Effect of workplace noise on hearing ability in tile and ceramic industry workers in Iran: a 2-year follow-up study

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

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

Establishing multifactorial risk factors for adult-onset hearing loss: A systematic review with topic modelling and synthesis of epidemiological evidence

BACKGROUND

This systematic review explores the multifaceted nature of risk factors contributing to adult-onset HL. The objective was to synthesise the most recent epidemiological evidence to generate pooled proportional incidences for the identified risk factors.

METHODS

We conducted an extensive search of electronic databases (MEDLINE, EMBASE, and psychINFO) for studies providing epidemiological evidence of risk factors associated with hearing loss. Topic modelling using Latent Dirichlet Allocation (LDA) was first conducted to determine how many risk factor themes were available from the papers. Data were analysed by calculating the pooled proportional incidence using a meta-analysis of proportions.

RESULTS

From the 72 studies reviewed, six key risk factor themes emerged through LDA topic modelling. The review identified ototoxicity, primarily caused by cancer treatments and antibiotics, infectious diseases like COVID-19, occupational noise exposure, lifestyle factors, health conditions, biological responses, and age progression as significant risk factors for HL. The highest proportional incidence was found with cancer-related ototoxicity at 55.4% (95%CI: 39.0-70.7), followed closely by ototoxicity from infectious diseases at 50.0% (95%CI: 28.5-71.5). This high proportional incidence suggests the need to explore less destructive therapies and proactively monitor hearing function during treatments.

CONCLUSIONS

The findings of this review, combined with the synthesis of epidemiological evidence, enhance our understanding of hearing loss (HL) pathogenesis and highlight potential areas for intervention, thereby paving the way for more effective prevention and management of adult-onset hearing loss in our ageing global population.

Noise-induced Hearing Loss: Continuous versus Impact/impulse Noise

Background

Impact/impulse and continuous noise are two main causes of noise-induced hearing loss (NIHL) in workplaces. The aim of this study was to compare the effects of impulse/impact noise and continuous noise on hearing status.

Methods

In this study, 259 workers referred to the occupational medicine clinic of Shahid Rahnemoun hospital, Yazd, Iran, entered the study and were divided into two groups: with exposure to impact/impulse noise and with exposure to continuous noise. Hearing thresholds were measured and compared between the two groups by pure-tone audiometry (PTA). The frequency of hearing loss and audiometric notch according to the results of PTA was compared between the two groups. Data were analyzed by SPSS (ver. 16) using Student's t-test, Chi-square test, and Mann-Whitney U test.

Results

Hearing thresholds were significantly higher at all frequencies in the impact noise group. The hearing threshold at 6000 Hz was higher than other frequencies in both groups. The frequency of hearing loss at high frequencies was higher in the impact group. The frequency of audiometric notch was not significantly different between the two groups.

Conclusions

The results of this study showed that hearing loss after exposure to impact/impulse noise is probably more frequent and more severe than exposure to continuous noise, but the pattern of hearing loss is similar in both types of noise exposure.

An assessment of noise exposure and hearing health status among auto body workers in Kermanshah, Iran

BACKGROUND

Unwanted sound is recognized as the most extensive source of contaminant in the workplace. Exposure to intense, continuous, and higher than 85 dB level noise can lead to noise-induced hearing loss. The aim of the present study was to determine the level of noise exposure and its impact on hearing health among auto body workers.

MATERIALS AND METHODS

This descriptive-analytic study was conducted in 2020 to investigate the hearing health status of workers in auto body workshops. Sixty-one participants were randomly selected for audiometric testing. The equivalent sound level (Leq) of the workers was measured using a Casella CEL-320 noise dosimeter. Audiometric testing was performed using an AC40 audiometer. The mean hearing threshold levels (HTLs) of both ears were calculated for different frequencies. The results obtained were analyzed using SPSS v21.0 at a significance level of 95%.

