screening level are given in the next slide (Slide 3). They claim that the use of the dust storm data is appropriate because two other studies gave the same results. . In estimating doses to the lung and bone they used the organ weights in the next slide (Slide 4). The chief discrepancy is in the lung weight where the EPA tried to describe the tissues irradiated more closely than most. Of course, the new ICRP calculations used the dose to the bone surface assumed to weigh 120 grams rather than the average bone dose. calculations are given in the next slide (Slide 5). These ICRP bone surface It is of some interest that this calculation gives a factor of 10 over the average bone dose while the older calculation uses a factor of 5 as derived from early animal experiments. The air screening level is given in the next slide (Slide 6). It is based on a particle size of 0.1 wm presumably because it is intended to apply to effluents from a facility. As such, it does not really apply to the resuspended component where particle sizes are typically on the order of a few micrometers. However, the difference between the EPA air value and that for several micrometers fis only about a factor of two to three. The EPA insists that the primary guidance of 1 mrad/yr to the lungs and 3 mrads/yr to the bone should take precedent. However, there are problems with this in terms of the data needed to predict the dose and the need to use models to determine the dose. The next slide (Slide 7) shows the distribution of plutonium in the bone and liver as obtained from the autopsy data of both public and workers. The wide distribution fs apparent so that it will be -2-