Abbas 2023 — Heavy metals in wild vs. farmed gilthead seabream (Sparus aurata), Egypt
This study measured six heavy metals (Fe, Pb, Cd, Ni, Cu, Zn) in muscle, liver, intestine, and gill tissues of gilthead seabream (Sparus aurata) from two sources: wild fish from Bardawil Lake (North Sinai, Egypt) and farmed fish from a private fish farm at Ezbet Elborg, Domeitta. Cooking effects on metal concentrations were assessed for frying, microwave heating, and grilling. Human health risk assessment was conducted using Target Hazard Quotient (THQ), Hazard Index (HI), and carcinogenic risk index.
Key numbers
Concentrations reported in µg/g dry weight basis (ICP-OES).
Wild fish, muscle tissue (Table 1, mean ± SE):
- Pb: 0.84 ± 0.07 µg/g dw
- Cd: 0.35 ± 0.03 µg/g dw
- Ni: 1.44 ± 0.85 µg/g dw
- Fe: highest across all metals (specific value in source Table 1)
Wild fish, liver tissue:
- Pb: 1.69 ± 0.88 µg/g dw
- Cd: 0.69 ± 0.07 µg/g dw
Farmed fish, muscle tissue:
- Pb: 0.74 ± 0.24 µg/g dw (lower than wild)
- Cd: 0.25 ± 0.02 µg/g dw (lower than wild)
Wild fish showed consistently higher concentrations of most metals compared to farmed fish across all tissues, consistent with Bardawil Lake receiving drainage from agricultural and industrial sources.
Cooking effects: all three cooking methods reduced heavy metal concentrations in muscle tissue. Order of effectiveness: microwave heating > grilling > frying (i.e., microwave reduces metal levels most). No cooking method eliminated contamination entirely.
Health risk: THQ values for all metals and HI < 1 for both wild and farmed consumption scenarios, indicating acceptable health risk under standard consumption assumptions. Carcinogenic risk indices for Cd and Pb were within acceptable limits.
Methods (brief)
Analytical method: ICP-OES (Perkin Elmer Optima 4300 DV). Dry weight basis. Tissue preparation by acid digestion. Quality control via certified reference material (unspecified in summary; standard practice for the method). Sample size: n=80 total (40 wild, 40 farmed). Speciation: none — total metals only. Limitations: single-site wild collection (Bardawil Lake); Bardawil Lake is a known semi-enclosed lagoon with documented industrial and agricultural drainage; results may not generalize to open-sea Egyptian seabream.
Implications
Certification: Provides A-tier primary data for wild vs. farmed Pb and Cd concentrations in seabream muscle; dry-weight basis requires conversion for as-consumed assessments (approximately 80% moisture in fish muscle). Farmed seabream shows lower Pb (0.74 vs 0.84 µg/g dw) and Cd (0.25 vs 0.35 µg/g dw) than wild caught from this Egyptian lagoon. Courses: Illustrates how aquaculture origin versus wild-catch origin shifts metal burden; useful for supply-chain sourcing modules. App: Pb and Cd in fish muscle (dry weight basis); requires wet-weight conversion before use in contamination_profile. Approximate wet weight values at 80% moisture: Pb ~0.17 µg/g ww (wild), ~0.15 µg/g ww (farmed); Cd ~0.07 µg/g ww (wild), ~0.05 µg/g ww (farmed). Microbiome: Not applicable.