measures

The primary outcome was a TTS on a standard audiogram for the frequencies 3.0- and 4.0-kHz. Multivariable linear regression was performed to determine which factors are associated with a TTS. A questionnaire on behavior, hearing, and tinnitus was distributed to the participants before and after the festival visit.

Results

A total of 51 participants were included (18 men [35%] and 33 women [65%]) with a mean (SD) age of 27 (6) years. Mean (SD) threshold change across 3.0 and 4.0 kHz was 5.4 (5.7) dB for the right ear and 4.0 (6.1) dB for the left ear. Earplug use (absolute difference in the left ear, -6.0 dB [95% CI, -8.7 to -3.2 dB]; in the right ear, -6.4 dB [95% CI, -8.8 to -4.1 dB]), quantity of alcohol use (absolute difference per unit in the left ear, 1.1 dB [95% CI, 0.5 to 1.7 dB]; in the right ear, 0.7 dB [95% CI, 0.1 to 1.4 dB]), drug use (absolute difference in the right ear, 6.0 dB [95% CI, 0.9 to 11.1 dB]), and male sex (absolute difference in the right ear, 4.1 dB [95% CI, 0.3 to 5.9 dB]) were independently associated with hearing loss, with earplug use being the most important factor. Unprotected participants reported significantly worse subjective hearing performance and tinnitus after the festival visit than did participants using earplugs (Cramer V, 0.62 [95% CI, 0.47-0.79] and 0.39 [95% CI, 0.16-0.62], respectively). In the earplug group, the perceived loudness (r = -0.72; 95% CI, -1.00 to -0.43) and appreciation (r = 0.53; 95% CI, 0.29 to 0.78) of music and speech perception (r = 0.21; 95% CI, 0.09 to 0.35) were correlated with the duration of earplug use.

Conclusions and Relevance

The present study identified nonuse of earplugs, use of alcohol and drugs, and male sex as associated with a TTS at an outdoor music festival. Physicians should consider these factors to raise awareness about the combined risk of attending music festivals without using earplugs while consuming alcohol and/or drugs. The intention to use earplugs was correlated with the loudness and appreciation of music with earplugs, which may advocate for the use of personalized earplugs.

Trial Registration

trialregister.nl Identifier: NTR5401.

The effect of simultaneous exposure to cigarette smoke and noise on distortion product otoacoustic emissions in rats

Cigarette smoking is a possible risk factor for hearing loss. However, the impact of simultaneous exposure to noise and smoke on hearing has remained controversial. This study investigated the combined effect of exposure to cigarette smoking and noise on hearing loss. Three groups of male Wistar rats (275 ± 25 g) were subjected to white noise (102 ± 0.5 dB), cigarette smoking (20 cigarettes), and both cigarette smoking and noise for 8 h and 10 days inside the exposure chamber. The control group was exposed to neither noise nor smoke. Distortion product otoacoustic emissions (DPOAE) were measured before any intervention, and it was repeated 1, 7, and 21 days after the last exposure. One-day postexposure to noise, cigarette smoking, and both cigarette smoking and noise, the mean of DPOAE amplitudes decreased significantly ( p < 0.05) between, respectively, 5.7-30.7, 1.5-7.5, and 5.2-32.6 dB within the frequency range of 4620-9960. Temporal DPOAE change in rats exposed to noise or both cigarette smoking and noise was not significantly different ( p > 0.05). DPOAE amplitudes returned to the baseline values in the group subjected to smoking 21 days postexposure. The most permanent change was observed in rats exposed to both cigarette smoking and noise. Accordingly, simultaneous subacute exposure to noise and cigarette smoking increases the effect of noise on permanent hearing loss. Therefore, smoking workers exposed to noise might be at a greater risk of developing hearing loss, and it is recommended that authorities in charge take note of this evidence.

The combined effect of cigarette smoking and occupational noise exposure on hearing loss: evidence from the Dongfeng-Tongji Cohort Study

Combined effect of cigarette smoking and occupational noise exposure on hearing loss has rarely been evaluated among Chinese population, especially among females. This cross-sectional study was conducted in 11196 participants of Dongfeng-Tongji cohort study. Smoking status was self-reported through questionnaire and occupational noise exposure was evaluated through workplace noise level and/or the job titles. Hearing loss was defined as a pure-tone mean of 25 dB or higher at 0.5, 1, 2, and 4 kHz in both ears. Compared with participants without occupational noise exposure, the risk of hearing loss was significantly higher for noise exposure duration ≥20 (OR = 1.45, 95%CI = 1.28–1.65). The association was particularly evident among individuals who were males (OR = 1.74, 95%CI = 1.45–2.08) and aged ≥ 70 (OR = 1.74, 95%CI = 1.30–2.33). Similarly, the risks increased with the increasing of pack-years in males and all age groups except for those aged <60. As to the combined effect, the hearing loss risk was highest for noise exposure duration ≥20 and pack-years ≥25 (OR = 2.41, 95%CI = 1.78–3.28), especially among males (OR = 2.42, 95%CI = 1.74–3.37) and those aged ≥70 (OR = 2.76, 95%CI = 1.36–5.60). Smoking may be an independent risk factor for hearing loss. And it may synergistically affect hearing when combined with occupational noise exposure, especially among males and older participants.

