استرونسيم -90 در شير تازه و شير خشك وارداتي مصرفي كودكان تهران و مناطق شمالي كشور

Sr-90 IN THE FRESH MILK AND MILK POWDER CONSUMED BY CHILDREN OF TEHRAN AND NORTH OF IRAN

Background and Objectives: Strontium - 90, one of the radionuclide produced during the fission of uranium and plutonium in the nuclear explosions and reactors, can readily replace calcium in the milk. It can put public health in danger both through its physical long half-life (over 28 years) and its existence in the milk that is a perfect nutrition of children. Materials and Methods: In this study, we collected 50 samples of fresh milk from Tehran, Mazandaran, eastern and western Azarbaijan and another 25 samples of milk powder imported from Netherlands, Denmark and Japan. After extraction of strontium by the method of Tri-butylphosphate (TBP) and preparation of the samples, Sr-90 reached in the radioactive equilibrium with Y-90 that was measured by the low-level beta detector. Results: The observations obtained in the study shows that the mean value of concentration of Sr-90 in the samples of fresh milk from Tehran, east and west Azarbaijan and Mazandaran was 5.43, 1.76, 1.70 and 2.90 Bq/kg respectively, while in the milk powder imported from Japan, Denmark and Netherlands, it was 6.93, 11.8 and 19.64 Bq/kg respectively. Conclusions: These results showed that the mean value concentration of Sr-90 in the imported milk powder was significantly higher than normal and thus, indicate the necessity of a precise control of imported nutrition products for children.