Report, January 23, 1928

Comments upon and Criticisms of a Report to U.S.Radium Corp. by Dr. Cecil K. Drinker, dated June 3,1924, Concerning the Cause of Necrosis of the Jaw among Dial Painters. This report is being submitted at the request of Dr. H.H. Barker, Vice President of the U. S. Radivm Corp. , as outlined in his letter to the writer, dated Jan. 11, 1928. All of my own experience and all of my reading of the literature lead me to believe that the magnitude of the physiological effect of radium, other things being equal, is more or less closely proportional to the product of the quantity of radium and the duration of the exposure -- the larger the quantity and the longer the time of exposure the more pronounced the effect. Furthermore, quantity and duration being fixed, distance of the radium from the person greatly influences the effect -- naturally the farther removed, the less the effect; the closer the approach, the more pronounced the effect. The effect of radium outside the body is due to so-called rays or radiations. These are of 3 kinds, a,l and to , each kind absolutely distinct and different from either of the others. The a rays are helium atoms which are wholly stopped by the glass walls of any tube in which the Ra is contained, if the glass is thicker than a sheet of writing paper. Therefore in exposure to external radium the a rays are to be left out of consideration. The B rays are electrons -- particles of electricity -- which can pene- trate thin glass with only partial absorption and can penetrate the skin and tissues to a slight extent. The rays are ether vibrations. These are of the same general nature as radio broadcasting waves, visible light, and X-rays. Broadcasting waves are very long - 200 to 500 meters. X-rays are very short, gamma rays are still shorter. The latter penetrate all kinds of material more or less readily; they are absorbed in passing through such material, being absorbed or stopped more readily by screens of metallic lead then by other material of equal thickness. The greater the thickness the greater the absorp- tion of the gamma rays. Only gamma rays can escape from radium screened with 1/8 of an inch of sheet lead. In brief, the physiological effect pr oduced by radium, external to the body, depends upon, 1. Quantity of radium 2. Duration of exposure 3. Distance from body 4. Screening Other radioactive substances behave in large measure like radium in respedt to the foregoing conditions. When radium is taken into the body, the effect produced will depend on the quantity of radium, on the length of time the radium remains in the body, which in turn is largely governed by the speed of its elimination from the body.