A Case of Insoluble Natural-Uranium Exposure: A Two-Year Follow-Up Study

The urine analysis and lung burden of a laboratory worker who was accidentally exposed to uranium dust in January 1967 is reported. The urine was examined over various periods and at varying times. Urine collections were done daily and for some time aliquots were also examined three times a day. After several months of this procedure the urine was examined on three consecutive days each month. The amount of uranium found varied from 60 to 4000 μg/litre. Following Cofield's method, direct lung measurements were also done in the whole-body counter. The estimated lung burden according to this method was: 210 μg/litre 5 months after the exposure, 110 μg/litre 8 months after the exposure, 61 μg/litre 1 year after the exposure, and 52 μg/litre 2 years after the exposure. As the amount of uranium varies between 20 to 4000 μg/litre, we cannot-find any correlation between the urine excretion of the uranium and the lung burden. This raises the question whether it is possible to estimate the lung burden of insoluble uranium by urine excretion only. (author)