Respiratory predictors of disability days: a five year prospective study of U.S. coal miners

A 5-year prospective analysis tests the hypothesis that coal miners who have impaired respiratory health also experience greater numbers of disability days due to occupational injury. Occupational and respiratory health information collected for the period 1977 through 1981 by the National Institute for Occupational Safety and Health (NIOSH) on 1,118 U.S. underground coal miners was linked to coal miner injury records collected under a mandatory reporting system by the Mine Safety and Health Administration (MSHA). Respiratory impairment, based on spirometric measures, and a questionnaire measure of chronic bronchitis symptoms, after adjustment for cigarette smoking and total years of underground mining, did not provide statistically significant prediction of average disability days. In addition, respiratory impairment did not predict the number of episodes of occupational injuries resulting in days lost from work.     

Occupational health: a classic example of class conflict

The history of class conflict in occupational health in the United States is illustrated by the current Pittston Company attack on coal miners' health benefits, the silicosis and asbestosis controversies, the corporate restrictions on state workers' compensation laws, and the unremitting management opposition to the federal Coal Mine Health and Safety Act of 1969 and the Occupational Health and Safety Act of 1970. A positive action program is presented as the basis for convening the long-overdue White House Conference on Occupational Health and Safety. Mining engineers are urged to support that action program to prevent unnecessary work-related death and disability.     

The United Mine Workers of American and the recognition of occupational respiratory diseases, 1902-1968.

This study examines the early efforts of the United Mine Workers of America to illuminate the problem of occupational respiratory diseases in the coal fields. The union used the hearings of the US Anthracite Coal Strike Commission of 1902-3 to draw public attention to "miners' asthma." In 1915, it began to agitate for the provision of workers' compensation benefits for victims of this disorder. Throughout the 1950s and 1960s, the union's Welfare and Retirement Fund disseminated information on advances in understanding chronic pulmonary diseases of mining. In particular, the miners' fund promoted the British conceptualization of a distinctive coal workers' pneumoconiosis. At the same time, the staff of the union health plan pressed the US Public Health Service and the Pennsylvania Department of Health to investigate the prevalence of occupational respiratory diseases among bituminous miners. Taken together, these endeavors contributed significantly to growing recognition of the severity and extent of this important public health problem and thus helped lay the foundation for the Federal Coal Mine Health and Safety Act of 1969.     

Assessment of respiratory exposures during gilsonite mining and milling operations

An industrial hygiene study of the entire United States gilsonite industry was done by the National Institute for Occupational Safety and Health (NIOSH) to evaluate the potential for occupational health problems resulting from exposures to gilsonite and its constituents. Gilsonite is a solidified hydrocarbon substance mined only in northeastern Utah to Colorado. Industrial hygiene samples were collected at four gilsonite mining companies including nine mines and three mills. Gilsonite workers had no measurable exposures to polynuclear aromatic hydrocarbon (PNA) compounds, asbestos fibers, or hydrogen sulfide gas. Several organic gases/vapors and metals were detected in the airborne samples; but, none exceeded the current exposure standards/health criteria of the Mine Safety and Health Administration (MSHA), the American Conference of Governmental Industrial Hygienists (ACGIH), or NIOSH. Gilsonite workers in some job categories were exposed to high levels of dust, exceeding ACGIH nuisance dust recommendations. These dusts, comprised largely of aliphatic hydrocarbons, had a large aerodynamic size distribution with average mass median aerodynamic diameters (MMAD) above 30 microns.     

Dermatitis in the mining industry: incidence, sources, and time loss

Occupational skin diseases and disorders are the most commonly reported nontrauma-related category of occupational illness in the United States, and mining has one of the highest incidence rates among all industries. The authors' objective in this study was to describe mining industry dermatitis incidence, sources of exposure, and resultant time lost from work. The authors reviewed Mine Accident, Injury and Illness Reports. From 1983 to 2002, the Mine Safety and Health Administration reported 975 cases of dermatitis in mines across the United States and its territories. Average annual incidence was 14.4 cases per 100 000 employees. Upper extremities and multiple body regions were most commonly involved. Twenty-five percent of miners with dermatitis lost at least 1 day of work. Exposure to plants, trees, and vegetation accounted for 24% of all cases. A greater understanding of this condition will assist health professionals in focusing on appropriate intervention strategies to reduce the occurrence of dermatitis and its associated morbidity in mine workers.     