RESULTS

The participants had an average age of 35.5 ± 11.8 years and an average work experience of 16.5 ± 9.8 years. The mean Leq was 92.3 ± 4.7 dB. The mean HTLs for the right ear and left ear were 20, 15, 17.6, 19.2 dB, respectively with the right ear suffering more loss. A significant relationship was found between hearing loss in both ears (P < 0.001). The highest prevalence of hearing loss in both ears was observed at a frequency of 4 kHz. About 73.8% of the subjects had a normal HTL, 23.3% had mild hearing loss, and 3.3% had severe hearing loss. With increasing work experience, HTLs also increased significantly, particularly at 2-8 kHz.

CONCLUSIONS

Chronic exposure to noise pollution threatens hearing health. Therefore, it is necessary to raise the level of awareness among workers in order to enable better hearing health protection and also to promote the use of hearing protection devices.

Office Distractions and the Productivity of Building Users: The Effect of Workgroup Sizes and Demographic Characteristics

Knowledge workers are experiencing ever-increasing distractions or unwanted interruptions at workplaces. We explored the effect of unwanted interruptions on an individual’s perceived productivity in various building types, user groups and workgroups. A case study of 68 buildings and their 5149 occupants using the Building Use Studies methodology was employed in this study. The database contains information on the occupants’ perceptions of physical and environmental parameters, including unmined data on the frequency of unwanted interruptions. Pearson’s correlation was used to test the correlation between the variables. In order to determine whether there are any statistically significant differences between the means of two or more independent (unrelated) groups, one-way ANOVA was employed to examine the significance of differences in mean scores between various user groups and workgroups. The evidence of clear correlations between the frequency of unwanted interruptions and perceived productivity is detailed in various user groups and in multiple building types. The Pearson correlation coefficients were −0.361 and −0.348 for sustainable and conventional buildings, respectively, demonstrating a lower sensitivity to unwanted interruptions in sustainable buildings. Females and older participants were more sensitive to unwanted interruptions and their productivity levels were reduced much more by unwanted interruptions. Comparing different sized workgroups, the highest sensitivity to unwanted interruptions for occupants in offices shared with more than 8 people was found. The findings of this study contribute to the understanding of different user needs and preferences in the design of workplaces.

Occupational noise induced hearing loss in the mining sector in South Africa: Perspectives from occupational health practitioners on how mineworkers are trained

Background

Historically, occupational health concerns associated with mining, particularly occupational noise-induced hearing loss (ONIHL), were ignored by the mining sector, policy-makers and academic researchers. As such, there is a dearth of literature related to ONIHL, especially in low- and middle-income countries such as South Africa. Consequently, mineworkers were not aware of the latent effects of excessive exposure to hazardous noise and the resultant hearing loss thereof.

Objectives

The aim of this study was to explore the perspectives of occupational health practitioners (OHPs) regarding education and training of mineworkers on occupational noise-induced hearing loss (ONIHL) and its impact on mineworkers’ health.

Method

Qualitative, in-depth telephonic and face-to-face interviews were conducted with 16 OHPs. Purposive and snowball sampling methods were utilised to recruit participants. Data were analysed using inductive thematic analysis.

Results

Three themes emerged from the data: ‘seeing is believing’, ‘not my department!’ and ‘barriers and facilitators to raising awareness’ with two subthemes: ‘blame it on the language and level of education’ and ‘compensation pay-outs’. Superficially, OHPs believe that mineworkers are aware of the impact of noise on health; however, the OHPs are not aware on how the mineworkers are educated on ONIHL and its latent consequences. Furthermore, language, low levels of education and literacy, as well as financial constraints, are the factors found to affect education and training of the mineworkers about the risks of ONIHL.

Conclusion

If the mining industry is committed in eliminating ONIHL, they should prioritise health literacy, and mines need to have an effective awareness-raising plan in place to eliminate ONIHL from every mine. This plan must consider diversity of workforce, including linguistic, as well as educational level diversity.

Recent advances in hearing conservation programmes: A systematic review

Background

Current evidence from low- and middle-income (LAMI) countries, such as South Africa, indicates that occupational noise-induced hearing loss (ONIHL) continues to be a health and safety challenge for the mining industry. There is also evidence of hearing conservation programmes (HCPs) being implemented with limited success.

