The risk of bone cancer in man from internally deposited radium

This title is that of a recent paper by G. Hems in this Journal (1967, Brit. J. Radiol., 40, 506). Pitfalls exist in the compilation and interpretation of data from investigations in progress in other laboratories. The risk assessments proposed by Hems result from oversimplifications of known facts and from the introduction of unsupported speculation, and appear to us to be untenable. Hems' paper: (1) employs only a small and arbitrarily chosen portion of the existing data; (2) errs by misinterpreting the isotopic character of mesothorium (228Ra) and radium (226Ra); (3) bases its risk estimates on a misleading concept of “initial radium content”, the numerical values of which are miscalculated throughout; (4) introduces misinterpretations and inaccuracies in previously published data; (5) omits corrections for the epidemiological bias introduced by the inclusion of self-selected patients who skew the tumour incidence quotients; (6) proclaims without statistical evaluation a linear non-threshold dose-v;.-response relationship by selectively ignoring some low-burden and high-burden cases; and (7) provides no commentary or refutation of the non-linear practical-threshold character of the dose-v.-response relationship as repeatedly reported in this Journal and elsewhere by those who have carefully utilised the entire body of available data.