ABSTRACT
Hormones are used in veterinary medicine for different purposes such as treatment, improving animal products, obstetrical cycles, breed performances and enhancing acceptability of feed. The most dangerous drug residues presented in food of animal origin are because of neglecting withdrawal time, masking the sign of diseases in slaughterhouse and using unapproved drugs. Hormone residues in food of animal origin have health impacts on consumers. This survey have been done for determining the probable presence of the most used and dangerous hormones in pasteurized milk distributed in Tehran, capital of Iran. 50 samples of pasteurized milk were randomly collected from Tehran market from different brands and fats [low, standard and full]. Residues of phenylbutazone [PBZ] and Dexamethasone [DXM] were detected by HPLC-UV method according to AOAC instructions. ELISA was applied for measuring of 17- beta Estradiol residues. Minimum detectable residue of PBZ in milks was 2.5 ng/ml. 45 samples [90%] had PBZ from 1 to 58 ng/ml [Minimum Residues Level [MRL] for PBZ in cow milk must be zero per milliliter]. Minimum detectable residue of DXM in milks was 5 ng/ml, which in 30 [60%] samples was more than 5 ng/ml [MRL for DXM in cow milk must be 0.3 ppb]. In 8 samples out of 50 [16%] residues of 17- beta Estradiol was more than natural hormone residue [natural residues of 17- beta Estradiol in milk is 10-30 pb/ml]. Although hormones are vital for many physiological functions of humand beings, but exceeding of them in the body make many health problems. PBZ residue in 90%, DXM in 60% and 17- beta Estradiol in 16% of milk samples pointing a dangerous situation of using veterinary drugs in food animals and their milks