The fox guarding the chicken coop: monitoring exposure to respirable coal mine dust, 1969-2000

Following passage of the Coal Mine Health and Safety Act of 1969, underground coal mine operators were required to take air samples in order to monitor compliance with the exposure limit for respirable dust, a task essential for the prevention of pneumoconiosis among coal workers. Miners objected, claiming that having the mine operators perform this task was like "having the fox guard the chicken coop." This article is a historical narrative of mining industry corruption and of efforts to reform the program of monitoring exposure to coal mine dust. Several important themes common to the practice of occupational health are illustrated; most prominently, that employers should not be expected to regulate themselves.     

Disease and illness in U.S. mining, 1983-2001

OBJECTIVES: We describe inconsistencies in disease and illness reporting in U.S. mining, identify under-reporting of disease and illness in U.S. mining, and summarize selected disease and illness in U.S. mining from 1983 through 2001. METHODS: We summarized information on mining-related disease and illness data for the years 1983-2001 from the Mining Safety and Health Administration database (MSHA). RESULTS: Discrepancies exist in types of information collected by the Centers for Disease and Control, the National Institute for Occupational Safety and Health, and the Mining Safety and Health Administration database. Several factors, including a worker's fear of losing his or her job, health insurance, or other job-related benefits contribute to under-reporting of disease and illness information in the US mining industry. CONCLUSIONS: Since 1997, both number of workers employed in mining and disease and illness rates have decreased; however, the highest disease and illness rates in mining continue to be coal worker's pneumoconiosis and hearing loss.     

Weight of the evidence or wait for the evidence? Protecting underground miners from diesel particulate matter

A coalition of mine operators has used a variety of tactics to obstruct scientific inquiry and impede public health action designed to protect underground miners from diesel particulate matter. These workers are exposed to the highest level of diesel particulate matter compared with any other occupational group.This case study profiles a decade-long saga of the Methane Awareness Resource Group Diesel Coalition to impede epidemiological studies on diesel exhaust undertaken by the National Institute for Occupational Safety and Health and the National Cancer Institute, and to derail a health standard promulgated by the Mine Safety and Health Administration. The case study highlights the coalition's mastery of legislative, judicial, and executive branch operations and the reaction of policymakers.     

Assessment of the respirable dust levels in the nation's underground and surface coal mining operations

This report presents a chronological overview of the status of respirable dust exposures in underground and surface bituminous coal mines since inception of the 1969 Federal Coal Mine Health and Safety Act. Data for various intervals from 1970 through 1977, are presented for selected mining operations. Comparisons are made using data available from the mine operators' sampling program and from MSHA surveys. The data demonstrate the marked decrease that has occurred in respirable dust exposures since inception of the 1969 Act.     

Promoting early exposure monitoring for respirable crystalline silica: Taking the laboratory to the mine site

The exposure to respirable crystalline silica (RCS) in the mining industry is a recognized occupational hazard. The assessment and monitoring of the exposure to RCS is limited by two main factors: (1) variability of the silica percent in the mining dust and (2) lengthy off-site laboratory analysis of collected samples. The monitoring of respirable dust via traditional or real-time techniques is not adequate. A solution for on-site quantification of RCS in dust samples is being investigated by the Office of Mine Safety and Health Research, a division of the National Institute for Occupational Safety and Health. The use of portable Fourier transform infrared analyzers in conjunction with a direct-on-filter analysis approach is proposed. The progress made so far, the necessary steps in progress, and the application of the monitoring solution to a small data set is presented. When developed, the solution will allow operators to estimate RCS immediately after sampling, resulting in timelier monitoring of RCS for self-assessment of compliance at the end of the shift, more effective engineering monitoring, and better evaluation of control technologies.     

Pneumoconiosis prevalence among working coal miners examined in federal chest radiograph surveillance programs--United States, 1996-2002

Coal workers' pneumoconiosis (CWP) is a chronic lung disease caused by inhalation of coal mine dust. To characterize the prevalence of CWP, the National Institute for Occupational Safety and Health (NIOSH) analyzed recent radiographic information from the U.S. National Coal Workers' X-ray Surveillance Program (CWXSP). Established under the Federal Coal Mine Health and Safety Act of 1969, CWXSP is administered by NIOSH under federal regulations. NIOSH is responsible for approving coal miner examination plans, submitted approximately every 5 years by companies that operate underground coal mines. This report summarizes the results of the analysis, which indicate that the overall prevalence of CWP among participating miners continues to decline; however, new cases are occurring among miners who have worked exclusively under current dust exposure limits. An evaluation of the mining conditions that have resulted in these cases is underway.     

