Mining Topic: Respiratory Diseases
What is the health and safety problem?
Occupational exposure to airborne contaminants can lead to respiratory disease in humans. Because of their regular exposure to airborne dust, mine workers are at increased risk of developing lung diseases called pneumoconioses (dusty lung). The two main pneumoconioses that affect mine workers are coal workers’ pneumoconiosis (CWP, commonly called black lung); and silicosis. While CWP is associated with coal mine workers, silicosis can affect workers in many types of mines and quarries, including coal mines. Other types of respiratory diseases, such as chronic obstructive pulmonary disease (COPD), may also occur in mine workers separately from, or in addition to pneumoconiosis. These diseases can cause impairment, disability, and premature death. Medical treatment of advanced cases of these diseases is not very successful.
What is the extent of the problem?
After a long period of declining occurrence, an increase in CWP in some areas of the country has been shown in recent years. A nationwide pneumoconiosis surveillance program administered by the National Institute for Occupational Safety and Health’s (NIOSH) Division of Respiratory Disease Studies (DRDS) for underground coal mine workers identified that 2.6% of workers examined during 2005-2009 had some degree of CWP. A newly published report shows that 2% of examined surface coal mine workers—most of whom had never worked in underground mines—had some degree of CWP.
How is OMSHR addressing the problem?
The NIOSH Office of Mine Safety and Health Research (OMSHR) focuses its research on ways to measure and control the potential exposure of mine workers to airborne dust. Reducing mine workers’ exposure to dust directly reduces their risk of developing dust-related respiratory disease. OMSHR has active research programs working to reduce dust exposure to coal mine workers operating longwall and continuous mining equipment, and activities to reduce dust exposure to miners in all commodities who operate roof bolting machines, exploratory and blasthole drills, surface transportation equipment, mills and processing equipment, and for surface mobile workers.
What are the significant findings?
OMSHR research has produced an instrument that can provide an accurate measurement of airborne dust at the end of a mine workers’ work shift, and provides on-shift information that the worker can use to reduce his or her exposure. This instrument has been approved for use as a coal mine dust personal sampler, and is commercially available. Other changes that have resulted from OMSHR research to lower worker dust exposure include modification of shrouds on blasthole drills and improvements to ensure the integrity of cabs on mobile equipment. OMSHR has developed a mobile video exposure monitoring method that combines real-time exposure data with concurrently recorded point-of-view video to identify exposure sources and magnitudes for mobile workers.
What are the next steps?
OMSHR is currently evaluating other dust control technologies such as tailgate spray manifolds on the longwall shear, redirection of continuous miner scrubber exhaust, delivery of clean air to equipment operators via original equipment manufacturer-installed components in equipment cabs, and the potential application of optical remote sensing technology to monitor dust sources and movement over extended areas. OMSHR has also undertaken development of an exposure assessment method that would provide information about a worker's exposure to respirable silica at the end of the work shift. If this method becomes validated, the current delay due to laboratory analysis would be eliminated, allowing the employer to implement enhanced exposure controls sooner. The improved controls would reduce the risk of silicosis among the exposed workers.
Noteworthy Publications & Products
- Best Practices for Dust Control in Coal Mining (2010-01)
This handbook was developed to identify available engineering controls that can help the industry reduce worker exposure to respirable coal and silica dust.
- Best Practices for Dust Control in Metal/Nonmetal Mining (2010-05)
This handbook was developed to identify available engineering controls that can assist underground and surface metal/nonmetal mining operations in reducing worker exposure to respirable silica dust.
- Dust Control Handbook for Industrial Minerals Mining and Processing (2012-01)
Mined ore undergoes crushing, grinding, cleaning, drying, and product sizing as it is processed, generating harmful dust. This handbook reviews technologies for lowering dust levels below the permissible or recommended occupational exposure limits.
- Handbook for Dust Control in Mining (2003-06)
This handbook describes effective methods for the control of mineral dusts in mines and tunnels. It assumes the reader is familiar with mining. The first chapter deals solely with dust control methods, regardless of the application. It is a brief tutori...
- Laboratory and Field Performance of a Continuously Measuring Personal Respirable Dust Monitor (2006-09)
This report includes the theory of operation, description, and the performance of the Personal Dust Monitor (PDM) compared to gravimetric-based reference dust sampling methods and laboratory verification of the instruments accuracy.