Table 2.
Estimated exposure to arsenic (μg kg−1 d−1) during the first year of life. These estimates were calculated using central tendency or upper-bound inputs for the body-weight adjusted ingestion rate, the concentration of arsenic in infant formula powder, and the concentration of arsenic in breast milk. Variability among infants is due to individual-level data on the concentration of arsenic in tap water (for Formula-fed and Mixed feeding infants) and change in feeding mode over time.
| A) Central tendency model | ||||||||
|---|---|---|---|---|---|---|---|---|
| All |
Breastfed |
Mixed |
Formula Fed |
|||||
| % (n) | GM (95% CI)a | % (n) | Valueb | % (n) | GM (95% CI) | % (n) | GM (95% CI) | |
| 4 months | 100 (356) | 0.10 (0.09, 0.12) | 45 (159) | 0.03 | 24 (85) | 0.20 (0.16, 0.25) | 31 (112) | 0.28 (0.23, 0.34) |
| 8 months | 100 (356) | 0.09 (0.08, 0.10) | 33 (119) | 0.02 | 16 (58) | 0.13 (0.10, 0.17) | 50 (179) | 0.20 (0.17, 0.24) |
| 12 months | 100 (356) | 0.07 (0.07, 0.08) | 21 (73) | 0.01 | 13 (48) | 0.07 (0.05, 0.09) | 66 (235) | 0.13 (0.11, 0.15) |
|
| ||||||||
| B) Upper bound model | ||||||||
|
| ||||||||
| All |
Breastfed |
Mixed |
Formula Fed |
|||||
| % (n) | GM (95% CI)a | % (n) | Valueb | % (n) | GM (95% CI) | % (n) | GM (95% CI) | |
|
| ||||||||
| 4 months | 100 (356) | 0.22 (0.20, 0.24) | 45 (159) | 0.09 | 24 (85) | 0.37 (0.30, 0.44) | 31 (112) | 0.51 (0.43, 0.61) |
| 8 months | 100 (356) | 0.24 (0.21, 0.26) | 33 (119) | 0.08 | 16 (58) | 0.30 (0.24, 0.38) | 50 (179) | 0.45 (0.40, 0.52) |
| 12 months | 100 (356) | 0.24 (0.21, 0.26) | 21 (73) | 0.06 | 13 (48) | 0.21 (0.17, 0.25) | 66 (235) | 0.37 (0.33, 0.41) |
a
GM=Geometric mean and 95% CI=95% confidence interval
b
There is no distribution for breastfed infants because all infants had the same input values for body-weight adjusted ingestion rate