Heavy metal contents in homemade milk and cheese from villages with possible risk of environmental pollution

Milk and dairy products are an important food group because of their nutritional features. Unfortunately, milk could be contaminated with heavy metals from the environment. The aim of this study was to investigate heavy metals (lead, cadmium and nickel) in homemade milk and cheeses from animals raised in villages with possible risk of pollution Zmeyovo and Borilovo. Materials and Methods: Raw goat and cow milk samples as well as cheese samples were taken from two herds in Zmeyovo, two herds in Borilovo and raw cow milk from remote mountain village was taken as a control. Samples were analyzed using flame and graphite furnace atomic absorption spectrometry after microwave or wet digestion. The results obtained were divided in groups depending on the kind of dairy animals, type of feeding and villages. Results: Mean lead contents in milk ranged from 0.022 mg/kg in cow milk to 0.032 mg/kg in milk from grass-fed goats. In all milk samples the lead content was over the maximum permissible level of 0.020 mg/kg determined by Regulation EC 1881/2006. Cadmium and nickel levels were highest also in milk from grassfed goats and in goats that were fed grass and locally grown barley and alfalfa. Lead and nickel contents in goat cheese were higher than in cow cheese, but cadmium contents were almost equal in all cheese samples. Conclusions: Lead levels in homemade milk and cheeses are cause of concern. Risk for heavy metals contamination of dairy products is higher in goat herds with grass pasture feeding.