Overview
Ogu and Akinnibosun bought 240 raw chicken muscle samples in open markets of four southern Nigerian cities over a year and measured lead, chromium, cadmium, manganese, nickel, zinc and copper by graphite-furnace atomic absorption spectrometry. They report range and mean per city and estimate daily intake, hazard indices and cancer risk for children and adults. Ado-Ekiti samples had the highest lead and cadmium; Warri samples the highest nickel, zinc and manganese.
Key numbers
- Lead: Ado-Ekiti “0.141 ± 0.025” mg/kg (range 0.061-1.151); Warri “0.122 ± 0.001” mg/kg; Akure “0.010 ± 0.000” mg/kg (Table 1).
- Cadmium: Ado-Ekiti “0.323 ± 0.022” mg/kg (range 0.212-1.007); Akure “0.005 ± 0.000” mg/kg, below its own printed range of 0.010-0.011 (Table 1).
- Nickel: Warri “1.981 ± 0.002” mg/kg; Benin City “1.203 ± 0.001” mg/kg (Table 1).
Methods (brief)
Samples were washed, oven-dried at 40 °C, ground, digested with nitric acid, perchloric acid and hydrogen peroxide at 150 °C and read by graphite-furnace AAS. Results are stated as mg/kg wet weight. Only reagent blanks are reported as quality control; there is no certified reference material, recovery or detection limit.
Evidence Fitness
A reasonably large sample (60 per city over four quarterly rounds) but weak quality assurance. Several printed statistics conflict: the Akure cadmium mean lies outside its range, some standard errors are implausible next to their ranges, and the stated wet-weight basis sits awkwardly with oven-drying. Raw chicken muscle is direct evidence for chicken, and only a proxy for chicken-broth, which is not linked.