Table 2

Exposure specific mortality rates and mortality rate ratios from silicosis

Adjusted† rate ratio
Cumulative exposure to crystalline silica (mg/m3-y)Person years (×100000)Silicosis mortality rate (per 100000 py)*Adjusted† silicosis mortality rate (per 100000 py)RR(95% CI)
*Each category includes 17 silicosis deaths (total 170).
†Adjusted for age in four categories, calendar period in eight categories, study in six categories, using Poisson regression.
n.a., not applicable.
0–0.993.6374.74.71.00(referent)
0.99–1.970.63126.915.93.39(1.42 to 8.08)
1.97–2.870.29158.429.26.22(2.56 to 15.12)
2.87–4.330.25267.444.29.40(3.71 to 23.80)
4.33–7.120.27861.164.313.69(5.04 to 37.18)
7.12–9.580.18890.6106.422.64(7.88 to 65.10)
9.58–13.210.20483.2112.623.97(8.05 to 71.32)
13.21–15.890.118144.7189.240.25(13.25 to 122.3)
15.89–28.100.23173.6118.025.11(8.09 to 77.91)
>28.100.073233.6299.163.63(19.87 to 203.8)
Total5.90328.8n.a.n.a.n.a.