Objectives

The aim of this study was to explore and document current evidence reflecting recent advances in HCPs in order to identify gaps within the South African HCPs.

Method

A systematic literature review was conducted in line with the Preferred Reporting Items for Systematic Reviews and Meta-Analysis. Electronic databases including Sage, Science Direct, PubMed, Scopus MEDLINE, ProQuest and Google Scholar were searched for potential studies published in English between 2010 and 2019 reporting on recent advances in HCPs within the mining industry.

Results

The study findings revealed a number of important recent advances internationally, which require deliberation for possible implementation within the South African HCPs context. These advances have been presented under seven themes: (1) the use of metrics, (2) pharmacological interventions and hair cell regeneration, (3) artificial neural network, (4) audiology assessment measures, (5) noise monitoring advances, (6) conceptual approaches to HCPs and (7) buying quiet.

Conclusion

The study findings raise important advances that may have significant implications for HCPs in LAMI countries where ONIHL remains a highly prevalent occupational health challenge. Establishing feasibility and efficacy of these advances in these contexts to ensure contextual relevance and responsiveness is one of the recommendations to facilitate the success of HCPs targets.

South African hearing conservation programmes in the context of tele-audiology: A scoping review

BACKGROUND

The limited involvement of audiologists in occupational noise-induced hearing loss (ONIHL) management through hearing conservation programmes (HCPs) is a global issue. In low- and middle-income (LAMI) countries such as South Africa, this is also exacerbated by demand versus capacity challenges. Tele-audiology is an option requiring serious deliberation by the audiology community within HCPs in LAMI contexts.

OBJECTIVES

This scoping review explores if tele-audiology has a potential value in HCPs and reviews what has been documented in the literature on the use of tele-audiology in HCPs.

METHOD

A scoping review was conducted using the Arksey and O'Malley's framework. A search was conducted in five electronic bibliographic databases including Science Direct, PubMed, Scopus Medline, ProQuest and Google Scholar and the grey literature to identify publications presenting considerations around tele-audiology in the implementation of HCPs.

RESULTS

Findings revealed significant dearth of evidence specific to the use or application of tele-audiology in ONIHL and/or HCPs both within the African context and internationally, despite the purported potential benefit of this service delivery model, particularly in resource-constrained contexts such as LAMI countries. Of the publications deemed potentially relevant to this scoping review, none were found that specifically investigated or addressed the use of tele-audiology in ONIHL or HCPs as their main objective. Nuanced analysis of publications revealed that in the last decade, indication for potential growth in the use of tele-audiology within occupational audiology is indicated.

CONCLUSION

Because of the significant demand versus capacity challenges in LAMI countries, and because of the need for scaling up audiology professionals' management of HCPs, careful consideration of teleaudiology as a platform to deliver services in these contexts is required.

Burden of disease: A scoping review of HIV/AIDS and TB in occupational noise-induced hearing loss

BACKGROUND

Occupational noise-induced hearing loss (ONIHL) does not occur in isolation from other influencing factors such as health conditions and illnesses like human immunodeficiency virus and acquired immunodeficiency syndrome (HIV and AIDS), as well as tuberculosis (TB). How the burden of disease influences the occurrence and/or management of ONIHL becomes a key if the goal of hearing conservation programmes (HCPs) is to be achieved within these contexts.

OBJECTIVES

The purpose of this scoping review was to conduct an investigation on how the burden of disease's influence on ONIHL is reported in literature, with a specific focus on the most prevalent diseases in South African mines - HIV and AIDS and TB.

METHOD

A scoping review was conducted using the Arksey and O'Malley's framework. A search was conducted in five electronic bibliographic databases and the grey literature.

RESULTS

The search procured 10 publications, with two specific to ONIHL within the South African context. In addition to the two publications specific to TB and ONIHL, findings revealed a serious gap in the evidence around the scoping review question globally. This obvious lack of investigations into the influence of these two conditions in the South African mining context raises serious implications about the responsiveness, and proactive nature of HCPs within this population.

