Table 1.
Expected mean IQ loss estimates for children exposed at the level of the standard.
| Potential Level for Standard (µg/m3) | Air-to-Blood Lead Ratio* | ||
|---|---|---|---|
| 1:5 | 1:7 | 1:10 | |
| 0.50 | 4.4 (3.9–7.4) | >5 a | >5 a |
| 0.40 | 3.5 (3.1–5.9) | 4.9 (4.4–8.2) | b |
| 0.30 | 2.6 (2.3–4.4) | 3.7 (3.3–6.2) | 5.3 (4.7–8.8) |
| 0.25 | 2.2 (2.0–3.7) | 3.1 (2.7–5.1) | 4.4 (3.9–7.4) |
| 0.20 | 1.8 (1.6–2.9) | 2.5 (2.2–4.1) | 3.5 (3.1–5.9) |
| 0.15 | 1.3 (1.2–2.2) | 1.8 (1.6–3.1)c | 2.6 (2.3–4.4) |
| 0.10 | 0.9 (0.8–1.5) | 1.2 (1.1–2.1) | 1.8 (1.6–2.9) |
| 0.05 | 0.4 (0.4–0.7) | 0.6 (0.5–1.0) | 0.9 (0.8–1.5) |
| 0.02 | 0.2 (0.2–0.3) | 0.2 (0.2–0.4) | 0.4 (0.3–0.6) |
* Ranges are based on the lowest and highest concentration-response functions. a For these combinations of air-to-blood ratio and standard, the resulting estimate is too uncertain to state with precision; b Not reported; c Final standard level and associated mean IQ loss highlighted for emphasis; Reference: 73 FR 66964 [11].