To the Editor.—In his letter to the editor1 proposing that occult exposure to asbestos in cosmetic talcum powder explains the nonasbestos-related malignant mesotheliomas described by Attanoos et al,2 Dr Finkelstein's citations of 4 articles3–6 deserve comment.
Finkelstein1 wrote that Rohl et al3 reported that 10 of 20 cosmetic talcum powder products contained tremolite and anthophyllite. The International Agency for Research on Cancer (IARC) monographs, volume 93, pointed out that little reliance can be placed on the reported concentrations of tremolite and anthophyllite and noted that Rohl et al “stated that their methodology did not distinguish between asbestos and non-asbestiform mineral fragments,”7 making the results of Rohl et al3 questionable and Finkelstein's citation unreliable.
Finkelstein claimed that Blount “reported asbestiform tremolite contamination of the ore used in a popular baby powder.” Blount4 wrote, “a baby powder with very large flakes [of talc] showed 0.4 to 0.8 million particles per milligram.” Blount did not identify the particles in the baby powder as asbestiform tremolite or any form of asbestiform fiber. Blount assayed high-grade talc products from 5 deposits in Montana, 3 in Vermont, 1 in North Carolina, 1 in Alabama, and 4 from outside the United States. In his article, Blount4 reported only cleavage particles in 4 samples, only prismatic pieces in 1 sample, and no particles in 6 samples. Finkelstein misrepresented the results.
Finkelstein cited a paper by Gordon et al5 noting the authors found asbestiform tremolite and anthophyllite in a popular baby powder. The accuracy of Dr Gordon's identification of asbestiform fibers in talcum powder has been questioned.8 Further, the article by Gordon et al5 is a case report. Case reports do not estimate disease frequency or risk because of the absence of a valid denominator and do not provide any methodologic basis for determining general causation. Dr Gordon's publication offers no credible scientific evidence to support conclusions that cosmetic talcum powder contains asbestos or that exposure to cosmetic talcum powder causes malignant mesothelioma.
Finkelstein wrongly claimed that Anderson et al6 found anthophyllite fibers in the same brand of talcum powder as Gordon et al.5 Anderson et al6 wrote, “TEM [transmission electron microscopy] analysis [of cosmetic talcum powder] for asbestos resulted in no confirmed asbestos fibers and only a single fiber classified as ‘ambiguous.'” Anderson et al6 added, “We note that these results contrast with those reported recently by Gordon et al.5 for user simulations of unidentified commercial talcum powders.”
Finkelstein cited analyses performed by Victor L. Roggli, MD, of Duke University Medical Center but offered no citation of any peer-reviewed publications authored by Dr Roggli to validate claims that asbestos contaminates cosmetic talcum powder. That Dr Roggli reportedly found an association between the detection of tremolite and anthophyllite and the presence of talc in lung fiber burden analyses offers no evidence that talc exposure was the source of asbestos, invalidating Finkelstein's conjecture.
Finkelstein offers no properly cited peer-reviewed articles to support his contention that retail [his term] talc products create occult amphibole asbestos exposures that contribute to the cause of malignant mesotheliomas, leading to skepticism about his proposition.
Author notes
Dr Geyer provides pathology expert witness services to parties involved in both asbestos and talcum powder litigation cases. The author has no other relevant financial interest in the products or companies described in this article.