Sex-Related Cochlear Impairment in Cigarette Smokers

Background

A number of studies have documented the influence of cigarette smoking on hearing. However, the association between sex and hearing impairment in smokers as measured by otoacoustic emissions (OAEs) has not been clearly established. The aim of this study was to analyze sex-specific effects of smoking on hearing via conventional and ultra-high-frequency pure tone audiometry (PTA), and OAEs, specifically spontaneous OAEs, click-evoked OAEs, and distortion-product OAEs.

Material/Methods

The study included 84 healthy volunteers aged 25–45 years (mean 34), among them 46 women (25 non-smokers and 21 smokers) and 38 men (16 non-smokers and 22 smokers). The protocol of the study included otoscopic examination, tympanometry, low-, moderate-, and ultra-high-frequency PTA, evaluation of spontaneous click-evoked (CEAOEs) and distortion-product otoacoustic emissions (DPOAEs), assessment of the DP-grams for 2f₁-f₂ (f₁ from 977 to5 164 Hz), and input/output function at L₂ primary tone level of 40–70 dB SPL.

Results

Smokers and non-smokers did not differ significantly in terms of their hearing thresholds assessed with tone audiometry. Male smokers presented with significantly lower levels of CEAOEs and DPOAEs than both male non-smokers and female smokers.

Conclusions

Smoking does not modulate a hearing threshold determined with PTA at low, moderate, and ultra-high frequencies, but causes a significant decrease in OAE levels. This effect was observed only in males, which implies that they are more susceptible to smoking-induced hearing impairment. Sex-specific differences in otoacoustic emissions level may reflect influences of genetic, hormonal, behavioral, and/or environmental factors.

Association between metabolic syndrome and sensorineural hearing loss: a cross-sectional study of 11,114 participants

BACKGROUND/OBJECTIVES

Hearing loss (HL) is associated with certain diseases and affects health, resulting in a low quality of life. Some components of the metabolic syndrome (MetS) coincide with the risk factors for sensorineural hearing loss (SNHL). To date, very few studies have examined the link between MetS and HL. The aim of the current study was to try to understand the potential association between MetS and HL.

METHODS

Using Iranian health surveys of professional drivers, we enrolled 11,114 individuals aged 20-60 years, whose main job is to operate a motor vehicle. We examined participants for the presence and absence of SNHL and the components of the MetS. Additionally, we investigated the relationship between MetS and the pure tone air conduction hearing thresholds of participants with SNHL, including low-frequency and high-frequency thresholds.

RESULTS

This cross-sectional study consisted of 11,114 participants: 3202 (28.81%) diagnosed with MetS and 7911 (71.18%) without and 2772 (24.94%) with SNHL and 8432 (75.86%) without. Participants with SNHL had a higher number of components of MetS (P<0.001 for all components).

CONCLUSION

Our results demonstrated that an association possibly exists between different components of MetS (obesity, hypertension, hypertriglyceridemia, high fasting glucose levels, and waist circumference) and SNHL in a population of West Azerbaijan drivers. Therefore, it is important to schedule periodic checkups for drivers to detect and avoid the increase in MetS components at an early stage in this population.

The Effects of Earphone Use and Environmental Lead Exposure on Hearing Loss in the Korean Population: Data Analysis of the Korea National Health and Nutrition Examination Survey (KNHANES), 2010-2013

BACKGROUND

Although previous studies have reported that frequent earphone use and lead exposure are risk factors for hearing loss, most of these studies were limited to small populations or animal experiments. Several studies that presented the joint effect of combined exposure of noise and heavy metal on hearing loss were also mainly conducted on occupational workers exposed to high concentration.

OBJECTIVES

We investigated both the individual and joint effects of earphone use and environmental lead exposure on hearing loss in the Korean general population.

METHODS

We analyzed data from 7,596 Koreans provided by the Korea National Health and Nutrition Examination Survey (KNHANES) during the period 2010-2013. The pure-tone average (PTA) of hearing thresholds at 2, 3, and 4 kHz frequencies was computed, and hearing loss was defined as a PTA ≥ 25 dB in one or both ears.

RESULTS

A dose-response relationship in hearing loss with earphone use time and blood lead level is observed after adjustment for confounding factors. With a 1-hour increase in earphone use time and 1 μg/dL increase in blood lead concentration, the odds of hearing loss increased by 1.19 and 1.43 times, respectively. For hearing loss, the additive and multiplicative effect of earphone use and blood lead level were not statistically significant.

CONCLUSIONS

Earphone use and environmental lead exposure have an individual effect on hearing loss in the general population. However, the estimated joint effect of earphone use and lead exposure was not statistically significant.

Hearing impairment and contributing factors among fertilizer factory workers

Introduction:

Hearing impairment remains the main occupational health problem in the manufacturing industry, and its contributing factors have not been well controlled.

