HRs for first time acute myocardial infarction in male and female workers occupationally exposed to respirable crystalline silica (RCS) during the follow-up period 1992–2006
| RCS (mg/m3-year) | Person-years (n) | Cases (n) | HR* (95% CI) | HR† (95% CI) |
| Men | ||||
| Unexposed | 6 289 437 | 28 298 | 1 | 1 |
| Ever exposed | 2 193 607 | 10 612 | 1.01 (0.99 to 1.04) | 1.02 (1.00 to 1.04) |
| Cumulative exposure Q1 0–0.27 | 573 528 | 1907 | 0.97 (0.93 to 1.02) | 0.98 (0.94 to 1.03) |
| Q2 0.27–0.62 | 518 674 | 2163 | 0.95 (0.91 to 1.00) | 0.97 (0.92 to 1.01) |
| Q3 0.62–1.54 | 549 361 | 2629 | 1.03 (0.99 to 1.07) | 1.03 (0.99 to 1.07) |
| Q4 1.54+ | 552 045 | 3913 | 1.06 (1.03 to 1.10) | 1.07 (1.03 to 1.10) |
| Trend per mg/m3-year | 1.02 (1.01 to 1.02), p<0.001 | |||
| Trend per mg/m3-year among the exposed | 1.02 (1.01 to 1.03), p<0.001 | |||
| Women | ||||
| Unexposed | 6 788 714 | 9301 | 1 | 1 |
| Ever exposed | 168 186 | 281 | 1.30 (1.15 to 1.46) | 1.29 (1.15 to 1.46) |
| Cumulative exposure Q1 0–0.27 | 57 076 | 73 | 1.18 (0.94 to 1.48) | 1.18 (0.94 to 1.48) |
| Q2 0.27–0.62 | 48 832 | 62 | 1.08 (0.84 to 1.38) | 1.07 (0.84 to 1.38) |
| Q3 0.62–1.54 | 43 295 | 93 | 1.43 (1.17 to 1.75) | 1.42 (1.15 to 1.74) |
| Q4 1.54+ | 18 983 | 53 | 1.66 (1.27 to 2.18) | 1.66 (1.27 to 2.18) |
| Trend per mg/m3-year | 1.18 (1.10 to 1.27), p<0.001 | |||
| Trend per mg/m3-year among exposed | 1.16 (1.03 to 1.30), p=0.016 | |||
Results are presented for cumulative exposure (quartile 1–4), for subjects ever exposed to RCS. The HR for trend indicates the increase in risk per mg-year of RCS.
*HRs adjusted for age.
†HRs adjusted for age, socioeconomic group and urbanisation index.