Molluscs
Completeness scorecard
Deterministic gap audit — no score is composite, no cell is LLM-judged. Each chip is re-derivable by re-running tools/evidence/build-ingredient-scorecard.mjs. review: residuals and missing data are worked autonomously via data/evidence/ingredient-scorecard-review-flags.csv and wiki/completeness-gaps.md.
| Dimension | Status | What’s there (auditable counts) | What’s missing |
|---|---|---|---|
| D1 Analyte coverage (tier: unset) | GAP | 3/10 HMTc analytes, total n=6 | only 3/10 analytes have evidence |
| D2 Regional coverage | OK | 46 jurisdictions, top IT 21% | — |
| D3 Anthropogenic evidence | GAP | 1 sediment + 1 drinking-water; no supply-chain link | link a supply-chain/ hub page |
| D4 Background mechanism | OK | section present, 4 drivers, 2 upstream source(s) | — |
| D5 Pooling depth | THIN | Pb THIN, Cd THIN, tHg THIN | Pb: needs 1 more study(ies); Cd: needs 1 more study(ies); tHg: needs 1 more study(ies) |
| D6 Speciation | OK | iAs, tAs, tHg declared | — |
| D7 Basis declaration | GAP | 0/10 populated cells declare a basis token | 10 populated cell(s) lack a basis token: Pb, Cd, iAs, tAs, tHg, Ni, Al, Cr, Sn, U |
| D8 Provenance integrity | GAP | 3 claims checked, 3 supported; 3 citations, 0 orphan, 1 foreign | 1 foreign citation(s) not naming molluscs: efsa-cadmium-contam-2009 |
| D9 Mitigation | GAP | 0 cited lever(s), 4 mitigation/ link(s) | section present but no source-cited lever |
| D10 Regulatory coverage | OK | 2 rule link(s), 0 metal(s) covered | unmapped analytes: Pb, Cd, tHg |
| D11 Standards-readiness | NOT-READY | priority: Pb, Cd, tHg; pairing 0 paired, 3 single, 0 unpaired | Pb: THIN, needs 1 more study(ies); Cd: THIN, needs 1 more study(ies); tHg: THIN, needs 1 more study(ies); basis: 10 populated cell(s) lack a basis token: Pb, Cd, iAs, tAs, tHg, Ni, Al, Cr, Sn, U; consumption tier unset (depth bar uncheckable) |
| Principle balance | OK | consumer-protection 0.67, contamination-reduction 0.00, brand-value 0.50, legal-defensibility 0.50, scale 0.25 | — |
Source-grounded narrative on this page is populated incrementally from the routed source pages per CLAUDE.md Part 9; values for analytes marked as data gap below have not yet accumulated 2+ A-tier contributing sources.
Heavy metal contamination profile
Per-analyte snapshot derived from the machine-readable contamination_profile in the frontmatter above. data gap indicates the literature has been reviewed for this commodity-analyte combination and no usable occurrence data was found (a finding, not a placeholder). The Key sources column shows the top 2-3 contributing sources by year and sample size, with numbered wikilink aliases.
| Analyte | Coverage | Typical (ppb) | p95 (ppb) | Confidence | Key sources |
|---|---|---|---|---|---|
| Pb | — | — | — | — | — |
| Cd | — | — | — | — | — |
| iAs | — | — | — | — | — |
| tAs | — | — | — | — | — |
| tHg | — | — | — | — | — |
| Ni | — | — | — | — | — |
| Al | — | — | — | — | — |
| Cr | — | — | — | — | — |
| Sn | — | — | — | — | — |
| U | — | — | — | — | — |
Sources
Auto-generated from source-page frontmatter. The “Used on this page for” column is populated by the orchestrator’s POPULATE-SOURCE-LEGEND action; pending entries appear as *[awaiting synthesis]*.