Methods:

Unmatched case control and comparative studies were carried out among fertilizer factory workers in Sarawak with the aim of determining contributing factors for hearing impairment. Respondents consisted of 49 cases that were diagnosed from 2005 to 2008 with 98 controls from the same work places. Chi-square test and Mann-Whitney test were used in a univariate analysis to determine the association between hearing impairment and the contributing risks being studied.

Results:

The results of the univariate analysis showed that hearing impairment was significantly (p<0.05) associated with older age, lower education level, high smoking dose, high occupational daily noise dose, longer duration of service, infrequent used of hearing protection device (HPD), and low perception of sound on HPD usage. Multivariate logistic regression of hearing impairment after controlling for age found the following five variables: occupational daily noise dose ≥50% (OR 3.48, 95% CI 1.36-8.89), ≥15 years of services (OR 2.92, 95% CI 1.16-7.33), infrequent use of HPD (OR 2.79, 95% CI 1.15-6.77), low perception of sound on HPD (POR 2.77, 95% CI 1.09-6.97), and smoking more than 20 packs per year (OR 4.71, 95% CI 1.13-19.68).

Discussion:

In conclusion, high occupational noise exposure level, longer duration of service, low perception of sound on HPD, infrequent used of HPD, and smoking more than 20 packs per year were the contributing factors to hearing impairment, and appropriate intervention measures should be proposed and taken into considerations.

Empirical estimation of the grades of hearing impairment among industrial workers based on new artificial neural networks and classical regression methods

Background:

Prediction models are used in a variety of medical domains, and they are frequently built from experience which constitutes data acquired from actual cases. This study aimed to analyze the potential of artificial neural networks and logistic regression techniques for estimation of hearing impairment among industrial workers.

Materials and Methods:

A total of 210 workers employed in a steel factory (in West of Iran) were selected, and their occupational exposure histories were analyzed. The hearing loss thresholds of the studied workers were determined using a calibrated audiometer. The personal noise exposures were also measured using a noise dosimeter in the workstations. Data obtained from five variables, which can influence the hearing loss, were used as input features, and the hearing loss thresholds were considered as target feature of the prediction methods. Multilayer feedforward neural networks and logistic regression were developed using MATLAB R2011a software.

Results:

Based on the World Health Organization classification for the grades of hearing loss, 74.2% of the studied workers have normal hearing thresholds, 23.4% have slight hearing loss, and 2.4% have moderate hearing loss. The accuracy and kappa coefficient of the best developed neural networks for prediction of the grades of hearing loss were 88.6 and 66.30, respectively. The accuracy and kappa coefficient of the logistic regression were also 84.28 and 51.30, respectively.

Conclusion:

Neural networks could provide more accurate predictions of the hearing loss than logistic regression. The prediction method can provide reliable and comprehensible information for occupational health and medicine experts.

Determining the effect of worker exposure conditions on the risk of hearing loss in noisy industrial workroom using Cox proportional hazard model

In noisy workrooms, exposure conditions such as noise level, exposure duration and use of hearing protection devices are contributory factors to hearing loss. The aim of this study was to determine the effect of exposure conditions on the risk of hearing loss using the Cox model. Seventy workers, employed in a press workshop, were selected to study their hearing threshold using an audiometric test. Their noise exposure histories also were analyzed. The results of the Cox model showed that the job type, smoking and the use of protection devices were effective to induce hearing loss. The relative risk of hearing loss in smokers was 1.1 times of non-smokers The relative risk of hearing loss in workers with the intermittent use of protection devices was 3.3 times those who used these devices continuously. The Cox model could analyze the effect of exposure conditions on hearing loss and provides useful information for managers in order to improve hearing conservation programs.

Analysis of Predisposing Factors for Hearing Loss in Adults

We aimed to estimate the effects of various risk factors on hearing level in Korean adults, using data from the Korea National Health and Nutrition Examination Survey. We examined data from 13,369 participants collected between 2009 and 2011. Average hearing thresholds at low (0.5, 1, and 2 kHz) and high frequencies (3, 4, and 6 kHz), were investigated in accordance with various known risk factors via multiple regression analysis featuring complex sampling. We additionally evaluated data from 4,810 participants who completed a questionnaire concerned with different types of noise exposure. Low body mass index, absence of hyperlipidemia, history of diabetes mellitus, low incomes, low educational status, and smoking were associated with elevated low frequency hearing thresholds. In addition, male sex, low body mass index, absence of hyperlipidemia, low income, low educational status, smoking, and heavy alcohol consumption were associated with elevated high frequency hearing thresholds. Participants with a history of earphone use in noisy circumstances demonstrated hearing thresholds which were 1.024 dB (95% CI: 0.176 to 1.871; P = 0.018) higher, at low-frequencies, compared to participants without a history of earphone use. Our study suggests that low BMI, absence of hyperlipidemia, low household income, and low educational status are related with hearing loss in Korean adults. Male sex, smoking, and heavy alcohol use are related with high frequency hearing loss. A history of earphone use in noisy circumstances is also related with hearing loss.

