Signes-Pastor et al. 2022 - infant urinary elements during the first year of life

This Exposure and Health study measured urinary elements in infants from the New Hampshire Birth Cohort Study to evaluate how internal exposure changed between early infancy and one year of age, and whether one-year rice consumption was associated with urinary element concentrations. The study is biomonitoring evidence, not direct product-composition evidence: no infant cereal, formula, or baby-food products were chemically analyzed. Its HMT&C value is exposure-context support for rice and rice-based infant foods, especially the arsenic and molybdenum signal during weaning and the borderline urinary nickel signal among rice consumers.

Key numbers

Paired urine samples at 6 weeks and 1 year (subgroup 1; n=187):

The authors report the largest median-ratio increases for sum-As and Mo: sum-As rose nearly 15-fold and Mo rose 31.8-fold between 6 weeks and 1 year. In the WQS mixture model for 1 year versus 6 weeks, the highest positive weights were assigned to urinary sum-As (0.516) and Mo (0.289), followed by Co (0.081). Hg, V, Sb, Ni, Cr, and U had smaller positive weights ranging from 0.001 to 0.028.

Rice consumption at 1 year (subgroup 2; n=147):

The authors describe sum-As as inorganic arsenic plus MMA plus DMA, excluding arsenobetaine, and use it as a proxy for inorganic-arsenic exposure. They report moderate correlation between urinary sum-As and Mo at 1 year (Spearman rho=0.64), with correlations also present among rice consumers (rho=0.48) and non-rice consumers (rho=0.55).

Methods (brief)

The NHBCS recruited pregnant women in New Hampshire using private, unregulated home water systems. Subgroup 1 included 187 infants who were exclusively breastfed at approximately 6 weeks and had paired urine samples at approximately 6 weeks and 1 year. Subgroup 2 included 147 one-year-old infants with rice-consumption information collected by 3-day food diary just before urine collection.

Spot urine samples were collected with cotton urine pads, transferred to polyethylene containers, aliquoted within 24-72 hours, and frozen at -80°C. Urinary specific gravity was measured with a handheld refractometer. Multi-element urine analysis used an Agilent 8900 ICP-MS in direct-solution acquisition mode. Urinary arsenic species were measured using an Agilent 8900 ICP-MS interfaced with an Agilent 1260 liquid chromatograph and Thermo AS7/AG7 column system. NIST human urine standard reference materials 2669 levels I and II were included in each batch; reported recoveries for arsenobetaine, DMA, MMA, and iAs were 105% (SD 3), 115% (SD 9), 100% (SD 4), and 101% (SD 11), respectively.

The LOD was calculated as the blank mean plus 3 standard deviations multiplied by dilution factor. Only zero or negative ICP-MS calibration values were imputed as LOD/sqrt(2); other values below LOD were retained. Urinary concentrations, including sum-As, were specific-gravity corrected and natural-log transformed before statistical analysis. Paired t-tests evaluated 6-week versus 1-year changes; two-sample t-tests compared one-year rice consumers with non-consumers; WQS regression evaluated the mixture pattern.

Implications

Standards work: This source supports rice and rice-based infant foods as an exposure-context priority during weaning, but it should not be used as product concentration evidence because the measured matrix is infant urine. It strengthens the biological plausibility for rice-linked arsenic exposure and flags Mo and Ni as co-occurring rice-associated biomarkers.

Courses: Useful for teaching the difference between product occurrence evidence and biomonitoring evidence. The same infant-food risk category can be supported by both product testing and internal exposure data, but the two cannot be collapsed into the same standards math.

App: Supports warning copy for rice-containing infant foods that distinguishes inorganic-arsenic product limits from urinary exposure biomarkers. The page should not drive product ppb calculations directly.

Microbiome: Not addressed.

Wiki pages this source may touch

• arsenic-inorganic
• lead
• cadmium
• mercury-total
• aluminum
• antimony
• tin
• uranium
• vanadium
• nickel
• molybdenum
• rice
• infant-rice-cereal
• baby-cereals-dry-rice-based
• infant-and-child-foods-master
• eu-2015-1006-iAs-rice
• fda-iAs-rice-cereal-100ppb

Verification notes

• Merge-enhanced 2026-05-18 from the gap-driven auto-fetch PDF. The PDF identifies DOI 10.1007/s12403-022-00489-x, correcting the prior doi: null / no_doi_assigned: true frontmatter.
• The auto-fetched PDF is the same article as the existing FM_9971144 Marker source; this is a merge-enhancement, not a duplicate source page.
• Corrected scope: this source measured urinary biomarkers and rice-consumption associations, not infant-formula powder or product metal concentrations. Formula-product routing was removed.
• Strict brand firewall: the paper does not report commercial baby-food brand names. Instrument and reference-material vendor names are retained only in Methods, where Part 12 Exception 2 permits them.

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.