scholarly journals Predicting standard threshold shifts for occupational hearing loss among miners at a large-scale platinum mine in South Africa

Author(s):  
L. Ntlhakana ◽  
G. Nelson ◽  
K. Khoza-Shangase ◽  
I. Maposa

Occupational noise-induced hearing loss (ONIHL) is associated with various risk factors in South African mines. We investigated the association between standard threshold shifts (STSs) and exposure to noise and platinum mine dust (PMD), using demographic data, five years of annual audiometry screening results, and noise and dust exposure data. Miners' age, sex, percentage hearing loss (PLH), and dust and noise exposure data were gathered, and a linear mixed effects regression model used to predict STS. Average occupational exposure levels to noise and dust were calculated from recorded measurements. A total of 12 692 records were analysed. Most miners were male (89.6%) and more than 50% were younger than 41 years. More than 70% were exposed to > 85 dBA noise and 58% were exposed to 1.5-2.99 mg/m3 PMD. Changes in hearing levels ranged from 8.3 dBHL at baseline (2014/2015) to 10 dBHL in 2016 (STS), with no changes thereafter. The model showed that the estimated effect on STS for males was 27% and 21% higher than for females, for the left and right ear, respectively The estimated effect of age, PLH, noise exposure and years of exposure on STS was < 10% for each variable. There was no statistically significant association between PMD and STS. The combined effects of age, sex, years of exposure to noise, and noise exposure levels, and strength of associations can be used to predict STS for this group of miners. Our findings may be used to measure the efficacy of the mine's hearing conservation programme.

2007 ◽  
Vol 22 (4) ◽  
pp. 160-165 ◽  
Author(s):  
Vanessa L Miller ◽  
Michael Stewart ◽  
Mark Lehman

Twenty-seven student musicians were surveyed regarding musical practice and playing habits, knowledge of hearing conservation practices, use of hearing protective devices (HPD), and the occurrence of tinnitus after exposure to loud music. In addition, noise exposure levels during practice and sporting events (football and basketball games) at which they played were monitored with a dosimeter simultaneously set to measure noise levels using the OSHA (1983) and NIOSH (1998) measurement criteria. Forty-eight percent of the subjects reported practicing or playing their instrument <10 hours a week. Most musicians (74%) reported having been taught about the effects of noise on hearing and health; however, less than a third used ear protection while playing their instruments, and those who did used it inconsistently. Sixty-three percent of subjects reported experiencing tinnitus after exposure to loud music. Finally, 8-hour time-weighted averages (TWA) and daily noise doses were significantly higher using the NIOSH measurement criteria than the OSHA measurement criteria. Both measurement criteria yielded values that exceeded a 100% daily noise dose for all subjects. Overall, these results indicate that university student directors and musicians appear to be at high risk for permanent noise-induced hearing loss secondary to excessive exposure to loud music. These results support the need for on-going hearing conservation programs to educate student musicians and student directors about the dangers of excessive exposure to loud music.


2020 ◽  
Vol 64 (6) ◽  
pp. 604-613 ◽  
Author(s):  
Zara Ann Stokholm ◽  
Mogens Erlandsen ◽  
Vivi Schlünssen ◽  
Ioannis Basinas ◽  
Jens Peter Bonde ◽  
...  

Abstract Occupational noise exposure is a known risk factor for hearing loss and also adverse cardiovascular effects have been suggested. A job exposure matrix (JEM) would enable studies of noise and health on a large scale. The objective of this study was to create a quantitative JEM for occupational noise exposure assessment of the general working population. Between 2001–2003 and 2009–2010, we recruited workers from companies within the 10 industries with the highest reporting of noise-induced hearing loss according to the Danish Working Environment Authority and in addition workers of financial services and children day care to optimize the range in exposure levels. We obtained 1343 personal occupational noise dosimeter measurements among 1140 workers representing 100 different jobs according to the Danish version of the International Standard Classification of Occupations 1988 (DISCO 88). Four experts used 35 of these jobs as benchmarks and rated noise levels for the remaining 337 jobs within DISCO 88. To estimate noise levels for all 372 jobs, we included expert ratings together with sex, age, occupational class, and calendar year as fixed effects, while job and worker were included as random effects in a linear mixed regression model. The fixed effects explained 40% of the total variance: 72% of the between-jobs variance, −6% of the between-workers variance and 4% of the within-worker variance. Modelled noise levels showed a monotonic increase with increasing expert score and a 20 dB difference between the highest and lowest exposed jobs. Based on the JEM estimates, metal wheel-grinders were among the highest and finance and sales professionals among the lowest exposed. This JEM of occupational noise exposure can be used to prioritize preventive efforts of occupational noise exposure and to provide quantitative estimates of contemporary exposure levels in epidemiological studies of health effects potentially associated with noise exposure.


2015 ◽  
Vol 16 (1) ◽  
pp. 15-24
Author(s):  
Vance Gunnell ◽  
Jeff Larsen

Hearing thresholds and distortion product otoacoustic emissions were measured for teachers of vocal performance who were gathered for a national conference. Results showed mean audiometric thresholds to be consistent with noise induced hearing loss, more than what would be expected with normal aging. Years of instruction and age were considered as factors in the hearing loss observed. It was concluded that hearing conservation should be initiated with this group to help raise awareness and protect them from hearing loss due to occupational noise exposure.


