Table 4
Predictions of risk (%) of silicotic signs of profusion 2/1+, 15 years after exposure ends, as a function of 15 years spent in low concentrations and additional months in high (2 mg.m−3) concentrations
| Extra months at 2.0 mg.m−3 (SEM in italics) | |||||||||
|---|---|---|---|---|---|---|---|---|---|
| Silica conc. (mg.m−3) | Equivalent cum. exp. (g.h.m−3)* | 0 | 4 | 8 | 12 | ||||
| Population aged 50–74, post-1964 exposures. ln(p2/(1 − p2)) = −4.83 + 0.44 × CE<2 + 1.32 × CE>2. | |||||||||
| *Assumes a standard working year of 1740 hours. | |||||||||
| 0.30 | 7.83 | 20.52 | 4.95 | 54.51 | 8.74 | 84.76 | 7.83 | 96.27 | 3.25 |
| 0.20 | 5.22 | 7.50 | 1.77 | 27.36 | 5.96 | 63.61 | 13.22 | 89.03 | 8.59 |
| 0.10 | 2.61 | 2.49 | 0.89 | 10.58 | 3.72 | 35.46 | 14.18 | 71.84 | 18.37 |
| 0.08 | 2.09 | 1.98 | 0.78 | 8.59 | 3.32 | 30.36 | 13.49 | 66.93 | 20.36 |
| 0.06 | 1.57 | 1.58 | 0.68 | 6.93 | 2.94 | 25.70 | 12.58 | 61.62 | 22.08 |
| 0.04 | 1.04 | 1.26 | 0.59 | 5.58 | 2.58 | 21.53 | 11.53 | 56.02 | 23.40 |
| 0.02 | 0.52 | 1.00 | 0.51 | 4.48 | 2.25 | 17.88 | 10.39 | 50.26 | 24.18 |
| 0.00 | 0.00 | 0.80 | 0.44 | 3.59 | 1.95 | 14.73 | 9.23 | 44.50 | 24.37 |
