Radon and Smoking Status

To the Editor.—  The generally excellent study entitled "Lung Cancer Mortality Among Nonsmoking Uranium Miners Exposed to Radon Daughters"¹ is flawed in two ways. First, the investigators failed to validate the lifelong non-smoking status of the 14 lung cancer decedents by discussions with surviving relatives, coworkers, and physicians. Such specific validation is needed because of workers' compensation implications and because of the many years' lapse from ascertainment of smoking status (1950 through 1969) to death as late as 1984.Second, the investigators entirely ignored the key issue of what proportion of radon daughter—α-particle exposure was due not to uranium in mine ore but to tobacco smoke—polonium 210 in mines, bars, and home environments, generated by associates.² Furthermore, the authors did not define nonsmoking status, eg, never smoked a cigarette, pipe, or cigar; never smoked 100 such; or never smoked regularly.³