Since the promulgation of the first Federal Asbestos Standard by the Occupational Safety and Health Administration in 1972, other federal agencies have modified the standard to better carry on their own unique missions. The instruments used to identify and measure asbestos, the sampling protocol, and the criteria used to define asbestos, have been modified to some degree. The Mine Safety and He...

Quantitative estimates of the risk of lung cancer or mesothelioma in humans from asbestos exposure made by the U.S. Environmental Protection Agency (EPA) make use of estimates of potency factors based on phase-contrast microscopy (PCM) and obtained from cohorts exposed to asbestos in different occupational environments. These potency factors exhibit substantial variability. The most likely reas...

© 2001 Canadian Medical Association or its licensors In this issue (page 489), Joseph LaDou and colleagues on behalf of the Collegium Ramazzini call for an immediate and total ban on “asbestos” products because the current health risks associated with the use of “asbestos” are not acceptable, “controlled use” is not possible and “safer” substitutes are readily available. The logic is indisputab...

© 2001 Canadian Medical Association or its licensors In this issue (page 489), Joseph LaDou and colleagues on behalf of the Collegium Ramazzini call for an immediate and total ban on “asbestos” products because the current health risks associated with the use of “asbestos” are not acceptable, “controlled use” is not possible and “safer” substitutes are readily available. The logic is indisputab...

[1] Ultramafic xenoliths of spinel dunite, harzburgite, lherzolite, amphibole/phlogopite-bearing pyroxenite, and clinopyroxenite occur in andesitic pyroclastic debris from the 1964 eruption of Shiveluch volcano, Kamchatka. Peridotites have coarse/protogranular, porphyroclastic, and granuloblastic textures, abundant kink-banded olivine, and refractory mineral compositions with forsteritic olivin...

We present Thermobar, a new open-source Python3 package for calculating pressures, temperatures, and melt compositions from mineral mineral-melt equilibrium. Thermobar allows users to perform calculations with >100 popular parametrizations involving liquid, olivine-liquid, olivine-spinel, pyroxene only, pyroxene-liquid, two pyroxene, feldspar-liquid, feldspar, amphibole amphibole-liquid, gar...

Mast cell counts were performed on sections taken from the lungs of rats exposed by inhalation to different UICC samples of asbestos fibres for periods ranging from a few days to two years. A comparison of mast cell counts with grades of fibrosis showed that there is a sevenfold increase when there is interlobular linking of the fibrotic lesions (grade 5). Submesothelial mast cells showed a tre...