Occurrence of chemical contaminants in wild-caught fishery products of relevance to Scottish and wider UK Fishing Waters: A Review

MacDonald S; Stead S; Rose M; Boss K; Campbell K

MacDonald, Stead, Rose, Boss & Campbell 2025 — Chemical contaminants in wild-caught fishery products of Scottish and wider UK waters

Fera Science Ltd, commissioned by Food Standards Scotland, screened over 3,600 records and selected 125 for inclusion to evaluate the occurrence of regulated and emerging chemical contaminants in wild-caught and smoked fish, shellfish, crustaceans, and cephalopods landed in Scotland and wider UK fishing waters. The review integrates UK-funded surveys from 2009 (FSAS), 2015 (FSA-Fera), and the 2022-23 FSA Wild Caught Fish study reported in 2025, alongside published primary literature. Heavy-metal results are reported below the maximum permitted level (ML) for most species, with the principal regulated-metal exceedances identified as cadmium in crab and scallops, lead in mussels, and mercury in sea bass. Emerging and unregulated contaminants — PBDEs, PCNs, PXDD/Fs, PFAS, microplastics — were detected widely; PFAS in particular exceeded EU MLs in several species despite not being currently regulated in Great Britain. The report concludes that significant data gaps exist for Scottish-landed fish across PFAS, dioxins, PCBs, and inorganic arsenic.

Key numbers

Pooled regulated-metals summary (Table 13; n=192 fish samples from known UK locations, FSA-2015 Fera survey, reproduced from Mortimer 2018). Values in mg/kg whole weight.

Lead — mean 0.02, 95th percentile 0.07, maximum 0.90, ML 0.30 mg/kg (all species: sardines, mackerel, herring, grey mullet, sprats, sea bass, turbot, shark spp., halibut, haddock, plaice, lemon sole, witch, megrim, monkfish).
Cadmium — mean 0.01, 95th percentile 0.02, maximum 0.06, ML 0.05 mg/kg (all species excluding mackerel and sardines).
Cadmium (mackerel) — mean 0.03, 95th percentile 0.10, maximum 0.16, ML 0.10 mg/kg.
Cadmium (sardines) — mean 0.03, 90th percentile 0.06, maximum 0.06, ML 0.25 mg/kg (90th rather than 95th percentile flagged by ** in the source table).
Mercury (total) — mean 0.07, 95th percentile 0.19, maximum 0.43, ML 0.50 mg/kg (all species excluding halibut, mullet, dogfish).
Mercury (total, halibut/mullet/dogfish) — mean 0.18, 95th percentile 0.82, maximum 1.0, ML 1.00 mg/kg.

2022-23 FSA Wild Caught Fish survey (Table 14; n=152 across 16 categories; reported FSA Research and Evidence 2025). Values in mg/kg whole weight; reported as concentration ranges. Detection counts shown as (samples above LOQ / total samples).

Lead — cod 1/13 (0.010); crab 26/27 (<0.005-0.05); cuttlefish 10/11 (<0.005-0.013); dogfish 0/2 (<0.005); gurnard 0/2 (<0.005); haddock 0/2 (<0.005); hake 0/5 (<0.005); herring 3/7 (<0.005-0.008); lobster 3/4 (<0.005-0.041); mackerel 1/16 (<0.005-0.006); monkfish & anglers 1/7 (<0.005-0.010); plaice 2/3 (<0.005-0.017); sardines 32/32 (0.007-0.034); sea bass 2/9 (<0.005-0.013); skates & rays 3/4 (<0.005-0.006); sole 0/6 (<0.005); squid 1/2 (<0.005-0.009). Lead not found above the ML in any sample.
Cadmium — cod 0/13 (<0.005); crab 15/27 (<0.005-0.157); cuttlefish 8/11 (<0.005-0.022); dogfish 0/2 (<0.005); gurnard 2/2 (0.006 and 0.011); haddock 0/2 (<0.005); hake 0/5 (<0.005); herring 7/7 (0.011-0.027); lobster 4/4 (0.016-0.047); mackerel 15/16 (<0.005-0.075); monkfish & anglers 1/7 (<0.005-0.009); plaice 0/3 (<0.005); sardines 32/32 (0.005-0.021); sea bass 0/9 (<0.005); skates & rays 0/4 (<0.005); sole 0/6 (<0.005); squid 2/2 (0.007-0.010). One mackerel sample 0.16 mg/kg (0.13 mg/kg minus measurement uncertainty) above the mackerel ML of 0.1 mg/kg; the report states the 19% measurement-uncertainty figure only for the three Hg sea bass exceedances and does not quote a percentage for the Cd mackerel uncertainty adjustment.
Mercury (total) — detected in all 152 samples. Concentration ranges: cod 13/13 (0.08-0.12); crab 27/27 (0.05-0.30); cuttlefish 11/11 (0.04-0.08); dogfish 2/2 (0.52 and 0.55); gurnard 2/2 (0.61 and 0.14); haddock 2/2 (0.03 and 0.11); hake 5/5 (0.04-0.42); herring 7/7 (0.011-0.027); lobster 4/4 (0.12-0.40); mackerel 16/16 (0.03-0.08); monkfish & anglers 7/7 (0.10-0.20); plaice 3/3 (0.07-0.16); sardines 32/32 (0.02-0.05); sea bass 9/9 (0.20-0.87); skates & rays 4/4 (0.07-0.32); sole 6/6 (0.03-0.06); squid 2/2 (both 0.01). Three sea bass samples above the 0.5 mg/kg fish ML: 0.74 (0.60 minus 19% uncertainty), 0.69 (0.56), 0.87 (0.70) mg/kg.

