Hossain et al. 2023 — Heavy metals in edible chicken parts, Bangladesh
Hossain et al. measured lead, cadmium, chromium, iron, copper, and zinc in six edible body parts (breast muscle, liver, gizzard, heart, kidney, brain) of 18 broiler chickens from six markets in Dhaka North City Corporation (DNCC), Bangladesh. The study found that lead concentrations were notably elevated — up to 4.6 mg/kg fresh weight in the brain, roughly six times above FAO/WHO maximum allowable concentrations — while cadmium and chromium were mostly within regulatory limits. The authors conclude that while most target hazard quotients (THQ) for adult and child consumers remained below 1.0, the Pb levels in certain body parts (brain, kidney) warrant continued monitoring, and that tannery-waste-derived poultry feed is a likely contamination pathway.
Key numbers
All values are fresh weight (mg/kg = ppm), by AAS.
- Pb: range 0.33 ± 0.2 to 4.6 ± 0.4 mg/kg fw; highest in chicken brain (4.6 mg/kg); lowest in muscle; overall mean not clearly stated per part but approximately 1.0–2.0 mg/kg in muscle
- Cd: range 0.004 ± 0.0 to 0.125 ± 0.2 mg/kg fw; mostly at or below regulatory limits
- Cr: range 0.006 ± 0.0 to 0.94 ± 0.4 mg/kg fw
- Fe: range 4.05 ± 4.2 to 92.31 ± 48.8 mg/kg fw (highest in liver)
- Cu: range 0.67 ± 0.006 to 4.15 ± 2.7 mg/kg fw
- Zn: range 4.45 ± 0.62 to 23.75 ± 4.3 mg/kg fw
- THQ for Pb: 0.037–0.073 (adults and children); all < 1.0 by THQ metric but Pb in brain exceeds FAO/WHO MAC
- Moisture contents: muscle 72.78 ± 2.5%; liver 69.74 ± 8.9%
- Acceptable Pb recovery: 115.0% (slightly high; flag for systematic overestimation risk)
Sample collection: 18 broiler chickens from 6 markets (Uttara, Gabtoli, Madhya Badda, Karwan Bazar, Mohammadpur Town Hall Bazar, Rayer Bazar) in Dhaka, Bangladesh. Flame AAS (Shimadzu AA-7000). Digestion with HNO3/HClO4 (3:1) at 160°C.
Analytical note: Pb recovery at 115% is above the typical 80–120% acceptable range upper end and may introduce modest upward bias in Pb values. Cr values reported as total chromium; no speciation for Cr-VI.
Methods (brief)
Flame atomic absorption spectrometry (AAS), Shimadzu AA-7000. HNO3/HClO4 digestion at 160°C. Samples dried at 80°C for 48h. Metal recoveries: Pb 115.0%, Cd 80.36%, Cr 108.54%, Fe 76.67%, Cu 85.24%, Zn 92.23%. Three replicates per sample. Concentrations expressed as mg/kg dry weight, then converted via moisture content to fresh weight.
Limitation: Total Cr only, no Cr-VI speciation. Pb recovery slightly elevated. Study reports fresh weight values; dry-weight conversion requires the moisture fractions listed above. Markets sampled are all within Dhaka DNCC; generalizability to rural or other urban Bangladeshi poultry is uncertain.
Implications
Certification: Poultry organs (especially brain and kidney) show substantially higher Pb than muscle in contaminated supply chains. For HMT&C products using chicken as an ingredient, whole-bird or offal-inclusive sourcing carries higher risk than muscle-only sourcing. Bangladesh-sourced broiler Pb levels should not be assumed representative of cleaner-supply-chain poultry.
Courses: Demonstrates pathway of tannery-waste poultry feed → heavy metal accumulation in edible poultry organs; a real-world supply chain contamination route.
App: Pb and Cd data for poultry liver and muscle in a developing-country context. App should flag chicken liver and offal ingredients as higher risk than chicken breast for Pb.