Skip to main content

Table 1 Demographic factors and clinical findings of underground copper miners from selected mines in Zambia

From: The risk of pulmonary tuberculosis in underground copper miners in Zambia exposed to respirable silica: a cross-sectional study

Characteristics Mine 1 (n = 137) Mine 2 (n = 99) Mine 3 (n = 121)
Age at certificationa, years, (mean (SD)) (Range) 30.8 (5.9) (19.6–49.1) 31.9 (6.9) (21.2–54.2) 31.3 (6.0) (19–52.2)
Sex, n, (%)
 Male 137 (100) 99 (100) 121 (100)
Smoking, n, (%) b
 Non-smokers 121 (88.3) 76 (76.8) 98 (81)
 Smokers 14 (10.2) 17 (17.2) 20 (16.5)
 Unknown 2 (1.5) 6 (6.1) 3 (2.5)
Chest radiographs, n, (%)
 Normal 117 (85.4) 82 (82.8) 98 (81)
 Abnormal (PTB) c 12 (8.8) 7 (7.1) 14 (11.6)
 Abnormal (Non-PTB) d 8 (5.8) 10 (10.1) 9 (7.4)
AFB Positive n, (%) 4 (33.3) 5 (62.5) 7 (50)
ESR mm/h, mean, (SD) (Range) 76.9 (31.0) (35–127) 73.3 (25.2) (30–108) 85.2 (22.1) (54–133)
  1. ESR Erythrocyte sedimentation rate (positive if >20 mm/h)
  2. AFB Acid-fast bacillus
  3. aAge at certification – mean age of the miners at the time of certification compared across the Mines
  4. bSmoking status –current smokers at employment
  5. cAbnormal radiographs (PTB) = Chest radiographs suggestive of PTB
  6. dAbnormal radiographs (Non PTB) = Chest radiographs suggestive of chest pathology other than PTB