PRIVACY ACT MATERIAL REMOVED ‘Table 2— POTASSIUM AND CAESIUM CONTENTS OF 16 MEN NOT OCCUPATIONALLY EXPOSED TO Cs!*?, MEASURED BETWEEN JUNE 1956 AND JULY 1957 , Potassium content Date measured Subject z cs!3? content % body weight mye puc/g of K 0.239 + 0.026 0.219 + 0.023 0.202 40.022 0.2014 0.014 0.236 +0.015 0.206 + 0.007 4.7+#1.2 <Bz1 4.7 + 0.8 4,241.3 6.14 0.7 3.2 + 0.4 3139 <4B + 8B 2544 27+9 3444 20+3 153 +9 0.214 + 0.012 5.24 0.7 3445 Jan. 22 187 +10 0.244 + 90.013 4.74 0.8 25 +4 Feb. 15 133 47 0.183 40.010 5.34 0.5 4044 _ Feb. 21 Comments 1956 June June June June Sept. Nov. 25 26 27 28 28 22 Nov. 30 Dec. 6 153 168 188 155 177 r69 417 + 18 + 20 +11 + 11 + 5 110 +9 0.191 40.016 4.30.7 3947 See also Mar. 7, 1957 See also Jan. 22, 1957 See also Feb, 19, 1957 See also Nov, 22, 1956 Resident of Leeds Mean of 2 measurements 1957 143 +8 Q.181 + 6.010 4,440.6 31434 Feb. 19 Feb, 21—- 183 + 6 0.198 + 0.007 7.140.5 39 + 3 Mean of 2 measurements Mar. 5 159 + 4 0.255 + 0.006 4.34 0.3 27+ 2 Mean of 3 measurements 158 + 4 0.208 + 0.005 3.8 + 0.3 2442 Mean of 3 measurements Mar. 7 14647 0.225 + 0.011 6.5 + 0.5 4444 Mar. 11 15449 0,184 40.011 5.7 4 0.7 37 + 5 Apr. 24 163 +8 12947 6,230 + 0.011 0.196 40.011 6.5 + 0.6 40+4 Australian June 24 190 + 8 0.238 + 0.010 B.4 4 0.6 4444 Londoner July 22 149 «9 U.186 4 0.011 68.5 2 U7 4445 Feb. 20— Feb. 25 May 30 Mean Standard deviation Standard error 0.212 0.023 0.005 5.2405 , 4145 34.0 7.6 1.7 reported (0.188 + 0.006 per cent for 12 men) by this method’ (Marinelli, 1957). Because of the biological variation such comparisons are not strictly valid, but there is also the possibility that the method of calibration used at the Argonne National Laboratory gives different results from that used here. American practice has been to administer orally a small quantity of KY? and to compare the counting rates in various energy bands obtained in vivo with those obtained from a source of the same activity tn vitro. The mean value for the Cs!*" content of the same 16 subjects as above is 34.0 puc per gram of potassium, with a standard deviation of 7.6 uuc per gram of K. The lowest and highest value observed are 20 and 44 uc per gram of K, respectively. Miller and Marinelli® reported that there were no substantial changes in the caesium contents between the spring of 1956 and the end of the year, The values for four of their subjects studied systematically ranged from about 33 to about 45 yuc per gram of K. Anderson et al.* reported an average Cs!8? content of 5 muc for about 250 subjects measured during 1956 in the U.S.A. This is about the same as found here. Bird’ reported values of 5 to 8 muc for the Cs!3" content of three subjects resident in Leeds, measured in April 1957, in general agreement with the levels for the same time shown ‘in Table 2, These were a little higher than the results reported by Burch et al."! for subjects measured between May and October 1956, but the data are too sparse for any definite conclusions to be drawn. Further, in view ‘of the variation of the Cs'*? content of milk with geographi- cal location (Booker, 1957), comparisons on a regional basis are unjustified.'” In conclusion, it may be noted that if the distribution of potassium and caesium in the body differ markedly from uniform, as used in the phantom, then the absolute results may be in error. 251 PRIVACY ACT MATERIAL REMOVED eae