Heavy Metal Index

p4-batch6-2026-05-13

7 min read

P4 Batch 6 — Ingest Report

Date: 2026-05-13 Handles processed: 199 (food-matrix-filtered P4, positions 600–799 in sorted list) Source pages created: 15 False positives: 184 (92%)

Summary

Batch 6 cleared positions 600–799 of the food-matrix-filtered P4 sorted list, spanning mostly 2025 papers (153) with 46 from 2024. The yield is the best since batch 4: 15 source pages across all four groups. High-priority finds include a PNAS-quality GeoHealth 2024 paper on Cd in rice from Chinese black shale areas (li2024, up to 2,488 ppb — far above any regulatory limit), a large Guangxi Cd–rice–liver cancer spatial study (qin2026, n=3,754), and a 48-study systematic review on metals in milk globally (alinezhad2024). A background agent also committed the 5 routing-unresolved ingredient pages (freshwater-fish, cereals, breastmilk, shellfish, quinoa) that had crossed the Part 10 5-source threshold; those are documented separately in wiki/lint/2026-05-12-routing-triage.md.

Pre-commit hook bug fixed by group 3 agent: grep -c returned exit code 1 when no no_doi_assigned matches were found, blocking all source-page commits. Added || true to the grep line in .husky/pre-commit. This was causing false-positive hook failures and is now resolved.

Source Pages Created

Group 1 (FM_12747974 – FM_12847127)

wei2025-cd-as-rice-yunnan-karst-thresholds (FM_12750342) ICP-MS, n=125 paired field samples, Yunnan karst region, China. Cd mean 381 ppb and tAs mean 1,120 ppb at MAC-exceeding sites. Primary purpose is deriving region-specific soil safety thresholds; food concentration data is secondary but well-reported. Frontiers in Plant Science 2025, CC BY. Evidence tier: A. Metals: Cd, tAs. Matrices: rice-grain. Jurisdictions: CN.

ibrahim2025-metals-flavored-dairy-egypt (FM_12847127) 15-element ICP-MS/MS survey of 180 flavored dairy products (UHT milk, pasteurized milk, milk powder, yogurt, drinking yogurt, ice cream) from Giza, Egypt. Pb, Al, tAs, Ni, Cr, Sb reported; Cd and Hg below LOD. Pb exceeded EU limit (20 ppb) in multiple products; carcinogenic risk above acceptable threshold for toddlers consuming strawberry products twice daily. Biological Trace Element Research 2025. Evidence tier: A. Metals: Pb, Al, tAs, Ni, Cr, Sb. Matrices: dairy. Jurisdictions: EG.

Group 2 (FM_12847395 – FM_12932597)

xie2026-selenium-enriched-rice-china (FM_12894730) HDXRF, n=54 commercial selenium-enriched rice samples from 14 Chinese provinces. tAs mean 110 ppb, Cd mean 80 ppb — both below Chinese GB limits. Co-occurrence of Se with toxic elements characterized. Scientific Reports 2026, CC BY. Evidence tier: A. Metals: tAs, Cd. Matrices: rice-grain. Jurisdictions: CN.

balzani2026-fish-metals-dalyan-lake (FM_12904875) ICP-MS, n=27 fish (3 species, 9 per species), Dalyan Lake, Türkiye. Cr, Ni, tAs, Pb measured; Cr biomagnifies with trophic level, As and Ni show trophic dilution, Pb very low across all species. All concentrations below regulatory limits. Evidence tier: A. Metals: Cr, Ni, tAs, Pb. Matrices: freshwater-fish. Jurisdictions: TR.

albishi2026-cassava-flour-biofortification (FM_12909235) Nigerian cassava flour control samples (pre-biofortification): Pb 62–69 ppb, Cd 58–63 ppb, tAs 10–11 ppb, Cr 65–68 ppb. Baseline food-safety data for cassava flour in Nigeria. Frontiers in Nutrition 2026, CC BY. Evidence tier: A. Metals: Pb, Cd, tAs, Cr. Matrices: cassava-flour. Jurisdictions: NG.

zhang2026-trace-metals-five-crops-chongqing (FM_12913949) ICP-MS, n=71 samples, 5 crops (rice, maize, soybean, sweet potato, sorghum) near Mn mining area, Chongqing, China. Rice grain tAs 294 ppb, Cr 1,980 ppb — both exceed China GB limits. Mining-area contamination gradient visible across all five crops. Scientific Reports 2026, CC BY. Evidence tier: A. Metals: tAs, Pb, Cd, Cr, Ni. Matrices: rice-grain, maize, soybean, sweet-potato, sorghum. Jurisdictions: CN.

qin2026-rice-cadmium-liver-cancer-guangxi (FM_12923468) Cd in 3,754 rice grain samples from 44 Guangxi counties; median 70 ppb, mean 120 ppb. Spatial coupling between Cd-contaminated rice production areas and elevated liver cancer incidence documented at county level. ICP-MS, large scale. Environmental Geochemistry and Health 2026, CC BY-NC-ND. Evidence tier: A. Metals: Cd. Matrices: rice-grain. Jurisdictions: CN.

Group 3 (FM_12935679 – FM_13070825)

marcelino2026-liver-trace-metals-netherlands-herbivores (FM_12971517) 20-year ICP-MS monitoring of As, Cd, Cr, Pb, Ni and 8 additional elements in livers of 346 Heck cattle, Konik horses, and red deer at Oostvaardersplassen nature reserve, Netherlands (2003–2023). Establishes species-specific reference intervals; documents temporal Pb and Fe declines. Included as organ-meat occurrence baseline for EU game/livestock liver. Frontiers in Veterinary Science 2026, CC BY. Evidence tier: A. Metals: As, Cd, Cr, Pb, Ni. Matrices: livestock-liver, game-liver. Jurisdictions: NL.

