Heavy Metal Index

p4-batch11-2026-05-13

12 min read

P4 Batch 11 — Ingest Report

Date: 2026-05-13 Handles processed: 200 (P4 year-descending, positions 3968–4167; 2023 cohort) Source pages created: 41 False positives: 159 (79.5%)

Summary

Batch 11 is the highest-yield single batch to date (41 pages), with a false-positive rate of 79.5% — noticeably lower than recent batches. The 2023 cohort zone appears to be denser in food-matrix papers. High-value finds cluster in three areas: arsenic speciation (raab2024 microalgae arsenolipids, sim2024 seaweed HPLC-ICP-MS, walenta2024 mushroom arsenobetaine amide — all reinforcing the batch 10 seafood-arsenic-speciation synthesis candidate), mitigation science (sowers2023 PNAS dual-metal jarosite remediation, hao2024 AMF meta-analysis), and mercury in freshwater systems (willacker2023 reservoir stratification driving Hg, paez-osuna2024 mine-tailing spill Mexico, hall2023 tidal marsh MeHg).

Cumulative source pages after this batch: 513.

Group 1 (FM_10697903_Arsenic… – FM_10764562) — 11 pages, 39 FP

sandil2023-arsenic-bean-lettuce (FM_10697903_...) ICP-MS; As uptake in bean and lettuce at contaminated-irrigation treatments (Hungary). Lettuce edible parts 0.30–1.21 mg/kg dw at highest treatments. Evidence tier: A. Metals: tAs, iAs. Matrices: vegetables, leafy-vegetable, legumes.

hall2023-methylmercury-tidal-marsh (FM_10710764) Direct mercury analyzer; MeHg production and bioaccumulation across tidal marsh features, San Francisco Bay. Marsh edges and interiors produce higher tissue MeHg than channels; relevant to estuarine food-web MeHg dynamics. Evidence tier: A. Metals: MeHg, tHg. Matrices: freshwater-fish, estuarine-organism.

henriksen2023-chromium-nordic-nnr (FM_10711720) Systematic review for Nordic Nutrition Recommendations 2023. Cr(III) and Cr(VI) in foods; most foods <10 µg/100 g. No evidence base for a dietary recommendation for Cr. First wiki entry anchoring the NNR 2023 Cr assessment. Evidence tier: A. Metals: Cr. Matrices: dietary-intake.

leclerc2023-methylmercury-periphyton-river (FM_10722175) Run-of-river dam study, St. Maurice River (Québec). Dam impoundments increase MeHg/tHg ratio up to 2.9× relative to unimpounded reaches via periphyton proliferation. Mechanism: periphyton mats are hotspots for Hg methylation. Evidence tier: A. Metals: MeHg, tHg. Matrices: freshwater-fish, river-water.

sowers2023-jarosite-pb-as-remediation (FM_10728717) PNAS. Jarosite mineral treatment simultaneously reduces soil Pb bioaccessibility from ~65% to <10% and As bioaccessibility from ~70% to <10% in a single application. Rare dual-metal remediation result. Highly relevant to mitigation pages. Evidence tier: A. Metals: Pb, iAs. Matrices: soil.

ramos-miras2023-pte-shrimp-ecuador (FM_10731273) ICP-MS; As, Cd, Cr, Pb, Hg in farmed Pacific White shrimp (cephalothorax and muscle), Ecuador. As in cephalothorax 3.52–6.11 mg/kg dw exceeds EU ML; muscle THQ <1 for all elements. Farming-origin shrimp baseline for South America. Evidence tier: A. Metals: tAs, Cd, Cr, Pb, tHg. Matrices: shellfish, shrimp.

palombieri2023-triticum-turgidum-cadmium (FM_10732328) Field trial (Italy). Polish wheat accession Pol2 shows significantly lower Cd content than reference cultivars while retaining better micronutrient profile. Agronomic lever for Cd reduction in durum wheat. Evidence tier: A. Metals: Cd. Matrices: wheat, cereal-grain.

willacker2023-mercury-fish-snake-river (FM_10740167) USEPA 7473; tHg in smallmouth bass across 30 sites on the Snake River system (Idaho/Oregon). Reservoir and tailrace fish show tHg 76% higher than free-flowing reaches; 52–80% of fish from stratifying reservoirs exceed human health consumption benchmarks vs 6–17% from unstratified sites. Mechanism: thermal stratification creates anoxic hypolimnion that drives sulfate-reducing bacteria Hg methylation. Evidence tier: A. Metals: tHg, MeHg. Matrices: freshwater-fish.

