Carignan et al. 2015 — Arsenic Sources in Infancy: Well Water vs Breast Milk
This 2015 New Hampshire Birth Cohort study quantified the relative contributions of private well water and breast milk to infant arsenic exposure at 6 weeks of age, establishing that formula-fed infants in well-water homes have substantially higher arsenic exposure than breastfed infants.
Key numbers
Breast milk tAs (n=9 breastfeeding mothers, µg/L): Median 0.31, range <0.22–0.62. LOD 0.22 µg/L.
Infant urinary arsenic (minus arsenobetaine) by feeding mode (n=72 infants, µg/L): Formula-fed: median 0.17, range <LOD–2.9. LOD 0.05 µg/L. Breastfed infants had 7.5× lower urinary arsenic than formula-fed.
Home tap water from private wells (n=874 households, µg/L): Median 0.44; range <0.01–189; some wells far above EPA MCL of 10 µg/L.
Estimated daily intake (µg/kg bw/day): Formula-fed (median): 0.22. Breastfed (median): 0.04. 5.5× difference.
Methods
HPLC-ICP-MS speciation. 72 infants; 9 breastfeeding mothers; well water from 874 households. NHBCS northeastern US private well water area. LOD breast milk 0.22 µg/L; urinary 0.05 µg/L.
Key finding: In well-water households, formula preparation with arsenic-contaminated well water is the dominant route of infant As exposure in early infancy, not the formula powder itself. Breast milk median As (0.31 µg/L) from non-contaminated-water mothers is extremely low.
Implications
App: Formula preparation water quality is a critical determinant; municipal water vs well water vs bottled water creates large differences in infant formula As exposure.
Wiki pages updated on ingest
Page history
The five most recent substantive edits to this page. The full version history lives in git; when DOI minting comes online (see schema docs), each entry below will also link to a version-pinned DataCite DOI.
| Commit | Date | Description |
|---|---|---|
| b0f3d38 | 2026-06-12 | batch | corpus rescreen b04 old terminal skips |