Table 2.
RRs (95% CIs) for mortality from IHD and all CVD from internal comparisons, by dioxin exposure level.
| Study | No. | IHD | All CVD |
|---|---|---|---|
| IARC (Vena al. 1998), TCDD/HCD exposure | 21,384 | ||
| No | 7,553 | 1.00 (—) | 1.00 (—) |
| Yes | 13,831 | 1.67 (1.23–2.26) | 1.51 (1.17–1.96) |
| NIOSHa (Steenland et al. 1999), cumulative exposure | 3,538 | ||
| 0 to < 19 | 505 | 1.00 (—) | NA |
| 19 to < 139 | 505 | 1.23 (0.75–2.00) | NA |
| 139 to < 581 | 505 | 1.34 (0.83–2.18) | NA |
| 581 to < 1,650 | 505 | 1.30 (0.79–2.13) | NA |
| 1,650 to < 5,740 | 505 | 1.39 (0.86–2.24) | NA |
| 5,740 to < 20,200 | 505 | 1.57 (0.96–2.56) | NA |
| ≥20,200 | 505 | 1.75 (1.07–2.87) | NA |
| Trend p-value = 0.05 | |||
| Ranch Handb (Ketchum and Michalek 2005), dioxin exposure category (ppt lipid) | 2,452 | ||
| Comparison | 1,436 | NA | 1.00 (—) |
| Background | 442 | NA | 0.80 (0.4–1.8) |
| Low (32.2–117.4) | 287 | NA | 1.80 (0.9–3.5) |
| High (117.9–4221.9) | 287 | NA | 1.50 (0.7–3.3) |
| Trend p-value = 0.07 | |||
| Hamburgc (Flesch-Janys et al. 1995), total I-TEQ (ng/kg lipid) | 1,177 | ||
| 1.19–39.5 | 471 | 1.00 (—) | 1.00 (—) |
| 39.6–98.9 | 235 | 0.85 (0.41–1.75) | 1.34 (0.85–2.13) |
| 99.0–278.5 | 235 | 0.86 (0.41–1.83) | 1.18 (0.71–1.95) |
| 278.6–545.2 | 118 | 1.31 (0.57–3.00) | 1.21 (0.66–2.25) |
| 545.3–4361.9 | 118 | 1.89 (0.79–4.51) | 1.40 (0.71–2.76) |
| Trend p-value = 0.03 | Trend p-value = 0.05 | ||
| Dutchd (Hooiveld et al. 1998), TCDD dose (ppt lipid) | 1,031 | ||
| Low (7.1) | 530 | 1.00 (—) | 1.00 (—) |
| Medium (7.7–124.1) | 259 | 1.50 (0.7–3.6) | 1.50 (0.8–2.8) |
| High (124.2–7307.5) | 242 | 2.30 (1.0–5.0) | 1.50 (0.8–2.9) |
| BASFe (Ott and Zober 1996), estimated TCDD dose | 243 | ||
| 1 μg/kg increase | NA | 0.93 (0.70–1.24) |
Abbreviations: HCD, higher chlorinated dioxins; NA, data not available.
The number for each exposure group was estimated by dividing the sample into septiles, as done by Steenland et al. (1999). The cumulative exposure measure is a relative ranking; the units cannot be interpreted as a specific dose of dioxin.
The serum dioxin levels were extrapolated back to the end of service in Vietnam. No extrapolated dioxin levels were presented for the comparison or background categories.
The number for each exposure group was estimated by combining the two lowest quintiles and halving the highest quintile, as done by Flesch-Janys et al. (1995). The serum dioxin levels were extrapolated back to the end of occupational exposure.
The serum dioxin levels were extrapolated back to the end of occupational exposure.
This study presented the RR for all CVD only for a 1-μg/kg increase in estimated TCDD dose.