García Salcedo et al. 2022 — Arsenic Biomonitoring in Mothers and Neonates, Mexico
This 2022 comparative study from Mexico measured total arsenic in multiple biological matrices (breast milk, placenta, maternal and neonate urine) comparing an arsenic-exposed area (Comarca Lagunera) with a non-exposed comparison area (Saltillo), demonstrating transplacental and lactational arsenic transfer.
Key numbers
Arsenic concentrations by matrix and area (tAs):
| Matrix | Exposed (Comarca Lagunera) | Non-exposed (Saltillo) |
|---|---|---|
| Drinking water (µg/L) | 47.7 | 0.05 |
| Maternal urine (µg/g-Cr) | 77.04 | 6.71 |
| Maternal placenta (µg/kg) | 7.80 | 2.17 |
| Breast milk (µg/L) | 4.30 | 0.87 |
| Neonate urine, 3 days post-birth (µg/g-Cr) | 107.92 | 14.78 |
Key finding: neonate urinary As at 3 days post-birth was 107.92 µg/g-Cr in exposed area vs 14.78 in non-exposed — a 7× difference reflecting transplacental As transfer during gestation, documented before lactational exposure can be a factor.
Methods
Comparative cross-sectional study; ICP-MS or HFAAS (method not specified in excerpt). Comarca Lagunera is a semi-arid region with naturally high groundwater arsenic (geogenic, volcanic origin).
Implications
Health: Demonstrates that neonatal arsenic burden in high-exposure areas reflects gestational (transplacental) exposure, not just postnatal lactational exposure. This has implications for understanding the full scope of early-life metal exposure windows.