Overview
Hull and colleagues investigated arsenic trophic transfer through aquatic food webs in ten arsenic-contaminated urban lakes in Washington State’s Puget Sound lowlands, a region with legacy pollution from historical copper smelting operations. Their key finding is that littoral sediment arsenic concentration is a reliable predictor of arsenic bioaccumulation across trophic levels, including in edible fish muscle tissue, providing a low-cost screening tool for human health risk from recreational fish consumption. The percent inorganic arsenic (%iAs) increased with decreasing trophic level across all lakes, confirming that iAs dilutes with trophic transfer while total arsenic biodiminishes.
Key numbers
- Sediment As: 7–213 µg As/g in littoral sediment across the 8 contaminated lakes; two deepest-lake profundal sediments reached 206–208 µg/g
- Fish (Lepomis spp.) muscle THg: not primary outcome; primary outcome was total As and iAs in muscle
- Arsenic in fish muscle: correlated significantly with littoral sediment As (r significant, p < 0.05 across species and lakes)
- Periphyton contained higher total As than other primary producers
- Snails contained higher As than zooplankton or insect macroinvertebrates at equivalent trophic position
- Percent iAs consistently increased as trophic level (measured by δ15N) decreased, across all lakes regardless of depth or mixing regime
- Modeled fish consumption from the most contaminated shallow lake resulted in incremental cancer risk > 10−5 (Washington State health threshold)
- Deeper seasonally stratified lakes showed lower bioavailability despite comparable profundal sediment concentrations; mixing regime was a significant modifying factor
Methods (brief)
Stable isotope analysis (δ13C, δ15N) for trophic position and resource use. Total As by ICP-MS; speciation by HPLC-ICP-MS. Samples from 10 lakes in UW Superfund Research Program study area. AAS not used; ICP-MS for trace metals. LOD/LOQ not individually stated in the section reviewed.
Implications
Certification: Supports the principle that sediment arsenic measurements in sourcing watersheds can serve as a screening proxy for fish tissue contamination; relevant to wild-caught freshwater fish ingredient risk.
Courses: Good illustration of iAs/tAs speciation distinction in the context of trophic transfer — iAs proportion increases near the base of the food chain.
App: Freshwater fish sourced from urban contaminated lakes in the Pacific Northwest are a specific contamination risk scenario. iAs (not just tAs) is the relevant metric for risk.
Microbiome: Not applicable.
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Update history
The five most recent substantive edits to this page, classified major (evidence or structure moved), correction (a published value or statement was wrong and has been fixed), or minor (narrative rewritten without changing the underlying evidence). Each description is derived from what the edit did to this page; the linked commit is the authoritative record, routine regeneration passes are excluded, and 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.
| Commit | Date | Change | Description |
|---|---|---|---|
| a8052bb | 2026-08-09 | major | 6 sections added; narrative text revised |