Content of heavy metals in cow milk-raw materials of Poltava district (Ukraine)

Abstract

The concentration of heavy metals (Pb, Cd, Cu, As, Zn, Hg) in cow milk-raw materials was detected on the territory of the Poltava district (central part of Ukraine). Milk is one of a person's most valuable foods. It enriches the human body with necessary substances: proteins, fats, and carbohydrates, which are in balanced proportions and easily assimilated. At the same time, it contains different enzymes, vitamins, and low-molecular microelements, which are necessary to ensure the regular exchange of substances. On the other hand, the choice of cow's milk is considered to be one of the largest sources of food, which is contaminated by toxic elements. The work aimed to determine the level of heavy metals in milk-raw materials received from cows from personal peasant farms in the Poltava district (Ukraine). We divided working samples into three groups; they had a territorial affiliation with the Dykanka, Reshetylivka, and Poltava communities (8 each). The samples were immediately cooled, transported to the laboratory, and stored at -20 °C for further analysis. The research was carried out using atomic and absorption spectrometry based on the Regional State Laboratory of Veterinary Medicine in the Poltava region. The Mann-Whitney test was used to compare the results. The P value below 0.05 was considered significant. So, in the milk of the group of the Dykanka territorial community, the contents of Cu were at 0.05 ± 0.01. In contrast, in the cows of the Poltava territorial community, this indicator was probably higher and made 0.08 ± 0.01 mg/kg (Р < 0.05). The concentration of copper in the milk of animals of the Reshetylivka territorial community did not exceed 0.06 ± 0.01 mg/kg, and it did not have a reliable difference from other groups. Content of Zn is probably lower in the group of the Dykanka territorial community, compared to other groups (2.6 ± 0.13), while in the group of Poltava territorial community, its concentration was 3.3 ± 0.25 (Р < 0.05), and in the group of the Reshetylivka territorial community – 3.45 ± 0.24 mg/kg (P < 0,01). In our studies, the range of heavy metals is presented as follows: Zn>Pb>Cu>As>Cd>Hg.