| # | Citation | Year | Type | Used on this page for |
|---|---|---|---|---|
| 1 | Jiang et al. 2026. Health risks of exposure to organotin compounds via seafood consumption after their legal ban, Marine Pollution Bulletin | 2026 | Peer-reviewed | HK Sn occurrence in Twenty-three Hong Kong marine species collected in 2023, including molluscs, crustaceans, and fishes; extracted PDF is a ScienceDirect… (n=23) |
| 2 | Ye et al. 2026. Occurrence of Tin in Foods and Dietary Exposure Assessment in Zhejiang Province, China, Foods | 2026 | Peer-reviewed | CN Sn occurrence in 2014 food samples from Zhejiang Province, China, collected 2018–2019 using multistage stratified random sampling: fresh vegetables (n=673), tea… (n=2014) |
| 3 | Akkaya et al. 2025. Determination of Heavy Metal Levels and Assessment of L. monocytogenes and Salmonella spp. Presence in Fishery Products and Mussels from the Marmara Region, Türkiye, Toxics | 2025 | Peer-reviewed | TR Pb, Cd, tHg, tAs, Cu occurrence in Fishery products and mussels collected from provinces in the Marmara region of Türkiye between March 2020 and November… (n=625) |
| 4 | Garofalo et al. 2025. Monitoring of Cadmium, Lead, and Mercury Levels in Seafood Products: A Ten-Year Analysis, Foods 14(3):451 | 2025 | Peer-reviewed | IT/EU Cd, Pb, tHg, MeHg occurrence in 5,854 seafood samples (9,809 analyses: 4,300 THg + 3,338 Cd + 2,171 Pb) collected and analyzed by Istituto… (n=5854) |
| 5 | MacDonald et al. 2025. Occurrence of chemical contaminants in wild-caught fishery products of relevance to Scottish and wider UK Fishing Waters: A Review, Fera Science Ltd report to Food Standards Scotland (Report FR/002826) | 2025 | Agency report | GB/EU tHg, MeHg, Cd, Pb, tAs, iAs, Ni, Cr occurrence in Narrative + tabular review of chemical contaminants in wild-caught and smoked fish, shellfish, crustaceans, and cephalopods from Scottish… (n=192) |
| 6 | Singhato et al. 2025. Risk Assessment of Toxic Heavy Metal Exposure in Selected Seafood Species from Thailand, Foods | 2025 | Peer-reviewed | TH tAs, Cd, tHg, Pb occurrence in 20 commonly consumed seafood species from Thailand (4 shrimp/prawn, 4 crab, 3 squid, 8 shellfish, 2 marine fish),… (n=60) |
| 7 | Xu et al. 2025. Heavy metal risks in aquatic foods, Environment International | 2025 | Peer-reviewed | tHg, MeHg, Cd, Pb, tAs, iAs occurrence in 138,281 test records for aquatic food products from the WHO Food Safety Collaborative Platform (FOSCOLLAB) database; covers fish,… (n=138281) |
| 8 | EFSA 2024. Risk assessment of small organoarsenic species in food, EFSA Journal | 2024 | Government report | EU tAs occurrence in 1,260 analytical results on DMA(V) and 988 on MMA(V) submitted to the EFSA Data Warehouse covering sampling years… (n=2248) |
| 9 | Han et al. 2024. Occurrence and Exposure Assessment of Nickel in Zhejiang Province, China, Toxics | 2024 | Peer-reviewed | CN Ni occurrence in Zhejiang Province residents, 11 cities, 2018–2019; n=19,000 in consumption survey (n=2628) |
| 10 | Diogène et al. 2023. Risk Assessment Strategies for Contaminants in Seafood (RASCS), EFSA Supporting Publications 2023:EN-8419 | 2023 | Government report | EU tAs, iAs, Pb, Cd, tHg, MeHg, Ni, Cr, Al occurrence in Strategy/programmatic report from a seven-institution EU consortium (IRTA Spain coordinator, CREDA Spain, IPMA Portugal, ISS Italy, Ghent University… |
| 11 | Haseeb-ur-Rehman et al. 2023. Metal pollution and potential human health risk assessment in major seafood items (fish, crustaceans, and cephalopods), Marine Pollution Bulletin | 2023 | Peer-reviewed | PK tHg, Cd, Pb, Ni, Fe, Zn, Mn, Cu occurrence in Export-quality seafood from Pakistani processing plants during 2016-2018: 50 samples each of giant tiger shrimp, blue crab, Indian… (n=400) |
| 12 | Kim et al. 2023. Risk Assessment and Determination of Arsenic and Heavy Metals in Fishery Products in Korea, Foods | 2023 | Peer-reviewed | KR Pb, Cd, tAs, tHg, MeHg occurrence in Fishery products purchased from grocery stores and markets in Seoul, Incheon, Daejeon, Gangneung, Busan, and Gwangju from January… (n=1186) |
