The mortality of Appalachian coal miners was evaluated and a followup study was conducted after 14 years. Of 3726 underground coal miners evaluated in 1962, 2850 were still living, 25 could not be traced, and 843 had died. Death certificates were obtained for all but 51 of those who had died and cause of death was determined. A significant excess of deaths from all causes was seen for miners with progressive massive fibrosis (PMF) who smoked, worked underground for more than 30 years, or who had a forced expiration volume, forced vital capacity percent ratio greater than 70. Smokers had higher mortalities from all causes, ischemic heart disease, and lung cancer than nonsmokers. The contribution of PMF and smoking to mortality from these causes was similar. Coal mine exposure did not contribute to deaths from ischemic heart disease, digestive cancer, or accidents, but PMF increased mortalities from nonmalignant respiratory disease and all other causes. The author concludes that the cohort should be followed for at least 5 to 10 more years to determine any excess mortality from lung cancer among low risk groups after sufficient time is allowed for long latency.
Epidemiological Investigations Branch, NIOSH, Morgantown, West Virginia, NTIS PB83-235-556, 56 pages, 42 references