Smolikova et al. 2016 — Heavy metals in fish products sold in Czech Republic

This conference-proceedings paper reports Cd, Pb, and total Hg (tHg) in 159 fish muscle samples representing 33 species from 17 FAO fishing localities, purchased from Brno, Czech Republic markets between September 2015 and June 2016. Cd and Pb were measured by electrothermal atomic absorption spectrometry (ETAAS) after microwave digestion; tHg was measured by direct mercury analysis (AMA 254). Ten samples exceeded the EU mercury maximum levels then set under Commission Regulation (EC) No 1881/2006 (0.5 mg/kg for most fish; 1.0 mg/kg for selected predatory species), and three samples exceeded the cadmium limit applicable to the relevant fish rows. No lead exceedances were found.

The most contaminated species were white marlin (tHg 10.42 ± 2.08 mg/kg; Cd 0.1809 ± 0.0362 mg/kg) and other large predatory fish including swordfish and blue shark. The source states that several above-limit findings from this research were reported through the EU RASFF system and led to withdrawal of some fish batches from Czech markets.

Key numbers

• Total Hg was detected in all samples. The highest reported value was white marlin (Tetrapturus albidus) at 10.42 ± 2.08 mg/kg; the lowest was Nile tilapia (Oreochromis niloticus) at 0.0031 ± 0.0002 mg/kg.
• Ten samples exceeded EU Hg maximum levels. The source identifies dusky grouper above the 0.5 mg/kg row and swordfish, blue shark, and white marlin above the 1.0 mg/kg predatory-fish row.
• Cd exceedances were reported for tub gurnard (0.0950 ± 0.0047 mg/kg), ray (0.1203 ± 0.0060 mg/kg), and white marlin (0.1809 ± 0.0362 mg/kg). The source notes a 0.05 mg/kg default fish limit, with higher species-specific Cd rows for selected species including swordfish.
• Pb did not exceed the 0.3 mg/kg EU limit in any sample. The highest Pb value was in swordfish at 0.0250 ± 0.0013 mg/kg.
• Reported analytical detection limits were 0.12 µg/kg for Cd, 3.11 µg/kg for Pb, and 0.1 µg/kg for tHg.
• The source gives diet-context calculations for a 70 kg adult: approximately 9 g of the analyzed white marlin would reach the weekly Hg intake benchmark used by the authors, while approximately 27 portions of 100 g white marlin would reach the Cd weekly intake benchmark.
• The paper reports 14 Czech RASFF heavy-metal notifications for fish since 2004 (6 Hg, 6 Cd, and 2 for both Hg and Cd); it states that this research led to eight above-limit reports submitted to RASFF.

Methods (brief)

The study sampled fresh and frozen fish sold in Czech markets. Table 1 lists 33 fish species, including white marlin, swordfish, blue shark, dusky grouper, tub gurnard, ray, Nile tilapia, salmon, mackerel, hake, tuna, and other marine and freshwater species. Samples were bought from Brno City markets; each batch had at least three samples, and fish were stored at -20 °C until analysis.

Cd and Pb were measured after microwave digestion in nitric acid using ETAAS with Zeeman background correction. The paper reports digestion and furnace conditions, calibration standards, and matrix modifier use. Total Hg was measured directly by AMA 254 cold-vapor AAS after thermal drying and decomposition. The paper does not report methylmercury (MeHg) speciation; its mercury values should therefore be treated as tHg, not MeHg, even though fish-muscle tHg is commonly used as a MeHg proxy in seafood risk assessment.

Evidence tier B: conference proceedings publication (MendelNet 2016), not peer-reviewed journal. Data quality appears rigorous (RASFF submissions accepted), but publication venue limits tier assignment.

Implications for wiki use

This is a seafood-category occurrence and enforcement-context source. It supports species-level routing for high-trophic marine fish, especially marlin, swordfish, and shark, and provides an unusually high tHg value for white marlin sold through retail channels in a landlocked country. The study should not be pooled with low-trophic fish or infant-food finished-product data without species, geography, tissue, and speciation caveats.

For metals pages, this source is strongest for total mercury in fish muscle and secondarily useful for Cd exceedances in selected species. For Pb, it is useful as negative evidence: Pb was measured with a defined method and no sample approached the EU limit.

For regulation pages, the source explicitly applies the then-operative EC 1881/2006 maximum levels to fish and discusses RASFF reporting, but it is not itself a regulation or guidance document.

Wiki pages this source may touch

• mercury-total
• cadmium
• lead
• fish
• seafood
• marlin
• swordfish
• shark
• fresh-fish
• fish-marine-predatory
• seafood
• eu-1881-2006-contaminants-superseded

Verification notes

• The manual-fetch filename says “sold in Spain,” but the source article describes fish purchased in Brno, Czech Republic markets.
• No DOI was found in the paper, the MendelNet article page, or bibliographic index records checked during ingest; no_doi_assigned: true is therefore retained.
• Instrument/reference-material vendor names appear only in methods context and are allowed under the strict brand-firewall exception for analytical vendors.

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.