Letters Sent to Arthur Roeder [A. Roeder], July 14, 1924

COPY Harvard University School of Public Health 55 Van Dyke Street, Boston, Massachusetts. July 14, 1924. Mr. Arthur Roeder, United States Radium Corporation, 30 Church Street, New York City. My dear Mr. Roeder: Inspection of the work done with our animals leads me to feel that further delay in reporting upon them will give us no more information. On May 13th we gave intratracheal injections of luminous zinc sulphide to one cat and of "Undark to three cats. The reason for this method of administration is because it assures a prompter and more efficient absorption of the substance used, and is, furthermore, similar to one of the routes by which your employees take in these substances. In no case did we gain evidence of any local damage to the lungs. After one to four weeks time we sacrifieed the animals, and found no noteworthy abnormalities at autopsy. Upon chemical analysis, the bones of the cats receiving "Undark: contained large amounts of radium more than we could obtain from the lungs, the site of the original deposition, or from all the rest of the body. Our apparatus does not permit the giving of a quantitative figure on this point, but it has established very definitely that inhaled "Undark is removed from the lungs and the radium carried by it is deposited in bone. In both the luminous zinc sulphide and "Undark" animals the skeleton contained some zinc, deposited apparently as a double phosphate in the compact bone, and being analogous in this particular to lead and a number of other heavy metals, though probably less permanent. On perusal of our report, you will note that we cited abundant evidence from the literature to the effect that intravenously or subcutaneously injected radium preparations deposited radium in large amounts in bone. We felt it desirable to find out whether radium introduced by inhalation, as "Undark", is deposited in the same way. This has been definitely established by these experiments. To you, I suppose, they will seem unnecessary, but we feel that they bring out in rather a bold relief the fact that radium administered as it slowly is to your employees, readhes bone. You will ask why, if we have done this, we have not gone on to the question of necrosis production, thereby clinching matters. If this phase of the situation could be established experimentally, it would require a considerable series of animals dosed over a long period of time in several