Letters Sent to Ernest C. Pohle [Ernst C. Pohle], February 3, 1930

February 3rd,1930. Dr. Ernest C. Pohle, c/o Wisconsin General Hoopital, Madison, lis. Dear Dr. Pohle: I an glad to herewith confirm in letter form the matter discussed with you personally on Wednesday January 29th. From 1916 to 1925, the United States Radium Corporation or its predecessors maintained an application plant for applying radioactive luminous material to watch, clock dials, etc., during which period there were probably employed a total of approxinately 400 girls. The radioactive luminous material was applied to the numerals of the dials with suall camel's hair brushes. As you realize, this operation is rather a delicate one and requires considerable skill. The brushes had to be well "pointed" and to do this/good many of the operators used their lips, although there were other methods provided. While the practice of "pointing" the brushes 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 felt there was an industrial hasard existing in our work. Te immediately had a study made, with reference to the naterials used as well as working conditions, by the Public Health Depertment 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 cause, they advised us that they would look upon the radioactive constituents of our material with suspicion, and advised certain recommendations which we immediately put into effect. lie followed this up by discussing the possibilities of the radium presenting a hasard, with both sedical and scientific nen versed in the sub- ject of radioactivity, and they both felt that the conclusions drawn by the public llealth 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 at our plant. However, as time progressed and more data and information became available regarding the con- ditions 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 sork. The seat of the trouble could be traced back to the practice of "pointing* the brushes with the lips, thereby serv- ing as a means of introducing the material into the system, The radioactive lominous material consisted of phosphorescent sine sulphide, which is primarily zine sulphide of e special crystaline nature, containing one (1) part of cadmium sulphide to 820 parts of sine sulphide, one (1) part of copper sulphide to 7150 parts of zine sulphide, and one (1) part of manganous sulphide to 23000 parts of zine sulphide. The radion or