Postexposure progression of pneumoconiosis among former Appalachian coal miners.

BACKGROUND: The prevalence of pneumoconiosis among working United States underground coal miners has been increasing for the past two decades, with the highest rates of disease observed among miners in the central Appalachian states of Kentucky, Virginia, and West Virginia. Surveillance for this disease in the United States focuses on working coal miners, who continue to be occupationally exposed to dust. This study examines the radiographic evidence for postexposure progression of pneumoconiosis in a population of former coal miners no longer occupationally exposed to coal mine dust who were seen at a community radiology clinic in eastern Kentucky. METHODS: Data were obtained and analyzed from clinical records of former coal miners who had a clinic encounter during January 1, 2017-August 1, 2019, a recorded final year of employment, and ≥2 postemployment digital chest radiographs. Radiographs were classified according to the International Labour Office guidelines by at least two B Readers. A final summary pneumoconiosis severity score (range, 0-13), accounting for both small and large opacities, was assigned to each chest radiograph. Progression was defined as an increase in severity score between a miner's radiographs over time. RESULTS: Data for 130 former coal miners were analyzed. All miners were male and most (n = 114, 88%) had worked primarily in Kentucky. Information on race/ethnicity was not available. The most common job types were roof bolters (n = 51, 39%) and continuous miner operators (n = 46, 35%). Forty-one (31.5%) miners had evidence of radiographic disease progression after leaving the workforce, with a median of 3.6 years between first and latest postretirement radiograph. A total of 80 (62%) miners had evidence of pneumoconiosis on their latest radiograph, and two-thirds (n = 53) of these were classified as progressive massive fibrosis (PMF), the most severe form of the disease. CONCLUSIONS: Postexposure progression can occur in former coal miners, emphasizing the potential benefits of continued radiographic follow-up postemployment. In addition to participating in disease screening throughout their careers to detect pneumoconiosis early and facilitate intervention, radiographic follow-up of former coal miners can identify new or progressive radiographic findings even after workplace exposure to respirable coal mine dust ends. Identification of progressive pneumoconiosis in former miners has potential implications for clinical management and eligibility for disability compensation.

Patterns of progressive massive fibrosis on modern coal miner chest radiographs.

Clinical teaching generally asserts that large opacities of progressive massive fibrosis (PMF) on chest radiographs present primarily bilaterally in the upper lung zones, and with an elevated background profusion of small opacities. However, the contemporary basis for these descriptions is limited.Radiographs taken for the Coal Workers' Health Surveillance Program during 2000-2015 and previously determined to have large opacities ("PMF radiographs", n = 204), and a random sample previously deemed free of large opacities (n =22), were independently reevaluated by three National Institute for Occupational Safety and Health (NIOSH) B Readers. Large opacities were noted primarily in the upper right (41%) or upper left (28%) lung zone, but 31% were in middle or lower zones. Unilateral involvement was observed in 34% of readings, with right lung predominance (82%). The median small opacity profusion category for the radiographs with PMF was 2/1. The number of large opacities was not correlated with small opacity profusion category. The "classic" descriptions of PMF as bilateral, associated with elevated background profusions of small pneumoconiotic opacities, were each absent in a third of miners.

The National Institute for Occupational Safety and Health B Reader Certification Program-An Update Report (1987 to 2018) and Future Directions.

OBJECTIVE: The National Institute for Occupational Safety and Health (NIOSH) B Reader Program provides the opportunity for physicians to demonstrate proficiency in the International Labour Office (ILO) system for classifying radiographs of pneumoconioses. We summarize trends in participation and examinee attributes and performance during 1987 to 2018. METHODS: Since 1987, NIOSH has maintained details of examinees and examinations. Attributes of examinees and their examination performance were summarized. Simple linear regression was used in trend analysis of passing rates over time. RESULTS: The mean passing rate for certification and recertification for the study period was 40.4% and 82.6%, respectively. Since the mid-1990s, the number of B Readers has declined and the mean age and years certified have increased. CONCLUSIONS: To address the declining B Reader population, NIOSH is currently taking steps to modernize the program and offer more opportunities for training and testing.