Comparison between subgroups of estimated cumulative exposure to dust in active miners in 1994 (n=131)
| High for ⩾14 y | Low for ⩾4 y | |||||||
|---|---|---|---|---|---|---|---|---|
| >68 mg/m3.y (n=19) | ⩽68 mg/m3.y (n=29) | p Value | >68 mg/m3.y (n=18) | 21–68 mg/m3.y (n=16) | ⩽21 mg/m3.y (n=49) | p Value | ||
| Selenium concentration (ng/ml, mean (SD)) | 52.1 (19.0) | 64.4 (17.0) | 0.03 | 61.1 (17.9) | 62.1 (16.8) | 68.9 (20.1) | 0.2 | |
| Plasma GSH-Px (U/l, mean (SD)) | 685 (185) | 687 (217) | 0.9 | 577 (221) | 713 (166) | 739 (274) | 0.06 | |
| Erythrocyte GSH-Px (U/g Hb, mean (SD)) | 43.4 (12.6) | 34.4 (13.4) | 0.03 | 39.1 (9.9) | 40.4 (9.1) | 38.9 (13.3) | 0.9 | |
| Adjusted means: | ||||||||
| Age and smoking adjusted Se concentration (ng/ml) | 54.6 | 64.6 | 0.08 | 62.9 | 62.5 | 67.6 | 0.5 | |
| Age and smoking adjusted plasma GSH-Px (U/l) | 704 | 689 | 0.8 | 581 | 705 | 709 | 0.14 | |
| Age and smoking adjusted erythrocyte GSH-Px (U/g Hb) | 45.6 | 35.6 | 0.02 | 39.5 | 39.8 | 38.7 | 0.9 | |