. 2 Om airmen apathetRnewstidliven Fe ee a Bein * and aerial cloud sampling results are used, not because they represent potential exposures of the population, but because they are a conser- vative upper estimate of potential exposures. The following tabulations of tritium results are indicative of the concentrations encountered following a few representative events. 1. SCROLL 4/23/68 1130 PST DELETED Midpoint of 4 Location _ - Sampling Time 1 ue “ as ” ~ yi A Aerial Sampling ° Underground ~Tritium pCi/ml of — ‘Moisture / —— 1407 Over GZ 8.9 x 10° 1407 Over GZ 2.9 x 10 3 A pt pCi/m? - =, of Air ° - 3 x 10 Raa eee ; 9.3 x 10 7), an BT 4 a ar 3 OF LS 1 RT vo “a : - * 3 yo wD The first sample was taken over a shorter period of time than the second and thus is averaged over a shorter period of time. Normal background levels of 1 - 2 pCi/ml have been subtracted. All later references to background values . for this type of sample will be taken to mean 1-2 pCi/ml of moisture. 2. NASH DOE ARCHIVE 1/19/67 845 PST DELETED Underground (Venting did not start until about 1800 on 1/19/67 and continued until about 1100 on 1/21/67.)