ortiz-garcia2023-arsenic-maternal-exposure (FM_10748820) Narrative review; global dietary As 20–300 µg/day; outcome thresholds range from miscarriage (>100 µg/L) to neurobehavioral effects in newborns (0.73 µg/L). Relevant to health and vulnerable-populations pages. Evidence tier: B. Metals: iAs, tAs. Matrices: dietary-intake.

zhou2023-inosperma-mushroom-elements (FM_10752948) ICP-MS; 24 elements in a newly described Inosperma mushroom species from tropical China. As 36.76 mg/kg dw, the highest-concern element by toxicity in the profile. Mushroom As hyperaccumulation evidence. Evidence tier: A. Metals: tAs, Pb, Cd. Matrices: mushrooms.

jurowski2023-heavy-metals-green-tea-poland (FM_10760843) ICP-MS; As, Pb, Cd in 12 green tea infusions (Polish market). Pb mean 0.891 µg/L infusion (3–4× higher than As or Cd); China-origin teas consistently higher than Sri Lanka-origin. No PTWI exceedance at normal consumption. Evidence tier: A. Metals: Pb, tAs, Cd. Matrices: tea.

Group 2 (FM_10765559 – FM_10876981) — 9 pages, 41 FP

adhikari2024-leafy-vegetables-johannesburg (FM_10796695_...) ICP-MS; 10-metal survey in five leafy vegetables from Johannesburg roadside vs. large-store markets. Roadside market produce significantly higher for Pb, Cd, and As than supermarket equivalents. Evidence tier: A. Metals: Pb, Cd, tAs, Cr, Ni. Matrices: leafy-vegetable, vegetables.

paez-osuna2024-fish-mercury-selenium-mexico (FM_10800898) CVAAS + HPLC; tHg and Se in three fish species from El Comedero dam (Sinaloa, Mexico) post-mine-tailing spill. MeHg/tHg ratio elevated post-spill. Se:Hg molar ratio <1 in most samples, indicating Hg bioavailability not offset by Se. Evidence tier: A. Metals: tHg, MeHg. Matrices: freshwater-fish.

abdel-tawwab2023-cadmium-seabream-yeast (FM_10808558) Controlled aquaculture experiment. Cd bioaccumulation in gilthead seabream muscle; Saccharomyces cerevisiae dietary additive mitigates muscle Cd accumulation. Evidence tier: A. Metals: Cd. Matrices: fish, marine-fish.

mohamed2023-heavy-metals-beef-egypt (FM_10811004) ICP-OES; Pb, Hg, As, Cd in chilled vs. frozen beef from Sharkia province (Egypt). Frozen beef consistently lower than chilled; some samples exceed EU/Codex limits. Evidence tier: A. Metals: Pb, tHg, tAs, Cd. Matrices: beef, meat.

morshdy2023-heavy-metals-salted-fish-egypt (FM_10811111) ICP-OES; Pb, Cd, As, Hg in four traditional Egyptian salted and fermented fish products (Fesikh, Renga, Melouha, Sardine). Some samples exceed WHO/EU limits, particularly Fesikh. Evidence tier: A. Metals: Pb, Cd, tAs, tHg. Matrices: fermented-fish, fish.

decharat2023-lead-cadmium-drinking-water-thailand (FM_10824086) GFAAS; Pb and Cd in 210 drinking water samples at child development centres (Thailand). Pb detected in 38% of samples; 12% exceed WHO drinking water guideline. No DOI — assigned no_doi_assigned: true. Evidence tier: A. Metals: Pb, Cd. Matrices: drinking-water.

apdraim2023-vermiculite-quail-meat (FM_10829780) Controlled feeding trial. Cd and Pb baseline in quail pectoral muscle; vermiculite dietary additive reduces muscle Cd and Pb at 2% inclusion. Evidence tier: A. Metals: Cd, Pb. Matrices: poultry-meat.

walenta2024-arsenic-speciation-mushrooms (FM_10844786) LC-ICP-MS; arsenic speciation in four mushroom species. Discovery of a novel arsenobetaine amide species not previously reported in any organism. Relevant to the seafood arsenic speciation synthesis thread — extends the “unexpected organoarsenical metabolites” pattern to terrestrial fungi. Evidence tier: A. Metals: iAs, tAs. Matrices: mushrooms.

zahran2023-mercury-tilapia-nannochloropsis (FM_10876981) Controlled aquaculture experiment. Hg bioaccumulation in Nile tilapia muscle reduced by Nannochloropsis microalgae dietary supplementation. Evidence tier: A. Metals: tHg. Matrices: freshwater-fish.

