Cadmium and lead in hen eggs from cage, barn, and free-range systems: distribution, dietary exposure, and consumer health risk

Eggs are widely consumed and may contribute to dietary exposure to toxic metals such as cadmium (Cd) and lead (Pb). This study determined Cd and Pb concentrations in eggs from free-range, barn, and cage systems sold in Poland. It evaluated associated non-carcinogenic and carcinogenic health risks under different consumption scenarios. A total of 74 commercial eggs (individual albumen and yolk separately; n = 148 analytical units) were analysed using electrothermal atomic absorption spectrometry. Risk assessment was performed for adults and age-specific child populations. Three intake scenarios (1–3 eggs/day) were assessed for adults; additional age-specific exposure scenarios were evaluated for children aged 2–5 and 6–12 years. Risk characterisation included hazard quotient (HQ), hazard index (HI), and lifetime cancer risk (LCR), based on internationally recommended reference values. Mean Cd and Pb concentrations varied by housing system, with generally higher levels in free-range eggs. HQ and HI values were below one in all scenarios, indicating no non-carcinogenic risk. However, LCR values for both metals frequently fell within the upper acceptable range (1 × 10−6 – 1 × 10−4) across housing systems and intake scenarios. Cadmium showed consistent contributions across systems, while lead displayed greater variability. By egg component, Cd predominated in albumen and Pb in yolk, and both contributed similarly in whole eggs. Although no sample exceeded carcinogenic thresholds, the frequent LCR values within the alert range support intensified monitoring, particularly in free-range production systems.