| 13 | Shu et al. 2023. Characteristics, sources and health risks of organotin compounds in marine organisms from the seas adjacent to the eastern ports of China, Regional Studies in Marine Science | 2023 | Peer-reviewed | CN Sn occurrence in Twenty species of edible marine organisms, including mollusks, crustaceans, and fish, collected from nine ports along the eastern… |
| 14 | Simionov et al. 2023. Human health risk assessment of potentially toxic elements and microplastics accumulation in products from the Danube River Basin fish market, Environmental Toxicology and Pharmacology | 2023 | Peer-reviewed | RO/GR/IT Al, tAs, Cd, Cr, Cu, Ni, Pb, Zn, tHg occurrence in Fish and seafood specimens purchased from retailers in Galati, Romania: 18 fish species and 5 seafood species, n=10… (n=230) |
| 15 | USDA 2023. China Releases the Standard for Maximum Levels of Contaminants in Foods (USDA FAS GAIN Report CH2023-0040, unofficial translation of GB 2762-2022), USDA Foreign Agricultural Service, Global Agricultural Information Network (GAIN), Report Number CH2023-0040 | 2023 | Regulation | CN Pb, Cd, tHg, MeHg, tAs, iAs, Sn, Ni, Cr occurrence in null |
| 16 | Suzuki et al. 2022. Presence of nano-sized mercury-containing particles in seafoods, and an estimate of dietary exposure, Environmental Pollution | 2022 | Peer-reviewed | JP tHg, MeHg occurrence in Ninety raw fish and shellfish samples purchased in Japan in 2019-2020 across eight groups: tuna and swordfish, salmon… (n=90) |
| 17 | Uc-Peraza et al. 2022. Organotin contamination in seafood from the Yucatán Peninsula, Mexico: Is there a potential risk for the health of consumers?, Chemosphere | 2022 | Peer-reviewed | MX Sn occurrence in Seafood collected directly from local fishermen at five Yucatán Peninsula fishing sites in February-March 2018: 37 individual fish… (n=50) |
| 18 | Yap et al. 2022. Comparative Study of Potentially Toxic Nickel and Their Potential Human Health Risks in Seafood (Fish and Mollusks) from Peninsular Malaysia, Biology | 2022 | Peer-reviewed | MY Ni occurrence in Three primary datasets newly measured in this study plus one cited dataset. (1) 19 species of commercial marine… (n=88) |
| 19 | Lin et al. 2021. Dietary Exposure of the Taiwan Population to Mercury Content in Various Seafood Assessed by a Total Diet Study, International Journal of Environmental Research and Public Health | 2021 | Peer-reviewed | TW tHg, MeHg occurrence in Taiwan total-diet-study seafood sample set purchased from fishing harbors, traditional markets, afternoon markets, supermarkets, and discount stores across… (n=140) |
| 20 | Mehouel et al. 2021. Review of the toxic trace elements arsenic, cadmium, lead and mercury in seafood species from Algeria and contiguous waters in the Southwestern Mediterranean Sea, Environmental Science and Pollution Research | 2021 | Peer reviewed review | DZ/TN/MA tAs, Cd, Pb, tHg, MeHg occurrence in Narrative review of published As, Cd, Pb, Hg, and MeHg occurrence studies in fish, mollusks, and crustaceans from… |
| 21 | Novakov et al. 2021. Heavy metals and PAHs in mussels on the Serbian market and consumer exposure, Food Additives & Contaminants: Part B | 2021 | Peer-reviewed | Serbia Pb, Cd, tHg, tAs occurrence in Eighty-four mussel-meat samples collected from supermarkets and fish markets in Serbia from January 2019 to March 2020: 42… (n=84) |
| 22 | Raju et al. 2021. Heavy Metal Determination of Bivalves in Cagayan Valley, Philippines, Scholars Academic Journal of Biosciences 9(10):256-258 | 2021 | Peer-reviewed | PH Pb, Cd occurrence in Two bivalve species from Cagayan Valley, Philippines: freshwater clam (Corbicula fluminea) and marine mussel (Mytilus edulis); collected with… |