Analysis of the prevalence and associated risk factors of tinnitus in adults

Background

Tinnitus is a common condition in adults; however, the pathophysiology of tinnitus remains unclear, and no large population-based study has assessed the associated risk factors. The aim of this study was to analyze the prevalence and associated risk factors of tinnitus.

Methods

We conducted a cross-sectional study using data from the Korea National Health and Nutrition Examination Survey, with 19,290 participants ranging in age from 20 to 98 years old, between 2009 and 2012. We investigated the prevalence of tinnitus using a questionnaire and analyzed various possible factors associated with tinnitus using simple and multiple logistic regression analysis with complex sampling.

Results

The prevalence of tinnitus was 20.7%, and the rates of tinnitus associated with no discomfort, moderate annoyance, and severe annoyance were 69.2%, 27.9%, and 3.0%, respectively. The prevalence of tinnitus and the rates of annoying tinnitus increased with age. The adjusted odds ratio (AOR) of tinnitus was higher for females, those with a smoking history, those reporting less sleep (≤ 6 h), those with more stress, those in smaller households, those with a history of hyperlipidemia osteoarthritis, rheumatoid arthritis, asthma, depression, thyroid disease, an abnormal tympanic membrane, unilateral hearing loss, bilateral hearing loss, noise exposure from earphones, noise exposure at the workplace, noise exposure outside the workplace, and brief noise exposure. Additionally, unemployed individuals and soldiers had higher AORs for tinnitus. The AOR of annoying tinnitus increased with age, stress, history of hyperlipidemia, unilateral hearing loss, and bilateral hearing loss.

Conclusions

Tinnitus is very common in the general population and is associated with gender, smoking, stress, sleep, hearing loss, hyperlipidemia, osteoarthritis, rheumatoid arthritis, asthma, depression, and thyroid disease history.

Cigarette smoking causes hearing impairment among Bangladeshi population

Lifestyle including smoking, noise exposure with MP3 player and drinking alcohol are considered as risk factors for affecting hearing synergistically. However, little is known about the association of cigarette smoking with hearing impairment among subjects who carry a lifestyle without using MP3 player and drinking alcohol. We showed here the influence of smoking on hearing among Bangladeshi subjects who maintain a lifestyle devoid of using MP3 player and drinking alcohol. A total of 184 subjects (smokers: 90; non-smokers: 94) were included considering their duration and frequency of smoking for conducting this study. The mean hearing thresholds of non-smoker subjects at 1, 4, 8 and 12 kHz frequencies were 5.63 ± 2.10, 8.56±5.75, 21.06 ± 11.06, 40.79 ± 20.36 decibel (dB), respectively and that of the smokers were 7 ± 3.8, 13.27 ± 8.4, 30.66 ± 12.50 and 56.88 ± 21.58 dB, respectively. The hearing thresholds of the smokers at 4, 8 and 12 kHz frequencies were significantly (p<0.05) higher than those of the non-smokers, while no significant differences were observed at 1 kHz frequency. We also observed no significant difference in auditory thresholds among smoker subgroups based on smoking frequency. In contrast, subjects smoked for longer duration (>5 years) showed higher level of auditory threshold (62.16 ± 19.87 dB) at 12 kHz frequency compared with that (41.52 ± 19.21 dB) of the subjects smoked for 1-5 years and the difference in auditory thresholds was statistically significant (p<0.0002). In this study, the Brinkman Index (BI) of smokers was from 6 to 440 and the adjusted odds ratio showed a positive correlation between hearing loss and smoking when adjusted for age and body mass index (BMI). In addition, age, but not BMI, also played positive role on hearing impairment at all frequencies. Thus, these findings suggested that cigarette smoking affects hearing level at all the frequencies tested but most significantly at extra higher frequencies.

Concurrent effect of noise exposure and smoking on extended high-frequency pure-tone thresholds

OBJECTIVE

Concurrent effect of noise and smoking on hearing loss is a recent concern. In this study, the concurrent effect of noise and smoking on hearing loss in conventional frequencies and frequencies higher than 8 kHz was assessed.

DESIGN

This was a cross-sectional study on workers exposed to noise who were divided into two groups: smokers and non-smokers. Hearing thresholds were assessed by conventional audiometry, and HFA. Data were analysed using non-parametric tests and Student's t-test.

STUDY SAMPLE

There were 212 workers.

RESULTS

Ninety-seven subjects were smokers and 115 individuals were non-smokers. All subjects were exposed to 92.1 ± 2.4 dBA (Leq8h). The highest threshold in conventional and high-frequency audiometry was observed at 6 kHz and 16 kHz, respectively. Hearing threshold at frequencies above 1 kHz was significantly higher in the smokers than non-smokers. There was no correlation between hearing thresholds and pack-years of smoking.

CONCLUSIONS

Concurrent exposure to noise and smoking may be associated with more hearing loss than exposure to noise alone in the conventional and high frequencies. However, other differences between smokers and non-smokers may explain these differences as well.

