Radium bromide Institute had four grams of radium total, which at the time was more than half the world supply. Countries all over the world set out to make as much radium as possible, a time consuming and expensive task. It was reported in "Science" magazine in 1919 that the United States had produced approximately 55 grams of radium since 1913, which was also more than half the radium produced in the world at the time. A principal source for radium is pitchblende, which holds a total of 257 mg of radium per ton of UO. Obviously with so little product recovered
Radium dials 186 keV gamma emission 3% of the time. Also, Ra is rarely present without other transuranic elements or decay products, which may emit beta or gamma radiation. Therefore, the radiation hazards from radium paint may not be entirely removed by the varnish, case or container. Care should be taken to prevent the inhalation or ingestion of flakes or dust which may contain radioactive materials. Radium dials have been shown to have dose rates near the face of in excess of 10uSv / hr, which would deliver a dose equivalent to one days background exposure in around 20 minutes. This dose