Concentration of Toxic Heavy Metals in Raw Milk from Dairy Farms in R. N. Macedonia

Background and aim: The presence of toxic heavy metals is a matter of importance due to their ability to contaminate and damage the trophic chain. Determination of the content of heavy metals in raw milk is an important indicator of the quality and safety of this product, and the level of pollution in the region where the milk is produced. The main purpose of this research was to examine the content and distribution of toxic elements (cadmium - Cd, lead - Pb, copper - Cu, zinc - Zn, nickel - Ni and manganese - Mn) in individual samples of cow's milk from seven different locations.
Materials and methods: A total of 140 samples of milk were taken. For the assessment of the elements an Atomic Absorption Spectrometry technique (Agilent Technologies 55) was used. Statistically, the results obtained from the conducted surveys were interpreted using variation -statistical methods, which are applied for scientific research purposes (ANOVA). Results: In our results from the annual average value of the elements we found that the content of 
all elements except lead was within the normal prescribed permissible limits. The calculated annual average value of lead from all seasons is 35,937 μg / L or 0.035937 mg / L. The differences between the mean values for the content of lead in the milk, in the different seasons, were found at the level of 0.05. Conclusion: This study will contribute to improving the awareness of the current state of contamination of milk with toxic elements in the country, as well as raising consciousness of the farmers and consumers about the importance of food safety and public health maintenance.