Metal (Pb, Cu, Cd, and Zn) Transfer along Food Chain and Health Risk Assessment through Raw Milk Consumption from Free-Range Cows

Abstract

Background: Metal transfer along the food chain has raised concerns about impacts on human health due to dietary exposure to low but chronic concentrations. Soil–forage–milk–consumer is a short food chain through which metals are able to reach an organism. Methods: Pb, Cu, Cd, and Zn were determined in water, soil, forage, and milk samples collected from free-range cattle farms situated near Baia Mare, Romania. The soil-to-forage (TFsf) and forage-to-milk (TFfm) transfer factors for metals and the health risk for three population groups (females, males, and children) through the consumption of milk containing low levels of metals were assessed. Results: TFsf indicated that the uptake capabilities of the metals from soil to forage were in the following order: Zn > Cd > Cu > Pb. TFfm indicated a lack of metal accumulation through forage ingestion. Estimated daily (EDI) and provisional tolerable weekly (PTWI) intake values revealed a minimal exposure of the population to those metals through milk consumption. A noncarcinogenic hazard index indicated that milk consumption from local markets does not pose any risk for human health; however, the average cancer risk showed a high potential carcinogenic risk. Conclusions: The consumption of milk produced by small local farmers does not pose noncarcinogenic risks. More extended studies should be carried out in order to identify the potential carcinogenic risk caused by the low levels of metals in the milk consumed.