CONCLUSION

Considering the burden of diseases on otology and audiology is critical as certain diseases cause hearing impairment either as a primary effect, as a secondary/opportunistic effect or as a side effect of treatment options for that disease. An employee suffering from any such disease with concomitant exposure to hazardous noise levels presents an even bigger challenge to HCPs if such is not taken into consideration in the conception, implementation and monitoring of HCPs.

Risk versus benefit: Should not audiologists assess this in the context of occupational noise-induced hearing loss in the mining industry?

BACKGROUND

Hearing conservation programmes (HCPs) are an important aspect of occupational health efforts to prevent occupational noise-induced hearing loss (ONIHL). In low- and middle income (LAMI) countries, where the incidence of ONIHL is significant, it is important to deliberate on the risk or benefit of HCPs.

OBJECTIVES

This article is an attempt at highlighting important strategic indicators as well as important variables that the occupational health and audiology community need to consider to plan efficacious HCPs within the South African mining context.

METHOD

The current arguments are presented in the form of a viewpoint publication.

RESULTS

Occupational audiology vigilance in the form of engagement with HCPs in the mining industry has been limited within the South African research and clinical communities. When occupational audiology occurs, it is conducted by mid-level workers and paraprofessionals; and it is non-systematic, non-comprehensive and non-strategic. This is compounded by the current, unclear externally enforced accountability by several bodies, including the mining industry regulating body, with silent and/or peripheral regulation by the Health Professions Council of South Africa and the Department of Health. The lack of involvement of audiologists in the risk or benefit evaluation of HCPs during their development and monitoring process, as well as their limited involvement in the development of policies and regulations concerning ear health and safety within this population are probable reasons for this.

CONCLUSIONS

Increased functioning of the regulatory body towards making the employers accountable for the elimination of ONIHL, and a more central and prominent role for audiologists in HCPs, are strongly argued for.

Effect of Combined Exposure to Noise and Vibration on Hearing

Aim:

This study was conducted to examine the effect(s) of combined exposure to whole-body vibration (WBV) and noise in railway workers.

Methods:

In this historical cohort study, train drivers with combined exposure to WBV and impermissible noise as the case group (n = 85) and shunters with just exposure to impermissible noise as the control group (n = 30) were recruited. The hearing threshold at the conventional audiometric frequencies was measured in both the groups, and the standard threshold shift (STS) and hearing threshold shift at higher frequencies were calculated. Data were analyzed by SPSS version 20 using t-test, Chi-square, and paired t-test.

Results:

There was no significant difference between the groups for age of participants as well as work duration and body mass index. Increased hearing threshold was most frequently observed at 3000, 4000, and 6000 Hz. STS and hearing threshold shift at high frequencies were observed at 6.0% and 3.3%, and 8.2% and 26.7% in train drivers and shunters in the left ear, respectively, but these were not statistically significant.

Conclusion:

Despite the unauthorized exposure to noise and WBV of train drivers, the STS and hearing threshold shift at higher frequencies were not more prevalent compared with the shunters who were exposed only to impermissible noise levels; hence, no association was found between noise and vibration in this study.

Unexpected association between subclinical hearing loss and restorative sleep in a middle-aged and elderly Japanese population

OBJECTIVE

Hearing loss may be associated with certain sleep abnormalities. We recently reported that subclinical hearing loss (SHL) was more prevalent in individuals in a broad Japanese population who slept longer than 8 h; however, the underlying mechanism was unknown. Therefore, we investigated the association between SHL and self-reported restorative sleep (RS), assessed by questionnaire, in a database of 33,888 Japanese aged 40-69 years without overt or diagnosed hearing loss (20,225 men, 13,663 women).