Compliance with the carbon monoxide standard in the workplace.

The carbon monoxide standard which the Department of Labor uses for the protection of workers' health is reviewed. The legislation, origin of the standard, and enforcement in the workplace are summarized. The agencies within the Department of Labor with enforcement responsibilities are the Occupational Safety and Health Administration (OSHA) and the Mine Safety and Health Administration (MSHA). Comparisons are made with the current federal standard of 50 ppm and other existing or proposed standards. An increasing awareness of the effects of carbon monoxide suggests changes in the standard. A standard based on carboxyhemoglobin levels of exposed nonsmokers that overlaps the levels of normal smokers raises difficult questions. The importance of maintenance and monitoring as well as controls in the management of potential carbon monoxide exposure in the workplace is stressed.     

Symbolic solutions for deadly dilemmas: an analysis of federal coal mine health and safety legislation

Numerous studies of coal mine laws have argued that the passage of all significant health and safety legislation can be attributed to a succession of catastrophic disasters which heightened awareness and propelled lawmakers into action. This paper takes issue with this "disaster-law" argument because it obscures the intricacies of law creation by focusing on a single factor. More accurately, mining disasters represent one dimension of a process aimed at resolving conflicts occurring within a specific social context. Historically, legislation has been utilized to avert economic crises by addressing the demands of protesting miners. Unfortunately, while the "written law" assured improvements, the "law in action" did not meet these guarantees and the deaths in the mines continued. A case study of the Coal Mine Health and Safety Act of 1969 demonstrates how a law with apparently progressive standards can fail to effect change because of its dualistic nature and incomplete implementation.     

Metal and non-metal miners' exposure to crystalline silica, 1998-2002

BACKGROUND: Crystalline silica is well known to cause silicosis and other diseases. Exposure is common in the mining industry and consequently, the US Mine Safety and Health Administration (MSHA) evaluates miners exposure to silica to determine compliance with its exposure limit. METHODS: MSHA exposure measurements were obtained for the 5-year period from 1998 to 2002 and average exposure was calculated classified by occupation and by mine. Evaluation criteria were whether average values exceeded MSHA's permissible exposure limit or the limit recommended by the National Institute for Occupational Safety and Health (NIOSH), whether there was a risk of exposure to freshly fractured silica, and whether there was a risk of a high rate of exposure to silica. RESULTS: Miners in certain jobs are exposed to silica above permissible and recommended exposure limits. Some miners may also be exposed at a high rate or to freshly fractured silica. CONCLUSIONS: Known dust control methods should be implemented and regular medical surveillance should be provided.     

Exposure-related health effects of silver and silver compounds: a review

A critical review of studies examining exposures to the various forms of silver was conducted to determine if some silver species are more toxic than others. The impetus behind conducting this review is that several occupational exposure limits and guidelines exist for silver, but the values for each depend on the form of silver as well as the individual agency making the recommendations. For instance, the American Conference of Governmental Industrial Hygienists has established separate threshold limit values for metallic silver (0.1 mg/m3) and soluble compounds of silver (0.01 mg/m3). On the other hand, the permissible exposure limit (PEL) recommended by the Occupational Safety and Health Administration and the Mine Safety and Health Administration and the recommended exposure limit set by the National Institute for Occupational Safety and Health is 0.01 mg/m3 for all forms of silver. The adverse effects of chronic exposure to silver are a permanent bluish-gray discoloration of the skin (argyria) or eyes (argyrosis). Most studies discuss cases of argyria and argyrosis that have resulted primarily from exposure to the soluble forms of silver. Besides argyria and argyrosis, exposure to soluble silver compounds may produce other toxic effects, including liver and kidney damage, irritation of the eyes, skin, respiratory, and intestinal tract, and changes in blood cells. Metallic silver appears to pose minimal risk to health. The current occupational exposure limits do not reflect the apparent difference in toxicities between soluble and metallic silver; thus, many researchers have recommended that separate PELs be established.     

