June 10, 1968

Asbestos and Mesothelioma

Author Affiliations

Hines, Ill

JAMA. 1968;204(11):1009. doi:10.1001/jama.1968.03140240065025

To the Editor:—  A recent letter (203:1142, 1968) states that the problem of mesothelioma formation is "not one that involves the whole asbestos industry, but only users of crocidolite, and this mineral represents a relatively small proportion of total consumption. It has been shown1 that mesothelioma occurs in workers exposed to chrysotile extensively mined in Canada. We have seen mesothelioma formation in workers weaving brake lining, which is made from chrysotile. Exposure was three years as a young adult, and death was caused by a peritoneal mesothelioma at 43. Another case was a 50-year-old man who worked in a Canadian asbestos mine five years and who died of pleural mesothelioma 15 years after the first exposure. Analysis of tissue by x-ray diffraction indicated that chrysotile was the only form of asbestos present. Wagner and Skidmore2 induced mesotheliomas in the pleura of rats that inhaled chrysotile, crocidolite, amosite,