The following table is proposed for the GI-tract of Standard Man.

The Recommendations of the International Commission on Radiological Protection (1959) give maximum permissible concentrations for uranium in air and water, but before the issue of I C R P Publication 6 in 1964, there were no instructions concerning the time over which MPC's based on chemical toxicity of uranium might be averaged. The present paper, which was circulated informally in the U.K. Atomic Energy Authority before the issue of ICRP Publication 6, makes some suggestions regarding maximum single intakes of natural uranium under various circumstances, for instance : (a) Maximum single intake of inhaled uranium in 1 day 2.5 mg (b) Maximum single intake of ingested uranium in 1 day 150 mg ( c ) Maximum planned emergency inhalation for occupationally-exposed persons 10 mg The first two of these sucgestions are now in line with the recommendations of ICRP Publication 6.

No abstract

Acceptable limits for the inhalation of radiostrontium in an emergency are calculated. Several methods are used to calculate the acceptable limits based on the body burden concept, the maximum allowable dose to the whole skeleton or the maximum allowable dose to a particular site in the bone. The authors conclude that 0.5 pc is an acceptable amount for inhalation by adults of strontium-90 and 16 pc for strontium-89 in conformity with the accepted levels for the permissible dose in bone. A short discussion is given on applicability of these values to children in the environmental population.