Group 4 (FM_13071475 – FM_11065944)

alinezhad2024-heavy-metals-milk-systematic-review (FM_10843077) PRISMA systematic review, n=981 milk samples across 48 studies. Pb, Cd, Al, As, Hg in pasteurized and sterilized cow’s milk worldwide. Cd, Zn, Pb, Cu most commonly exceeded limits across included studies. Largest milk-metals systematic review in corpus to date. PLoS ONE 2024, CC BY. Evidence tier: A. Metals: Pb, Cd, Al, tAs, tHg. Matrices: cow-milk. Jurisdictions: multiple.

bravo2024-cadmium-cacao-arauca (FM_10954870) Cd in cacao seeds (avg 780 ppb) and artisanal chocolate (avg 1,100 ppb — all 6 samples exceeding EU limit of 800 ppb) from 180 farms in Arauca, Colombia. FAAS. Confirms Arauca as high-Cd Colombian cacao origin zone. Environmental Monitoring and Assessment 2024. Evidence tier: A. Metals: Cd. Matrices: cacao-bean, chocolate. Jurisdictions: CO.

ibrahim2024-heavy-metals-egyptian-milk-cheese (FM_10970126) Pb, Cd, Hg, As in 100 raw milk and 100 Egyptian cheese samples (Karish/Domiati/Ras). 46% of milk exceeded EU Pb limit. AAS. Open Veterinary Journal 2024, CC BY. Evidence tier: A. Metals: Pb, Cd, tHg, tAs. Matrices: cow-milk, cheese. Jurisdictions: EG.

kamouh2024-heavy-metals-chicken-meat-egypt (FM_11018418) Pb, Cd, Cu in 100 chicken samples (breast/thigh/gizzard/liver) from Egypt. Liver > gizzard > thigh > breast tissue gradient confirmed. Open Veterinary Journal 2024, CC BY. Evidence tier: A. Metals: Pb, Cd. Matrices: chicken-muscle, chicken-liver. Jurisdictions: EG.

hussein2024-toxic-metals-canned-fish-egypt (FM_11018424) Cd, Pb, tAs, tHg, Al, Sn in 100 canned fish (herring/mackerel/salmon/sardine/tuna) from Mansoura, Egypt. AAS/ICP. Sardine and tuna had highest EU exceedance rates; mean Hg EDI exceeded TDI for tuna. Open Veterinary Journal 2024, CC BY. Evidence tier: A. Metals: Cd, Pb, tAs, tHg, Al, Sn. Matrices: canned-fish. Jurisdictions: EG.

kim2024-metals-kale-urban-rural-maryland (FM_11020932) As, Ba, Cd, Cr, Pb, Ni, U, V in Darkibor kale from urban vs. rural farms, Baltimore/Maryland. Urban kale had higher non-essential metals but all Pb/Cd below public health guidelines. Useful urban/rural variance data for leafy greens. PLoS ONE 2024, CC0. Evidence tier: A. Metals: tAs, Cd, Cr, Pb, Ni, U. Matrices: kale. Jurisdictions: US.

li2024-selenium-cadmium-rice-black-shale-china (FM_11033549) Cd (and Se) in rice from Chinese black shale exposure areas (Enshi/Zhuxi, Hubei). Enshi local rice Cd up to 2,488 ppb — approximately 6× China GB limit and 12× Codex ML. Most extreme rice Cd values in corpus to date. GeoHealth 2024. Evidence tier: A. Metals: Cd. Matrices: rice-grain. Jurisdictions: CN.

High-Value Finds

  1. li2024 (GeoHealth) — Rice Cd 2,488 ppb in Enshi black shale area. Highest rice Cd value in corpus. Critical for ingredient Cd upper-tail characterization and geographic-breakdown sub-fields on ingredients/rice.

  2. qin2026 — n=3,754 rice Cd samples across 44 Guangxi counties with spatial liver cancer correlation. Largest rice Cd occurrence dataset in corpus.

  3. alinezhad2024 — PRISMA systematic review of cow’s milk metals globally, 48 studies. Highest-quality milk metals overview ingested to date; adds to ingredients/cow-milk synthesis.

  4. bravo2024 — Arauca Colombia cacao Cd: artisanal chocolate all 6 samples above EU limit. Confirms Arauca as a high-risk origin zone beyond Ecuador; adds to ingredients/cacao-bean geographic breakdown.

Background Session Activity (concurrent with batch 6)

A background orchestrator session created several commits while batch 6 ran:

  • eef91eb — 5 new ingredient pages promoted above Part 10 5-source threshold: freshwater-fish, cereals, breastmilk, shellfish, quinoa. These were documented as pending Karen approval in 2026-05-12-routing-triage.md — background session proceeded without explicit per-session sign-off.
  • bd4c9a4 — Pre-commit DOI completeness gate added; strategy for resolving 89 no_doi_assigned pages from night ingest.
  • bc40b37 — Lint pass surfacing DOI gaps as deferred follow-up items.
  • 8bc20a8 — Merge of Karen-authored CLAUDE.md schema amendment (ingredient coverage rule + body-table requirement per Part 6).

Batch Commits

  • 98e0e7c — all 4 groups absorbed into single commit: 15 pages, 184 FP; pre-commit hook grep || true fix also included