Table 2. Distribution (percentiles and mean) of lead concentration by source of exposure.
| Exposure variables |
Percentiles |
GM (95% CI) | ||
|---|---|---|---|---|
| 10th | 50th | 90th | ||
| Kitchen tap water (μg/L) (n=306) | ||||
| 5M1L | 0.16 | 1.24 | 4.51 | 0.89 (0.77, 1.04) |
| 30M1L | 0.44 | 2.33 | 7.05 | 1.91 (1.69, 2.16) |
| 30M2L | 0.31 | 2.24 | 7.39 | 1.66 (1.45, 1.90) |
| 30M3L | 0.24 | 1.99 | 7.39 | 1.55 (1.33, 1.80) |
| 30M4L | 0.25 | 1.90 | 10.06 | 1.53 (1.30, 1.80) |
| AM of 5 samplesa | 0.30 | 2.08 | 7.51 | 1.60 (1.40, 1.84) |
| Dust (μg/ft2) | ||||
| Floor (n=305) | 0.19 | 0.70 | 4.70 | 0.85 (0.73, 0.98) |
| Windowsill (n=263) | 1.06 | 7.15 | 50.89 | 7.14 (5.84, 8.73) |
| Paint (mg/kg) | ||||
| Paint chips (n=157)b | 15 | 1,300 | 24,000 | — |
Abbreviations: 5M1L: first liter after 5 min flushing; 30 M, after 30 min of stagnation; 1L, first liter; 2L, second liter; 3L, third liter; 4L, fourth liter; AM, arithmetic mean; CI, confidence interval; GM, geometric mean.
a
Arithmetic mean of the 5 kitchen tap water samples (1 liter after 5 min flushing and 4 consecutive liters after 30-minute stagnation).
b
Highest concentration of lead in paint chip per home.