Group 3 (FM_10878390 – FM_10984215) — 9 pages, 41 FP

webster2024-mercury-thyroid-cancer (FM_10881592_...) Meta-analysis; Hg and MeHg exposure associations with thyroid cancer. Evidence tier: B (meta-analysis without primary concentration data). Metals: tHg, MeHg. Matrices: dietary-intake (biomonitoring).

aljufaili2024-garra-shamal-oman (FM_10884084) ICP-MS; 10 metals in freshwater fish (Garra and Shamal species) from Oman, n=120. All below FAO/WHO limits; Pb and Cd detected in most samples. Adds Gulf region freshwater-fish baseline. Evidence tier: A. Metals: Pb, Cd, Cr, Ni. Matrices: freshwater-fish.

janiga2024-alpine-bullhead-metals (FM_10894169) AAS; tHg, Zn, Mo in alpine bullhead (Cottus poecilopus) post-flood, Slovakia, n=66. Post-flood tHg elevated in downstream stations. Seasonal/event-driven Hg dynamics in mountain streams. Evidence tier: A. Metals: tHg. Matrices: freshwater-fish.

dorevitch2024-drinking-water-lead-spikes (FM_10907284) Environmental Health (NPG). Particulate Pb spike simulation in drinking water treatment; >90th percentile filter effluent events at 30+ US utilities. Pb spikes from corrosion events are not captured by routine first-draw sampling protocols. Evidence tier: A. Metals: Pb. Matrices: drinking-water.

levin2024-us-drinking-water-contaminants (FM_10907308) Environmental Health (NPG) review. Pb, As, U, Cd, Hg, Cr in US drinking water: regulatory timeline, enforcement gaps, and environmental justice dimension. Adds regulatory context for drinking water metals. Evidence tier: B. Metals: Pb, tAs, U, Cd, tHg, Cr. Matrices: drinking-water.

rohonczy2024-arctic-foodweb-cd-hg (FM_10927903) ICP-MS + CVAAS; Cd, tHg, MeHg trophic magnification across the Hudson Bay Arctic food web, n=781. Both Cd and MeHg show biomagnification; MeHg TMF higher at upper trophic levels. Evidence tier: A. Metals: Cd, tHg, MeHg. Matrices: marine-fish, marine-mammal, freshwater-fish.

guo2024-duck-eggs-hg-mining-china (FM_10932963) ICP-MS; Cr, Pb, Zn in duck eggs from villages near legacy Hg mines in SW China. Pb elevated in duck eggs relative to background; proximity to mine correlated with egg Pb. Evidence tier: A. Metals: Pb, Cr. Matrices: poultry-egg.

chirinos2023-milk-lead-cadmium-arsenic-peru (FM_10954997) FAAS; Pb, Cd, tAs in raw cow milk from 19 farms near mining activity in Peru. Both Pb and Cd exceeded Codex MPLs in multiple samples. Direct mining-impact-to-dairy-supply-chain evidence. Evidence tier: A. Metals: Pb, Cd, tAs. Matrices: cow-milk, dairy.

capcarova2023-mozzarella-trace-elements-slovakia (FM_10955032) ICP-MS; 17 elements in mozzarella from Slovak market, n=27. Pb detected 0.58–0.81 mg/kg. EU market baseline for cheese trace elements. Evidence tier: A. Metals: Pb, Cd, Cr, Ni. Matrices: cheese, dairy.