2017 ◽  
Vol 26 (3S) ◽  
pp. 352-368 ◽  
Author(s):  
Vincent Nadon ◽  
Annelies Bockstael ◽  
Dick Botteldooren ◽  
Jérémie Voix

Purpose In spite of all the efforts to implement workplace hearing conservation programs, noise-induced hearing loss remains the leading cause of disability for North American workers. Nonetheless, an individual's susceptibility to noise-induced hearing loss can be estimated by monitoring changes in hearing status in relation to the level of ambient noise exposure. The purpose of this study was to validate an approach that could improve workplace hearing conservation practices. The approach was developed using a portable and robust system designed for noisy environments and consisted of taking continuous measurements with high temporal resolution of the health status of the inner ear using otoacoustic emissions (OAEs). Method A pilot study was conducted in a laboratory, exposing human subjects to industrial noise recordings at realistic levels. In parallel, OAEs were measured periodically using the designed OAE system as well as with a commercially available OAE system, used as a reference. Results Variations in OAE levels were analyzed and discussed along with the limitations of the reference and designed systems. Conclusions This study demonstrates that the monitoring of an individual's OAEs could be useful in monitoring temporary changes in hearing status induced by exposure to ambient noise and could be considered as a new tool for effective hearing conservation programs in the workplace.


2019 ◽  
Vol 76 (Suppl 1) ◽  
pp. A5.3-A6
Author(s):  
Zara Ann Stokholm ◽  
Inge Brosbøl Iversen ◽  
Henrik Kolstad

Current legislation and threshold limits for occupational noise exposure may not sufficiently account for higher vulnerability of the foetus. We conducted a systematic literature review and identified 20 relevant studies of prenatal noise exposure levels and health. Maternal tissues attenuate industrial noise by about 30 dB. The foetus responds the earliest to noise exposure from the 19th week of gestational age. There is some evidence of an increased risk of hearing loss at prenatal noise levels≥85 dBA (8 hour average) and little evidence at lower levels. Increased risks for preterm birth, small-for-gestational-age and congenital malformations are seen as single study findings at levels≥90 dBA. There is little evidence for how noise exposure may increase the risk of extra-auditive effects in the foetus. Methodological shortcomings and the scarce number of studies limit the conclusions that can be drawn. Still, we recommend pregnant women avoid working at noise levels≥85 dBA.


2009 ◽  
Vol 5 (4) ◽  
pp. 565-567 ◽  
Author(s):  
T. Aran Mooney ◽  
Paul E. Nachtigall ◽  
Stephanie Vlachos

There is increasing concern that human-produced ocean noise is adversely affecting marine mammals, as several recent cetacean mass strandings may have been caused by animals' interactions with naval ‘mid-frequency’ sonar. However, it has yet to be empirically demonstrated how sonar could induce these strandings or cause physiological effects. In controlled experimental studies, we show that mid-frequency sonar can induce temporary hearing loss in a bottlenose dolphin ( Tursiops truncatus ). Mild-behavioural alterations were also associated with the exposures. The auditory effects were induced only by repeated exposures to intense sonar pings with total sound exposure levels of 214 dB re: 1 μPa 2  s. Data support an increasing energy model to predict temporary noise-induced hearing loss and indicate that odontocete noise exposure effects bear trends similar to terrestrial mammals. Thus, sonar can induce physiological and behavioural effects in at least one species of odontocete; however, exposures must be of prolonged, high sound exposures levels to generate these effects.


2003 ◽  
Vol 29 (2) ◽  
Author(s):  
R. J. Steenkamp

Noise-induced hearing loss (NIHL) is on the priority list of the World Health Organisation (WHO). Hearing loss due to industrial noise exposure is the most prevalent industrial disease. Noise (above 85 dB) is not only a physical hazard, but also a psychological hazard that may create or exacerbate ergonomic or mechanical hazards. Conventional hearing protection devices (HPDs) are widely applied but also misused in the mining sector. In this investigation ownership and general attitudes were measured by determining how unconventional hearing protectors (custom-made hearing protectors) (CHPDs) is experienced by the mine- workers. The results could indicate whether these protectors, which is perceived by management to be costly, sophisticated and difficult to implement on a large scale, are a viable alternative to conventional hearing protectors. The results indicated certain positive directions in terms of quality hearing conservation and confirmed that CHPDs (with its unique features) do not only protect hearing but has several other occupational benefits. Opsomming Geraasdoofheid is op die prioriteitslys van die Wêreld Gesondheidsorganisasie (WHO). Gehoorverlies wat deur industriële geraasblootstelling veroorsaak word, word as die mees prominente beroepgesondheidsiekte beskou. Geraas (bo 85 dB) is nie net ’n fisiese risiko nie, maar hou ook ook psigologiese gevare in, wat ander meganiese en ergonomiese risiko’s kan veroorsaak of vererger. Konvensionele geraasdempers word op grootskaal in die mynsektor gebruik, maar ook wanaangewend. In hierdie ondersoek is eienaarskap en die algemene gesindhede van gebruikers gemeet deur te bepaal hoe onkonvensionele gehoorbeskermers (doelgemaakte gehoorbeskermers) deur die mynwerkers self ervaar word. Die resultate kan as ‘n aanduiding dien of hierdie beskermers, wat dikwels deur bestuur as duur, gesofistikeerd en moeilik op ‘n grootskaal implementeerbaar is, as ’n lewensvatbare alternatief tot konvensionele gehoorbeskermers oorweeg moet word. Die resultate toon sekere positiewe aspekte ten opsigte van gehalte gehoorkonservering en het bevestig dat doelgemaakte gehoorbeskermers (met hul unieke eienskappe) nie slegs gehoor beskerm nie, maar verskeie ander beroepsverwante voordele inhou.


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