FSAS 2009 study (Fernandes et al. 2009b; 32 marine fish, 16 freshwater fish, 5 marine shellfish from Scottish waters). Values in mg/kg whole weight.

Mercury (total) — all marine fish positive, range 0.035-0.746; all freshwater fish positive, range 0.029-0.454; all shellfish, range 0.025-0.47. Three samples above ML for Hg (a ling, a blue ling, a torsk).
Methylmercury subset — range 0.14 (trout) to 0.77 (ling, highest tHg sample); blue ling sample 0.66 mg/kg MeHg. Methylmercury concentrations similar to total mercury levels.
Cadmium — 17 marine fish samples positive (0.004-0.059); 7 freshwater fish positive (0.004-0.039).
Lead — 7 of 32 marine samples positive (0.005-0.009); 10 freshwater positive (0.006-0.084); all 5 shellfish contained residues (0.242-1.551) — no ML exceedances (n=5 mussels only).

FSA-2015 study by-species lead ranges (Fernandes et al. 2015, 2018). mg/kg ww.

Sardines 0.005-0.007; mackerel <0.002-0.018; herring <0.002-0.064; grey mullet <0.002-0.901; sprat 0.005-0.226; sea bass <0.002-0.157; turbot <0.002-0.028; shark spp. <0.002-0.009. Two grey mullet samples above Pb ML of 0.3 mg/kg, both from the Pembrokeshire coast (Wales).

FSA-2015 cadmium notable exceedances. One dogfish sample above the general Cd limit of 0.05 mg/kg; one Cornish mackerel sample above the mackerel-specific Cd limit of 0.1 mg/kg.

UK Total Diet Study fish-group sample (FSA 2015, Baxter and Brereton; 28 food groups across 24 UK Local Authority areas). Mercury (total) 0.0497 mg/kg (vs 0.056 in 2006 TDS); cadmium 0.014 mg/kg; lead 0.004 mg/kg (just above LOQ). Iodine 0.811 mg/kg (highest of all food groups); selenium 0.29 mg/kg. All Pb, Cd, Hg values below MLs.

Brown crab surveys (Bolam and Bersuder 2013a, b). 399 samples of brown crabmeat and products: Cd 0.01-26 mg/kg ww across products; mean 3.4, median 2.8 mg/kg ww. Hepatopancreas (n=6 replicates, four UK locations: Fraserburgh, Aberdeen, Dorset, Newlyn) mean Cd 4.0 ± 0.18 mg/kg ww; other edible tissues from cephalothorax mean Cd 0.27 ± 0.02 mg/kg ww. No specific ML for Cd in brown crabmeat; mean concentrations exceed the 0.50 mg/kg ML that applies to muscle from appendages.

Rockall Trough deep-sea fish (Mormede and Davies 2001). Cd in muscle 0.007-0.034 mg/kg ww across five categories; maximum Cd in muscle 1.178 mg/kg in blue whiting (would exceed current ML but not in force at time of study). Pb median muscle 0.0016-0.0094 mg/kg ww; maximum Pb in muscle below current ML of 0.3 mg/kg in all five categories. Total arsenic muscle median 1.25-8.63 mg/kg ww, highest in monkfish and blue ling.

Arsenic — total and inorganic.