Group 4 (FM_10990099 – FM_11097031) — 12 pages, 38 FP

ramadan2024-bahr-mouse-egypt-water (FM_10995087) AAS; 8 metals in Bahr Mouse drain surface water (Egypt), n=38. WQI 28–39 (good-to-medium). Irrigation water context for Nile Delta agricultural production. Evidence tier: A. Metals: Pb, Cd, Cr, Ni, As. Matrices: irrigation-water.

bakhshalizadeh2024-caspian-sturgeon-metals (FM_10998770) ICP-MS; As, Cd, Hg, Pb, Ni, V in stellate sturgeon pectoral fin (Caspian Sea), n=40. THQ <1; fin as a non-lethal monitoring matrix. Caspian region baseline for an endangered species. Evidence tier: A. Metals: tAs, Cd, tHg, Pb, Ni. Matrices: marine-fish, fish.

gajdosechova2023-nanoparticles-trace-element-food (FM_11009757_...) TrAC Trends in Analytical Chemistry review. HgS and As nanoparticles in food challenge standard bioaccessibility and ICP-MS digestion protocols; nanoparticle forms may pass through conventional sample prep intact. Methodological implications for testing reliability. Evidence tier: B. Metals: tHg, tAs. Matrices: food (analytical review).

raab2024-arsenolipids-chlamydomonas (FM_11009773) LC-ICP-MS/MS; first report of AsSugPhytol in any organism; 57% of tAs in Chlamydomonas reinhardtii is arsenolipids. Critical for microalgae-derived ingredients (algae protein, spirulina, chlorella, seaweed): iAs fraction may be underestimated by total-As methods if arsenolipid extraction efficiency is low. Evidence tier: A. Metals: iAs, tAs. Matrices: microalgae.

meligy2024-camel-meat-toxic-elements (FM_11018421) GFAAS; Co, Cr, Mn, Se, As in camel muscle, offal, hair, and blood (three breeds, Saudi Arabia), n=225. As below detection in most matrices; Cr detected in offal. Adds camel meat to the HMI product space. Evidence tier: A. Metals: tAs, Cr. Matrices: camel-meat, meat.

chamorro2024-bluefin-tuna-mercury-review (FM_11018964) Review; Atlantic bluefin tuna Hg risk-benefit synthesis. EU 1.0 mg/kg limit; MeHg ~85% of tHg. Se:Hg molar ratio analysis; most Mediterranean and Atlantic samples show molar Se:Hg >1 suggesting some Se protection, but not universal. Evidence tier: B. Metals: tHg, MeHg. Matrices: marine-fish, tuna.

guo2024-cadmium-bioaccessibility-pak-choi (FM_11024290) Frontiers in Nutrition. PBET in vitro digestion; wollastonite + phosphate co-treatment reduces pak choi Cd bioaccessibility by 66%; THQ for children falls below 1 with treatment. Evidence tier: A. Metals: Cd. Matrices: leafy-vegetable, vegetables.

hao2024-amf-arsenic-plants-meta-analysis (FM_11026667) Frontiers in Plant Science. 76-paper meta-analysis. AMF (arbuscular mycorrhizal fungi) inoculation reduces grain As 34% and shoot As 19% across diverse crop species and soil types. Strongest agronomic lever for As in grains identified in the corpus to date at this evidence level. Evidence tier: A. Metals: iAs, tAs. Matrices: rice-grain, cereal-grain, vegetables.

sim2024-inorganic-arsenic-seaweed-hplc (FM_11045606) DoE-optimized HPLC-ICP-MS; iAs determination in seaweed. 99±9% recovery on hijiki CRM. Laminaria digitata iAs >50% of tAs. EU 2023/915 now sets iAs limits for seaweed; this method is directly relevant to compliance testing. Evidence tier: A. Metals: iAs, tAs. Matrices: seaweed, algae.

berber2024-crayfish-metal-content-turkey (FM_11052787) ICP-MS; 10 metals in narrow-clawed crayfish (12-month seasonal study, 5 Turkish sites). THQ <1; seasonal variation documented. Adds freshwater crustacean data. Evidence tier: A. Metals: Pb, Cd, Cr, Ni, As. Matrices: freshwater-fish, shellfish.

lockwood2023-sri-lanka-rice-heavy-metals (FM_11052878) LA-ICP-MS spatial imaging; 11 Sri Lankan traditional rice varieties. Suwadel variety Cd 113±13 µg/kg; Pb is bran-concentrated while Cd distributes uniformly across grain layers. CKDu research context. Evidence tier: A. Metals: Cd, Pb, iAs. Matrices: rice-grain.

salem2024-tomato-remediated-soil-egypt (FM_11096225) ICP-MS; Cd, Ni, Cu, Zn, Pb in tomatoes from contaminated Egyptian soil. Bioremediation reduces Ni by 75–80%; Cd below detection in fruit even from contaminated soil (root-barrier effect). THQ <1. Evidence tier: A. Metals: Cd, Ni, Pb. Matrices: tomato, vegetables.

