Heavy Metal Index

Monitoring of Cadmium, Lead, and Mercury Levels in Seafood Products: A Ten-Year Analysis

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Source access

Publication
Foods 14(3):451
Year
2025
Authors
Garofalo L; Sala M; Focardi C; Pasqualetti P
Source type
peer reviewed
License
CC BY

Garofalo et al. 2025 — 10-year Italian seafood Cd/Pb/Hg compliance monitoring

This study reports 10 years (2014-2023) of regulatory compliance monitoring on seafood by the Italian Istituto Zooprofilattico Sperimentale del Lazio e della Toscana (IZSLT), analyzing 5,854 samples / 9,809 chemical analyses for cadmium, lead, and total mercury against EU 2023/915 maximum levels. 142 samples (2.43%) were non-compliant. Cadmium exceedances concentrate in cephalopods (n=17, mainly squids). Mercury exceedances concentrate in marine fish (n=118), with the highest non-compliance rates in swordfish (11.30%), sharks (6.48%), and tuna species (3.11%) — the top predators where biomagnification is highest. Lead exceedances are rare (one bivalve sample). The 10-year trend data and the per-species predator-level exceedance fractions are the most useful contributions for HMTc Cat 1 seafood threshold-setting; the regulatory framework is EU 2023/915 (which superseded EC 1881/2006).

Key numbers

Sample distribution across taxonomic groups (5,854 samples):

Groupn samples% of total
Marine fish2,70146.14%
Cephalopod molluscs1,53626.24%
Bivalve molluscs1,01917.41%
Crustaceans4507.69%
Freshwater fish1332.27%
Echinoderms + marine gastropods<1%<1%

Analyses count per metal (some samples analyzed for multiple metals):

  • 4,300 THg analyses
  • 3,338 Cd analyses
  • 2,171 Pb analyses
  • 9,809 total

Non-compliance findings:

  • Total non-compliant samples: 142 (2.43% of 5,854)
  • Cadmium exceedances: 17 samples, primarily cephalopods (squids)
  • Mercury exceedances: 118 samples, all marine fish:
    • Swordfish: 11.30% of all swordfish samples non-compliant
    • Sharks: 6.48% of all shark samples non-compliant
    • Tuna species: 3.11% of all tuna samples non-compliant
  • Lead exceedances: 1 sample (bivalve)

Regulatory anchors:

  • EU 2023/915 Commission Regulation: maximum contaminant levels for seafood (replaces EC 1881/2006)
  • Cd: matrix-specific (lower for fish muscle, higher for bivalves/cephalopods)
  • Pb: matrix-specific
  • THg: 0.5 mg/kg for most fish species; 1.0 mg/kg for certain predators (swordfish, sharks, tuna species — the species exceeding the higher cap above are exceeding the 1.0 mg/kg ceiling, not just the 0.5 baseline)

Health risk preliminary finding: The paper conducted a preliminary assessment of weekly Hg exposure through swordfish consumption and concluded that the frequent intake of marine top predators raises concerns for vulnerable populations (pregnant women, children).

Methods

Sample collection: 5,854 seafood samples from across Italy under four sampling-plan types — HACCP self-control by food companies, official import control, official control during processing/trading, official control of Italian primary production. Samples stored at −20 °C until analysis.

Digestion: 1.0 g sample + 8.0 mL HNO3 (67-69%) + 1.0 mL H2O2 in Teflon tubes; Milestone Ethos One SK10T microwave at 1500 W, 190 °C for 20 min; diluted to 100 mL with Milli-Q water.

Instrumentation: Thermo Fisher iCap Q ICP-MS with CETAC 500 Series ASX-520 autosampler. RF 1550 W; auxiliary gas 0.8 L/min; nebulizer 1.06 L/min; plasma 14.0 L/min. Internal standards: Ge, In, Y at 1 µg/mL final. Daily tuning. Multi-element CRM + Hg-certified CRM for QC.

Method validation per EC 333/2007 (specificity, linearity, LOD, LOQ, repeatability, reproducibility, recovery, precision). Earlier years of the study used different but equivalent methods.

Speciation: Total Hg by ICP-MS (note: not CVAAS). For seafood muscle, THg ≈ MeHg is the working assumption (per established Bloom 1992 evidence + EPA convention). Cd and Pb are speciation-irrelevant (no organic forms in food). No iAs/tAs analyses in this study.

Implications

Certification: For HMTc Cat 1 seafood + fish-containing baby foods row:

  1. Marine top predators (swordfish, sharks, tuna) are the binding Hg-non-compliance risk at the 1.0 mg/kg EU ceiling. HMTc Cat 1 fish-containing baby food certification can either (a) preclude these species from baby-food formulations (most defensible) or (b) require species-specific testing at every lot. The 11.3% non-compliance rate in swordfish alone makes single-lot certification insufficient.

  2. Cephalopod Cd contamination is a Cat 1 concern for any product using squid, octopus, or cuttlefish (rare in baby food but present in some toddler meal formulations and ethnic baby foods). The 17 of 1,536 cephalopod sample exceedances (~1.1%) is a real signal.

  3. The “frequent intake of marine top predators raises concerns for vulnerable populations” finding aligns with EPA/FDA advice for pregnant women and children to limit swordfish/shark/tilefish/king mackerel consumption. HMTc Cat 1 framing should reference this explicitly when comparing fish-containing baby food vs the non-fish baby food contamination platform.

  4. 10-year trend data: the paper’s Figure 2 shows analyses-per-year and per-sampling-plan-type over 2014-2023. Aggregate non-compliance trend (not detailed in the pages read) would inform whether EU seafood contamination is improving or stable over the decade. The wiki’s Cat 1 fish-row trend assessment should pull this.

  5. The EU 2023/915 replaces EC 1881/2006: regulation pages need updating to the new framework. HMTc Cat 1 thresholds should reference EU 2023/915.

Courses: Excellent case study for 10-year regulatory compliance monitoring. The IZSLT methodology (HACCP + import + processing + production sampling plans aggregated) is a model for multi-stakeholder food-safety surveillance.

App: For the consumer app, swordfish/shark/tuna should carry an “elevated MeHg risk” flag in the per-species risk weights. The 11.3% non-compliance rate in swordfish is concrete and should drive a higher app-displayed risk weight than for, say, salmon or pollock.

Microbiome: Not addressed.

Wiki pages updated on ingest