Methylmercury contamination in Mediterranean seafood: Exposure assessment and cost of illness implications

Overview

Kennedy and colleagues modeled methylmercury exposure from Mediterranean seafood by combining a large seafood contamination literature dataset with seafood supply/provenance data from ARTIS and consumption estimates from the Global Dietary Database. The paper is a transdisciplinary exposure and cost-of-illness analysis, not a new laboratory survey.

The contamination dataset uses total Hg and MeHg observations from the literature. For risk assessment, total Hg concentrations were converted to MeHg using EFSA conversion factors: 1.0 for fish and 0.8 for molluscs/crustaceans.

Key numbers

Literature-screening and dataset construction:

Share of seafood-category observations above JECFA concentration limits:

Table 1 reports mean MeHg levels in ug/g wet weight by seafood group and Mediterranean FAO division. The prefixes S_ and L_ denote small (trophic level < 4) and large (trophic level >= 4) demersal fish and pelagic fish.

Table 1 footnotes state that Gulf of Lions cephalopod MeHg was estimated from the arithmetic mean of neighboring FAO Divisions 37.1.1 and 37.1.3, and that Aegean cephalopod MeHg was estimated from the arithmetic mean of neighboring divisions. The Aegean footnote prints 37.2.2 and 37.3.1; this page preserves the source wording.

Other source-reported values:

Methods (brief)

The authors searched Scopus and PubMed for "mediterranean" AND "mercury" in titles and abstracts, limited to publications from 2015-2022, then manually screened papers for relevant seafood MeHg/Hg estimates. They combined newly screened observations with Cinnirella et al. 2019’s Mediterranean biota Hg compilation.

The dataset was refined to FAO Mediterranean divisions 37.1, 37.2, and 37.3, excluding unclear fishing areas, Black Sea and Marmara Sea observations, inedible or rarely consumed species, non-edible tissues, and duplicate total-Hg observations where MeHg was reported for the same study/species/tissue/location combination. Observations were harmonized to ug/g; wet/dry-weight conversions followed Cinnirella et al. 2019 where needed, and unspecified weight type was assumed to be wet weight.

Seafood consumption and provenance modeling combined ARTIS supply data, FAO capture statistics, GDD consumption estimates, IHME population data, edible-weight conversion factors, and rfishbase trophic-level assignments. Economic cost estimates linked modeled prenatal MeHg exposure to IQ loss and productivity loss.

Implications

This source is useful as B-tier synthesized seafood evidence for Mediterranean MeHg exposure, especially for differentiating large predatory marine fish from smaller fish and shellfish. It also documents that international trade can shift seafood contamination exposure between regions.

Because the paper is a modeling and literature-synthesis study, its values should not be treated as a new primary occurrence survey. The compiled Table 1 means are useful for route-level context and gap targeting; species-level benchmark pooling should use the underlying primary records or the authors’ data/codebook where available.

Wiki pages this source may touch

• Fish — marine, predatory (tuna, swordfish, shark, king mackerel)
• Fish — marine, non-predatory (sardines, anchovies, salmon, cod)
• Shellfish (shrimp, crab, lobster, clams, oysters, mussels)
• Mercury
• Methylmercury

Verification notes

• Identity check: DOI 10.1016/j.scitotenv.2024.177953, raw handle RPMEHG_10-1016-j-scitotenv-2024-177953, candidate cite-key kennedy2025-mediterranean-seafood-methylmercury, and SHA-256 d00864dad0663ba0b1ff794fded990a6a99a0e69778827d4e1029b9342366626 were searched before creation; no existing clean post-2026-05-14 source page was found.
• Full-PDF read performed from the 13-page Science of the Total Environment PDF. Table 1 and all main-text numeric findings captured above were checked from pdftotext -layout; figures were read for qualitative country-pattern findings only, without digitizing plotted bars. Supplementary tables and R code are referenced by the paper but were not bundled in the local PDF.
• Brand firewall: the source reports seafood groups, species, countries, and FAO fishing divisions, not branded commercial products.
• HMTc firewall: page records source facts only; no certification threshold, percentile, or pass/fail calculation is derived from this source.

Update history

The five most recent substantive edits to this page, classified major (evidence or structure moved), correction (a published value or statement was wrong and has been fixed), or minor (narrative rewritten without changing the underlying evidence). Each description is derived from what the edit did to this page; the linked commit is the authoritative record, routine regeneration passes are excluded, and 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.