Overview
aluminum (Al) Ghoul et al. measured tin, zinc, aluminum, and bisphenol A in 51 commercially available canned tuna samples from Lebanese markets, analyzing center and outer portions separately across 17 brands. Tin was detected in all 102 sub-samples (100% detection rate). The mean tin concentration was 3.347 mg/kg wet weight, with a range of 0.990 to 8.960 mg/kg. All values were below the JECFA provisional tolerable weekly intake (PTWI) and the health risk indices (HRI) for tin were well below 1 for all three dietary scenarios (US, EU, Lebanese consumption rates), indicating no significant health risk from tin in canned tuna consumed at typical rates.
Key numbers
All concentrations are wet weight (mg/kg = µg/g).
Tin concentration in canned tuna (n=102 sub-samples from 51 cans):
| Statistic | Value (mg/kg, wet weight) |
|---|---|
| Mean | 3.347 |
| Median | 3.280 |
| Standard deviation | 1.423 |
| Minimum | 0.990 |
| Maximum | 8.960 |
| Detection frequency | 100% |
Health risk assessment for tin:
| Parameter | Value |
|---|---|
| Oral reference dose (RfD) used | 0.20 mg/kg bw/day |
| PTWI (JECFA, cited) | 14 µg/g per kg body weight per week (= 2 mg/kg bw/day) |
| EDI, US scenario | 0.00012 mg/kg bw/day |
| EDI, EU scenario | 0.00019 mg/kg bw/day |
| EDI, Lebanon scenario | 0.00013 mg/kg bw/day |
| HRI, US scenario | 0.00060 |
| HRI, EU scenario | 0.00095 |
| HRI, Lebanon scenario | 0.00065 |
All HRI values are well below 1.0 (the threshold for significant health concern). The EDI was calculated as: EDI = (FIR x C) / BW, where FIR is the fish ingestion rate per population scenario, C is the mean tin concentration, and BW is body weight. The paper confirms that tin intake from canned tuna is negligible relative to the PTWI across all three consumption scenarios.
Evidence Fitness
Reconstructable dataset for tin in canned tuna from a Lebanese retail market; full sub-sample analysis provides mean, median, and range. The 100% detection rate and the relatively narrow concentration range (0.99 to 8.96 mg/kg) support characterization of this matrix. These concentrations are approximately an order of magnitude below the EU regulatory limit of 200 mg/kg for canned fish. The HRI and EDI calculations use the JECFA PTWI as the reference.
Methods
51 canned tuna samples from Lebanese retail markets; 17 different brands. Each can was divided into center and outer portions and analyzed in duplicate (102 sub-samples total). Metals were measured by ICP-MS (Agilent 7500); digestion by microwave-assisted acid extraction (HNO3/H2O2). Recovery not stated. LOD/LOQ not reported for tin.
The EDI was computed using three country-specific fish ingestion rate (FIR) values: FIR = 2.75 x 10 to the power of negative 3 kg/person/day for US and Lebanon scenarios; FIR = 0.02900 kg/person/day for EU scenario; body weight of 70 kg was used. The oral RfD of 0.20 mg/kg bw/day was applied.
Implications
- Certification: tin in canned tuna is in the low single-digit mg/kg range (mean 3.3 mg/kg), far below both the EU limit (200 mg/kg) and the JECFA PTWI. Canned tuna is not a high-tin food.
- Courses: useful data point showing that canned fish (non-acidic matrix) has much lower tin than acidic canned fruits or fruit juices; supports the pH-dependence of tin migration.
- App: canned tuna tin concentration is in the 1 to 9 mg/kg range; much lower than canned acidic fruits.
- Microbiome: not addressed.
Provenance notes
Open access under CC BY-NC-ND license. Retrieved from PMC as PMC7511825. Heliyon (Elsevier), volume 6, 2020.
Related evidence
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