Respiratory disease and suicide among U.S. coal miners: is there a relationship?

A case-control study was performed to test whether or not respiratory disease in coal miners presented a risk for suicide. While coal miners in general do not experience elevated rates of suicide, coal miners with respiratory disease have been found to have high rates of psychiatric disability, especially depressive reactions. Further, depression has been related to suicide. To test the hypothesis, 50 suicide deaths from four National Institute for Occupational Safety and Health cohorts of coal miners were matched by age at death to two series of controls, a noncancer, nonaccident control series, and a cancer control series. Using odds ratios (tested by chi-square) the risks of obstructive lung disease and coal workers pneumoconiosis were evaluated together with the risks of years of underground mining, cigarette smoking at the time of cohort creation, and ever having smoked cigarettes. Neither respiratory disease was found to pose a statistically elevated risk of suicide in this sample of U.S. white male coal miners.     

Pneumoconiosis and advanced occupational lung disease among surface coal miners--16 states, 2010-2011

Coal workers' pneumoconiosis (CWP) is a chronic occupational lung disease caused by long-term inhalation of dust, which triggers inflammation of the alveoli, eventually resulting in irreversible lung damage. CWP ranges in severity from simple to advanced; the most severe form is progressive massive fibrosis (PMF). Advanced CWP is debilitating and often fatal. To prevent CWP, the Coal Mine Health and Safety Act of 1969 established the current federal exposure limit for respirable dust in underground and surface coal mines. The Act also established a surveillance system for assessing prevalence of pneumoconiosis among underground coal miners, but this surveillance does not extend to surface coal miners. With enforcement of the exposure limit, the prevalence of CWP among underground coal miners declined from 11.2% during 1970-1974 to 2.0% during 1995-1999, before increasing unexpectedly in the last decade, particularly in Central Appalachia. Exposure to respirable dust is thought to be less in surface than underground coal miners. Although they comprise 48% of the coal mining workforce, surface coal miners have not been studied since 2002. To assess the prevalence, severity, and geographic distribution of pneumoconiosis among current surface coal miners, CDC obtained chest radiographs of 2,328 miners during 2010-2011 through the Coal Workers' Health Surveillance Program of the National Institute for Occupational Safety and Health (NIOSH). Forty-six (2.0%) of 2,257 miners with >1 year of surface mining experience had CWP, including 37 who had never worked underground. Twelve (0.5%) had PMF, including nine who had never worked underground. A high proportion of the radiographs suggested silicosis, a disease caused by inhalation of crystalline silica. Surface coal mine operators should monitor worker exposures closely to ensure that both respirable dust and silica are below recommended levels to prevent CWP. Clinicians should be aware of the risk for advanced pneumoconiosis among surface coal miners, in addition to underground coal miners, to facilitate prompt disease identification and intervention.     

The Effects of Cigarette Smoking Cessation on 5-year Pulmonary Function Changes in US Underground Coal Miners

A 5-year prospective study of cigarette smoking cessation wasperformed using 1300 US underground coal miners who were studiedin 1977 and re-studied in 1982 as part of an ongoing NationalInstitute for Occupational Safety and Health (NIOSH) project.Five-year changes in the spirometry-based measures of pulmonaryfunction were analysed separately for Western and Eastern whitemale miners using least-squares means models which allowed adjustmentfor the biological variables of age and height and also foroccupational exposure to coal mine dust. Western and Easternminers were analysed separately because Eastern miners experiencedmuch greater average pulmonary function declines than Westernminers. Smoking status was statistically related to the declinein forced expiratory volume in 1 second (FEV₁) in Western miners.Miners reporting smoking cessation showed a rebounding of valuescompared with declines for continuing smokers and lifetime non-smokers.This rebounding of FEV₁ among workers whose occupational exposuresare known to reduce pulmonary function (coal mine dust) is discussedfrom the perspective of smoking cessation programmes. Requests for reprints should be addressed to: Dr Richard G. Ames, Appalachian Laboratory for Occupational Safety and Health, Morgantown, WV 26505, USA.     

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.     

Respiratory impairment and symptoms as predictors of early retirement with disability in US underground coal miners.

