Evaluating hearing loss risks in the mining industry through MSHA citations

Transport and mining machinery cabins' ergonomic evaluation as a path to its redesign

Transport and mining machinery cabins are still not well adapted to their users, while checklists for their evaluation are not common in the literature. This article proposes a new checklist for ergonomic evaluation and tests its universality empirically with a sample of 96 transport and mining machine operators. The objective of the article is two-fold. First, the article checks whether there are anthropometric dimension differences between different machines' operators. Second, statistical significance testing regarding items in the proposed checklist is performed to check its universality. Significant differences have not been found between anthropometric dimensions of transport and mining machine operators. Group comparisons prove that mining machines have better ergonomics characteristics of the chair, manual controls and vision field. The recommendation for crane designers is to examine mining machines solutions and analyze the possibility of adapting these solutions, due to anthropometric fit. Wide usage of the checklist is recommended.

Noise-induced hearing loss and hearing protection: Attitudes at a South African coal mine

BACKGROUND

 Negative attitudes and beliefs are major contributing factors to the rising numbers of noise-induced hearing loss (NIHL) cases in coal mines both locally and internationally. International literature confirms limited knowledge surrounding employees' attitudes and beliefs regarding NIHL and hearing protection devices (HPDs), hence the need for the study.

OBJECTIVES

 To ascertain the attitudes and beliefs about NIHL and HPD use among employees at a large scale underground coal mine in Mpumalanga.

METHOD

 A descriptive and exploratory cross-sectional study was conducted using a self-administered questionnaire, developed by the National Institute for Occupational Safety and Health (NIOSH) on Beliefs about Hearing Protection and Hearing Loss (BHPHL). Participants (n = 241) included employees from a coal mine in Mpumalanga, South Africa.

RESULTS

 Out of 241 completed surveys, this study found that 84% were aware of when to replace earmuffs; 95% believed wearing HPDs could prevent hearing loss in noisy environments; 83% felt their hearing was impacted by loud noise. Additionally, 86% mentioned discomfort from earmuff pressure; 95% emphasised HPD importance; and 95% used HPDs around loud sounds. Moreover, 98% knew how to properly wear earplugs, while lower education levels were linked to higher susceptibility to NIHL.

CONCLUSION

 The study identified positive attitudes towards NIHL and HPD use, but existing NIHL cases must be acknowledged. Organisations can use the findings to develop tailored hearing conservation programmes (HCP), including education, involving employees in protection decisions and promoting diligent HPD usage.Contribution: This study contributes to the limited literature on noise perceptions, NIHL, and HPD use in mining, emphasising the impact attitude has on HPD use and assessing the effect of miners NIHL knowledge on compliance. The findings, unique to coal mining, hold significance for enhancing hearing conservation and reducing NIHL.

Noise exposure assessment of non-coal mining workers in four provinces of China

Objective

This study aimed to understand the noise exposure of non-coal mines in China to take appropriate controls to protect workers' health.

Methods

An assessment of non-coal miners' noise exposures was conducted in four provinces in China. Individual noise exposure levels were measured, and the survey on the hearing protector device (HPD) equipment was administered.

Results

423 noise dosimeter measurements were obtained, including drilling, blasting, ore drawing, transportation, winching, crushing, screening and ball milling, and auxiliary (air pressure, pump, and maintenance). A total of 31.9% of the individual noise levels (L_EX,8h) exceeded 85 dB(A), and the median dosages of non-coal miners with high noise exposure were: excavation workers-89.1 dB(A), mill operators-88.7 dB(A), and crusher operators-87.0 dB(A). The noise dose of underground mine workers is higher than that of surface mine workers (P < 0.001). A total of 53.7% of non-coal mining enterprises are not equipped with HPD for workers, mainly small and micro enterprises.

Conclusions

High levels of hazardous noise exposure are typical in non-coal mines. Noise exposure data can help to develop more feasible noise controls.

