Final Report to the Generic Mineral Technology Center for Respirable Dust

Prepared by: Frank L. Saus, Director, WVU

July 2000

Instrument: Subcontract USDI-TPSU-WVU-1155242-1102

Submitted by:

West Virginia University
National Research Center for Coal and Energy
P. O. Box 6064
Morgantown, WV 26506

We take the simple act of breathing for granted. We laugh, cry, scream, and yell with a minimum of physical effort or exertion. Muscles in our chest work automatically to force air into and out of our lungs - and we go on, unthinking and unconcerned.

To a worker inflicted with a lung disease caused by the dust of silica, coal, asbestos or some other mineral, getting out of bed in the morning and walking across a room becomes a major life challenge. Simple acts, such as speaking, crying, laughing, screaming or yelling are feared, for they can leave the body racked with uncontrollable, painful spasms. The lungs of such afflicted persons are likened to two strong hands with the fingers tightly intertwined. So tightly are the fingers interlocked that they cannot be pulled apart - in the lungs, this means no expansion to allow fresh air to enter. The air that does enter will provide little relief to the person. The interior structure of the lungs has been so destroyed by the dust that it resembles large expansive caves where a few streams of blood might be found to receive the badly needed oxygen. Thus, a slow un-reversible, unrelenting and inevitable death overtakes the body. In the coalfields of Appalachia, another is claimed by "Black Lung".

Melodramatic? Maybe! But, even today, in our so-called enlightened high-tech world, miners are still dying at alarming numbers from Black Lung. You ask, "How can this possibly be true with all the research, benefits, and monitoring that has been performed over the past century?" However, the simple, fact remains that the causative factors that instruct the body to self-destruct after inhalation of certain types of mineral dusts still remain elusive and unknown.

Excerpt from "Fighting for Air", 1995 Annual Report, National Research Center for Coal and Energy, WVU

The Generic Mineral Technology Center for Respirable Dust (GMTCRD) was the only recognized research entity engaged in studying the engineering, scientific and medical aspects leading to respirable coal dust disease - Coal Workers' Pneumoconiosis (CWP) - a.k.a. Black Lung. The Center, established in 1983, was given the mandate to enhance the health, safety, and productivity of miners through advancing the fundamental understanding of all aspects of respirable dust associated with mining, milling and the interaction of dust with lungs to reduce the incidence of the disease.

The earliest historical accounts of "melanosis", i.e., the growth of dark tissue in or on the body as a recognized health problem in the mining industry, were first noted around 1831. Numerous studies performed over the past 169 years have arrived at the consensus that melanosis and other lung diseases are associated with workers’ exposure to respirable dust [dust small enough to enter into the lungs]. Correlations were also discovered with respect to the concentration of dust in the air and the amount of time a worker was exposed to these concentrations.

In spite of the repeated correlation of respirable dust with lung and airway diseases, it was only 30 years ago that the United States enacted the Coal Dust Standard (1969) which called for the lowering of dust concentrations in the mines. This Standard was the first health issue to receive legislative prominence over safety and accident issues in the mining industry. This enactment was driven by studies revealing that Appalachian miners were exhibiting a high mortality rate directly attributed to lung cancer similar to miners in Great Britain.

The National Academy of Science conducted a study in the late 1970's on the measurement and control of respirable dust in the mining industry. The Academy's findings suggested that the number of deaths from black lung had declined, but there were still many unresolved issues and unanswered questions with respect to the disease. The Academy charged the U. S. Bureau of Mines to conduct research in order to obtain fundamental knowledge regarding the origin, transport and characteristics of respirable dust. The Bureau established the Generic Mineral Technology Center for Respirable Dust in August 1983 to address such a diversity of topics. The Center was composed of five members - Pennsylvania State University (co-lead), West Virginia University (co-lead), University of Minnesota (associate), Michigan Technological University (associate), and Massachusetts Institute of Technology (associate).

The Center adopted a holistic approach to the challenges proposed by the National Academy of Sciences and formulated a five front research program. The research programs dealt with (1) control of dust generation, (2) dilution, dispersion and collection in mine airways, (3) characterization of dust particles, (4) interaction of dust and lungs, and (5) the relationship of the mine environment, geology, and seam characteristics to dust generation and mobility. In spite of the numerous past epidemiological studies, only a comprehensive understanding of the disease could lead to resultant controls and reduction of the disease's prevalence. Therefore, many of the initial studies at the Center were fact-finding explorations to establish a knowledge base regarding the disease and upon which to strategize a logical and focused approach to achieve future research objectives.

