Determination and Safety Evaluation of Heavy Metals in Canned Fish from Liaoning Province

Overview

Gu and colleagues measured seven metal elements in canned fish purchased from retail outlets in Liaoning Province, China. The analyzed edible portion included muscle and soup from canned mackerel, tuna, sardines, yellow croaker, trichiurus haumela, dace, and anchovy. The source reports wet-weight total elemental concentrations; chromium is total chromium (Cr), and tin is elemental tin (Sn) rather than organotin speciation.

Key numbers

Table 3 reports heavy-metal concentrations in canned fish as mean ± standard deviations, mg/kg, wet weight:

Additional source-reported values:

• Asterisks in Table 3 mark cadmium (Cd) values “out of limits” for canned sardines and yellow croaker.
• The paper states Chinese maximum levels used in the comparison: Cd 0.1 mg/kg, lead (Pb) 1 mg/kg, Sn 250 mg/kg, Zn 50 mg/kg, Cr 2 mg/kg, and Cu 50 mg/kg; no limited iron level for fish samples in China standards.
• Table 4 estimated weekly intakes for an adult consuming 0.182 kg canned fish/week, using the per-element maximum concentration across species (Cd 0.18, Cr 1.28, Cu 7.39, Fe 42.70, Pb 0.34, Sn 6.34, Zn 20.13 mg/kg) rather than a species mean: Cd 0.33 mg (7.86% PTWI), Cr 0.23 mg (57.5%), Cu 1.34 mg (0.64%), Fe 7.77 mg (2.31%), Pb 0.062 mg (4.13%), Sn 1.54 mg (0.18%), and Zn 3.66 mg (0.87%).
• The abstract and conclusion state that Cr, Cu, Pb, and Zn were below maximum levels, Cd in canned sardines and yellow croaker exceeded the maximum levels, and all estimated heavy-metal intakes were below PTWI.

Methods (brief)

Representative canned fish samples were randomly purchased from retail outlets in 14 Liaoning cities from January to May 2011. The edible portion, including muscle and soup, was homogenized and stored at -20 °C. Samples of 0.5 g were microwave-digested in HNO3/H2O2 (6:2), made up to 10 mL, and analyzed using an AA320N atomic absorption spectrometer with GA 3202 graphite furnace system. Each reported result was the average of three analyses. Recovery was 90-110%, and RSD ranged 0.76-5.65%.

Implications

This source contributes China-market canned-fish occurrence evidence for Cd, total Cr, Cu, Fe, Pb, elemental Sn, and Zn on a wet-weight basis. It is especially relevant to canned-fish Cd because sardines and yellow croaker exceeded the source-cited Chinese maximum level. The mixed species list includes marine fish and dace, so fish-row routing is broad context until species-specific row fit is resolved. The chromium result is not Cr(VI)-specific, and the tin result is elemental tin rather than organotin.

Related evidence

• Fish
• Tinned fish
• Canned Fish — REDIRECT (Cat 6 → canned-seafood)
• Fish — marine, non-predatory (sardines, anchovies, salmon, cod)
• Fish — marine, predatory (tuna, swordfish, shark, king mackerel)
• Fish — freshwater (tilapia, catfish, trout)
• Cadmium
• Chromium
• Copper
• Iron
• Lead
• Tin
• Zinc

Update history

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