Health risk assessment of metals in chicken meat and liver in Egypt

**Background:** Heavy metal pollution in food is increasing due to industrial and agricultural anthropogenic activities. Poultry are exposed to metals through contaminated feed, drinking water, and litter, leading to bioaccumulation in tissues. Heavy metals are characterized by persistence, no taste or smell, biomagnification in the food chain, and toxic effects on vital body systems. Essential metals (Fe, Cu, Zn, Se) play roles in enzyme and vitamin structure but can be harmful in excess, while heavy metal pollutants (Al, Cd, Pb) can cause toxic effects even at low levels. This study aimed to evaluate concentrations of aluminum (Al), cadmium (Cd), lead (Pb), barium (Ba), bismuth (Bi), cobalt (Co), nickel (Ni), chromium (Cr), iron (Fe), copper (Cu), zinc (Zn), and selenium (Se) in poultry chest, thigh muscles, and liver from six commercial brands in Assiut, Egypt; compare concentrations with Egyptian and international maximum permissible limits; and assess health risks using estimated daily intake (EDI), target hazard quotient (THQ), hazard index (HI), and target cancer risk (TR).

**Methods:** Three hundred and sixty samples (chest muscles, thigh muscles, and liver) were randomly collected from Assiut city markets from six brands (A–F), with 20 samples per brand. Samples were stored at −20°C until analysis. Approximately one gram of each sample was digested with 5 ml of high-grade nitric acid (68%) overnight at room temperature, then heated at 150°C for 5 hours until colorless. Residual solutions were cooled, filtered, and stored. Metal concentrations were determined using inductively coupled plasma mass spectrometry (ICP-MS, iCAP 6000 series) at the central laboratory of the Faculty of Agriculture, Assiut University. Quality control included procedural blanks, duplicates, and spiked recovery analysis; accepted recoveries ranged from 92.1% (Ni) to 105.6% (Co). Health risk assessment followed USEPA guidelines. EDI was calculated as (C × FIR)/BW, where C = metal concentration (µg/g), FIR = ingestion rate (39.53 g/day for meat, 0.1 g/day for liver), and BW = 70 kg for Egyptian adults. THQ was calculated using exposure duration of 30 years for non-cancer risk and 70 years for cancer risk, with reference doses (RfD) for each metal. HI was the sum of all HQs. TR was calculated using carcinogenic potency slope (CPSo) values for Cd (0.38), Pb (0.0085), Co (0.7), Ni (1.7), and Cr (0.5). Statistical analysis used SPSS version 16.0 with one-way ANOVA and Tukey/Dunnett tests.

**Key Results:** All analyzed samples were positive for all 12 metals. Aluminum was the most concentrated heavy metal, with ranges of 8.610–21.985 µg/g in chest, 5.729–18.533 µg/g in thigh, and 5.873–14.005 µg/g in liver. Lead concentrations ranged from 2.560–5.552 µg/g in chest, 0.334–1.082 µg/g in thigh, and 0.146–0.952 µg/g in liver; 94% of samples (240 muscles and 100 livers) exceeded FAO/WHO permissible limits (0.1 mg/kg for meat, 0.5 mg/kg for liver), and 33% (chest muscles from all six brands) exceeded Egyptian Organization for Standardization (EOS) limits (2 mg/kg). Cadmium ranged from 0.014–0.054 µg/g in chest, 0.015–0.088 µg/g in thigh, and 0.027–0.104 µg/g in liver; 17% of samples (40 muscles and 20 livers) exceeded FAO/WHO limits (0.05 mg/kg for meat, 0.5 mg/kg for liver), but all samples were below EOS limits (0.5 mg/kg). Iron ranged from 7.631–31.604 µg/g in chest, 4.583–18.360 µg/g in thigh, and 24.151–48.142 µg/g in liver; 67% of samples (120 chest and thigh muscles and 120 livers) exceeded EOS limits (15 µg/g for meat, 20 µg/g for offal). Chromium exceeded the international permissible limit of 1.0 ppm in 11% of samples (20 chest muscles and 20 livers). Zinc exceeded the international limit of 20 µg/g in 44% of samples (40 thigh muscles and 120 livers). Selenium exceeded the international limit of 0.5 µg/g in 33% of samples (120 livers). All THQ values were far below 1.0 (ranging from 10⁻³ to 10⁻⁶), and HI values for chest, thigh, and liver across all six brands ranged from 8.42 × 10⁻³ to 23.99 × 10⁻³, all significantly below 1.0. TR values for Cd, Pb, Co, Ni, and Cr were all within the USEPA acceptable cancer risk range of 1 × 10⁻⁶ to 1 × 10⁻⁴.

**Clinical Implications:** Although lead, cadmium, and iron exceeded some permissible limits in a substantial proportion of samples, the health risk assessment using EDI, THQ, HI, and TR indicated that consumption of these poultry products poses minimal non-carcinogenic and carcinogenic health risks to Egyptian consumers. However, given that about 25% of human diseases today are attributed to long-term environmental pollution exposure, and the increasing rates of renal failure, liver cirrhosis, and chronic anemia in Egypt, continuous monitoring of heavy metals in poultry products is warranted. This is especially important in Egypt due to high poultry meat consumption and shortages of other protein sources.