Letters Received to H.H. Barker, June 18, 1931

UNIVERSITY OF MISSOURI JON 22 1931 COLUMBIA DEPARTMENT OF CHEMISTRY June 18th, 1931. Mr. H. H. Barker United States Radium Corporation 535 Pearl Street New York City, New York My dear Barker: Your criticism of Dr. Leake's report I have read with more than ordinary interest, but I have been in- terrupted many times, so that I have found it difficult to organize my own views in final form. Although sone confusion still exists in my own mind on sone points, there is no tell- ing that I shall be any further advanced tomorrow. Let me, then, give you my reaction to some of the points you raise. It seems to me that the paging in the copy of the report which I have does not correspond at some places to the copy you must have had before you, but this will not make any confusion. Some of your criticisms it seems to me are sound, and should be taken into considoration and revisions made before the re- port is printed. Other of your criticisms, I do not regard with favor. I shall give you frankly my reactions. Splitting the report into two sections seems to me would disturb its unity seriously. In most instances tables and graphs--the workers employed since 1926, are designated as a group and so are segregated. Cf. Fig. 13 and also insert of Fig. 12. Personally, I fail to see in the report cause for alarm about the dangers in radium painting as practiced at pre- sent, except in the dusting process. The survey, however, shows clearly that the workers gradually become active under present practice, but the rate of accumulation of radium is so slow in the average case, that there is no cause for alarm. The fact that a large number of workers do not become active at all, seens to me indicates that some persons eliminate radium more rapidly than others. Brush painters while at work inhale per day about 20 to 30 x 10-10 g. radium as dust or per year of 300 working days, about 0.7 microgram. Most of this is elim- inated as comparison with accumulation curve, Fig. 13, shows. In short the normal elimination keeps the quantity of radium well within the range of safe tolerance, if we assume that it takes five years to gather one milligram. And this value is much reduced if we throw out the few persons who show 2 to 5 pg. Such cases I am inclined to regard in the light of our experiences with workers employed in our refining laboratories as accidental happenings. Systematic electrosoopic examinations catch these cases, before any damage is done. Eliminating these accidental infections leaves the rest of the workers completely within the