Researchers at WVU centered their investigations on the generation of respirable dust, characterization of the dust, and the biological interaction between the inhaled dust particulates and lung tissue. The following compendium highlights several activities and findings that focused on investigations to provide a safer environment for miners.

One major project involved mapping the location, distribution and concentration of respirable particles at the mine face. Controlling the generation of respirable dust particulates at the working face of a mining operation is critical. Data from the project implied the apparent existence of an area where dust concentrations are reduced from the surrounding area that may be a safer location for miners. The data also indicate that the use of water sprays has a more pronounced effect on lowering the distribution of dust levels than previously believed. The results of these earlier studies regarding dust generation are currently being used to evaluate the technology and methodology used in the remediation of hazardous waste sites, especially operations involving the removal of contaminated soils.

An Automated Rotary Coal Cutting Simulator was developed to test the performance of multiple bit configurations on various rock and coal strata. The unit demonstrated that bits were not always rotating properly during the cutting process and that worn bits were capable of generating significant amounts of respirable dust. From these initial results, research focused on developing and testing various types of bits and bit coatings and the use of sprays to consolidate dust particles. Tests using carbide tipped bits and the development of the new poly-crystalline diamond tips appear highly promising; they may soon be used in mining operations. However, these studies indicate that this is a research area in which the technology may need to be re-addressed, especially with respect to the fracturing and re-grinding issues.

A Small Animal Inhalation Facility was designed, constructed and operated at WVU. The facility was used by all Center investigators and provided consistency in the time- concentration exposures for investigations into the biological initiation and biochemical processes of the disease. The facility would allow three groups of non-primate animals to be exposed simultaneously to three different dust concentrations. The researcher who designed the facility and provided oversight to the operation discovered that the standard stainless steel mill routinely used to generate the respirable dust particulates was also responsible for generating small amounts of contaminants from the mill's matrix.

Experimental results from one project revealed that the personal cyclonic sampling device used to assess individual miners exposure to respirable dust was biased in the collection process. Personal sampling devices were giving consistently lower readings than larger stationary counterparts under windy mine conditions. A new, accurate multi-inlet cyclonic sampling device was designed and was proven a more efficient sampling device under such conditions.

In a study involving over 478 miners and control subjects, one group of miners, when examined by a simple non-invasive machine referred to as spirometer, showed a rapid decline in lung function. The study included the patient's medical and work history, a physical examination and a pulmonary function test (spirometry test). Over the eight-year time frame of the study, the finding indicates that 25% of the miners showed a decline in lung function based on the pulmonary tests. These findings implicate the potential use of spirometry as a surveillance tool in occupational respiratory diseases.

Scanning Electron Microscopy coupled with Energy Dispersive X-ray analysis was used to investigate respirable coal mine dust particles. The technique revealed that quartz, a known fibrogenic agent, in respirable dust occurs differently in various coal seams. The crystalline surface of quartz was more exposed in the higher coal rank seams and was found to exhibit the most biological activity. The quartz surface in lower rank coal seams is coated (occluded) in various degrees with mineral matter (alumninosilicates). These findings may provide a partial explanation of the discrepancy found among bulk analysis findings for quartz, coal seams and coal workers pneumoconiosis and may offer a testing procedure to determine quartz availability and potential danger in mining operations.

An acoustical monitoring technology was developed as a means to provide a non-invasive mechanism to diagnose Coal Workers’ Pneumoconiosis (CWP). While, the methodology proved to be unsuccessful for deep lung CWP due to multiple branching of the bronchi in the lower lung cavities, the methodology was being investigated by NIOSH as a possible use for detecting upper respiratory problems such as bronchitis.

Experimentation revealed that recently fractured dust particles have surface borne free radicals - referred to as "fresh dust" - and that these dust particles were highly toxic to lung cells. Given time and exposure, the free radicals react with the surrounding atmosphere and the charges are negated resulting in less harmful or "aged" dust. The presence of free radicals on dust particles entering and depositing on the inner lung surface promotes a number of biochemical and/or physical reactions ranging from direct cell damage to the initiation of inflammation and fibrotic activators. A national conference on Free Radical Effects on Biological Systems was held in Morgantown in August 1993 and was partially sponsored by the Dust Center.

Medical studies involving lung lavages - animal and human - have assisted researchers in diagnosing and eliciting many of the biochemical reaction pathway steps that occur at the dust-lung interface. The interaction of cellular constituents involved in the dust-lung-macrophage phenomena is slowly being discovered with respect to macrophage-generated mediators/regulators that may lead to inflammation and fibrogenic developments.