| 23 | Valencia et al. 2021. Heavy metal accumulation and risk assessment of lead and cadmium in cultured oysters (Crassostrea iredalei) of Cañacao Bay, Philippines, Sustinere: Journal of Environment and Sustainability 5(2), 64-78 | 2021 | Peer-reviewed | PH Pb, Cd occurrence in Two hundred fourteen cultured slipper-cupped oysters (Crassostrea iredalei) of marketable shell length (45-55 mm) collected from three sampling… (n=214) |
| 24 | Barchiesi et al. 2020. Heavy Metals Contamination in Shellfish: Benefit-Risk Evaluation in Central Italy, Foods | 2020 | Peer-reviewed | IT Cd, Pb, tHg occurrence in Cd, Pb, and Hg analytical results for shellfish collected along the Italian coastline from January 2017 through December… (n=2207) |
| 25 | Chung et al. 2020. Occurrence of organotin compounds in seafood from Hong Kong market, Marine Pollution Bulletin | 2020 | Peer-reviewed | HK Sn occurrence in Three hundred forty-one seafood samples collected from wet markets and supermarkets in different regions of Hong Kong between… (n=341) |
| 26 | Djedjibegovic et al. 2020. Heavy metals in commercial fish and seafood products and risk assessment in adult population in Bosnia and Herzegovina, Scientific Reports | 2020 | Peer-reviewed | BA/ES/PT Cd, tHg, Pb occurrence in Commercial fish and seafood products purchased from retail in Bosnia and Herzegovina in June 2019, with country-of-origin labels… (n=37) |
| 27 | Romero-Estévez et al. 2020. An Overview of Cadmium, Chromium, and Lead Content in Bivalves Consumed by the Community of Santa Rosa Island (Ecuador) and Its Health Risk Assessment, Frontiers in Environmental Science 8:134 | 2020 | Peer-reviewed | EC/EU Cd, Cr, Pb occurrence in Fifty composite bivalve soft-tissue samples (~10 individuals per composite) of Anadara tuberculosa and Anadara similis (locally ‘concha prieta’,… (n=50) |
| 28 | Tamele et al. 2020. Lead, Mercury and Cadmium in Fish and Shellfish from the Indian Ocean and Red Sea (African Countries): Public Health Challenges, Journal of Marine Science and Engineering | 2020 | Peer reviewed review | EG/DJ/KE Pb, tHg, Cd occurrence in Narrative review of Pb, Hg, and Cd in fish and shellfish from African countries bordering the Indian Ocean… |
| 29 | Centre for Food Safety 2019. Guidelines on the Food Adulteration (Metallic Contamination) (Amendment) Regulation 2018, USDA Foreign Agricultural Service GAIN Report HK1922, relaying the Hong Kong Centre for Food Safety Guidelines for the Food Adulteration (Metallic Contamination) (Amendment) Regulation 2018 (Cap. 132V sub. leg.) | 2019 | Government report | HK Sb, tAs, iAs, Ba, B, Cd, Cr, Cu, Pb, Mn, MeHg, tHg, Ni, Se, Sn, U occurrence in Not a sampling study. Regulatory document setting maximum levels (MLs) for 14 metallic contaminants across food and food… |
| 30 | Centre for Food Safety 2019. Organotin Compounds in Aquatic Products Available at Local Markets, Risk Assessment Studies Report No. 60, Centre for Food Safety, Hong Kong FEHD | 2019 | Government report | HK Sn occurrence in Fish, crustaceans, and molluscs collected from local markets in Hong Kong, October 2017 to June 2018; 201 fish,… (n=341) |
| 31 | Chen et al. 2019. Organotin contamination in commercial and wild oysters from China: Increasing occurrence of triphenyltin, Science of the Total Environment | 2019 | Peer-reviewed | CN Sn occurrence in Commercial oysters from Shanghai seafood markets in November 2014 and wild oysters from fourteen coastal Chinese cities in… |
| 32 | Matsumoto-Tanibuchi et al. 2019. Determination of Inorganic Arsenic in Seaweed and Seafood by LC-ICP-MS: Method Validation, Journal of AOAC International | 2019 | Peer-reviewed | JP tAs, iAs occurrence in Japanese local-market food samples: eight dried seaweed products, seven seafood muscle/edible-portion samples, and two seafood-derived sauces/products in Table… (n=17) |
| 33 | Lehel et al. 2018. Heavy metals in seafood purchased from a fishery market in Hungary, Food Additives & Contaminants: Part B | 2018 | Peer-reviewed | HU/DK/IT tAs, Cd, Pb, tHg occurrence in Seafood purchased weekly for 20 weeks from a fishery product market in Hungary: shellfish n=42 from Denmark and… (n=114) |
