Mining

Participating core and specialty programs: Exposure Assessment, Personal Protective Technology, and Surveillance.

Industry, labor, other government agencies, professional organizations, equipment manufacturers, and academics use NIOSH information to reduce respiratory diseases caused by mineral dusts among mining workers.

NOTE: Goals in bold in the table below are priorities for extramural research.

  Health Outcome Research Focus Worker Population Research Type
A Asbestos-related disease Early screening for diagnosis related to exposure to elongate mineral fibers Metal/non-metal; stone, sand and gravel mine workers Intervention

Surveillance research

B Asbestos-related disease Identify toxicity of commercial elongate mineral particles Metal/non-metal; stone, sand and gravel mine workers Basic/etiologic
C Asbestos-related disease Improved exposure assessment for elongate mineral fibers and controls Metal/non-metal; stone, sand and gravel mine workers Basic/etiologic

Intervention

D Coal workers’ pneumoconiosis (CWP), Chronic Obstructive Pulmonary Disease (COPD), Diffuse fibrosis Coal dust engineering controls Coal mine workers Intervention

Translation

E CWP, COPD, Diffuse fibrosis, silicosis Improved screening and surveillance for respiratory health (esp. in Appalachia) Metal/non-metal; coal; stone, sand and gravel mine workers Surveillance research
F Silica-related diseases More accurate and timely monitoring of crystalline silica and controlling exposures Metal/non-metal; coal; stone, sand and gravel mine workers Basic/etiologic

Intervention

G Silica-related diseases Increase usage of crystalline silica interventions Metal/non-metal; coal; stone, sand and gravel mine workers Translation

Activity Goal 5.8.1 (Basic/Etiologic Research): Conduct basic/etiologic research to improve measurement of exposures and to better understand relationships between exposures to mining-related dusts and risks for respiratory diseases among mining workers.

Activity Goal 5.8.2 (Intervention Research): Conduct studies to develop and assess the effectiveness of interventions to prevent exposure to elongate mineral fibers, coal mine dust, and crystalline silica and reduce respiratory diseases among mining workers.

Activity Goal 5.8.3 (Translation Research): Conduct translation research to understand barriers and aids to implementing interventions for coal mine dust and crystalline silica among mining workers.

Activity Goal 5.8.4 (Surveillance Research): Conduct surveillance research to improve screening and surveillance for respiratory health among mining workers.

Burden

Mineral dusts and the respiratory diseases that they cause continue to be important problems. Each type of dust exposure can cause a spectrum of respiratory diseases. For example, respirable coal mine dust can cause coal workers’ pneumoconiosis (CWP; a fibrotic lung disease), chronic obstructive pulmonary disease (COPD; includes chronic bronchitis and emphysema); dust-related diffuse fibrosis, and other conditions [Petsonk et al. 2013]. Respirable crystalline silica can cause silicosis (a fibrotic lung disease), COPD, lung cancer, and other conditions [NIOSH 2002]. Asbestos and elongate mineral particles (EMP) with asbestos-like effects can cause nonmalignant pleural disease, asbestosis (a fibrotic lung disease), lung cancer, and mesothelioma [NIOSH 2011]. These diseases can have a severe impact on affected miners and be disabling or even fatal. In addition to being potentially severe, dust-related respiratory diseases are a substantial risk to miners. For example, risks for CWP in coal miners are well-documented, with recent data suggesting that about 5% of coal miners in Kentucky, Virginia and West Virginia with more than 25 years’ tenure have progressive massive fibrosis, the worst type of CWP [CDC 2016]. Miners accounted for 23% of silicosis deaths in the U.S. from 1990-1999 [NIOSH 2008a]. COPD is the third-leading cause of death in the U.S., and workers in the mining industry sector have the greatest risk of dying from COPD of any industry, with a rate about 70% higher than industry in general [NIOSH 2008b].

Need

There is need for a range of work to reduce the burden of dust-related respiratory diseases in mining. Basic/Etiologic research is needed to improve methods for exposure assessment, including real or near-real time silica exposure monitoring, improved detection thresholds for silica exposure assessment, and better approaches to characterizing EMP exposures. In addition, work is needed to understand the relative toxicities of various EMP and to improve the ability to predict which EMP will have asbestos-like health effects (see NIOSH Roadmap [NIOSH 2011]). Intervention research is needed to improve engineering controls and document the impact of interventions on dust levels and associated disease risk. A specific need is to evaluate the effectiveness of interventions implemented through the Mine Safety and Health Administration 2014 Coal Mine Dust Rule [MSHA 2014]. Translation research is needed to identify barriers and improve uptake of known effective interventions for primary and secondary prevention of disease associated with respirable coal mine dust and respirable crystalline silica exposures. Surveillance research is needed to develop new data sources to track the burden of hazardous exposures and respiratory disease in the metal and nonmetal and sand, stone, and gravel segments of the mining industry, where relatively little surveillance information is currently available. Even in coal mining, improved surveillance to track the burden of disease in former miners not eligible for NIOSH respiratory health surveillance is needed. Improved approaches to medical screening and surveillance are also needed, including improved understanding of the role of low and ultra-low dose CT scanning of the chest and improved approaches to assessment of lung function for purposes of secondary prevention.

Industry, labor, other government agencies, professional organizations, equipment manufacturers, and academics use NIOSH information to reduce respiratory diseases caused by mixed exposures among mining workers.

