Levels of Essential and Xenobiotic Elements and Their Relationships in Milk Available on the Slovak Market with the Estimation of Consumer Exposure

The monitoring of various elements in the cow milk is important in the agricultural sector. The goal of this study was to determine the concentrations of calcium (Ca), cadmium (Cd), copper (Cu), iron (Fe), mercury (Hg), potassium (K), magnesium (Mg), sodium (Na), nickel (Ni), lead (Pb), and zinc (Zn) in the milk samples coming from different origins (local region in Nitra, nationwide sample represents the common Slovak brands of milk and common brands of milk from Czech Republic widely available in Slovakia). The samples were analyzed using atomic absorption spectrometry. A high level of variability in the Cu, Fe, Na, Ni, and Zn contents was observed. Magnesium was comparatively high in the milk sample from Slovakia (273.23 +/- 16.32g/mL) against sample from Nitra (230.91 +/- 9.48g/mL) and Czech Republic (202.70 +/- 10.83g/mL). Potassium was significantly higher in milk from Nitra region (3301.98 +/- 95.66) against SK sample (2925.16 +/- 75.74g/mL). There were no significant differences in other elements among the three regions. The provisional tolerable weekly intake (PTWI) contribution suggested low dietary exposure to observed toxic metals (Cd, Hg, and Pb) in milk samples. Margin of exposure (MOE) evaluation denoted that even higher consumption of milk poses no high cardiovascular and nephrotoxicity threat. However, Cd and Pb are known for their cumulative effect and the monitoring of these elements in milk is strongly required.