FSAS 2009 (Fernandes et al. 2009b): total As — marine fish 4.8 (John Dory) to 79.18 (Cuckoo ray) mg/kg; freshwater <0.04 (trout) to 1.25 (trout); shellfish 1.08-3.53 (mussels). Inorganic As subset (27 marine fish, 1 shellfish) range <0.005 (ling) to 0.149 (spurdog) mg/kg (~2.53% of total).
FSA-Fera 2015 (152 samples, Wales and England landings): total As measured in all 152; inorganic As subset of 76 — when HPLC-ICP-MS speciation method used, 70/76 samples below the LOQ of 0.007 mg/kg; highest inorganic As 0.011 mg/kg in a lobster sample.
2022-23 FSA survey (FSA Research and Evidence 2025): total As 0.5-38.2 mg/kg; inorganic As subset (76/152) <0.007-0.011 mg/kg; species with detectable inorganic As were crab, lobster, and sardines.
Julshamn et al. 2012 (Barents Sea and West coast of Scotland mackerel): cod total As 0.38-110 mg/kg, inorganic As <0.002-0.006; Norwegian spring-spawning herring total As 1.8-34 mg/kg, inorganic <0.004; mackerel total As n.d. to 4.3 mg/kg, inorganic <0.003-0.006.
TDS fish-group sample: total As 2 mg/kg (mostly organic); inorganic As <0.012 mg/kg.
De Gieter et al. 2002 (south coast UK, French coast, North Sea): highest total As in lemon sole, dogfish, ray, and witch, up to 20 mg/kg ww; toxic-species inorganic As >0.1 mg/kg in species with high total As; AsTox/AsT% >2% in seabass, ling, John Dory, pouting, dab, brill.
Larsen et al. 2003 (Baltic and North Sea): up to 10.9 mg/kg total As; total As increases with salinity.

PAH4 in smoked products (PAH4 = benzo[a]pyrene + benz[a]anthracene + benzo[b]fluoranthene + chrysene). Sankey/dashboard sums report 115 PAH4 results across smoked species in the included studies. By smoked species (sample counts): Arbroath smokies n=10; smoked cod n=3; smoked haddock n=21; smoked herring n=3; smoked kipper n=20; smoked mackerel n=16; smoked salmon n=22; smoked trout n=17; smoked whiting n=3. 2004 retail survey: hot-smoked products BaP <0.06-0.43 µg/kg in mackerel and 0.56-1.34 µg/kg in Arbroath smokies; cold-smoked products BaP <0.06-0.14 µg/kg for kippers, others below LOQ in range <0.06 to <0.18 µg/kg. 62-smoked-product follow-up: 4/62 above the then-proposed ML for BaP; PAH4 0.11-54 µg/kg in smoked fish.

PCBs / PCDD/Fs (Fernandes et al. 2015, 2018; 2023 wholesale market study; FSA 2025). All samples below UK/EU MLs for dioxins and PCBs. PCDD/F WHO-TEQ upper-bound highest 0.57 ng/kg whole (ML 3.5 ng/kg); PCDD/F + PCB WHO-TEQ upper 1.79 ng/kg whole (ML 6.5 ng/kg); sum of ICES-6 PCBs upper 12.01 µg/kg whole (ML 75 µg/kg). 2009 FSAS Scottish data: highest PCB WHO-TEQ 3.5 ng/kg in a freshwater fish sample; freshwater higher than marine.

PBDEs (Fernandes et al. 2015). All samples positive for measured congeners except BDE-126. Highest mean concentrations: herring 2.08, sea bass 2.0, mackerel 1.45, sprat 1.27 µg/kg ww. Older Scottish data: deep-sea muscle and liver positive; flatfish from Scottish waters max 2.36 µg/kg ww in mussels and <LOD-1.67 µg/kg ww in flatfish (BDE-47 dominant).

Pooled brominated-compound sum (Table 15 PBDEs row; 2022 pooled samples directly from Scottish waters). Table 15 places these values in the PBDE row but the “Results, Data gaps or comments” column labels them verbatim as “Results reported as for ∑PCB32 for pooled samples, results expressed as μg/kg lipid weight” — the source uses ∑PCB32 (a PCB-32 sum metric) as the reporting basis within a PBDE-headed row. Pelagic roundfish muscle 198.8-373.9 µg/kg lipid weight; pelagic roundfish liver 668.6-1202 µg/kg; demersal roundfish muscle <0.02-1858 µg/kg; demersal roundfish liver 57.91-3065 µg/kg; flatfish muscle <0.02-40.91 µg/kg; flatfish liver <0.05-899.2 µg/kg.

