Small mine size is associated with lung function abnormality and pneumoconiosis among underground coal miners in Kentucky, Virginia and West Virginia

Abstract

Objectives To describe the prevalence of lung function abnormality and coal workers’ pneumoconiosis (CWP) by mine size among underground coal miners in Kentucky, Virginia and West Virginia. Methods During 2005–2012, 4491 miners completed spirometry and chest radiography as part of a health surveillance programme. Spirometry was interpreted according to American Thoracic Society and European Respiratory Society guidelines, and radiography per International Labour Office standards. Prevalence ratios (PR) were calculated for abnormal spirometry (obstructive, restrictive or mixed pattern using lower limits of normal derived from National Health and Nutrition Examination Survey (NHANES) III) and CWP among workers from small mines (≤50 miners) compared with those from large mines. Results Among 3771 eligible miners, those from small mines were more likely to have abnormal spirometry (18.5% vs 13.8%, p<0.01), CWP (10.8% vs 5.2%, p<0.01) and progressive massive fibrosis (2.4% vs 1.1%, p<0.01). In regression analysis, working in a small mine was associated with 37% higher prevalence of abnormal spirometry (PR 1.37, 95% CI 1.16 to 1.61) and 2.1 times higher prevalence of CWP (95% CI 1.68 to 2.70). Conclusions More than one in four of these miners had evidence of CWP, abnormal lung function or both. Although 96% of miners in the study have worked exclusively under dust regulations implemented following the 1969 Federal Coal Mine Safety and Health Act, we observed high rates of respiratory disease including severe cases. The current approach to dust control and provision of safe work conditions for central Appalachian underground coal miners is not adequate to protect them from adverse respiratory health effects.

Respiratory morbidity among U.S. coal miners in states outside of central Appalachia

“…Higher disease prevalence has been associated with coal rank, mine employment size, mine seam height, and mining practices. 3,13,14,19–21 These risk factors differ across mining regions, and likely play a role in the differences in CWP prevalence and lung function impairment we observed in this report. However, it is important to note that our study found that both underground and surface miners working in each of the U.S. coal-mining regions have developed CWP and lung function impairment.…”

“…Recent reports have focused on increases in coal mine dust-related respiratory disease in central Appalachia, 2,3,12 but these findings point to an ongoing need for prevention and surveillance wherever coal miners work. Previous studies of respiratory morbidity in all U.S. coal mining regions have generally found lower rates of CWP and respiratory impairment among miners in regions outside of central Appalachia.…”

“…11 Spirometry results were classified into four patterns: normal, obstructive, restrictive, and mixed as previously described. 3 …”

“…1–3 In 2005, the National Institute for Occupational Safety and Health (NIOSH) implemented the Enhanced Coal Workers’ Health Surveillance Program (ECWHSP). 4 The ECWHSP’s mobile examination unit has targeted regions where coal workers’ pneumoconiosis (CWP) is more common; areas where NIOSH’s routine surveillance program, the Coal Workers Health Surveillance Program (CWHSP), has had low participation; and surface miners who were not covered under routine surveillance.…”

Injury and Illness Data for Illinois Mining Industry Employees, 1990 to 2012

“…3 In addition, employment in smaller establishments has been noted as a risk factor for injury and illness in many industries, including mining. [11][12][13][14][15] Risk of injury is increased among young workers and during their first few years of mining employment. 11 Occupational injury and illness data for the United States are substantially underreported; although it is unclear to what degree underreporting occurs in the mining sector.…”