Abstract:
The present paper is a study based on the survey of the heavy metal milk residue levels (Pb, Cd, Hg, Ni, Cu, Zn) in the NE
Romania (Moldavia) and on the statistical interpretation of the analytical results that allowed for assessment of the contamination
seasonality of the substrates during a four-year period.
The analytical results revealed that the residues of Pb were found in 71.43 to 85.71% of samples at average concentrations of 2.49
to 3 μg/L, below the accepted legal limits (20 μg/L); those of Cd and Hg were zero in the analyzed samples or were in lower
quantities than the method detection limits; those of Ni, Cu and Zn were determined in all investigated samples at average
concentrations ranging from 11.24 to 11.90 μg/L, 237.10 to 303.43 μg/L and 2051.21 to 2628.64 μg/L, respectively. The
investigated heavy metals showed higher seasonality during the autumn (csi = 1.00 to 1.21) and winter (csi = 1.09 to 1.34), and a
lower one in spring (csi = 0.58 to 0.92). Ni was determined less than the provisional tolerable daily intake set by the World Health
Organization for human consumers (5 μg/kg). Cu was found at concentrations considered as legal (-) for cow`s milk and some
concentrations of Zn were found at levels that could provide the daily human consumption requirements of 3-10 mg.

Andrei - Cristian Grădinaru, Ovidiu Popescu, Gheorghe Solcan