Evaluating Occupational Noise Exposure as a Contributor to Injury Risk among Miners

OBJECTIVES

This study: (i) assessed the relationship between noise exposure and injury risk, comprehensively adjusting for individual factors, psychosocial stressors, and organizational influences; (ii) determined the relative importance of noise on injuries; (iii) estimated the lowest observed adverse effect level (LOAEL) of noise on injury risk to determine the threshold of noise considered hazardous to injuries; and (iv) quantified the fraction of injuries that could be attributed to hazardous noise exposure.

METHODS

In this cross-sectional study at 10 US surface mine sites, traditional mixed effects, Poisson regression, and boosted regression tree (BRT) models were run on the number of reported work-related injuries in the last year. The LOAEL of noise on injuries was identified by estimating the percent increase in work-related injuries at different thresholds of noise exposure using a counterfactual estimator through the BRT model. A population attributable fraction (PAF) was quantified with this counterfactual estimator to predict reductions in injuries at the LOAEL.

RESULTS

Among 18 predictors of work-related injuries, mine site, perceived job safety, age, and sleepiness were the most important predictors. Occupational noise exposure was the seventh most important predictor. The LOAEL of noise for work-related injuries was a full-shift exposure of 88 dBA. Exposure ≥88 dBA was attributed to 20.3% (95% CI: 11.2%, 29.3%) of reported work-related injuries in the last year among the participants.

CONCLUSIONS

This study further supports hypotheses of a dose-response relationship between occupational noise exposure and work-related injuries, and suggests that exposures ≥88 dBA may increase injury risk in mining.

Area Noise Assessment at Surface Stone, Sand, and Gravel Mines: Application for Reducing Worker Noise Exposure

Repeated noise exposure and occupational hearing loss are common health problems across industries and especially within the mining industry. Large mechanized processes, blasting, grinding, drilling, and work that is often in close quarters put many miners at an increased risk of noise overexposure. In stone, sand, and gravel mining, noise is generated from a variety of sources, depending on the type of ore being mined as well as the final consumer product provided by that mine. Depending on the source of noise generation, different strategies to reduce and avoid that noise should be implemented. The National Institute for Occupational Safety and Health (NIOSH) has evaluated the noise profile at three operational surface stone, sand, and gravel mines. A-weighted sound level meter data as well as phase array beamforming data were collected throughout the mines in areas with high noise exposure or high personnel foot or vehicle traffic. Sound level meter data collected on a grid pattern was used to develop sound profiles of the working areas. These sound contour maps as well as phase array beamforming plots were provided to the mines as well as guidance to modify work areas or personnel traffic to reduce noise exposure.

Prevalence of hearing loss among noise-exposed workers within the Mining and Oil and Gas Extraction sectors, 2006-2015

BACKGROUND

The purpose of this study was to estimate the prevalence of hearing loss (HL) among noise-exposed US workers within the Mining, and Oil and Gas Extraction (OGE) sectors.

METHODS

Audiograms of 1.9 million workers across all industries (including 9389 in Mining and 1076 in OGE) from 2006 to 2015 were examined. Prevalence and adjusted risk as compared to a reference industry (Couriers and Messengers) were estimated for all industries combined and the Mining and OGE sectors and subsectors.

RESULTS

The prevalences of HL in Mining and OGE were 24% and 14%, respectively, compared with 16% for all industries combined. Many Mining and one OGE subsector exceeded these prevalences and most had an adjusted risk (prevalence ratio) significantly greater than the reference industry. Some subsectors, particularly in OGE, could not be examined due to low sample size. The prevalences in Construction Sand and Gravel Mining and Natural Gas Liquid Extraction were 36% and 28%, respectively. Workers within Support Activities for Coal Mining had double the risk of HL than workers in the reference industry.

CONCLUSIONS

The many subsectors identified with high prevalences and/or worker risks for HL well above risks in the reference industry need critical attention to conserve worker hearing and maintain worker quality of life. Administrative and engineering controls can reduce worker hazardous noise exposures. Noise and ototoxic chemical exposure information is needed for many subsectors, as is audiometric testing results for OGE workers. Additional research is also needed to further characterize exposures and improve hearing conservation measures.