Metal pollution and potential human health risk assessment in major seafood items (fish, crustaceans, and cephalopods)

Overview

Haseeb-ur-Rehman and colleagues measured metals in 400 export-quality seafood samples from Pakistani processing plants. The study reports edible-portion concentrations in mg kg-1 w.w for fish, crustaceans, and cephalopods. Mercury was analyzed and was not detected in any sample; the page therefore treats mercury as total mercury (tHg) nondetect context, not as methylmercury.

Key numbers

• Sample frame: 50 samples each of Penaeus monodon, Portunus pelagicus, Loligo duvauceli, Sepia recurvirostra, Cynoglossus bilineatus, Otolithes ruber, Lepturacanthus savala, and Nemipterus japonicus.
• Mercury: Table 2 note states “Mercury was not detected in any of the samples”; the Results text identifies the detection level as 0.01 mg kg-1.
• P. monodon mean concentrations, mg kg-1 w.w: cadmium (Cd) 0.038, lead (Pb) 0.4, nickel (Ni) 1.2, Fe 115, Zn 15, Mn 3.4, Cu 12; ranges were Cd 0.034-0.040, Pb 0.2-0.6, Ni 0.9-1.5, Fe 109-123, Zn 14-18, Mn 2.7-4.5, Cu 10-15.
• P. pelagicus: Cd 0.032, Pb 0.6, Ni 0.04, Fe 266, Zn 5, Mn 2.8, Cu 17; ranges were Cd 0.026-0.040, Pb 0.2-1, Ni ND-0.1, Fe 256-282, Zn 3-6, Mn 2-4.0, Cu 14-20.
• Cephalopods: L. duvauceli means were Cd 0.066, Pb 0.8, Ni 0.3, Fe 21, Zn 4, Mn 0.8, Cu 12; S. recurvirostra means were Cd 0.097, Pb 0.3, Ni ND, Fe 25, Zn 4, Mn 0.6, Cu 9.
• Fish: C. bilineatus means were Cd 0.064, Pb 0.6, Ni ND, Fe 26, Zn 2, Mn 0.6, Cu 6; O. ruber means were Cd 0.05, Pb 0.4, Ni 0.02, Fe 44, Zn 1, Mn 0.7, Cu 2.
• Fish continued: L. savala means were Cd 0.03, Pb 0.7, Ni ND, Fe 29, Zn 4, Mn 2.5, Cu 9; N. japonicus means were Cd 0.057, Pb 0.4, Ni ND, Fe 22.4, Zn 5, Mn 7.4, Cu 6.
• Category-range comparison table for this study: fish mercury (Hg) ND, Cd 0.03-0.06, Pb 0.36-0.67, Ni 0.003-0.025, Fe 22.36-44.96, Zn 1.43-4.45, Mn 0.64-7.39, Cu 2.01-5.63 µg/g, w.w; crustaceans Hg ND, Cd 0.03-0.04, Pb 0.399-0.635, Ni 0.044-1.195, Fe 115.72-266.36, Zn 4.536-15.389, Mn 2.84-3.40, Cu 11.83-16.60; cephalopods Hg ND, Cd 0.07-0.10, Pb 0.31-0.84, Ni ND-0.31, Fe 21.01-25.15, Zn 3.56-4.33, Mn 0.56-0.77, Cu 9.30-12.44.

Methods (brief)

Frozen seafood samples from export consignments were thawed, dissected for edible tissue, homogenized, and stored at -18 °C before analysis. Homogenized edible tissue (2 ± 0.01 g) was acid-digested. Mercury was measured by cold-vapour atomic absorption spectroscopy; cadmium and lead were measured by graphite furnace atomic absorption spectroscopy with Zeeman background correction; nickel, iron, zinc, manganese, and copper were measured by flame atomic absorption spectroscopy. Quality control used standard solutions, reagent blanks, certified reference material LGC7164 brown crab meat paste, and one CRM per batch of 10 samples.

Related evidence

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

Update history

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