Radium-226 in human diet and bone

The mean radium-226 content of samples of vertebrae from New York City and San Francisco is 0.032 and 0.026 picocuries of radium-226 per gram of calcium, respectively. The ratio of these two mean values is associated with a similar ratio of radium-226 to calcium found in the diet at the two locations. A plot of the radium-226 content of bone as a function of age indicates that there is no marked difference in levels of bone radium with age.