Prediction of hearing loss among the noise-exposed workers in a steel factory using artificial intelligence approach

PURPOSE

Prediction of hearing loss in noisy workplaces is considered to be an important aspect of hearing conservation program. Artificial intelligence, as a new approach, can be used to predict the complex phenomenon such as hearing loss. Using artificial neural networks, this study aims to present an empirical model for the prediction of the hearing loss threshold among noise-exposed workers.

METHODS

Two hundred and ten workers employed in a steel factory were chosen, and their occupational exposure histories were collected. To determine the hearing loss threshold, the audiometric test was carried out using a calibrated audiometer. The personal noise exposure was also measured using a noise dosimeter in the workstations of workers. Finally, data obtained five variables, which can influence the hearing loss, were used for the development of the prediction model. Multilayer feed-forward neural networks with different structures were developed using MATLAB software. Neural network structures had one hidden layer with the number of neurons being approximately between 5 and 15 neurons.

RESULTS

The best developed neural networks with one hidden layer and ten neurons could accurately predict the hearing loss threshold with RMSE = 2.6 dB and R(2) = 0.89. The results also confirmed that neural networks could provide more accurate predictions than multiple regressions.

CONCLUSIONS

Since occupational hearing loss is frequently non-curable, results of accurate prediction can be used by occupational health experts to modify and improve noise exposure conditions.

Noise-induced hearing loss in small-scale metal industry in Nepal

Background:

There has been no previous research to demonstrate the risk of noise-induced hearing loss in industry in Nepal. Limited research on occupational noise-induced hearing loss has been conducted within small-scale industry worldwide, despite it being a substantial and growing cause of deafness in the developing world.

Method:

The study involved a cross-sectional audiometric assessment, with questionnaire-based examinations of noise and occupational history, and workplace noise level assessment.

Results:

A total of 115 metal workers and 123 hotel workers (control subjects) were recruited. Noise-induced hearing loss prevalence was 30.4 per cent in metal workers and 4.1 per cent in hotel workers, with a significant odds ratio of 10.3. Except for age and time in occupation, none of the demographic factors were significant in predicting outcomes in regression analyses. When adjusted for this finding, and previous noise-exposed occupations, the odds ratio was 13.8. Workplace noise was significantly different between the groups, ranging from 65.3 to 84.7 dBA in metal worker sites, and from 51.4 to 68.6 dBA in the control sites.

Conclusion:

Metal workers appear to have a greater risk of noise-induced hearing loss than controls. Additional research on occupational noise-induced hearing loss in Nepal and small-scale industry globally is needed.

Cardiovascular risk factors as causes for hearing impairment

The purpose of this paper is to provide a contemporary review of the correlation between cardiovascular risk factors (CVRFs) and hearing impairment (HI) . We conducted a comprehensive review of the literature in order to assess the effects of the different CVRFs on HI. We focused on the pathological findings in the inner ear and their correlation with cochlear function in population-based studies. We found that CVRFs adversely affect hearing acuity. HI diagnosis should be accompanied by detecting and treating CVRFs, according to the presented outline, which may augment hearing rehabilitation and improve the general health and the well-being of the patient. © 2014 S. Karger AG, Basel.

Cigarette smoking, passive smoking, alcohol consumption, and hearing loss

The objective of this large population-based cross-sectional study was to evaluate the association between smoking, passive smoking, alcohol consumption, and hearing loss. The study sample was a subset of the UK Biobank Resource, 164,770 adults aged between 40 and 69 years who completed a speech-in-noise hearing test (the Digit Triplet Test). Hearing loss was defined as speech recognition in noise in the better ear poorer than 2 standard deviations below the mean with reference to young normally hearing listeners. In multiple logistic regression controlling for potential confounders, current smokers were more likely to have a hearing loss than non-smokers (odds ratio (OR) 1.15, 95 % confidence interval (CI) 1.09-1.21). Among non-smokers, those who reported passive exposure to tobacco smoke were more likely to have a hearing loss (OR 1.28, 95 %CI 1.21-1.35). For both smoking and passive smoking, there was evidence of a dose-response effect. Those who consume alcohol were less likely to have a hearing loss than lifetime teetotalers. The association was similar across three levels of consumption by volume of alcohol (lightest 25 %, OR 0.61, 95 %CI 0.57-0.65; middle 50 % OR 0.62, 95 %CI 0.58-0.66; heaviest 25 % OR 0.65, 95 %CI 0.61-0.70). The results suggest that lifestyle factors may moderate the risk of hearing loss. Alcohol consumption was associated with a protective effect. Quitting or reducing smoking and avoiding passive exposure to tobacco smoke may also help prevent or moderate age-related hearing loss.

Interaction between noise and cigarette smoking for the outcome of hearing loss among women: a population-based study

BACKGROUND

We investigated the interaction between exposure to noise and smoking in relation to prevalence of hearing loss among women.

