Quantification of toxic metals contamination and health risk assessment in processed and raw dairy products in Abbottabad city

Toxic metal contamination (such as Cd, Cr and Pb) in processed and raw dairy products is an important environmental and public health concern. The accumulation of these metals in dairy products causes health threats to consumers. Various anthropogenic and natural activities discharge metals into the soil, where they are consumed by plants and become a part of the food chain. In addition, there is a considerable risk of metal contamination in dairy products during various business processes. The present study was carried out to determine the quantities of toxic metals found in dairy product samples. These dairy products have been classified into two groups: raw dairy products, which were self-extracted from cows and buffaloes employing adequate hygiene, and processed dairy products, which were bought from the Abbottabad market. These samples were generated using a double acid digestion approach, and toxic metals were quantified using atomic absorption spectrophotometry (AAS). For health risk assessment, the Health Risk Index (HRI), Target Hazard Quotient (THQ), and the Target Cancer Risk (TCR) indices were used. The relative levels of toxic metals in processed dairy product samples were as follows: Cd levels were highest in cheese (0.106±0.006 mg/kg), followed by butter and desi ghee (0.089±0.066 and 0.074±0.043 mg/kg, respectively). Cr concentrations were maximum in flavored milk (0.471± 0.290 mg/kg) and desi ghee (0.371± 0.01 mg/kg). Pb levels found in cheese were higher (1.753±0.194 mg/kg), then desi ghee and butter (1.025±0.01 and 0.652±0.397 mg/kg, respectively). Toxic metals in raw dairy products were measured in cow samples in the order of Cr ≥ Pb ≥ Cd. In a similar manner for buffalo samples, toxic metals followed the same trend as in cow samples. Though the concentrations of targeted metals in both raw and processed dairy product samples exceeded the threshold levels, the estimated levels of THQ and TCR were within the permissible range. However, our findings suggest that these metals in dairy products should be assessed on a continuous basis, as anthropogenic activities are contributing substantially to metal contamination.