Overview
Ten cans each of five canned mollusk products (one product per type) were drained, freeze-dried and analyzed for total mercury. All values were far below Mexican limits; mussels had the lowest mercury. Methylmercury was estimated from literature ratios, not measured.
Key numbers
- Canned clams cooked in brine (Mexico): 0.016 ± 0.028 mg/kg dry weight; 0.0026 mg/kg wet weight (Tables 1-2, p. 5).
- Canned smoked oysters (Mexico) 0.014 mg/kg dw; canned octopus 0.020 mg/kg dw, the highest (Table 1).
- Canned smoked mussels 0.008 ± 0.012 mg/kg dw; 0.0013 mg/kg ww (Tables 1-2).
Methods (brief)
Cans drained, half the contents taken per can, lyophilized, digested with nitric acid on a hot plate and analyzed by cold vapor AAS. NIST 2976 mussel tissue recovery 98.7 ± 3.1%; detection limit 0.002 mg/kg.
Evidence Fitness
Canned clams are a processed clam product but still a proxy for clam-chowder; that thin page is not linked. Each type is a single product, several SDs exceed their means, and the text’s wet-weight range (0.003 to 0.007 mg/kg) does not match Table 2.