A five-year prospective study of 1,394 United States underground coal miners was undertaken to study the effects of respiratory impairment on the rate of early retirement with disability (ERD). Using a logistic regression analysis, ERD was found to be related to reported persistent phlegm after adjustment was made for other respiratory symptoms, respiratory function measurements, cigarette smoking, and some demographic characteristics. No prediction of ERD occurred for spirometrically determined measures of respiratory function. The data thus give limited support to the hypothesis that early retirement with disability in underground coal miners can be predicted prospectively by measures of respiratory symptoms.     

Mobility of diesel versus non-diesel coal miners: some evidence on the healthy worker effect.

Workers who are particularly susceptible to the effects of their occupational exposure, from the perspective of the healthy worker effect, soon leave the workplace. The result of this mobility, called survival bias, is that cross sectional studies based on the survivors underestimate the true risk of occupational exposures. Two questions are addressed in this empirical study of the "survival bias" component of the "healthy worker" effect. Do miners with respiratory impairment or symptoms disproportionately leave jobs that have a potentially harmful respiratory exposure? And does the presence of an additional potentially harmful respiratory exposure, in this case diesel emissions, accelerate the rate of mobility for miners with respiratory impairment or symptoms? No confirmation was found for the survival effect in a study of 738 diesel and 420 non-diesel US underground coal miners. No additional increment in mobility was associated with exposure to both coal mine dust and diesel emissions.     

Current knowledge of US metal and nonmetal miner health: Current and potential data sources for analysis of miner health status

Little is known about the current health status of US metal and nonmetal (MNM) miners, in part because no health surveillance systems exist for this population. The National Institute for Occupational Safety and Health (NIOSH) is developing a program to characterize burden of disease among MNM miners. This report discusses current knowledge and potential data sources of MNM miner health. Recent national surveys were analyzed, and literature specific to MNM miner health status was reviewed. No robust estimates of disease prevalence were identified, and national surveys did not provide information specific to MNM miners. Because substantial gaps exist in the understanding of MNM miners' current health status, NIOSH plans to develop a health surveillance program for this population to guide intervention efforts to reduce occupational and personal risks for chronic illness.     

The derivation of estimated dust exposures for U.S. coal miners working before 1970.

A number of reports on the prevalence of coal workers' pneumoconiosis in U.S. coal miners have been published, yet very little is known about the relationship between dust exposure and pneumoconiosis levels in the U.S. This report describes the derivation of cumulative dust exposure estimates by back-extrapolation of data processed by the Mine Safety and Health Administration after 1970 by using a ratio of dust concentrations based on information collected during environmental surveys at certain U.S. mines by the Bureau of Mines between 1968 and 1969. Cumulative personal dust exposure estimates were calculated by using occupational histories obtained from the miners and job-specific estimates of dust concentration. In other reports, the resulting estimated exposures have been shown to correlate well with various measures of respiratory morbidity.     

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.     

Workers' health in Israel.

BACKGROUND: Occupational hazards are important causes of morbidity, mortality, and disability in the community. This article presents a review of workers' health in Israel. METHODS: Data were collated from the Occupational Health Institute of the University of Tel Aviv, the National Insurance Institute, the Occupational Health Departments of the General Sick Fund, and the Institute of Safety and Hygiene of the Ministry of Labor and Welfare. International comparisons are based on data derived from the WHO Health for All database for the European region. RESULTS: Levels of most biological and chemical exposures in 1996 were found to be in accordance with the standards, except for dust, gases, pesticides, and noise exposure. In 1996, 4.3% of the working population received injury compensation from the National Insurance Institute. 78% of workers' claims approved in 1992-1994 were for injuries to the back and spine. 93% of new cases of occupational diseases and injuries reported in 1996 by the occupational health service of the largest Health Fund were due to noise-induced hearing impairments. In 1996, there were 87 reported deaths following work accidents; about 50% of them were falls that occurred in the construction industry, and 26% of fatalities were among foreign workers. Rates of work accidents, average days of incapacity per accident, and fatalities have been increasing since 1991. Rates of occupational accidents and of occupational fatalities are higher than the European Community average. CONCLUSIONS: Rates of occupational diseases and of injury compensation among workers are increasing, despite the efforts and resources invested in the prevention of work accidents and the promotion of workers' health. These findings indicate the necessity for further research and efforts toward the prevention of injuries and the promotion of occupational health in Israel.     