METHODS

A sample of women aged 20-49 years (n = 1,723) from a population-based cross-sectional study carried out in Brazil in 2006 was examined. Hearing loss was assessed using a yes-no validated question. Biological interaction was analyzed using the additive scale and measured with interaction contrast ratio (ICR) and assessment of dose-response relationship.

RESULTS

The combined effect of exposure to noise and cigarette smoking on hearing loss (adjusted prevalence ratio (PRadj) = 3.94, 95% confidence interval (CI): 2.81, 5.52) was greater than expected based on the additive single effects of smoking (PRadj = 1.39, 95% CI: 1.07, 1.81) and noise (PRadj = 2.66, 95% CI: 1.86, 3.82). ICR estimates were not statistically significant. The prevalence of hearing loss among noise-exposed women increased with duration of smoking (P trend = 0.026), number of cigarettes smoked per day (P trend = 0.034), cumulative tobacco use (P trend = 0.030), and early age at smoking initiation (P trend = 0.047).

CONCLUSIONS

Noise and smoking may have a combined effect on hearing loss but further studies are still needed. A dose-response relation of smoking for the noise effect among women is suggested.

Relationship of cigarette smoking and hearing loss in workers exposed to occupational noise

Objectives

To investigate the effects of smoking on hearing loss among workers exposed to occupational noise.

Methods

From the results of a special workers health examination performed in 2011, we enrolled 8,543 subjects exposed to occupational noise and reviewed the findings. Using self-reported questionnaires and health examination results, we collected data on age, smoking status, disease status, height, weight, and biochemistry and pure tone audiometry findings. We divided the workers into 3 groups according to smoking status (non-smoker, ex-smoker, current smoker). Current smokers (n = 3,593) were divided into 4 groups according to smoking amount (0.05–9.9, 10–19.9, 20–29.9, ≥30 pack-years). We analyzed the data to compare hearing thresholds between smoking statuses using analysis of covariance (ANCOVA) after controlling for confounder effects.

Results

According to ANCOVA, the hearing thresholds of current smokers at 2 k, 3 k, and 4 kHz were significantly higher than that of the other groups. Multiple logistic regression for smoking status (reference: non-smokers) showed that the adjusted odds ratios of current smokers were 1.291 (95% confidence interval [CI]: 1.055–1.580), 1.180 (95% CI: 1.007–1.383), 1.295 (95% CI: 1.125–1.491), and 1.321 (95% CI: 1.157–1.507) at 1 k, 2 k, 3 k, and 4 kHz, respectively. Based on smoking amount, the adjusted odds ratios were 1.562 (95% CI: 1.013–2.408) and 1.643 (95% CI: 1.023–2.640) for the 10–19.9 and ≥30 pack-years group, respectively, at 1 kHz (reference: 0.05–9.9 pack-years). At 2 kHz, the adjusted odds ratios were increased statistically significantly with smoking amount for all groups. At all frequencies tested, the hearing thresholds of noise-exposed workers were significantly influenced by current smoking, in particular, the increase of hearing loss at low frequencies according to smoking amount was more prevalent.

Conclusions

Current smoking significantly influenced hearing loss at all frequencies in workers exposed to occupational noise, and heavier smoking influenced low-frequency hearing loss more greatly. There was a dose–response relationship between smoking amount and low-frequency hearing thresholds; however, this was not observed for high-frequency hearing thresholds. Therefore, well-designed prospective studies are needed to clarify the effects of smoking on the degree of hearing loss.

Effects of cigarette smoking on hearing recovery from noise-induced temporary hearing threshold shifts in mice

HYPOTHESIS

Cigarette smoking may potentiate noise-induced hearing loss.

BACKGROUND

Many epidemiological studies have shown that cigarette smoking is a major risk factor for noise-induced hearing loss.

METHODS

BALB/c mice were exposed to passive smoking for 2 h/d for 2 weeks before exposure to 110-dB sound pressure level white noise for 3 hours once. Hearing was assessed via the auditory brainstem response with tone-burst stimulation and distortion product otoacoustic emissions before and at 1, 3, 5, 7, 14, 21, and 28 days after noise exposure. Oxidative stress and hypoxia were assessed by immunostaining with 8-oxoG and hypoxia-inducible factor 1α, respectively.

RESULTS

Control mice unexposed to both smoking and noise and mice exposed to smoking only showed no shift in hearing threshold. In contrast, mice exposed to noise only or smoking plus noise showed abrupt increases in hearing threshold. In mice exposed to noise only, hearing threshold returned to prenoise levels after 2 weeks. However, in mice exposed to smoking plus noise, the loss of hearing was significantly higher, and hearing threshold did not return to the pre-exposure levels until 4 weeks later. Positive staining with 8-oxoG and hypoxia-inducible factor 1α were observed in the inner ear of the smoking-only and smoking-plus-noise group similar to noise-only mice, whereas no positive staining was observed in control group.

CONCLUSION

These results indicate that cigarette smoking may potentiate the harmful effects of noise on hearing and disturb the recovery mechanism in the cochlea.

