Letters Sent to Harry H. Bowing [H.H. Bowing], February 1, 1930

February lst,1930. Dr. Harry H. Bowing, c/o Mayo Clinic, Rochester, linn. Dear Dr. Bowing: I an glad to herewith confirm in letter form the matter dis- cussed with you personally on -onday January 27th. From 1916 to 1925 the United States Radium Corporation or its predecessors maintained an application plant for applying radioactive luminous natorial to watch, clock dials, etc., during which period there wore probably employed a total of approximately 400 girls. The radioactive luminous material was applied to the numerals of the dials with small camel's hair brushes. Ag you realiae, this operation is rather a delicate one and requires consider- able skill. The brushes had to be well "pointed* and to do this a good many of the operators used their lips, although there were other nethods provided. While the practice of "pointing" the brushos with their lips was forbidden on account of sanitary reasons, still the girls continued the practice with our knowledge. Early in 1924 a dentist in Newark called to our attention the fact that he folt there was an industrial hazard existing in our sork. We in ediately had a study made, with reference to the materials used as well as working conditions, by the Public Health Department of Harvard. Due to the fact that they could not attribute a similar condition which they found exist- ing in a number of our employees to any particular cauae, they advised us that they would look upon the radioactive constituents of our material with suspicion, and advised certain recomziendations which we inmediately put into effect. We followed this up by discussing the possibilities of the radium presenting B hasard, with both medical and scientific nen versed in the subject of radio- activity, and they both felt that the conclusions drawn by the Public Health School of Harvard were rather far fetched. We had other investigations made some of which indicated that it was questionable whether there was an industrial hazard existing in our plant. However, as time progressed and more data and information became available regarding the conditions existing among certain of our employees who had been engaged in this practice, our attitude changed and we recognized that there probably was a hasard connected with this work. The seat of the trouble could be traced back to the practice of #pointing" the brushes with the lips, theroby serving as a noans of introducing the material into the system. The redioactive luminous material consisted of phosphorescent which is primarily aine sulphide of a special orystaline nature, containing one (1) part of cadmium sulphide to 820 parts of sine sulphide, one (1) part of copper sulphide to 7150 parts of zinc sulphide, and one (1) part of was mon ganous sulphide to 23000 parts of aine sulphide. The radium or nesothorium