Ed. Kuempel et al., EXPOSURE-RESPONSE ANALYSIS OF MORTALITY AMONG COAL-MINERS IN THE UNITED-STATES, American journal of industrial medicine, 28(2), 1995, pp. 167-184
The quantitative relationship between exposure to respirable coal mine
dust and mortality from nonmalignant respiratory diseases was investi
gated in a study of 8,878 working male coal miners who were medically
examined from 1969 to 1971 and followed to 1979. Exposure-related mort
ality was evaluated using Cox proportional hazards modeling for underl
ying or contributing causes of death and modified lifetable methods fo
r underlying causes. For pneumoconiosis mortality, the lifetable analy
ses showed increasing standardized mortality ratios (SMRs) with increa
sing cumulative exposure category. Significant exposure-response relat
ionships for mortality from pneumoconiosis (p < 0.001) and from chroni
c bronchitis or emphysema (p < 0.05) were observed in the proportional
hazards models after controlling for age and smoking. No exposure-rel
ated increases in lung cancer or stomach cancer were observed. Pneumoc
oniosis mortality was found to vary significantly by the rank of coal
dust to which miners were exposed. Miners exposed at or below the curr
ent U.S. coal dust standard of 2 mg/m(3) over a working lifetime, base
d on these analyses, have an elevated risk of dying from pneumoconiosi
s or from chronic bronchitis or emphysema. (C) 1995 Wiley-Liss, Inc.