NTS during the cascade impactor run was measured to be 70 ug/m>. air, and do not consider the additional problems of resuspension of material from contaminated clothing or the resus- Such derived values must, of course, be used with a great deai of discretion. pension of material which has been trans- They are based on simple model systems ferred to pomes. Healy” which are believed to be generally conservative, but individual situations can be imagined which could exceed the predic~ tions, has considered these and other problems, and has provided tables of "decision levels" for surface contamination levels and home transfer levels. A decision level is based upon National Council on Radiation Protection and _ Other Considerations — Measurements (NCRP) recommended The above calculations relate only to the resuspended air activity in ambient Table 152. dose limitations, Because the derivations os 26 239 ; ; . Pu, and their equivalent in soil mass for soluble Decision levels based upon the “acceptable soil concentration" from Table 151. Pathwav Decision level A, Mass equivalent Direct personal contamination Direct inhalation® 2x10° nCi/ cm? 1x 107° g/ cm? Direct ingestion” 0.2 nCi/ cm” 0.2 g/cm Skin absorption® gxio+ uci - B. 0.8¢ Transfer (to homes) levels Resuspension? 0.01 uCi/day 10 g/day Direct inhalation 0.01 pCi/day 10 g/day Direct ingestion Skin absorption 100 ywCi/day 9.03 nCi/day 10° g/day 30 g/day a Ls . oo 3 a . , "The contamination level on clothing and skin that could result in inhalation of air : 2 at the MPC, for the public.” 6 biphe contamination level on skin or clothing that could result in ingestion of a quantity of radioactive material equivalent to the ingestion of water at the AIPC, . . . for an individual in the public.” 26 , "The total quantity of radioactive material maintained on the skin for 24 h/day that could result in absorntion of 2 quantity equal tu that whien would be absorbcd from the GI tract if water at the MPC_ for "soluble" isotopes public were . 1126 ineested, * for an individual in the + a ? = ‘ mfr 7 nan 1 a to duc ations csncentr r air in red per day that could result duphe amount transfer in individual an for MPC_ the at resuspension in a medium-sized home averaging the public. 126 I] --22