Osteogenic Sarcoma In Dial Painters Using Luminous Paint

were attributed to radium-mesothorium poisoning incurred while they were em ployed at painting watch dials with lumi nous paint, two were found to have os teogenic sarcoma of the bone. The etiology, the general and the spe cial symptomatology, the pathologic anatomy, the prognosis and the treat ment in this new industrial hazard were first described by Martland and his asso ciatesin 1925 and 1926.' Only a brief résumé of the observa tions on this disease is necessary in this paper. The paint used consisted of crystalline phosphorescent zinc sulphide, ZnS (Sidot's blend), rendered luminous by the addition of extremely small amounts of radium, mesothorium and radiotho rium. These radioactive substances were in the form of insoluble sulphates in the paint when it was used. The mode of poisoning in these cases was by ingestion. Owing to a general habit among these workers of pointing their brushes in their mouths while painting the dials, they swallowed small amounts of the radioactive paint day after day. They were also exposed to ra dioactivity by absorption of the sub stance through the skin and by inhala tion, especially of the dust of the lumi nous paint, but these portals of entry were not considered significant. The girls affected had swallowed the paint for periods of from one to four years or more. Most of the paint swallowed passed rapidly through the gastrointestinal tract and was eliminated. A small amount, however, was continually absorbed and eventually stored as insoluble sulphates of particulate or colloidal size in the main organs of the reticulo-endothelial system and,above all,inthebones.The exact mode of intestinal absorption is not clear. Whether the insoluble radio active substance was picked up by wan dering histiocytes of the intestine and taken into the thoracic duct, then to the blood and then to the storage organs, in which it was phagocytosed by the fixed histiocytes of the blood sinusoids, the Kupifer stellate cells of the liver and the splenic phagocytes, whether small quantities passed through the intestinal tract in a manner not understood, or whether the radioactive substances had some fixed position in the zinc suiphide molecule which allowed it to be ab sorbed with the zinc is unsettled at present. Perhaps the conceptions of ab sorption from the intestinal tract must be augmented and modified considerably. It should be recalled that the entrance into the body of insoluble matter of par ticulate size is thought to be easier by in halation than by ingestion. For instance, in anthracosis, the foreign matter is Reprintedfrom Archivesof Pathology7: 406-417, 1929. Read before the New York PathologicalSocietyat the New YorkAcademyof Medicine, New York, March 8, 1928.