| Figure 6: Data on dial painters, chemists, and others exposed to ingested radium. Ordinate is percent in each dose category that had tumours in the bone or head, and abscissa is the dose in cGy (rad) to the skeleton. |
 For doses above 1000 cGy, error bars are one standard deviation. There were no tumours for doses below 1000 cGy; asterisks show the ordinate if there had been one tumour in the dose category. A higher dose data point at 20 000 cGy with ordinate 38% (±13%) is off the plot (from Reference 19). |
 Validity of the Linear No-Threshold Theory of Radiation Carcinogenesis at Low Doses:Bernard L. Cohen |