Determinación de la biomangificación de oligoelementos tóxicos en leche cruda; por biotransferencia desde agua y pasto en una hacienda modelo de la parroquia Tarqui, Cuenca, Ecuador; y su posible riesgo toxicológico

Abstract

Environmental contamination by heavy metals constitutes a relevant threat to food safety and public health. This research evaluated the concentrations of arsenic (As), cadmium (Cd), and lead (Pb) in raw bovine milk produced at a model farm in the parish of Tarqui, Cuenca, Ecuador, as well as the biotransference of these metals from water and pasture, and the toxicological risks derived from their consumption. Samples of milk, water, and pasture were collected and analyzed using inductively coupled plasma mass spectrometry (ICP-MS), and the biotransference factors (BTF) and risk indices were calculated: Hazard Quotient (HQ), Hazard Index (HI), and Incremental Lifetime Cancer Risk (ILCR). The results showed elevated concentrations of lead (1.54 mg/kg), cadmium (0.058 mg/kg), and arsenic (0.2361 mg/kg) in milk, exceeding the limits established by Ecuadorian and international standards. Although the BTF values were low (below 1), indicating limited biomagnification from environmental sources, the final concentrations in milk reflected significant contamination in water and pasture. Toxicological analysis revealed HQ values greater than 1 in individuals under 55 years of age and HI values above 1 in all age groups, indicating non-carcinogenic risk. Likewise, ILCR values for arsenic (9.53 × 10−3) and cadmium (9.84 × 10−3) exceeded the acceptable range established by the EPA (10−6–10−4), evidencing a considerable carcinogenic risk. In conclusion, these findings reflect a serious food safety and public health issue, underscoring the need for environmental and sanitary control measures in rural milk-producing areas.