Evidence Does Not Support Exposure to Cosmetic Talc as Cause of Malignant Mesothelioma.

M oline et al 1 wrote, ‘‘Exposure to asbestos-contaminated talcum powders can cause [my emphasis] mesothelioma’’ but they failed to provide epidemiologic evidence or apply epidemiologic methods to support their assertion. The authors describe 33 individuals in whom mesothelioma developed following the reported use of cosmetic talcum powder. Tissue digestion and fiber burden analysis, ‘‘done according to standard methodology,’’ was reported in six individuals. The authors claim ‘‘[t]alcum powder usage was the only source of asbestos for all 33 cases.’’ The statement presumes, in the absence of proof, that talcum powder caused asbestos exposure in of the reported cases. Moline et al claim that tissue digestion and asbestos fiber analysis were performed ‘‘according to standard methodology.’’ The authors cite two publications as the source documents describing the ‘‘standard methodology’’ (their references 23 and 33). Neither reference describes a standard methodology, that is, a method accepted as correct by custom, consent, or authority or a criterion for measuring acceptability, quality, or accuracy. The paper’s use of the term ‘‘standard’’ creates ambiguity because a standard method for tissue fiber burden analysis has not been adopted by any professional society or published in peer-reviewed literature and generally accepted by individuals who perform fiber