  Health Outcome Research Focus Worker Population Research Type
A Chronic obstructive pulmonary disease (COPD), Asthma, Lung cancer Exposure to gas and particle phase diesel and dust mixtures All mining workers (esp. underground) Basic/etiologic

Intervention

B Coal workers’ pneumoconiosis (CWP), COPD, Diffuse fibrosis Toxicity of contemporary coal dust (silica, coal and other mineral mixture) Coal mining workers Basic etiologic

Intervention

C Respiratory diseases Interaction of work and personal risk factors on respiratory health outcomes All mining workers Basic/etiologic

Intervention

Activity Goal 5.9.1 (Basic/Etiologic Research): Conduct basic/etiologic research to better understand relationship between mixed respiratory exposures and respiratory diseases among mining workers.

Activity Goal 5.9.2 (Intervention Research): Conduct studies to develop and assess the effectiveness of interventions to prevent mixed exposures linked to respiratory disease among mining workers.

Burden

Most hazardous exposures in mining are not simple exposures to single agents. Instead, they are exposures to complex mixtures in the work environment. In addition, risks for adverse respiratory health outcomes from work exposures can be modified by non-work personal risk factors. It is important to understand the interactions between these exposures. For example, there has been a well-documented surge in coal workers’ pneumoconiosis (CWP), including very severe CWP, in Appalachian coal miners [Blackley et al. 2016]. Pathology studies have shown a mixture of particles in the lungs of these workers, including coal, crystalline silica, and other silicate minerals [Cohen et al. 2016]. In another example, workers in the mining industry are at the highest risk for dying of COPD of any industry [NIOSH 2008b]. These workers can have multiple work exposures with the potential to cause COPD (and other respiratory diseases such as lung cancer), such as respirable coal mine dust, respirable crystalline silica dust, and diesel exhaust. This can be further complicated by exposures from outside work, such as from tobacco smoke, since the mining industry has one of the highest prevalence rates for smoking [NIOSH 2013].

Need

Basic/Intervention research is needed to assess modification of risk for respiratory health outcomes by co-exposures to individual components of complex mixtures. Are effects additive, supra-additive, multiplicative, or is there some other effect? The interactions between dust exposure, diesel exposure, and tobacco smoke are an important issue. Results from past NIOSH research evaluating coal miners and metal and nonmetal miners have suggested that coal mine dust and diesel exhaust interact with tobacco smoke in complex ways; further validation in human or mechanistic experimental studies is needed. Similarly, the relative contributions and interactions between respirable coal, crystalline silica, and other silicate mineral dust in causing the severe emerging outbreak of CWP in Appalachian coal miners needs to be further evaluated in experimental studies. Intervention studies are also needed to demonstrate effectiveness of addressing these complex exposures, whether they occur at work or as a result of personal risk factors.

CDC [2016]. Resurgence of progressive massive fibrosis in coal miners — Eastern Kentucky, 2016. MMWR 65(49):1385-1389, https://www.cdc.gov/mmwr/volumes/65/wr/mm6549a1.htm

Cohen RA, Petsonk EL, Rose C, Young B, Regier M, Najmuddin A, Abraham JL, Churg A, Green FH. Lung [2016] Pathology in U.S. coal workers with rapidly progressive pneumoconiosis implicates silica and silicates. Am J Respir Crit Care Med 193(6):673-80.

MSHA [2014]. Respirable dust rule: a historic step forward in the effort to end black lung disease. Arlington, VA: U.S. Department of Labor, Mine Safety and Health Administration, https://www.msha.gov/news-media/special-initiatives/2016/09/28/respirable-dust-rule-historic-step-forward-effort-endexternal icon

NIOSH [2002]. Health effects of occupational exposure to respirable crystalline silica. Cincinnati, OH: U.S. Department of Health and Human Services, Public Health Service, Centers for Disease Control and Prevention, National Institute for Occupational Safety and Health, DHHS (NIOSH) Publication No. 2002-129, https://www.cdc.gov/niosh/docs/2002-129/pdfs/2002-129.pdfpdf icon

NIOSH [2008a]. Silicosis: Number and percent of deaths by NORA industrial sector, U.S. residents age 15 and over, selected states and years, 1990-1999. From: Work-Related Lung Disease Surveillance System (eWoRLD), 2008-128. Cincinnati, OH: U.S. Department of Health and Human Services, Centers for Disease Control and Prevention, National Institute for Occupational Safety and Health, https://wwwn.cdc.gov/eworld/Data/128

NIOSH [2008b]. Chronic obstructive pulmonary disease: Proportionate mortality ratio (PMR) adjusted for age, sex, and race by NORA industrial sector, U.S. residents age 15 and over, selected states, 1999. From: Work-Related Lung Disease Surveillance System (eWoRLD), 2008-636. Cincinnati, OH: U.S. Department of Health and Human Services, Centers for Disease Control and Prevention, National Institute for Occupational Safety and Health, https://wwwn.cdc.gov/eworld/Data/636

NIOSH [2011]. Asbestos fibers and other elongate mineral particles: state of the science and roadmap for research. Cincinnati, OH: U.S. Department of Health and Human Services, Centers for Disease Control and Prevention, National Institute for Occupational Safety and Health, DHHS (NIOSH) Publication No. 2011-159, https://www.cdc.gov/niosh/docs/2011-159/default.html

NIOSH [2013]. Current smokers: Estimated prevalence by current industry, U.S. working adults aged 18 and over, 2004–2011. From: Work-Related Lung Disease Surveillance System (eWoRLD), 2013-490. Cincinnati, OH: U.S. Department of Health and Human Services, Centers for Disease Control and Prevention, National Institute for Occupational Safety and Health, https://wwwn.cdc.gov/eworld/Data/490

Petsonk EL, Rose C, Cohen R [2013]. Coal mine dust lung disease. New lessons from old exposure. Am J Respir Crit Care Med 187(11):1178-85.

Page last reviewed: April 24, 2018