PCNs (sum of 12 congeners; Fernandes et al. 2009b, 2015, 2018). 2009 Scottish data: 32 marine fish and 5 shellfish; range 0.3-62.91 ng/kg ww in fish; highest in spurdog; haddock 0.49 ng/kg; herring 26.81 ng/kg; mussels 0.84-6.45 ng/kg. 2015 lower-bound sum PCN concentrations (ng/kg ww): sardines n=12, 5.1-63.1; mackerel n=14, 10-243; herring n=6, 18.3-89.5; grey mullet n=9, 4.2-33.5; sprat n=15, 29.4-264.5; sea bass n=13, 13.7-48.5; turbot n=6, 0.7-15.5. Most abundant congeners: PCNs 52/60, 53; toxicologically significant PCNs 66/67, 68, 69. Most recent samples from 2015.

PFAS (2006-2023, wholesale markets England/Wales). 3/13 cod samples exceeded EU ML for PFNA; 2 exceeded ML for PFHxS. EU MLs used as benchmarks because no UK MLs are in force. Data gap: no PFAS data for fish liver or for samples from Scotland.

Microplastics. Langoustine (Nephrops) from Scottish waters: 84% incidence in Clyde Sea, 28.7% North Sea, 43% North Minch (2016 study). Plastic-contaminated nephrops showed reduced feeding rate, body mass, and metabolic rate. English Channel 2013 study: all 10 species (5 pelagic + 5 demersal) had ingested plastic; 36.5% of 504 samples had ingested plastic; average 1.90 ± 0.10 pieces per affected fish; size range 0.13-14.3 mm. In finfish, microplastics primarily confined to gills and digestive tracts with minimal presence in edible muscle tissue.

Risk-dashboard regulated-metal sample counts (Figure 12, fish species, n≥10).

Cadmium — Arbroath smokies excluded (n<10); cod n=15; common dab n=549; cuttlefish n=11; European flounder n=59; haddock n=47; herring n=53; mackerel n=58; monkfish n=27; plaice n=94; sprats n=13 (mostly non-detects, traffic light green).
Lead — Arbroath smokies n=11; cod n=16; common dab n=479; cuttlefish n=11; European flounder n=59; haddock n=50; herring n=53; mackerel n=58; monkfish n=22; plaice n=93; sprats n=13.
Mercury — cod n=15; common dab n=479; cuttlefish n=11; European flounder n=59; haddock n=47; herring n=53; mackerel n=58; monkfish n=26; plaice n=94; sprats n=13.
Total arsenic — cod n=13; common dab n=11; mackerel n=16; plaice n=32.

Risk-dashboard regulated-metal sample counts (Figure 13, shellfish/molluscs, n≥10).

Cadmium — cockles n=36; common mussels n=423; crab n=598 (red, ML exceedance flag); Pacific oysters n=48; razor clams n=92; scallops n=316 (red); surf clams n=33.
Inorganic arsenic — crab n=11 (green/non-detect-dominant).
Lead — cockles n=48; common mussels n=416; crab n=584; Pacific oysters n=44; razor clams n=76; scallops n=314; surf clams n=14.
Mercury — cockles n=43; common mussels n=403; crab n=424; Pacific oysters n=36; razor clams n=66; scallops n=22; surf clams n=11.
Total arsenic — crab n=27.

Methods (brief)

Systematic literature review commissioned by Food Standards Scotland (Project FR/002826; Fera Science Ltd). Scope: regulated and emerging chemical contaminants in wild-caught and smoked fish, shellfish, crustaceans, and cephalopods from Scottish and wider UK fishing waters, with emphasis on the North Sea, Greater North Sea sub-region extending to Norway, and the Irish Sea. Methodology section (§§5-6) describes data sources, citation-based searching, search-term/string definition, and article screening. Over 3,600 records screened; 125 selected for inclusion. Inclusion covered peer-reviewed studies, grey literature, regulatory documents, and surveillance data spanning 2009-2025 UK-funded surveys and earlier referenced primary studies (Falconer 1983 onwards).

