emitting radionuclides in the deep respiratory zone is 2 particles. This corresponds to a MPLB of 0.14 pCi and repre- sents a reduction of 115,000 in the existing MPLB. implies that the DF for hot particles is This 115,000. Moreover, it requires a reduction of the MPCa for Pu-239 by 115,000 .to a value of 3.5x10716 uci/ml unless it is determined that the piutonium is not in hot particles. B. Exposure of the General Public As indicated in Table II, the MPLB for non-occupational exposure (members of the public) for occupational exposure. is tenfold less than that Such an exposure limit for a hot particle would be 9.2 narficles. Exposure at this level implies that on the average one out of five individuals would be contaminated by a particle and the other four would not. Obviously the exposed invididuals would be assuming a disproportionate fraction of the risk. In fact, since an ’ individual is exposed to whole particles, any non-occupational exposure to hot particles would be an overexposure. This condition does not meet the recommendations and admonitions of the FRC, ICRP and NCRP. Under certain conditions, such as widespread radioactive contamination of the environment, the only data available may be related to average contamination or exposure levels. Under these circumstances, it is necessary to make assumptions concerning the relationship between - er Pre tte: Bape \ tne, : Lamy ees ‘ae aoe . Le ay . oly a : . . . eet ae : . wots » ‘yey . nd ON Lote . : e ey: a $2 eh pew te wf ae te . aa Me A. . : ’ ‘ yaa ’ eyo ; x at a us