Interstitial Lung Diseases in the U.S. Mining Industry: Using MSHA Data to Examine Trends and the Prevention Effects of Compliance with Health Regulations, 1996-2015

Occupational Exposure to Mineral Dust in Mining and Earthmoving Works: A Scoping Review

Anthropogenic activity is related to several environmental imbalances, including dust. Particulate matter can also hinder humans with numerous health consequences, such as asthma, cancer, and pneumoconiosis. With a particular focus on mineral dust, this review is intended to determine in which circumstances occupational exposure occurs in the mining and earthmoving industries. Research followed the guidelines provided by the preferred reporting items for systematic review and meta-analysis protocols and its extension for scoping reviews. Of the 8993 records identified, only 24 passed both exclusion and inclusion criteria. Within the pool of results, it was possible to identify the following variables related to dust exposure: job-related (activity, job category, and site), engineering (equipment, transport system), technical (distance), and physical (season and weather) variables. Due to the significant variance in protocol settings, it was challenging to perform a general analysis, resulting in a study-by-study approach. The most significant conclusion of this study is not related to the setting of occupational exposure, although it derives from it. The necessity of adopting standard procedures for data collection, independent of research objective, was demonstrated within the context of occupational exposure to mineral dust.

Factors associated with self-rated health among mineworkers in Zambia: a cross-sectional study

Background

This study aims to examine miners’ working conditions and self-rated health status in copper mines in Zambia and to identify the conditions and factors necessary to improve the safety and health of mineworkers.

Methods

A cross-sectional study using a self-administered questionnaire was conducted anonymously among copper mineworkers in Zambia in 2015 and 2016. Five targeted mining companies among 33 were introduced by the Mineworkers’ Union of Zambia. Study participants were recruited at the waiting space for underground work, waiting rooms of company clinics/hospitals, and/or at training sessions, which were places permitted by the target companies to perform data collection via convenience sampling. Bivariate analyses (e.g., t tests, Kruskal-Wallis tests, chi-square tests, or Cochran-Armitage tests) and logistic regression analysis were used to analyze differences in demographic characteristics and to compare their working conditions, health conditions, safety management at the workplace, and training opportunities by employment status.

Results

In total, 338 responses were analyzed. Regular employees had better working conditions, including higher incomes (P = 0.001), more likely to be guaranteed sickness insurance by the company (P < 0.001), paid holidays (P = 0.094), and sick leave (P = 0.064), although the difference was not statistically significant. Mineworkers’ decreased self-rated health was determined by job category (adjusted odds ratio [AOR], 0.41; 95% confidence interval [CI], 0.21, 0.82; P = 0.012). Having experienced violence from the boss/manager (AOR, 0.54; 95% CI, 0.32, 0.91; P = 0.020) was negatively associated with better self-rated health in the crude odds ratio.

Conclusions

Among mineworkers in Zambia, nonunderground work and not having experienced violence from their boss/manager contributed to increased self-rated health. From the perspective of psychological safety and human security, the management of safety and the working environment, including human resource management and preventing harassment/violence, should be assured, especially for underground mineworkers.

Mortality among workers employed in the mining industry in the United States: A 29-year analysis of the National Health Interview Survey-Linked Mortality File, 1986-2014

BACKGROUND

Working in the mining industry increases the risk of chronic diseases and mortality. We investigated overall and cause-specific mortality rates among workers employed in the mining sector in the United States.

METHODS

We pooled 29 years of National Health Interview Survey (NHIS) public-use data from 1986 to 2014, with mortality follow-up until 31 December 2015. We grouped respondents into the mining and nonmining sectors based on the responses given at the time of the NHIS interview. We compared the overall and cause-specific mortality rates using standardized mortality ratios (SMR) and 95% confidence interval (CI) adjusted for the competing cause of death.

RESULTS

From 1986 to 2014, an estimated 14 million deaths were recorded among subjects eligible for mortality follow-up. Of these, an estimated 50,000 deaths occurred among those working in the mining sector. A significantly higher overall mortality (SMR = 1.26, 95% CI: 1.17-1.36), and mortality from heart diseases (adjusted SMR = 1.56, 95% CI: 1.31-1.83), cancer (adjusted SMR = 1.30, 95% CI: 1.14-1.48) and unintentional injuries (adjusted SMR = 1.41, 95%CI: 1.03-1.85) were observed among those employed in the mining sector. When the analyses were restricted to men, only the SMRs for heart disease and cancer remained statistically significant. No elevated SMR for deaths from chronic lower respiratory disease was observed in the study.