Interaction of occupational and personal risk factors in workforce health and safety

Most diseases, injuries, and other health conditions experienced by working people are multifactorial, especially as the workforce ages. Evidence supporting the role of work and personal risk factors in the health of working people is frequently underused in developing interventions. Achieving a longer, healthy working life requires a comprehensive preventive approach. To help develop such an approach, we evaluated the influence of both occupational and personal risk factors on workforce health. We present 32 examples illustrating 4 combinatorial models of occupational hazards and personal risk factors (genetics, age, gender, chronic disease, obesity, smoking, alcohol use, prescription drug use). Models that address occupational and personal risk factors and their interactions can improve our understanding of health hazards and guide research and interventions.

Effects of gene-environmental interaction on noise-induced hearing threshold levels for high frequencies (HTLHF)

In this study we assessed the interaction between glutathione S-transferase (GST) genetic polymorphisms and noise exposures, with regard to their effect on the hearing threshold levels for high frequencies (HTLHF). Research participants comprised 347 male workers, and each participant's cumulative noise exposure was determined using a job-exposure matrix. Approximately 64.6% of the participants' exposure in L(eq-8 h) was above 90 dBA. The mean HTLHF was 32.1 dB. A significant dose-response relationship was found between noise exposure and HTLHF. We further converted the estimated total noise exposure level over each participant's job history to a noise exposure level that corresponded to a 40-year exposure (L(eq-40y)). After we had adjusted the results for age, we found that workers carrying GSTM1 null, GSTT1 null, and GSTP1 Ile(105)/Ile(105) genotypes were susceptible to the HTLHF when their L(eq-40y) were above 90 dBA. Therefore, GST genetic polymorphisms might affect HTLHF only when workers are exposed to high noise levels.

Prevalence of Noise Induced Hearing Loss in Indian Air Force Personnel

BACKGROUND

Noise exposure is an inherent part of duty of the aircrew and maintenance staff in the Indian Air Force (IAF). An audiometric survey of IAF personnel was carried out to analyze the prevalence and severity of noise induced hearing loss (NIHL).

METHODS

An audiometric study of 1000 IAF personnel of various trades, age and exposure groups were carried out at an operational base. Age related correction of 5 dB per decade was applied for personnel above SO years of age. Personal factors like smoking, blood group and use of ear defenders were analysed for their effect on the prevalence of NIHL.

RESULT

The study revealed an overall incidence of NIHL of 22.9 % in the personnel with a higher prevalence among the technical trades (26.18 %) as compared to non technical trades (12.5 %). There was a significant increase in prevalence of hearing loss with duration of exposure with 50.8% of personnel above 30 years of exposure having hearing loss. A higher incidence of hearing loss was observed in personnel of blood group O and smokers whereas use of ear defenders was protective.

CONCLUSION

The study reveals a significantly increased prevalence of NIHL among the technical trades of the IAF personnel. The deleterious effects of smoking and protective effect of regular use of ear defenders are emphasized.

[Occupational noise induced hearing loss acknowledgement: Opinions of a regional occupational disease commission]

CONTEXT

In France, occupational noise-induced hearing loss is compensated by the "Régime Général" of the French Social Security according to the system of the tables of occupational diseases. If administrative and/or exposure criteria are lacking, the regional occupational disease commission (CRRMP) is seized to pronounce an opinion - favourable or not - on the direct link between occupational activity and the deafness.

OBJECTIVE

This study aimed at determining the decisive factors in this opinion.

METHODS

An exhaustive retrospective investigation analysed conclusions of CRRMP of the region Provence-Alpes-Côte d'Azur-Corsica related to the noise-induced hearing loss declarations emitted anonymously between January 1st, 2005 and December 31st, 2007. Favourable and unfavourable opinions were listed then cross-examined against the sociodemographics data of the employees, areas of expertise of the physicians at the origin of the initial medical certificate, grounds for submission to the commission, the occupational physician's opinion on the occupational origin, the results of the engineering consultant's investigation, the audiogram of the first observation of injury and those made in period of noise exposure.

RESULTS

One hundred and twenty conclusions were analyzed. Claimants, typically male, 59-year-old on average, mainly came from the sectors of the metal industry (46.7%), transportation (20.8%) and building and civil engineering works (15.8%). All in all, 57.5% of the declarations were refused. These refusals were mainly connected to an opinion unfavourable, unexploitable or absent in the occupational physician, an overrun of the care period when it lasted 5 years and more and the absence of hearing deficit during the exposure.

PERSPECTIVES

The results of our study lead to recommend the implementation of a certificate of noise exposure and the realization of an audiogram at the end of exposure to reduce the number of badly informed files and bring an answer more adapted to the demands of occupational noise-induced hearing loss acknowledgements.

Observational study of prevalence of long-term Raynaud-like phenomena and neurological side effects in testicular cancer survivors

Background

Sensory neuropathy (paresthesias), tinnitus, hearing impairment, and Raynaud phenomena are side effects of cisplatin-based chemotherapy used to treat testicular cancer patients. We assessed the long-term occurrence of these side effects among testicular cancer survivors according to the treatment they received.