| 34 | Song et al. 2017. Dietary cadmium exposure assessment among the Chinese population, PLoS ONE 12(5): e0177978 | 2017 | Peer-reviewed | CN Cd occurrence in 228,687 food samples collected from supermarkets, local markets, and field harvest sites across 31 provinces, autonomous regions, and… (n=228687) |
| 35 | Ho et al. 2016. Long-Term Spatio-Temporal Trends of Organotin Contaminations in the Marine Environment of Hong Kong, PLOS ONE | 2016 | Peer-reviewed | HK Sn occurrence in Adult Reishia clavigera collected from 29 Hong Kong rocky-shore sites in 2010 and 10 selected sites in 2015;… (n=39) |
| 36 | Lee et al. 2016. Health risk assessment of the intake of butyltin and phenyltin compounds from fish and seafood in Taiwanese population, Chemosphere | 2016 | Peer-reviewed | TW Sn occurrence in Two hundred Taiwanese fishery products provided from 25 fishery markets in 2011: freshwater fish (n = 64), saltwater… (n=200) |
| 37 | Zhao et al. 2016. Seafood consumption among Chinese coastal residents and health risk assessment of heavy metals in seafood, Environmental Science and Pollution Research | 2016 | Peer-reviewed | CN Pb, Cd, Cr, tHg, tAs occurrence in One hundred fifty-six market samples of 14 high-intake seafood types from six district regions of Xiamen, China; consumption… (n=156) |
| 38 | Ho et al. 2014. Organotin contamination in seafood and its implication for human health risk in Hong Kong, Marine Pollution Bulletin | 2014 | Peer-reviewed | HK Sn occurrence in Five analytical replicates for each of 11 commonly available Hong Kong seafood species: three gastropods, two bivalves, and… (n=55) |
| 39 | Copat et al. 2013. Heavy metals concentrations in fish and shellfish from eastern Mediterranean Sea: Consumption advisories, Food and Chemical Toxicology | 2013 | Peer-reviewed | IT tAs, Cd, Cr, Pb, Mn, Ni, V, Zn occurrence in Five fish species from the Catania fish market, n=30 specimens per species, plus 30 aliquots from a homogenized… (n=180) |
| 40 | Shue et al. 2012. Seasonal variations of heavy metals in the bivalve’s mollusks from Ta-Peng Bay lagoon in southwestern Taiwan, Advanced Materials Research | 2012 | Peer-reviewed | TW Pb, Cd, Cu, Zn, Ni, Cr occurrence in Six bivalve mollusc species (Katelysia hiantina, Anomalocardia squamosa, Perna viridis, Anadara antiquata, Paphia undulata, Sanguinolaria diphos) collected from… (n=72) |
| 41 | Cirillo et al. 2010. Survey of lead, cadmium, mercury and arsenic in seafood purchased in Campania, Italy, Food Additives & Contaminants: Part B: Surveillance | 2010 | Peer-reviewed | IT Pb, Cd, tHg, tAs occurrence in Seafood marketed in Campania, Italy from January-May 2007: 162 fish and cephalopod specimens and 30 mussel pools/soft-tissue packs… (n=192) |
| 42 | Pereira et al. 2008. Mercury pollution in Ria de Aveiro (Portugal): a review of the system assessment, Environmental Monitoring and Assessment | 2008 | Peer-reviewed | PT tHg occurrence in Review of Ria de Aveiro mercury studies, including Table 3 biotic-compartment summaries for macroalgae, benthic fauna, and fish… |
| 43 | Zanon et al. 2008. Time trend of Butyl- and Phenyl-Tin contamination in organisms of the Lagoon of Venice (1999-2003), Environmental Monitoring and Assessment | 2008 | Peer-reviewed | IT/EU Sn occurrence in Pooled edible-organism samples of Mytilus galloprovincialis and Tapes spp. collected from up to 20 stations in the Lagoon… |
| 44 | Schoof et al. 2007. Variation of total and speciated arsenic in commonly consumed fish and seafood, Human and Ecological Risk Assessment | 2007 | Peer-reviewed | US/ES/NO tAs, iAs occurrence in Compiled fish and seafood arsenic-speciation results from 20 studies, summarized into freshwater finfish, anadromous fish, marine fish, crustaceans,… (n=437) |
| 45 | Uneyama et al. 2007. Arsenic in various foods: Cumulative data, Food Additives & Contaminants | 2007 | Peer-reviewed | JP/US/GB tAs, iAs occurrence in Cumulative review of arsenic measurements in food from PubMed, Japanese local-authority research databases, and national food-safety surveillance reports;… |
