Traceability and Health Risk Assessment in the Feed-Animal-Milk Chain: A Comparative Evaluation of Traditional and...

Cow milk and dairy products may reflect environmental elemental inputs transferred through the feed-animal-milk chain. This study investigated the elemental traceability, regional differentiation, dairy processing effects, and dietary exposure associated with milk and dairy products from two contrasting Romanian dairy production systems: the traditional Vaideeni region and the industrial Ibănești region. A total of 88 samples (water, feed, raw milk, and dairy products) were seasonally collected during 2024-2025 and analysed for trace elements, geochemical fingerprint elements, and macroelements using ICP-OES and atomic absorption spectrometry. The strongest regional elemental contrasts were observed in groundwater for V (Δlog₁₀ = +1.30), U (+0.82), Sr (+0.61), and Mn (+0.60), but these differences were substantially attenuated during biological transfer. Nevertheless, Li, U, Sr, Mn, and Cu retained measurable regional differences in milk. Regional elemental contrasts within the feed indicated an important inverse relationship (Pearson r = -0.60, p = 0.018), whereas no significant correlation was found between water and milk (Pearson r = -0.19, p = 0.493), suggesting that the milk elemental patterns may be influenced by biological regulatory processes in addition to the environmental signatures. Dairy processing further modified the elemental distribution, with the trace elements showing increased redistribution compared to the macroelements, while the geochemical fingerprint elements preserved regional information. The dietary exposure estimates for Cd and Ni remained below the corresponding toxicological reference values, whereas the highest estimated Pb exposure from hard cheese reached 0.977 μg/kg body weight/day for children and 0.558 μg/kg body weight/day for adults, exceeding the EFSA BMDL₀₁ reference point. The results indicate that multielement fingerprinting may provide promising information for investigating elemental traceability and supporting dairy product authenticity assessment within the investigated production systems, although extensive geographical validation will be required before application as a general authentication tool.