Analytical methods are not original to this report; the report summarises analytical methods from each cited primary study. For the headline UK-funded heavy-metals surveys: FSAS 2009 reported metals in fish muscle by ICP-MS with methyl mercury subset analysed at a different laboratory; FSA-Fera 2015 (Fernandes et al. 2015, 2018) reported PTEs in fish muscle in mg/kg ww; FSA 2022-23 Wild Caught Fish survey (FSA Research and Evidence 2025) reported lead, cadmium, total mercury with stated 19% measurement uncertainty and quoted both raw and uncertainty-adjusted exceedance values; inorganic arsenic in a 76-sample subset was measured using HPLC-ICP-MS speciation (the new method that lowered the LOQ to 0.007 mg/kg and showed 70/76 samples below LOQ). Madgett et al. 2021 reported nine heavy metals (Hg, Cd, Pb, As, Ni, Se, Zn, Cu, Cr) in twenty-three species across four trophic levels around Scotland by ICP-MS on pooled samples; trophic magnification factors calculated for Hg, Cd, Cu, Ni, and Zn. UK TDS (FSA 2015, Baxter and Brereton) measured fish food-group sample for Al, Mn, Ni, Cu, Zn, As, Se, Sr, Mo, Cd, Sb, I, Ba, Hg, Pb across 24 UK Local Authority areas.

Mercury is reported as total mercury throughout unless explicitly noted; the FSAS 2009 study analysed a subset for methylmercury separately. Arsenic data are reported as total arsenic unless explicitly noted as inorganic; the report flags that recent HPLC-ICP-MS speciation has lowered apparent inorganic arsenic concentrations below older estimates and notes that EFSA 2024b applied a margin-of-exposure approach to inorganic arsenic concluding low MOEs that raise a health concern.

Regulatory comparators throughout: Assimilated Regulation (EC) 1881/2006 and its amendments (488/2014, etc.) for Hg, Cd, Pb; EU Regulation 2023/915 for current MLs; EU MLs for PFAS (PFNA, PFHxS) used as benchmarks because no UK MLs are in force; Marine Strategy Framework Directive (2008) for Good Environmental Status context.

Section 9.13 presents two risk-dashboards (Figure 12 fish, Figure 13 shellfish/molluscs/cephalopods) using a traffic-light system: green (most below LOQ), orange (quantifiable within regulatory limits), red (ML exceedances observed). Combinations with n<10 are excluded. Annex B contains waffle plots of occurrence by contaminant class and species group.

Implications

Certification: Provides the most current pooled UK regulated-metals dataset (n=192 fish in the Mortimer 2018 pool; n=152 in the 2022-23 wild caught survey) with quantified means, 95th percentiles, maxima, and per-species ranges in the native wet-weight basis used for ML compliance. Contributes high-A-tier occurrence data for Pb, Cd, tHg, MeHg, tAs, iAs across marine non-predatory fish (sardines, herring, mackerel, sprat, cuttlefish, plaice, sole), marine predatory fish (sea bass, dogfish, monkfish, skates and rays, shark spp.), freshwater fish (trout), and shellfish (crab, scallops, mussels, cockles, oysters, razor clams). The HPLC-ICP-MS speciation finding — that 70/76 inorganic arsenic samples are below 0.007 mg/kg LOQ — is particularly relevant to occurrence-based threshold work because it sharply revises downward the iAs occurrence distribution that older total-arsenic-as-proxy data implied.

Courses: Demonstrates the divergence between total and inorganic arsenic in fish — total As ranges to ~110 mg/kg in cod but inorganic As is <0.011 mg/kg, of which a few percent of total — and the importance of speciation methodology to risk assessment. Illustrates how dashboards (traffic-light over species × contaminant matrices) and waffle plots condense large pooled surveillance datasets into auditable summaries; relevant to teaching surveillance-data interpretation. Provides a worked example of the gap between “currently regulated in GB” (PFAS not regulated) and “currently of concern at EU benchmark levels” (PFAS exceedances in cod, crab, gurnard).

App: Contextual signal that mercury in sea bass is the regulated-metal exceedance most likely to surface in UK retail wild-caught fish; cadmium in brown crabmeat and scallops (shellfish) is the regulated-metal exceedance most likely to surface in shellfish. Lead exceedances are rare and concentrated in grey mullet from the Pembrokeshire (Wales) coast. PFAS exceedances in cod and crab against EU benchmarks merit flagging despite the GB regulatory gap.

