Table 1.
Number of workers, annual exposure, exposure duration and mortality among 10 pooled cohort studies of workers occupationally exposed to silica, 1919–1998, United States, South Africa, Australia, Finland, China.
| Industry | Workers | Person-years | Follow-up | Exposure period | Silica exposurea | Exposure durationc | Deaths | |
|---|---|---|---|---|---|---|---|---|
|
|
||||||||
| Median (IQR)b | Median (IQR)b | All | Lung cancer | |||||
| US diatomaceous | 2,342 | 66,057 | 1942–94 | 1942–94 | 127 (17,204) | 2.8 (0.7, 12.9) | 749 | 77 |
| South Africa gold | 2,260 | 31,477 | 1967–86 | 1967–72 | 154 (139,217) | 0.18 (0.1, 0.3) | 1009 | 77 |
| US gold | 3,345 | 114,345 | 1919–96 | 1919–78 | 27 (19,52) | 2.0 (1.0, 7.5) | 1925 | 156 |
| Australia gold | 2,209 | 43,636 | 1961–93 | 1961–93 | 214 (132,482) | 8.6 (4.2, 13.7) | 1342 | 135 |
| US granite | 5,408 | 121,019 | 1950–82 | 1950–82 | 40 (10,70) | 10.5 (3.0, 19.0) | 1762 | 125 |
| Finnish granite | 1,026 | 28,686 | 1940–93 | 1940–86 | 600 (390,1724) | 5.9 (1.4, 15.3) | 418 | 39 |
| US industrial sand | 4,064 | 93,766 | 1940–98 | 1940–89 | 52 (17,90) | 3.5 (0.9, 12.0) | 886 | 87 |
| China tungsten | 28,478 | 611,699 | 1972–94 | 1972–94 | 112 (22,303) | 14.5 (8.4, 21.8) | 4549 | 174 |
| China pottery | 9,011 | 194,098 | 1972–94 | 1972–94 | 36 (0,219) | 13.7 (7.6, 22.2) | 1592 | 85 |
| China tin | 7,856 | 170,404 | 1972–94 | 1972–94 | 69 (1,218) | 18.9 (10.8, 22.9) | 956 | 122 |
| Overall | 65,999 | 1,475,188 | 75 (2,236) | 14.7 (7.7, 22.1) | 15,188 | 1,077 | ||
Note that figures may differ from those reported in Steenland et al. (2001) due to averaging over different time-frames
a
Measured in μg/m3, average person–time at work
b
IQR indicates interquartile range
c
Measured in years, averaged over individuals