Interpretation of urine monitoring data due to natural uranium insoluble compounds incorporation

In facilities with possibility of incorporating type S compounds of natural uranium, the routine urine monitoring is one of the methods used for the occupational control. So, it is useful to have some reference values for a first interpretation of those data. In this work some of these values, calculated on the basis of the most recent recommendations of the ICRP, as far as biokinetic models and dose limits are concern, are presented. The analysis is limited to the intake by inhalation of type S compounds of natural uranium. As reference values, those corresponding to the theoretical urinary excretion due to an acute intake equal to the radiological annual limit on intake are presented, as well as the meaning of detecting a detection limit in terms of intake. For the case of chronic intake, the theoretical values of urinary excretion due to a chronic intake of 1 Bq per day are presented, as well as the mass of uranium that is accumulated in kidney for the same intake, for its comparison with the maximum acceptable kidney burden by toxicological risk. (author)