Letters Sent to Lt. Colonel J.F. Siler, June 26, 1928

June 26th, 1928. J. F. Siler, Lt. Colonel, Medical Corps, War Department, Office of the Surgeon General, Washington, D.C. Re: S.G.O. 230. 61-1 Dear Sir: Early in 1924, it was called to our attention that there was possibly an industrial hazard existing in our work, namely - the application of luminous material to watch and clock dials,etc. At the outset the hazard was ascribed to phosphorus, by a dentist who had occasion to do some dental work for a girl who had been working at our plant. He stated that this girl displayed a typical phosphorus jaw. Investigation, of course, proved conclusively that luminous material contains no phosphorus, but that the inference that phosphorus was probably present came from the common way of speaking of zine sulphide, which glows when exposed to either light or radium rays, namely phosphor- escency. We immediatel: y took steps to ascertain as to what if any hazard existed in the application of this material, and in this connec- tion we had a survey of our employees made by the Life Extension Institute of New York City, who reported that there apparently did not exist any industrial hazard among our employees. Later we called Dr. Cecil K. Drinker, at the suggestion of the New Jersey Zine Company, to make a survey of the situation. Dr. Drinker rendered a report to us in June of 1924, in which he stated that there was indication of a hasard existing in our plant, the cause of which he could not definitely establish, but that in view of being unable to ascribe this hazard to any particular condition in connection with the manufacture or application of luminous material, he felt that we sould regard radium with suspicion, and recommend- ed certain precautions. We did not entirely agree with Dr. Drinker in his conclusinns, which were based on negative evidence. Dr. Frederick B. Flinn of the Public Health Department of the College of Physicians and Surgedns, Columbia University, 630 West 168th Street, New York City, became interested in this subject, and has made tests and a study of it for the past three years. We are herewith enclosing reprints of gome of the work which Dr. Flinn has published along this line. While there are on record a few cases which would seem to indicate that there is a possibility of a hazard existing in this work, the feeling current among those having knowledge of the situation is that