Overview
The authors reared 220 day-old chicks on a commercial farm in Abak, Akwa Ibom State, and measured nine metals by ICP-AES in liver, meat and gizzard of the mature birds, along with feed, water, droppings and soil to trace sources. Arsenic, mercury and aluminum were below detection in all three tissues; cadmium and nickel were found only in gizzard. Lead was not measured.
Key numbers
- Meat: chromium 0.26 ± 0.44 mg/kg (BDL to 0.78), manganese 0.53 ± 0.12, zinc 4.57 ± 1.06; arsenic, cadmium, nickel and mercury BDL (Table 1).
- Gizzard: cadmium 0.54 ± 0.09 mg/kg (0.45 to 0.64), nickel 0.17 ± 0.29 (BDL to 0.51) (Table 1).
- Liver: zinc 40.63 ± 4.61, cobalt 1.19 ± 0.19, chromium 1.06 ± 0.19 mg/kg (Table 1).
Methods (brief)
Tissues were washed, oven-dried at 60 °C for 72 h, digested in nitric and hydrochloric acid and analyzed by ICP-AES. Detection limits were 0.002 (mercury) to 1.231 (zinc) mg/kg; arsenic 0.013 and cadmium 0.020 mg/kg. DORM-2 fish muscle reference material recovered 91 to 108%.
Evidence Fitness
A single-farm study of birds reared by the researchers, so it reflects one feed and water supply rather than retail chicken. The number of samples per tissue is not stated and raw data sit in an unavailable supplement. Results are on a dried-sample basis, though the table does not say so. Raw broiler meat is a proxy for chicken-nuggets; no processed product was measured, and lead was not analyzed.