Schoof 2007 - Seafood arsenic speciation

Schoof and Yager reviewed total arsenic and speciated arsenic data for commonly consumed fish and seafood. The review summarizes total arsenic (Astot) and inorganic arsenic (Asi) on a wet-weight basis for freshwater finfish, anadromous fish, marine fish, crustaceans, and molluscs. The paper also separately summarizes DMA and MMA, so those organic arsenic species must not be collapsed into inorganic arsenic.

Key numbers

The abstract reports mean inorganic arsenic concentrations of approximately 10 to 20 ng/g wet weight (ww) in freshwater, anadromous, and marine fish, and 40 to 50 ng/g ww in crustaceans and molluscs. It also reports that MMA was seldom detected, while DMA averaged 10 ng/g ww in freshwater fish and 45 to 95 ng/g ww in anadromous fish, marine fish, crustaceans, and molluscs. At the 75th percentile of the dataset, the paper reports inorganic arsenic as 2-3% of total arsenic in anadromous/estuarine/marine fish and crustaceans/molluscs, and 10% of total arsenic in freshwater fish.

Table 3 summarizes total arsenic and inorganic arsenic in ng/g, ww.

Table 3 also reports all-sample 75th percentile values for tAs / iAs / iAs percent of total: freshwater finfish 409 / 36 / 10; anadromous fish 956 / 10 / 2.0; marine fish 4,359 / 26 / 1.6; crustaceans 12,000 / 57 / 2.0; and molluscs 3,094 / 68 / 2.7. The all-sample 90th percentile values are freshwater finfish 558 / 43 / 16; anadromous fish 1,235 / 18 / 2.7; marine fish 7,948 / 62 / 2.8; crustaceans 26,222 / 97 / 5.3; and molluscs 3,740 / 132 / 4.3.

Table 4 summarizes organic arsenic species in ng/g ww, as As. DMA means were freshwater finfish 10.3, anadromous fish 95.5, marine fish 79.9, crustaceans 56, and molluscs 45. MMA means were freshwater finfish 0.9, anadromous fish 40.4, marine fish 4.6, crustaceans 1.8, and molluscs 15.4.

Methods (brief)

The review assembled total arsenic and arsenic-speciation data from 20 published studies and grouped seafood by habitat and product type. The authors also used U.S. seafood consumption information from USEPA based on USDA CSFII 1994-1996 and 1998 data, including a 17.5 g/day freshwater and estuarine fish consumption value used in arsenic ambient-water-quality-criterion calculations. Table 3 includes both all samples and raw samples only; cooked samples and paired raw/cooked results are identified in the group counts.

Implications

This source is useful for routing seafood arsenic evidence because it preserves total arsenic and inorganic arsenic in the same wet-weight table, with separate review summaries for DMA and MMA. The source-reported percentiles are review-summary descriptors from Schoof and Yager’s assembled dataset; they are not HMTc aggregate percentiles and should not be treated as certification thresholds. Downstream extraction should keep fish, freshwater fish, marine fish, crustaceans, and molluscs separated where row fit matters.

Verification notes

• PDF text was extracted with pdftotext -layout to /tmp/f3_resolve_texts/schoof2007.txt; the abstract, seafood-consumption section, Tables 3-5, and discussion of the inorganic-arsenic adjustment were checked.
• DOI 10.1080/10807030701506454, raw handle MFK_schoof2007, and cite-key checks found no existing source page before creation.
• Units are preserved as source-reported ng/g, ww, ng/g ww, as As, g/day, and percentages; no conversion was performed.
• Speciation: total arsenic and inorganic arsenic remain separate. DMA and MMA are documented in Key numbers as organic arsenic species and are not counted as inorganic arsenic.
• Brand firewall: the review reports category and literature-study summaries, not retail brand contamination values.
• Frontmatter slugs were checked against docs/gpt-collaboration/taxonomy-snapshot.md; narrow slugs for crustaceans as a standalone ingredient/product are absent, so the source is routed through broad seafood and shellfish slugs.

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.