Wiki pages this source may touch

Verification notes

Speciation: the report reports mercury as total mercury throughout unless explicitly noted (FSAS 2009 methylmercury subset); the page uses tHg as the primary metal and MeHg only for the FSAS 2009 subset that was actually speciated. Arsenic is reported predominantly as total; the page uses both tAs and iAs because the report includes a meaningful subset with HPLC-ICP-MS speciation (FSA-Fera 2015 and 2022-23 survey). Cr (not Cr-VI) per CLAUDE.md Part 14, since neither the report nor its cited primary surveys speciated hexavalent chromium.
Sample-size attribution: sample_n: 192 reflects the headline pooled regulated-metals table (Table 13, Mortimer 2018). The 2022-23 FSA Wild Caught Fish survey adds n=152 across 16 species categories and is reported with full ranges in Key numbers, but the field carries the pooled-table value because it is the primary cross-species summary the report itself foregrounds.
Units: all metal concentrations reported as mg/kg whole weight (wet weight) unless otherwise stated. PCB / PCDD-F WHO-TEQ in ng/kg whole; PCNs in ng/kg ww; PBDEs in µg/kg ww or pooled lipid weight as flagged in Key numbers; PAHs in µg/kg.
Geographic scope: the report’s title and FSS commissioning frame this as “Scottish and wider UK,” but UK-funded survey coverage is heavily England-and-Wales-dominated in the most recent (2022-23) wild-caught survey. The report itself flags data gaps for Scottish-landed fish, particularly for PFAS, dioxins, PCBs, and inorganic arsenic. Jurisdictions field uses GB and EU to reflect the regulatory comparators rather than narrower country codes.
Folder placement (02_Marine_Nonpredatory) is narrower than the report’s actual scope, which spans marine non-predatory (sardines, herring, sprats, mackerel, plaice, sole, cuttlefish, mussels, oysters, cockles), marine predatory (sea bass, dogfish, skates and rays, shark spp., monkfish, lobster, crab in part), and freshwater (trout). Frontmatter products list fish-marine-non-predatory, fish-marine-predatory, fish-freshwater, and fresh-fish per the broad-scope rule.
Brand firewall (Part 12): the report names Arbroath smokies as a protected-designation traditional product, not a brand, and as the smoked fish category with the highest reported PAH4 levels in the 2004 retail survey. Names are preserved as product-category descriptors; the report does not name commercial smoking-house brands.
Source-type and tier: government-commissioned agency report by Fera Science Ltd. for Food Standards Scotland (Report FR/002826), authorised by Emma Bradley, compiled by Susan MacDonald. Classed A-tier as a regulator-commissioned systematic review with pre-specified inclusion screening, dataset-level pooling tables (Table 13), and explicit data-gap analysis (Table 15).
DOI is null and no_doi_assigned: true is set because this is an agency report (FSS Project FR/002826, Fera Science Ltd) without a DOI. The access_url points to the Food Standards Scotland publications root; the specific report-slug URL was not verified at ingest time, so the publisher publications search page is used as the stable anchor. The report was supplied via Karen’s manual fetch (Kimi Agent Download Corruption Issue folder). License preserves the Fera “may not be reproduced except in full” notice.
Audit subagent (2026-06-03) flagged the Cd mackerel exceedance line as over-attributing “19% measurement uncertainty” to Cd. Verified against source p.60 — the report quotes the 19% uncertainty figure only for the three Hg sea bass exceedances (p.60 narrative and p.63 summary); the Cd mackerel exceedance is reported only as “0.16 mg/kg (0.13 mg/kg minus measurement uncertainty)” without a percentage. Corrected the Key-numbers Cd line to drop the unsupported “19%” attribution and document the asymmetry.
Audit subagent (2026-06-03) flagged “Pooled-sample sum-PCB32 lipid weight basis” appearing inside the PBDEs block as a probable PBDE vs PCB mis-labelling. Verified against source p.102 (Table 15, PBDE row 9.2.2.1): the source itself labels the 2022 pooled-sample pelagic-roundfish / demersal-roundfish / flatfish muscle and liver values as “Results reported as for ∑PCB32 for pooled samples, results expressed as μg/kg lipid weight” within a PBDE-headed row. This is a source-side labelling oddity — the report places ∑PCB32 results in the PBDE row of Table 15 — not a wiki transcription error. Restructured the Key-numbers block to surface that source-internal labelling explicitly so the apparent contradiction is visible rather than hidden.
The Fernandes 2009b / FSAS 2009 mercury range “0.025 to 0.47 mg/kg” appears in the report twice with slightly different formulations (0.025-0.047 mg/kg in the §9.3 narrative text; 0.025-0.47 mg/kg in the Mercury summary on p. 63 and Table 17 row). The page records the 0.025-0.47 mg/kg value because the report itself uses that range in the summary table that draws together the multiple FSAS 2009 result threads.

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
de9fe83	2026-06-03	audit: zhuzhassarova2024-fish-seafood-central-asia-review promoted

Heavy Metal Index

Index