Table 2

Comparison between active miners with high and low dust concentrations in 1994 (n=131)

High for ⩾14 years (n=48) Low for ⩾4 years (n=83) p Value
Age (y, mean (SD))45.7 (3.4)45.5 (3.1)0.7
Estimated cumulative exposure to dust (mg/m3.y, mean (SD))71.8 (35.8)39.3 (39.9)0.0001
Smoking (%):
 Current smokers6351
Selenium concentration (ng/ml, mean (SD))59.5 (18.6)65.9 (19.1)0.06
Plasma GSH-Px (U/l, mean (SD))686 (203)698 (251)0.7
Erythrocyte GSH-Px (U/g Hb, mean (SD))37.9 (13.6)39.3 (11.6)0.5
Adjusted means:
 Age and smoking adjusted Se concentration (ng/ml)59.465.80.06
 Age and smoking adjusted plasma GSH-Px (U/l)6826890.9
 Age and smoking adjusted erythrocyte GSH-Px (U/g Hb)38.639.10.8