One project involved the use of a drug called "tetrandrine" that had shown some previous success in the treatment of silicosis. Findings revealed that the drug was effective as long as it was directly applied to cells. The use of an aerosol inhaler to deliver the drug into the lung proved unsuccessful. However, the study led to the development of a new multiple-emulsion design for intravenous injection of drugs.

One program area initiated in the latter days of the Center was the investigation of diesel exhaust particulates. Diesel soot dispersed in "surrogate pulmonary surfactant" can express genotoxic activity in eucaryotic cells. One project demonstrated that soot particles dispersed in a more natural "phospholipid lecithin surfactant" could also express mutagenic activity. These results would imply that the lung is capable of dispersing hazardous components of diesel soot and making them available to express their genotoxic potential.

Published articles by faculty researchers are found in the Center's Annual Reports as well as Symposia Proceedings sponsored by the Center. These publications have proven to be a valuable asset to the international research community. A collection of the Annual Reports and Symposia, plus input from individual researchers, was submitted to NIOSH during their recent evaluation of the mine dust standard. This information represents a single, massive source of concentrated information about black lung experimentation in the United States

One indirect benefit received by WVU researchers was the involvement of NIOSH researchers as collaborators in numerous investigations. The Free Radical Conference attests to the close working relationship that had developed between the two groups over the years. In addition, NIOSH researchers have indirectly represented the Center by presenting Center findings at international conferences or meetings. Such collaborative efforts have lead the Center to attain world wide stature and prominence in the area of respirable coal dust research similar to the silica study group at North-Rhine Westphalia. Researchers at all the Center sites have responded to numerous correspondence, and entertained visitors and presented lectures for their European and Eastern counterparts.

Numerically, WVU has received approximately $ 10, 929, 929 over the span of the Center. These funds have sponsored 41 projects - 37 technical projects, two administrative projects, one service project, and one support project. The projects were distributed among the technical colleges at WVU, i.e., College of Mineral and Energy Resources, College of Engineering, College of Arts and Sciences, and the School of Medicine. Thirty students obtained advanced degrees under the Center program and many (25% at last count) have remained in the mining and mineral field or are in directly related fields. The number of post-doctoral students trained under the Center program is unknown, but easily matches that of the advanced degree students.

Lungs exposed to mineral dusts continue to become damaged with time. In some cases, it may take 10 to 30 years for the full effect of a mineral to be manifested. There are cases where miners have worked in mines for several years and left the mining industry with x-rays showing no lung problems. Yet, some of these same individuals have died of pneumoconiosis 15 years later, while others have exhibited no problems. Continued experimentation is still needed to single out and identify the biological reactions and pathways that occur in the lungs after a mineral insult. Such knowledge would lead to the development of engineering controls to increase the safety of the miner's environment and their subsequent exposure to respirable dusts.

The shotgun approach initially adopted at the Center generated much needed knowledge about the disease. As researchers became more knowledgeable of the complexity of the dust-lung issue, research questions became more focused in attempting to decipher engineering controls and the biological onset of the disease. However, the overall pathway has been found to be extremely complex and answers have yet to be fully attained. But, in the interim, the knowledge gained through the Center's efforts will aid in further reduction of the deaths of miners.

One unexplored aspect of the Dust Center's information base is in the application of the Center's findings to other mineral industries. Examples of potential uses of the information are presented below.

The amount of bit wear, non-rotation of the bits, and regrinding increased the amount of respirable dust generated at the coalface. The possibility of similar happenings occurring in other mineral mining operations may be overlooked and significant. Cursory investigations should be conducted in other mineral mining operations, in blasting operations, in open pit or strip mining, in road building, in remediation operations involving removing of contaminated strata, or any other industrial application where bits contact strata and respirable dust may be generated.

The awareness that diesel dust can lead to lung/health problems can be related to diesel operations in the real world, e.g., where waiting heavy machine or truck operators may be exposed repeatedly to diesel soot during loading and unloading operations.

Research findings on lung-dust interactions should alert architects and engineers to the growing problem of PM10 particulates in industrial buildings, in large cities, and to their potential health problems. The EPA appears to be slowly acknowledging PM10 as a potentially serious problem for children and older people who may not have the full potential to fight off this type of lung insult.

The use of spirometry testing as an early warning monitoring system should be advanced to the overall mineral industry as a monitoring methodology for drillers, laborers, blasters, or even road workers who must operate heavy machinery where respirable dust is generated.

The overall significance is that many of the Center's discoveries, in and of themselves, may not and do not appear significant in light of the declining coal industry. However, if removed from the coal-mining venue and applied to other industrial operations, it appears that these findings can become significant. They may have the potential to create an awareness of potential health problems and minimize life loss in other industries.