High-Value Finds

  1. sowers2023-jarosite-pb-as-remediation (PNAS) — Jarosite mineral treatment simultaneously reduces soil Pb and As bioaccessibility from ~65–70% to <10%. The first dual-metal remediation intervention in the wiki corpus with PNAS-level evidence. Directly feeds mitigation pages for both metals.

  2. sim2024-inorganic-arsenic-seaweed-hplc — HPLC-ICP-MS validated for iAs in seaweed; Laminaria digitata iAs >50% of tAs. EU 2023/915 now has seaweed iAs limits, making this a compliance-relevant method paper. Adds to the seaweed/algae risk profile.

  3. raab2024-arsenolipids-chlamydomonas — First AsSugPhytol in any organism; 57% of tAs in green microalgae as arsenolipids. Extends the seafood-arsenic-speciation synthesis candidate into microalgae-derived food ingredients (spirulina, chlorella, algae protein powders). Total-As testing may underestimate iAs-equivalent exposure from microalgae products.

  4. hao2024-amf-arsenic-plants-meta-analysis — 76-paper meta-analysis; AMF reduces grain As 34%, shoot As 19%. Strongest agronomic As mitigation lever in the corpus at this evidence level.

  5. willacker2023-mercury-fish-snake-river — Reservoir thermal stratification drives tHg 76% higher in fish; 52–80% vs 6–17% exceed consumption benchmarks. Adds a dam-related Hg elevation mechanism to the mining-impacted freshwater Hg synthesis thread — same methylation endpoint, different environmental driver.

  6. lockwood2023-sri-lanka-rice-heavy-metals — LA-ICP-MS spatial imaging showing Pb is bran-concentrated while Cd distributes uniformly in Sri Lankan traditional rice varieties. This is mechanistically important for processing mitigation: polishing reduces Pb more than Cd in these varieties.

  7. walenta2024-arsenic-speciation-mushrooms — Novel arsenobetaine amide discovery. Extends the organoarsenical metabolite diversity argument beyond seafood into terrestrial fungi.

  8. gajdosechova2023-nanoparticles-trace-element-food — HgS and As nanoparticles may survive conventional ICP-MS sample prep, meaning reported “total” concentrations from standard digestion methods may miss the nanoparticulate fraction. Methodological implication for testing reliability.

Synthesis Threads

Thread 1 — Seafood/microalgae arsenic speciation (updating existing candidate): walenta2024 (novel arsenobetaine amide in mushrooms), raab2024 (57% arsenolipids in microalgae), sim2024 (seaweed iAs >50% tAs) all add to the batch 10 seafood-arsenic-speciation candidate. The thread now spans marine fish, shellfish, mushrooms, microalgae, and seaweed — satisfying criterion 2 (multiple matrices/products). Promotion readiness upgrades from “3 of 4 criteria” to all 4 criteria met. Proposing for promotion: the finding that organoarsenical forms in seafood, fungi, and algae-derived ingredients are not toxicologically inert is non-obvious, cross-matrix, and has direct regulatory relevance (seaweed EU 2023/915, biomonitoring interpretation). Adding anchors to the candidate entry in synthesis-proposals.md.

Thread 2 — Reservoir stratification as a freshwater Hg driver (new dimension on pending candidate): willacker2023 (Snake River dams), leclerc2023 (Quebec run-of-river dam periphyton), hall2023 (SF Bay tidal marsh edge hotspots) together show that impoundment-related anoxic conditions create Hg methylation hotspots independently of mining or ASGM. This is mechanistically distinct from but parallel to the mining-impacted freshwater Hg thread. The synthesis page for mining-impacted freshwater Hg should note dam-related methylation as a co-driver.

Thread 3 — AMF as an agronomic As mitigation lever: hao2024 (76-paper meta-analysis, 34% grain As reduction) plus prior corpus entries on AMF mechanisms. Cross-references the mitigation architecture. Not a standalone synthesis finding (it is a single-metal, single-mechanism thread), but strong enough to anchor a dedicated mitigation page.

Batch Commits

  • cc296bd — g1: 11 pages, 39 FP
  • cacc8f4 — g2: 9 pages, 41 FP
  • 3dc7cbb — g3: 9 pages, 41 FP
  • bae0d21 — g4: 12 pages, 38 FP