Assessment of Heavy Metals in Table Eggs: Sources of Contamination, Associated Health Risks, and Potential Outcomes

Background: Poultry eggs serve as an essential source of protein, vitamins, and minerals, particularly for vulnerable populations like children and the elderly. With Pakistan’s poultry industry witnessing an annual growth rate of 8–20%, egg production continues to rise in response to increasing dietary demands. However, the presence of heavy metals in eggs poses a significant threat to food safety and public health. This study was conducted to assess and compare the concentration of toxic metals in eggs sourced from domestic and commercial poultry systems in Multan, Pakistan. Objective: To evaluate and compare the levels of heavy metals—specifically lead (Pb), cadmium (Cd), zinc (Zn), cobalt (Co), arsenic (As), iron (Fe), and copper (Cu)—in layer and domestic hen eggs to determine their safety for human consumption. Methods: This cross-sectional laboratory study was carried out at Bahauddin Zakariya University, Multan. Egg samples were collected randomly from domestic and commercial sources. Each sample underwent wet digestion using concentrated nitric and perchloric acid followed by analysis through Flame Atomic Absorption Spectrophotometry (FAAS). The concentrations of heavy metals were measured separately in egg whites and yolks. Results: Lead levels in domestic hen egg whites (0.830 ± 0.011 µg/g) and yolks (0.668 ± 0.214 µg/g) were significantly higher compared to commercial layers (white: 0.043 ± 0.014 µg/g; yolk: 0.024 ± 0.006 µg/g). Cobalt concentrations were also higher in domestic whites (2.369 ± 0.302 µg/g) versus layers (1.138 ± 0.023 µg/g). Copper levels peaked in domestic yolks at 0.360 ± 0.027 µg/g. Cadmium, arsenic, and iron levels showed minimal variation across all samples. Zinc was highest in domestic whites (0.968 ± 0.085 µg/g) and in layer yolks (0.863 ± 0.076 µg/g). Conclusion: Eggs from domestic poultry showed higher contamination with toxic metals, particularly Pb, Co, and Cu, raising serious public health concerns. These findings highlight the urgent need for regulatory oversight, environmental monitoring, and public awareness to ensure food safety and reduce exposure risks.