Coal Workers' Pneumoconiosis–Attributable Years of Potential Life Lost to Life Expectancy and Potential Life Lost Before age 65 Years — United States, 1999–2016

Jacek M. Mazurek, MD, PhD; John Wood, MS; David J. Blackley, DrPH; David N. Weissman, MD

Disclosures

Morbidity and Mortality Weekly Report. 2018;67(30):819-824. 

Discussion

CDC's National Institute for Occupational Safety and Health (NIOSH) examined information on CWP deaths reported during 1968–2006, which indicated that CWP deaths and annual YPLL65 attributed to CWP have been decreasing.[3] The findings in the current report indicate that CWP deaths among U.S. residents aged ≥65 years continued to decrease during 1999–2016; however, no significant changes in CWP deaths among persons aged 25–64 years and CWP-attributable YPLL65 were observed. Furthermore, there was a sharp increase in the mean YPLL65 per decedent since 2002, with a peak (9.6 years) in 2004, followed by a continual, albeit slow, decline. Also, while there was a decline in YPLL during 1999–2016, the increase in the mean YPLL per decedent during this period indicates that each year, on average, decedents aged ≥25 years with CWP lost more years of life relative to their life expectancies. These premature deaths are consistent with observed increased severity and rapid progression of disease.[6–8]

The decline in age-adjusted CWP death rates and CWP-attributable YPLL might be explained, in part, by the decline in employment in the mining industry. The growing gap between each decedent's actual age at death from CWP and his or her life expectancy corroborates recent reports of increasing prevalence and severity of CWP and of rapid disease progression among coal miners.[6–8] In particular, an 8.6-fold increase in the prevalence of progressive massive fibrosis (PMF) from an annual average of 0.37% during 1994–1998 to 3.23% during 2008–2012, was identified among longer-tenured Kentucky, Virginia, and West Virginia underground coal miners participating in the Coal Workers' Health Surveillance Program.[6,7] Most of the CWP deaths in this report (68%) occurred among mining machine operators. This finding is consistent with a report describing a cluster of PMF cases identified in coal miners at a clinic in Kentucky, which found that a high proportion (76%) of miners reported working as roof bolters or continuous miner operators.[6] In addition, a recent study of 416 primarily former miners with PMF served by a network of three Black Lung Clinics in Southwest Virginia represents the largest known cluster of PMF reported in the scientific literature; one third of miners with CWP had indications of exceptionally severe and rapidly progressive disease.[9] Moreover, an increase in lung transplants performed for patients with CWP has been reported during 2008–2014.[10]

The findings in this report are subject to at least four limitations. First, CWP diagnosis as the underlying cause of death could not be validated. Some deaths from CWP might have been attributed to other interstitial lung diseases (e.g., idiopathic pulmonary fibrosis) or other chronic diseases (e.g., chronic obstructive pulmonary disease) occurring in coal miners. Second, there is no specific ICD-10 code for PMF to allow better identification of decedents with severe CWP. Third, complete work histories were not available for analyses. Finally, YPLL and YPLL65 in this report did not account for reduced quality of life or work years lost attributed to disability from CWP.¶¶

In 2014, a new Federal Rule*** on miners' occupational exposure to respirable coal mine dust was introduced. The rule decreased allowable exposure to respirable coal mine dust, made changes in dust monitoring, and directed NIOSH to expand medical monitoring for coal mine dust lung diseases. CDC provides information about diseases caused by coal mine dust and the Coal Workers' Health Surveillance Program.††† The continuing occurrence of premature deaths from CWP underscores the need for primary prevention through prevention of exposures to hazardous levels of coal mine dust, secondary prevention through early disease detection and prevention of further hazardous exposures, and tertiary prevention through provision of appropriate medical care to persons with CWP.

¶¶Persons with CWP can live for many years with severely impaired lung function and be unable to work. Coal mining has also been associated with silicosis, mixed dust pneumoconiosis, dust-related diffuse fibrosis, and chronic obstructive pulmonary disease (COPD) including emphysema and chronic bronchitis. COPD might develop independently of CWP.
***https://www.gpo.gov/fdsys/pkg/FR-2014-05-01/pdf/2014-09084.pdf.
††† https://www.cdc.gov/niosh/topics/cwhsp.

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