CONCLUSION

Workers employed in the mining sector have a significantly increased total death rate and death rates from heart disease, cancer, and unintentional injuries.

Coal mining and lung disease in the 21st century

PURPOSE OF REVIEW

To review the impact of coal mining and resurgence of coal workers' pneumoconiosis (CWP) in 21st century and effect of ambient air pollution on lung function.

RECENT FINDINGS

At the beginning of 21st century, statistics by National Institute for Occupational Safety and Health showed a steep rise in pneumoconiosis. This was followed by numerous epidemiologic and pathologic studies that confirmed increasing CWP prevalence as well as disease in younger miners and those with a shorter mining tenure. Recent studies have demonstrated that poor dust control in mines, a relative shift in composition of the coal mine dust, small sized mines and increase in surface mining are all possible contributors to this resurgence. There is also growing literature evaluating the effects of worsening air pollution on health, including decreasing lung function and development of emphysema, worsening quality of life measures and lung cancer.

SUMMARY

This irreversible but preventable disease currently haunts approximately 60 000 miners across United States and millions across the world. Its resurgence despite the strict dust regulations is a setback from the public health standpoint. The continued reliance on coal for energy will continue to place coal miners at danger of developing disease as well as the world.

Current Review of Pneumoconiosis Among US Coal Miners

PURPOSE OF REVIEW

This review summarizes recent research on pneumoconiosis in coal workers following the identification of the resurgence of this disease among US coal miners in the early 2000s. We describe the impact of this research and how this has led to increased public attention, benefitting affected miners.

RECENT FINDINGS

The latest research shows that the prevalence of pneumoconiosis, including progressive massive fibrosis, continues to increase, especially in central Appalachia. Contributing factors may include mining of thin coal seams or cutting rock to access coal, which may expose miners to coal mine dust with a higher content of silica and silicates than in the past. The impact of recently implemented changes, such as the reduced occupational exposure limit for respirable coal mine dust and the introduction of continuous personal dust monitors, will likely take years to appropriately evaluate.

Prediction of the length of service at the onset of coal workers' pneumoconiosis based on neural network

Three environmental parameters, i.e. dust concentrations, dust dispersion, and free silica content, were introduced into the traditional indices of the neural network model in order to construct a new prediction index and explore a new method for preventing the incidence of pneumoconiosis with intelligent accuracy and universality. Data of the pneumoconiosis patients from Huabei Mining Group (HBMG) of China from 1980 to 2017 were collected. SPSS22.0 was used to develop the combined models based on Back Propagation (BP) neural network model, Radial Basis Function (RBF) neural network model, and Multiple Linear Regression (MLR) model. The paired sample t-test was performed between the real and predicted values. According to this model, it was predicted that 382 coal workers in HBMG were likely to suffer from pneumoconiosis in 2022 and the incidence rate was 4.48%. It is necessary to take prevention measures and transfer these workers from their current positions. In four combined models, the BP-MLR combined model achieved the optimal error parameters and the most accurate prediction. This study provided a scientific basis for effective control and prevention of the incidence of the pneumoconiosis.

Respirable coal mine dust in underground mines, United States, 1982-2017

BACKGROUND

This study summarized the mass concentration and quartz mass percent of respirable coal mine dust samples (annually, by district, and by occupation) from underground coal mines during 1982-2017.

METHODS

Respirable dust and quartz data collected and analyzed by Mine Safety and Health Administration (MSHA) were summarized by year, coal mining occupation, and geographical area. The older (before August 2016) 2.0 mg/m ³ respirable dust MSHA permissible exposure limit (PEL) was used across all years for comparative purposes. For respirable dust and quartz, geometric mean and percent of samples exceeding the respirable dust PEL (2.0 mg/m ³ or a reduced standard for samples with >5% quartz content) were calculated. For quartz samples, the average percent quartz content was also calculated.

RESULTS

The overall geometric mean concentration for 681 497 respirable dust samples was 0.55 mg/m ³ and 5.5% of the samples exceeded the 2.0 mg/m ³ PEL. The overall respirable quartz geometric mean concentration for 210 944 samples was 0.038 mg/m ³ and 18.7% of these samples exceeded the applicable standard. There was a decline over time in the percent of respirable dust samples exceeding 2.0 mg/m ³ . The respirable dust geometric mean concentration was lower in central Appalachia compared to the rest of the United States. However, the respirable quartz geometric mean concentration and the mean percent quartz content were higher in central Appalachia.

CONCLUSION

This study summarizes respirable dust and quartz concentrations from coal mine inspector samples and may provide an insight into differences in the prevalence of pneumoconiosis by region and occupation.