A survey of private sector respirator use in the United States: an overview of findings

Limitations of previous surveys of respirator use led the National Institute for Occupational Safety and Health (NIOSH) and the Bureau of Labor Statistics to undertake a survey of respirator use and practices among U.S. private sector employers. The survey was mailed to 40,002 private sector establishments in August 2001; the responses were used to develop national estimates. Respirator use was required in 4.5% of establishments and for 3.1% of employees. Of the establishments requiring respirator use, 95% used air-purifying respirators and 17% used air-supplied respirators. Manufacturing; mining (including oil and gas extraction); construction; and agriculture, forestry, and fishing had the highest rates of establishment respirator use. Respirators were used most frequently to protect against dust/mist, paint vapors, and solvents. Large percentages of establishments requiring respirator use had indicators of potentially inadequate respirator programs. Of establishments requiring respirator use, 91% had at least one indicator of a potentially inadequate respiratory protection program, while 54% had at least five indicators. The survey findings suggest that large numbers of employers may not follow NIOSH recommendations and Occupational Safety and Health Administration (OSHA) and Mine Safety and Health Administration (MSHA) requirements for the selection and use of respirators, potentially putting workers at risk. The findings will aid efforts to increase the appropriate use of respirators in the workplace.     

WNA's worldwide overview on front-end nuclear fuel cycle growth and health, safety and environmental issues

This paper presents the WNA's worldwide nuclear industry overview on the anticipated growth of the front-end nuclear fuel cycle from uranium mining to conversion and enrichment, and on the related key health, safety, and environmental (HSE) issues and challenges. It also puts an emphasis on uranium mining in new producing countries with insufficiently developed regulatory regimes that pose greater HSE concerns. It introduces the new WNA policy on uranium mining: Sustaining Global Best Practices in Uranium Mining and Processing-Principles for Managing Radiation, Health and Safety and the Environment, which is an outgrowth of an International Atomic Energy Agency (IAEA) cooperation project that closely involved industry and governmental experts in uranium mining from around the world.     

The incidence and progression of pneumoconiosis over nine years in U.S. coal miners: II. Relationship with dust exposure and other potential causative factors

Examination of the incidence and progression of pneumoconiosis over 9 years in 1,261 nationally distributed U.S. coal miners has been undertaken in relationship to potential causative factors. Use has been made of a large body of data on dust levels collected by the Mine Safety and Health Administration principally for compliance purposes. Reported dust levels were low and generally under the current 2 mg/m3 standard. No link between dust level and disease progression could be detected. Some evidence was seen that radiological change was related to dust exposures prior to the study in both coal and noncoal mines, and thus experienced before the current dust standards were mandated. Neither migration of miners nor mining method appeared to be associated with disease incidence or progression. None of these findings can be taken as final, as the period of study is short and the number of cases of pneumoconiosis few. Further study is under way to obtain more reliable information over a longer period of follow-up.     

Exposure of miners to diesel exhaust particulates in underground nonmetal mines

A study was initiated to examine worker exposures in seven underground nonmetal mines and to examine the precision of the National Institute for Occupational Safety and Health (NIOSH) 5040 sampling and analytical method for diesel exhaust that has recently been adopted for compliance monitoring by the Mine Safety and Health Administration (MSHA). Approximately 1000 air samples using cyclones were taken on workers and in areas throughout the mines. Results indicated that worker exposures were consistently above the MSHA final limit of 160 micrograms/m3 (time-weighted average; TWA) for total carbon as determined by the NIOSH 5040 method and greater than the proposed American Conference of Governmental Industrial Hygienists TLV limit of 20 micrograms/m3 (TWA) for elemental carbon. A number of difficulties were documented when sampling for diesel exhaust using organic carbon: high and variable blank values from filters, a high variability (+/- 20%) from duplicate punches from the same sampling filter, a consistent positive interference (+26%) when open-faced monitors were sampled side-by-side with cyclones, poor correlation (r 2 = 0.38) to elemental carbon levels, and an interference from limestone that could not be adequately corrected by acid-washing of filters. The sampling and analytical precision (relative standard deviation) was approximately 11% for elemental carbon, 17% for organic carbon, and 11% for total carbon. An hypothesis is presented and supported with data that gaseous organic carbon constituents of diesel exhaust adsorb onto not only the submicron elemental carbon particles found in diesel exhaust, but also mining ore dusts. Such mining dusts are mostly nonrespirable and should not be considered equivalent to submicron diesel particulates in their potential for adverse pulmonary effects. It is recommended that size-selective sampling be employed, rather than open-faced monitoring, when using the NIOSH 5040 method.