Overview
Researchers bought 11 tilapia from vendors across Calapan City, cut each into seven parts and measured ten elements in the dried tissue with a portable XRF analyzer. Cadmium means exceeded the FAO/WHO limit of 0.5 mg/kg in every part, including the meat. The authors estimated a cancer risk above the USEPA threshold, driven by cadmium.
Key numbers
- Meat: cadmium 1.45 ± 0.9 mg/kg; lead, arsenic and mercury not detected (Table 4).
- Skin: cadmium 3.00 ± 2.2, lead 1.35 ± 1.0 mg/kg (Table 4).
- Viscera: mercury 0.60 ± 1.9 mg/kg; fins: cadmium 3.82 ± 5.8 mg/kg (Table 4).
- XRF LODs: cadmium 2, lead 1, arsenic 1, mercury 1 mg/kg (Table 2).
Methods (brief)
Parts were oven-dried at 65 °C for eight hours, powdered and analyzed by a portable Olympus Vanta XRF in soil mode calibrated against ICP-OES results. Readings below the LOD were replaced by a number one step below the LOD before averaging.
Evidence Fitness
Market tilapia, so direct evidence for tilapia and white fish, but weak analytically: the portable XRF LODs (1 to 2 mg/kg) are far above typical fish levels, and several printed means (for example meat cadmium 1.45 mg/kg against a 2 mg/kg LOD) fall below the LOD because of the substitution rule. Those values are flagged. Results are on a dried-tissue basis. The fins nickel cell prints both a value and “ND”.