Ortiz-Garcia et al. 2023 — Maternal arsenic exposure and maternal/fetal health: review
This narrative review summarizes the evidence on arsenic exposure during pregnancy, covering sources, mechanisms of damage, and adverse maternal and fetal outcomes. The primary exposure pathways are food and water ingestion. The global population’s daily total arsenic intake from food and beverages is reported as 20–300 mcg/day. The review covers inorganic arsenic’s carcinogenicity (IARC Group 1), methylation metabolism (iAs → MMA → DMA; DMA accounts for 60–80% of urinary metabolites), and the spectrum of pregnancy-related adverse outcomes at different arsenic exposure concentrations.
Key numbers
Global daily total arsenic intake from food and beverages: 20–300 mcg/day
WHO drinking water limit (adopted 2001): 10 µg/L (lowered from 50 µg/L; proposal to lower to 2 µg/L rejected for financial reasons)
Mexico drinking water limit: 50 µg/L (progressive reduction to 25 µg/L in 2005; still exceeds WHO limit)
Arsenic exposure–outcome threshold table (from Table 2):
- Miscarriage/stillbirth: > 100 µg/L
- Gestational diabetes: > 50 µg/L
- Anemia during pregnancy: > 50 µg/L
- Low birth weight: > 50 µg/L
- Increased systolic blood pressure in pregnancy: 20–50 µg/L
- Congenital heart anomalies in female newborns: > 10 µg/L
- Passive muscle tone in newborns: 0.73 µg/L
- Behavioral ability in newborns: 0.73 µg/L
- Infant mortality: > 555 µg/L creatinine (urinary marker)
Arsenic metabolism: inorganic As → SAM-mediated oxidative methylation → MMA (10–20% of urinary metabolites) and DMA (60–80% of urinary metabolites). DMA V identified as teratogen, nephrotoxin, and complete carcinogen in mammals.
Dietary sources of arsenic: seafood (highest; algae, detritivorous fish, marine fish, invertebrates), groundwater, fruits, grains.
Methods (brief)
Narrative review; no systematic search protocol described. Published November 2023 in Cureus (peer-reviewed open-access medical journal). Evidence tier B (review without primary data; Cureus has lower methodological rigor than specialist journals). Useful for dietary exposure magnitude context and pregnancy outcome thresholds, but should be supported by primary literature for specific numeric claims.
Implications
Certification: The 20–300 mcg/day global total arsenic intake estimate is useful for framing how food-chain arsenic contributes to total dietary burden. At high-end dietary intakes, the pregnancy-outcome thresholds (10–50 µg/L water concentrations correlating with fetal effects) reinforce the importance of cumulative dietary iAs reduction.
Courses: The outcome-threshold table (Table 2) is pedagogically effective for showing that even low arsenic concentrations (0.73 µg/L) have documented effects on newborn neuromotor outcomes. Strong context for the “vulnerable population: pregnant women and infants” framing.
App: Pregnant women and infants are the highest-priority flagged populations for dietary arsenic exposure; this review reinforces the biological rationale for that flag.
Microbiome: Not addressed in this review.