Determination of some toxic substance levels in cow milk produced in gümüşhane

In this thesis, the effects of mining enterprises operating in Gümüşhane on the nutrient and mineral content as well as heavy metal levels of the cow milk produced in the province were investigated. Milk samples were taken twice in June 2021 from dairy cattle farms located in the closest distance to the mining enterprises operating in the city center and from dairy cattle enterprises located in Köse, Kelkit, and Şiran counties, which do not have a mining enterprise. Nutrient contents of the milk samples were determined in Atatürk University Faculty of Agriculture Milk Analysis laboratory by Lactoscan milk analyzer, mineral and heavy metal levels of the samples were determined by ICP-MS device in Gümüşhane University Central Research and Application Laboratory. Dry matter, non-fat dry matter, fat, protein, and lactose contents of the samples taken from Gümüşhane city center were determined as 12.83%, 9.28%, 3.59%, 3.12%, and 4.43% respectively. In addition, the same values were 12.81%, 9.38%, 3.43%, 3.6%, and 4.49% for the samples taken from the counties, respectively. Furthermore, Na, Mg, K, Ca, and Fe concentrations of milk samples from the Gümüşhane city center were 370.9 mg/L, 107.6 mg/L, 1552.0 mg/L, 321.0 mg/L, and 1806.0 µg/L, respectively. The same parameters obtained from the milk samples of the counties were 411.6 mg/L, 106.2 mg/L, 1555.5 mg/L, 323.4 mg/L and 1006.6 µg/L, respectively. From the results obtained, it was concluded that mining enterprises had no effect on nutrient content of milk produced in the province. While the Na and K levels of the cow milk taken from the city center were lower than the milk from the counties, the Fe content was higher. In order to reach a definite conclusion about the effects of mining enterprises on the nutrient content and heavy metal levels of the milk produced in Gümüşhane province, milk samples should be examined monthly, throughout the year. Also, mineral and heavy metal levels of the region's soil and plant cover shoud be examined regularly.