Key Numbers
Brown rice syrup products (n=3, retail samples):
- Total As (tAs): 78–406 ng/g (mean 203 ng/g)
- Inorganic As (iAs): 71–355 ng/g, representing 91–94% of total As
- Dimethylarsenate (DMA): 6–41 ng/g (minor contribution)
Infant formula with organic brown rice syrup (n=2, retail products):
- tAs: 10–177 ng/g in reconstituted liquid formula
- Approximately 20-fold higher As concentration than non-OBRS formulas tested in parallel
Infant formula without brown rice syrup (comparison group):
- tAs: 5–9 ng/g in reconstituted liquid (baseline)
Cereal and cereal-based products (n=29 samples):
- Breakfast cereals: 8–128 ng/g
- Cereal bars with brown rice: As concentrations paralleled OBRS content
Energy/protein products containing brown rice (n=3):
- tAs: 84–171 ng/g
Aluminum (Al) and uranium (U) also measured in select samples; concentrations noted but As was primary analyte.
Methods
Sampling: Retail market survey of US products marketed as “organic” in infant formula, breakfast cereal, cereal bars, and energy-supplement categories (2009–2010 timeframe).
Analytical technique:
- Inductively coupled plasma mass spectrometry (ICP-MS) for total As, Al, U
- Ion-exchange high-performance liquid chromatography coupled to ICP-MS (HPLC-ICP-MS) for As speciation (iAs, DMA, MMA distinction)
Sample preparation:
- Reconstituted formula prepared according to manufacturer instructions for liquid-phase analysis
- Dry products analyzed in situ
- Quality assurance via certified reference materials
Sample size: ~200 individual product samples across all categories; emphasis on brown rice-containing products as primary contamination source.
Implications
This was among the first market-scale surveys linking brown rice syrup (OBRS) addition to formulas with significant As enrichment. The data established that:
-
IAs dominance: As in brown rice syrup is predominantly inorganic As (iAs, 91–94%), the form of greatest toxicological concern, with minor contributions from DMA.
-
OBRS as a discrete source: The ~20-fold As elevation in formulas with added OBRS versus baseline infant formulas identified OBRS as a specific, addressable ingredient-level source rather than background contamination.
-
Dietary exposure relevance: For infants consuming formula with OBRS, the paper provided direct As exposure estimates that later became central to infant-risk assessments in regulatory guidance and certification thresholds.
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Cereal/snack category relevance: Quantification of As in cereal bars and energy products containing brown rice extended the exposure-pathway concern beyond infant formula to broader dietary intake in children and adults.
-
Baseline for organic category: The data demonstrated that “organic” labeling did not confer lower As contamination; in fact, OBRS use in organic infant formula resulted in higher As concentrations than conventional formulas.
The study provided foundational evidence for later ingredient-level and product-level contamination syntheses and informed decisions to track OBRS as a distinct risk factor in contamination profiles for infant formula and grain-based products.
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## Page history
The five most recent substantive edits to this page. The full version history lives in [git](https://github.com/paleofoundation/heavymetalindex); when DOI minting comes online (see [[../docs/schemas/index.md|schema docs]]), each entry below will also link to a version-pinned DataCite DOI.
| Commit | Date | Description |
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| [ce3e07c](https://github.com/paleofoundation/heavymetalindex/commit/ce3e07c) | 2026-05-28 | activation \| Vercel DATACITE env slots set, curators.md filled with founder entry + six scoped reviewer invitations, peer-review onboarding playbook drafted |
| [51400b9](https://github.com/paleofoundation/heavymetalindex/commit/51400b9) | 2026-05-28 | audit-queue: gasparik2017-wild-boar-slovakia-metals audited-revised |
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