Levels of super(90)Sr and super(137)Cs in the Urine of Finnish People

The aim of this study was to estimate the current concentrations of super(90)Sr and super(137)Cs in the urine of Finnish people and to estimate the doses. Two to three daily urine samples were collected from 18 adult Finnish volunteers in connection with studies of super(137)Cs body burdens in 1999-2001. The super(90)Sr activities in urine varied between 1.4 and 11 mBq l super(-1). The super(137)Cs activity in urine varied between 0.36 and 56 Bq l super(-1). The daily urinary excretion was found to be 4.8-17 mBq for super(90)Sr and 0.81-68 Bq for super(137)Cs. Assuming that the daily super(90)Sr intake was constant and that 18% of the ingested activity was excreted in urine, the mean intake in the investigated group would vary between 27 and 96 mBq d super(-1). Based on these estimated intake values, the respective annual effective internal doses from super(90)Sr and super(90)Y varied from 0.3 to 1.0 mu Sv and from super(137)Cs from 4 to 350 mu Sv during the sampling period.