This page is the index of the Heavy Metal Index’s synthesis layer. Each linked subpage is a self-contained synthesis findings page: a thesis statement built on at least three corroborating A-tier sources, presenting a non-obvious finding that emerges from the corpus and would not be evident from any single source page. Synthesis pages sit one layer above the source and product pages and one layer below the strategic / certification documents, and the wiki’s epistemic authority rests on them remaining provisional, source-traceable, and explicit about their own uncertainty.
Synthesis findings pages
Each row links to a self-contained synthesis page that carries the full anchor-source evidence and the reasoning behind the finding. Listed newest first.
When to promote a synthesis findings page
A synthesis findings page is warranted when a thematic cluster in the corpus meets all of the following criteria.
The finding rests on at least three independent A-tier or high-quality B-tier sources. Two sources are an interesting coincidence; three is the floor for treating the convergence as evidence of a real pattern rather than an artifact of any single research group’s framing. The sources should be independent in the sense of distinct authorship, distinct institutional context, and ideally distinct geographies.
The finding spans multiple metals, ingredients, or products. Findings that fit cleanly inside one existing page belong on that page, not in synthesis. Synthesis exists for claims whose support and implications span boundaries the existing taxonomy was not built to handle: a finding about climate effects on multiple food matrices, a finding about how regulatory bodies disagree across multiple metals, a finding about a vulnerable-population exposure pattern that aggregates across products and ingredients.
The finding is not obvious from any single source. A synthesis page is doing work that no source page can do on its own. If the finding is just “rice contains arsenic” or “cocoa contains cadmium,” that belongs in the relevant ingredient page’s body, not in synthesis. Synthesis findings are the connections, contradictions, and trajectories that emerge when the corpus is read as a whole.
The finding has strategic relevance to the wiki’s audiences. The wiki’s brand-legal, regulatory, and educational audiences are different from each other, but a synthesis finding should serve at least one of them in a load-bearing way: it should change how a defense counsel reads the wiki, how a regulator weighs the evidence, or how a course module is built. Findings that are intellectually interesting but operationally inert can live as notes on source pages or in the log; synthesis pages are reserved for findings that have downstream consequences.
When all four criteria are met, a candidate thread is promoted to a synthesis findings page at wiki/synthesis/<topic-slug>.md, written from the anchor sources under the prose conventions used across the wiki and added to the index above. Candidates surface from systematic review of the corpus as it grows and from curator judgment; the threshold is the four criteria, not the route by which a thread is first noticed. A new synthesis page is provisional until at least two further corroborating studies enter the corpus after promotion, at which point it is re-synthesized from the complete evidence set rather than patched.
The cadmium synthesis (in progress)
A dedicated cadmium synthesis page is in preparation. Most of its analytical substance is already written up on the cadmium page, which carries the cross-source account of cadmium toxicology, the four major dietary reference values and their derivations, the population-exposure picture, and the cocoa-and-children exposure finding. The dedicated synthesis page will consolidate that material with the full regulatory-toxicology record (EFSA 2009, JECFA 73rd and 91st, EPA IRIS, ATSDR 2012, OEHHA Prop 65, Codex CCCF17, and Codex CXS 193-1995) and the canonical toxicology textbook chapters, and will resolve two open questions the corpus has surfaced.
The first is the divergence among the four dietary cadmium reference values, which order from tightest to most permissive as ATSDR → EFSA → JECFA → EPA IRIS, an approximately eight-fold span that any certification threshold must name rather than average away. The values and their methodological derivations are documented on cadmium.
The second is whether the cadmium cardiovascular endpoint has undergone a genuine consensus shift between the 2015 Handbook framing, which treats it as contested, and the 2021 Essentials framing, which describes a strong association. The cadmium page records both positions without resolution, which is the correct posture under the drift-protection rule until the intervening literature is read in full.
Until the dedicated page is published, cadmium claims should be traced to cadmium and the underlying source pages.