Methods

A total of 1814 men who were treated for unilateral testicular cancer in Norway during 1980–1994 were invited to participate in a national multicenter follow-up survey conducted during 1998–2002. The men were allocated to six groups according to the treatment they had received. Self-reported symptoms were assessed by a mailed questionnaire that included the Scale for Chemotherapy-Induced Neurotoxicity. A total of 1409 participants who responded to the questionnaire and/or underwent audiometry were assessable in this study. Respondents to the questionnaire (n = 1402) scored the relevant symptoms according to how troubled they were by each (not at all, a little, quite a bit, or very much). Hearing impairment was objectively assessed by audiometry at 4000 Hz in 755 men (seven of whom did not respond to the questionnaire). Group comparisons of symptom assessments were performed with χ² or Kruskal–Wallis tests. Associations between relevant factors and self-reported symptoms or hearing impairment measured by audiometry were assessed using proportional odds ordinal logistic regression models and linear regression models, respectively. All statistical tests were two-sided.

Results

The median follow-up for the 1409 assessable men was 10.7 years (range = 4–21 years). All chemotherapy groups had statistically significantly higher odds for increasing severity of all assessed symptoms and inferior audiometric results compared with men who did not receive chemotherapy. Among chemotherapy-treated men, 39% (95% confidence interval [CI] = 35% to 43%) reported Raynaud-like phenomena (defined as white or cold hands or fingers [or feet or toes] on cold exposure), 29% (95% CI = 25% to 33%) reported paresthesias in the hands or feet, 21% (95% CI = 18% to 25%) reported hearing impairment, and 22% (95% CI = 19% to 26%) reported tinnitus as major symptoms troubling them quite a bit or very much. Hearing impairment (odds ratio [OR] = 5.3, 95% CI = 3.0 to 9.2) and tinnitus (OR = 7.1, 95% CI = 4.1 to 12.4) were particularly common in the dose-intensive chemotherapy group compared with the no chemotherapy group. Men who were treated with radiotherapy had higher odds of self-reported paresthesias in feet compared with those not treated with radiotherapy (OR = 1.5, 95% CI = 1.01 to 2.1, P = .04).

Conclusion

Long-term survivors of testicular cancer who were treated with cisplatin-based chemotherapy were more often troubled by dose-dependent neurological side effects and Raynaud-like phenomena compared with those who were not treated with chemotherapy.

Prevalence and risk factors of noise-induced hearing loss among liquefied petroleum gas (LPG) cylinder infusion workers in Taiwan

We assessed the exposure levels of noise, estimated prevalence, and identify risk factors of noise-induced hearing loss (NIHL) among male workers with a cross-sectional study in a liquefied petroleum gas cylinder infusion factory in Taipei City. Male in-field workers exposed to noise and administrative controls were enrolled in 2006 and 2007. Face-to-face interviews were applied for demographics, employment history, and drinking/smoking habit. We then performed the measurements on noise levels in field and administration area, and hearing thresholds on study subjects with standard apparatus and protocols. Existence of hearing loss > 25 dBHL for the average of 500 Hz, 1 kHz, and 2 kHz was accordingly determined for NIHL. The effects from noise exposure, predisposing characteristics, employment-related factors, and personal habits to NIHL were estimated by univariate and multivariate logistic regressions. A total of 75 subjects were involved in research and 56.8% of in-field workers had NIHL. Between the in-field and administration groups, hearing thresholds on the worse ear showed significant differences at frequencies of 4 k, 6 k, and 8 kHz with aging considered. Adjusted odds ratio for field noise exposure (OR=99.57, 95% CI: 3.53, 2,808.74) and frequent tea or coffee consumption (OR=0.03, 95% CI: 0.01, 0.51) were found significant. Current study addressed NIHL in a specific industry in Taiwan. Further efforts in minimizing its impact are still in need.

Cigarette smoking and occupational noise-induced hearing loss

BACKGROUND

Noise is the most common occupational hazard. Noise-induced hearing loss (NIHL) is a known occupational disease. The economic costs of NIHL have been estimated to be billions of dollars. Besides, cigarette smoking is a common habit worldwide.

METHODS

In a cross-sectional study, we surveyed the effect of smoking on NIHL in 504 workers in a large wagon manufacturing company exposed to noise >85 dBA. All required data were obtained using direct interview and questionnaires. To determine noise exposure level, we used industrial hygienist's reports of sound level measurements. A qualified audiologist assessed hearing status using standardized audiometric examination.

RESULTS

We concluded that the frequency of hearing loss in smokers was higher than non-smokers [based on Model 1: odds ratio (OR) = 9.35, 95% confidence interval (CI) = 5.74-15.22 and P-value < 0.001; and based on Model 2: OR = 9.06, 95% CI = 5.93-13.84 and P-value < 0.001]. Besides, these results were confirmed by logistic regression statistical method.

CONCLUSIONS

It can be concluded that smoking may accelerate NIHL, but for confirming this opinion, further studies are warranted.