Noise exposure and hearing conservation in U.S. coal mines--a surveillance report

This study examines the patterns and trends in noise exposure documented in data collected by Mine Safety and Health Administration inspectors at U.S. coal mines from 1987 through 2004. During this period, MSHA issued a new regulation on occupational noise exposure that changed the regulatory requirements and enforcement policies. The data were examined to identify potential impacts from these changes. The overall annual median noise dose declined 67% for surface coal mining and 24% for underground coal mining, and the reduction in each group accelerated after promulgation of the new noise rule. However, not all mining occupations experienced a decrease. The exposure reduction was accompanied by an increase of shift length as represented by dosimeter sample duration. For coal miners exposed above the permissible exposure level, use of hearing protection devices increased from 61% to 89% during this period. Participation of miners exposed at or above the action level in hearing conservation programs rapidly reached 86% following the effective date of the noise rule. Based on inspection data, the occupational noise regulation appears to be having a strong positive impact on hearing conservation by reducing exposures and increasing the use of hearing protection devices and medical surveillance. However, the increase in shift duration and resulting reduction in recovery time may mitigate the gains somewhat.     

Mobility of diesel versus non-diesel coal miners: some evidence on the healthy worker effect

Workers who are particularly susceptible to the effects of their occupational exposure, from the perspective of the healthy worker effect, soon leave the workplace. The result of this mobility, called survival bias, is that cross sectional studies based on the survivors underestimate the true risk of occupational exposures. Two questions are addressed in this empirical study of the "survival bias" component of the "healthy worker" effect. Do miners with respiratory impairment or symptoms disproportionately leave jobs that have a potentially harmful respiratory exposure? And does the presence of an additional potentially harmful respiratory exposure, in this case diesel emissions, accelerate the rate of mobility for miners with respiratory impairment or symptoms? No confirmation was found for the survival effect in a study of 738 diesel and 420 non-diesel US underground coal miners. No additional increment in mobility was associated with exposure to both coal mine dust and diesel emissions.     

Airway responsiveness and job selection: a study in coal miners and non-mining controls.

BACKGROUND--It has been suggested that health related job selection is a major cause of the healthy worker effect, and may result in inaccurate estimates of health risks of exposures in the working environment. Improved understanding of self selection, including the role of airway hyperresponsiveness, should improve accuracy in estimating occupational risks. METHODS--We evaluated symptoms of the respiratory tract, lung function, occupational and smoking histories, and airway responsiveness from a cross sectional survey of 478 underground bituminous coal miners and non-mining controls. Workers with abnormal spirometry were excluded from methacholine testing. RESULTS--Methacholine responsiveness (> or = 15% decline in forced expiratory volume in one second) was associated in both miners and controls with reduced ventilatory lung function and an increased risk of respiratory symptoms. Miners with the longest duration of work at the coal face had a low prevalence of methacholine responsiveness, compared with miners who had never worked at the coal face (12% v 39%, P < 0.01). Throughout their mining careers, miners who responded to methacholine were consistently less likely to have worked in dusty jobs than miners who did not respond to methacholine. CONCLUSIONS--These results provide evidence that workers who are employed in dusty jobs are less likely than their unexposed coworkers to show increased non-specific airway responsiveness, presumably as a result of health related job selection. Surveys of workers in which responsiveness data are unavailable may underestimate the effects of dust exposure on respiratory health.     

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.     

川南小型民营煤矿企业矿工职业健康现况

目的了解川南小型民营煤矿企业矿工的健康现况,分析存在的主要健康问题,提出保护其健康的对策。方法采取整群抽样的方法,结合职业卫生现况调查,按照《职业健康监护技术规范》要求,对1314名煤矿工人进行职业性健康体检。结果此次体检人数中肺功能检查正常为75．2％,高仟伏胸片检查正常为79．8％,尘肺病诊断人数占体检人数的2．06％,尘肺病发病高峰在接触矽尘10～20年间。结论预防川南小型煤矿尘肺病发病的重点是控制粉尘浓度,只有降低粉尘浓度,才是降低川南小型煤矿尘肺病发病率唯一可行的方法。     