RESULTS

The proportion of individuals with RS (more than half of the subjects) was significantly higher in the group with bilateral than with unilateral SHL at 4000 Hz and intact hearing; however, that was not the case at 1000 Hz, independent of age (P < 0.0001, two-way analysis of variance). Multivariate logistic regression analysis showed that bilateral SHL at 4000 Hz, but not at 1000 Hz, was significantly associated with RS. This relationship was independent of potential relevant confounders, including age, sex, and cardiometabolic risk factors. The present study extends our earlier work by revealing an unexpected association between early hearing impairment and satisfactory sleep in a middle-aged and elderly population. This association requires further confirmation regarding the possible underlying mechanism and clinical relevance.

Cochlear Proteins Associated with Noise-induced Hearing Loss: An Update

Noise-induced hearing loss (NIHL) is one of the major occupational disease that has influence on the quality of life of mining workers. Several reports suggest NIHL is attributed to noise exposure at workplace and approximately 16% of hearing loss is due to it. NIHL occurs as a result of exposure to high-level noise (>85 dB) in the workplace. Noise disrupts proteins present in the micromachinery of the ear that is required for mechano-electric transduction of sound waves. High-level noise exposure can lead to hearing impairment owing to mechanical and metabolic exhaustion in cochlea, the major organ responsible for resilience of sound. Several key proteins of cochlea include tectorial membrane, inner hair cells, outer hair cells, and stereocilia are damaged due to high-level noise exposure. Numerous studies conducted in animals have shown cochlear proteins involvement in NIHL, but the pertinent literature remains limited in humans. Detection of proteins and pathways perturbed within the micromachinery of the ear after excessive sound induction leads toward the early identification of hearing loss. The situation insisted to present this review as an update on cochlear proteins associated with NIHL after an extensive literature search using several electronic databases which help to understand the pathophysiology of NIHL.

Task distribution, work environment, and perceived health discomforts among Indian ceramic workers

BACKGROUND

The study examined the work environment of Indian ceramics workers and assessed associations between work hazards, work category, and self-reported symptoms.

METHODS

The multi-method ergonomic review technique (MMERT) checkpoints was used for work analysis and prevalence of self-reported symptoms among 329 male workers.

RESULTS

Ambient temperature and relative humidity in ceramic industries were 39.9°C and 17.4% respectively. Musculoskeletal discomfort was observed as a primary complaint; especially lower extremity pain (45%). Load handlers and machine operators had the highest levels of work hazards, including high skill requirement, strenuous work posture, poor commitment by the organization. Poor job autonomy, task clarity, hot workplace, inappropriate workplace design, inadequate auxiliary support, and mental overload were significantly associated with self-reported symptoms (P < 0.001).

CONCLUSION

Work categories are associated with work hazards and may lead to various health symptoms among ceramic workers. Control of workplace hazards may lower rates of symptoms and thus may lead to improved health, productivity, and well-being. Am. J. Ind. Med. 59:1145-1155, 2016. © 2016 Wiley Periodicals, Inc.

Subclinical hearing loss, longer sleep duration, and cardiometabolic risk factors in Japanese general population

Hearing loss leads to impaired social functioning and quality of life. Hearing loss is also associated with sleeping disorders and cardiometabolic risk factors. Here, we determined whether subclinical hearing loss is associated with sleep duration and cardiometabolic risk factors in a cross-sectional and longitudinal study of healthy Japanese general population. 48,091 men and women aged 20–79 years who underwent medical checkups were included in a cross-sectional study, and 6,674 were included in an 8-year longitudinal study. The prevalence of audiometrically determined hearing loss (>25 dB) at 4000 and 1000 Hz increased significantly with increasing sleep duration in any age strata. Logistic regression analysis showed that compared with reference sleep duration (6 h) longer sleep duration (≥8 h) was significantly associated with hearing loss, even after adjusting for potential confounding factors. Simultaneously, hearing loss was significantly associated with male sex, diabetes, and no habitual exercise. In the longitudinal study, the risk of longer sleep duration (≥8 h) after 8 years was significantly greater in subjects with hearing loss at 4000 Hz at baseline. In conclusion, current results suggest a potential association of subclinical hearing loss with longer sleep duration and cardiometabolic risk factors in a Japanese general population.