RETENTION OF STRONTIUM RADIOISOTOPES DURI NG PROCESSING OF MILK TO QUARG AND COTTAGE CHEESE

Sr-90 is one of the most important radionuclides concerning radiation exposure of men via ingestion of radioactivity with food. Since the Ch ernobyl accident in 1986 this radioisotope has found again growing int erest because of the deposition of substantial activities in the surro undings of this reactor. This paper describes experiments to determine retention factors for strontium radionuclides during processing milk to quarg and cottage cheese. Most of the work was done via determining the distribution of the naturally occuring stable strontium in milk a nd milk products by atomic absorption spectrometry. In some cases Sr-8 5 as a tracer had to be used. The strontium retention factor of quarg was found to be 0.88. The corresponding value for cottage cheese was s omewhat lower (0.61) due to a washing procedure of the cheese grain.