4329名煤矿职工职业健康检查结果分析

目的保护劳动者健康及其相关权益,为制定职工健康的预防措施提供科学依据。方法根据卫生部《职业健康监护管理办法》及《职业健康监护规范》(GBZ 188-2007)规定和要求进行调查。结果在检职工4 329人中,共查出各类疾病及单项指标异常1 552人次,总检出率为35.8%。检出疑似煤工尘肺48例、疑似职业性噪声聋101例(接尘工龄、接噪工龄均在10年以上,年龄均在30岁以上),检出率分别为1.1%、2.3%;粉尘作业职业禁忌证6例,噪声作业职业禁忌证16例,其他胸片异常97例,血压异常365例,心电图异常381例,转氨酶升高168例,血、尿常规异常370例。各种疾病及单项功能指标异常的检出率随年龄增长而增高,随着工龄的增加各种疾病及功能指标异常的检出率也随之增加。结论该市煤矿工人健康状况不容乐观,用人单位及广大职工应提高职业卫生法制意识,自觉养成良好的职业卫生习惯,做好职业健康检查工作。     

Chronic respiratory effects of exposure to diesel emissions in coal mines

A 5-yr prospective design was employed to test the hypothesis that exposure to diesel emissions leads to chronic respiratory effects among underground coal miners. Changes in respiratory function and development of chronic respiratory symptoms were measured during a 5-yr study period (i.e., 1977 to 1982) in 280 diesel-exposed and 838 control miners from Eastern and Western United States underground coal mines. Spirometry measures of respiratory function included forced expiratory volume in 1 sec (FEV1.0), forced vital capacity (FVC), and forced expiratory flow rate at 50% of FVC (FEF50). Chronic respiratory symptom measures, which included chronic cough, chronic phlegm, and breathlessness, were obtained by questionnaires, as were smoking status and occupational history. Based upon these data, the pattern of evidence did not support the hypothesis either in an age-adjusted comparison of diesel vs. nondiesel miners or in an internal analysis by cumulative years of diesel exposure.     

Respiratory Status of Surface Coal Miners in the United States

The United States Public Health Service examined 1,438 surface coal miners to determine the prevalence of coal worker’s pneumoconiosis (CWP), chronic bronchitis, and ventilatory impairment among them. Four percent (fifty-nine individuals) showed some roentgenographic evidence of pneumoconiosis, but only seven miners had films interpreted as CWP of category2 or greater (according to the UlCC/Cincinnati classification system). Moreover, most of the affected miners had worked in underground coal mines for prolonged periods. Significant decrements in pulmonary function to increasing exposure to surface mine dust were demonstrated only in the forced vital capacity of smokers. Increased prevalence of chronic bronchitis with increasing exposure was found in all smoking categories. However, significant airway obstruction was an uncommon finding (6.6%) in nonsmoking miners. Employment in surface mining was not likely to cause either the development of CWP or clinically significant respiratory impairment.     

Smoking cessation among coal miners as predicted by baseline respiratory function and symptoms: a 5-year prospective study

A prospective analysis was used to test whether respiratory impairment or the presence of respiratory symptoms predicts 5-year cigarette smoking cessation in a sample of 1,118 U.S. white, male, underground coal miners. Miners were examined in 1977 and re-examined in 1982 by NIOSH, and all miners with test abnormalities were so informed by letter. Respiratory impairment was measured by an index of airways obstruction combining the spirometric measures of Forced Vital Capacity (FVC) and Forced Expiratory Volume in 1 sec (FEV1). Bronchitis symptoms were measured by an index that combined chronic cough (3+ months/year) and chronic phlegm (3 + months/year). Among these coal miners, the presence of chronic respiratory symptoms initially was inversely associated with cigarette smoking cessation. Respiratory impairment, however, was positively associated with cigarette smoking cessation but did not reach statistical significance.     

合川区煤矿工人职业病防治知识知晓调查分析

目的了解合川区煤矿工人的人群特征和对职业病防治知识知晓情况,评价《职业病防治法》实施以来职业病健康促进工作对煤矿工人的影响,为今后进一步加强职业病防治健康教育和健康促进提供科学依据。方法使用统一设计的调查问卷对合川辖区内煤矿生产企业在岗的从业人员进行了抽样调查。结果绝大多数煤矿工人的文化程度为文盲或小学,对职业病防治知识知晓少,获取职业病防治知识的主要途径是人际传播。结论应将煤矿工人作为重点人群进行宣传教育,将职业病防治知识及相关政策作为重点内容,提高煤矿工人的职业病防治意识。