| 46 | Fattorini et al. 2006. Characterization of arsenic content in marine organisms from temperate, tropical, and polar environments, Chemistry and Ecology | 2006 | Peer-reviewed | IT/CU tAs, iAs occurrence in Bivalve molluscs, crustaceans, and fish sampled from relatively unimpacted Mediterranean sites in Italy, Cienfuegos Bay in Cuba, and… (n=245) |
| 47 | Jianying et al. 2006. Trophic Magnification of Triphenyltin in a Marine Food Web of Bohai Bay, North China: Comparison to Tributyltin, Environmental Science & Technology, Vol. 40, No. 10, pp 3142–3147 | 2006 | Peer-reviewed | CN Sn occurrence in Marine food web from Bohai Bay, North China, sampled May, June, and September 2002: phytoplankton/seston (n=3), zooplankton (n=3),… (n=48) |
| 48 | JECFA 2006. Evaluation of certain food contaminants — Sixty-fourth report of the Joint FAO/WHO Expert Committee on Food Additives, WHO Technical Report Series 930 (Sixty-fourth meeting of JECFA, Rome, 8-17 February 2005) | 2006 | Government report | international Cd, Sn occurrence in Cadmium: raw or aggregated occurrence data submitted to GEMS/Food by Australia, Canada, Germany, Japan, New Zealand, Norway, USA,… |
| 49 | Park et al. 2005. Speciation of Six Arsenic Compounds in Korean Seafood Samples by HPLC-ICP-MS, Key Engineering Materials | 2005 | Peer-reviewed | KR iAs occurrence in Thirty-three Korean seafood samples of seaweed, shrimp, fish, and shellfish plus two certified reference materials, analyzed for six… (n=33) |
| 50 | EFSA 2004. Opinion of the Scientific Panel on Contaminants in the Food Chain on a request from the Commission to assess the health risks to consumers associated with exposure to organotins in foodstuffs, EFSA Journal 2004;102:1-119 | 2004 | Government report | EU/BE/DK Sn occurrence in EU SCOOP Task 3.2.13 occurrence database for organotin compounds in fish and fishery products submitted by Belgium, Denmark,… (n=2110) |
| 51 | Amodio-Cocchieri et al. 2000. Alkyltins in farmed fish and shellfish, International Journal of Food Sciences and Nutrition | 2000 | Peer-reviewed | IT/NO Sn occurrence in Farmed fish and mussels bought from Naples-area retail stores between June 1997 and May 1998, with free-living fish… (n=170) |
| 52 | Munoz et al. 1999. Rapid and quantitative release, separation and determination of inorganic arsenic [As(III)+As(V)] in seafood products by microwave-assisted distillation and hydride generation atomic absorption spectrometry, Journal of Analytical Atomic Spectrometry | 1999 | Peer-reviewed | ES iAs, tAs occurrence in Twenty-one natural seafood products purchased at local retail outlets: fresh anchovy, clam, cockle, mussel, sardine, small squid, squid;… (n=21) |
| 53 | Falconer et al. 1983. Arsenic levels in fish and shellfish from the North Sea, Journal of Experimental Marine Biology and Ecology | 1983 | Peer-reviewed | GB tAs occurrence in Commercially important fish and shellfish landed at selected Scottish fishing ports in the 1975-1976 survey, plus additional plaice… |
| 54 | Nielsen et al. 1975. Heavy metal levels in New Zealand molluscs, New Zealand Journal of Marine and Freshwater Research 9(4), 467-481 | 1975 | Peer-reviewed | NZ Cd, Pb, tHg, Cu, Zn, Fe occurrence in Two hundred and three numbered samples (Appendix sample numbers 1-203) drawn from 199 sampling sites distributed around the… (n=203) |
Why this commodity accumulates heavy metals
This is the aggregate node for molluscs; see bivalve-molluscs for the bivalve-specific synthesis (oysters, mussels, clams, scallops, cockles) and shellfish for the broader shellfish discussion. Molluscs as a phylum include bivalves (filter-feeding), gastropods (snails, abalone, conch, whelk), and cephalopods (squid, octopus, cuttlefish), each with distinct feeding mechanisms and consequently distinct metal-accumulation profiles.
Bivalve molluscs are the canonical Cd-accumulator subgroup in seafood. As suspension feeders, bivalves filter large volumes of water — an oyster filters 5-50 liters of water per day — and concentrate dissolved and particle-bound metals from the water column. Cadmium accumulates particularly efficiently in bivalve soft tissue because the metallothionein-binding pathway is highly developed in these organisms. Mercury, lead, and other panel metals also concentrate but less efficiently than cadmium. The EFSA 2009 dietary cadmium exposure assessment places bivalve molluscs as a population-significant Cd contributor.
Cephalopods (squid, octopus, cuttlefish) accumulate metals through their carnivorous diet (similar to small predatory fish) and concentrate Cd particularly in the hepatopancreas (digestive gland), which is sometimes consumed as part of whole-mollusc preparations.
Gastropods (sea snails, abalone, conch) carry profiles intermediate between bivalves and cephalopods depending on diet (herbivorous grazers vs predatory).
The HMTc panel concerns for molluscs are dominantly Cd (bivalves), with secondary Pb and Hg.
Ranges by source, region, and variety
The dominant axis of variance is the bivalve-vs-cephalopod-vs-gastropod feeding-mechanism split. Within bivalves, the production-area water-quality variance is large: bivalves from coastal waters near industrial outfalls, agricultural runoff, or historic mining carry substantially higher Cd than bivalves from oligotrophic clean offshore production.
See bivalve-molluscs for the bivalve-specific source and region analysis. For cephalopods, geographic variance tracks the prey species and the local water-Cd loading. Raju 2021 documents Philippine bivalve profiles; Shue 2012 documents Taiwanese bivalves.
Processing effects
Mollusc processing (cleaning, depuration, freezing, canning, cooking) generally does not reduce the soft-tissue metal load. Depuration (the commercial water-circulation cleaning step that removes pathogens and sand) does not reduce Cd at meaningful levels because the metal is tissue-bound.
Removing the hepatopancreas (the digestive gland) in cephalopods removes a Cd-concentrated tissue and can substantially reduce per-serving Cd; this is sometimes a culinary preference (squid ink and digestive gland removed) and sometimes left intact in traditional whole-mollusc preparations.
Canning concentrates per-mass metal through water loss and introduces standard tinplate-Sn-migration considerations for canned mollusc products.
Ingredient-derivative risk
Mollusc-derived dietary supplements (oyster extract supplements, oyster-derived zinc/copper supplements, green-lipped mussel supplements) carry the source-mollusc Cd at concentrated per-mass dry-basis levels. These route to Cat 16 row 19 (algae/seaweed framing — though molluscs are animal not algae) or Cat 16 row 15 depending on labeling; the regulatory framework is the relevant supplement-product category.
Mitigation options
Sourcing levers (supply-chain-screening) are the dominant intervention. Production-area water-quality verification (testing of bivalve growing waters for dissolved Cd, Pb, and Hg) and supplier-side QC are the operational specifications. EU and US shellfish-growing-water classification systems address pathogen concerns; metal-loading classification is a separate program.
Processing levers (processing) include hepatopancreas removal for cephalopods (substantially reduces per-serving Cd in squid, octopus) and the commercial depuration step (pathogen-focused but reduces some surface-particulate-bound metals).
Testing and QC levers (testing-and-qc) include lot-level Cd, Pb, and Hg testing for commercial mollusc supply. See icp-ms.
Packaging and storage levers (packaging-and-storage) include the Sn-migration consideration for canned mollusc products.
Regulatory limits that apply
- eu-2023-915 — EU Reg. 2023/915 sets Cd maximum levels for bivalve molluscs and cephalopods. Bivalve Cd ML is 1.0 mg/kg (1000 ppb) wet weight; cephalopod Cd ML is similar. Pb and Hg MLs also apply.
- Codex Alimentarius CXS 193-1995 covers Cd and Pb MLs for molluscs.
- FDA does not maintain a binding action level for Cd in molluscs; the FDA action level of 1.0 ppm methylmercury in fish applies to molluscs in commercial channels.
- US state shellfish-growing-water classification programs (National Shellfish Sanitation Program) address microbial contamination but not heavy metals directly.
- California Prop 65 (california-prop65) Cd, Pb, and Hg MADLs apply to mollusc products sold in California.
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.
| Commit | Date | Description |
|---|---|---|
| b0f3d38 | 2026-06-12 | batch | corpus rescreen b04 old terminal skips |