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...

[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...

The crystal structure of gem-quality pargasite from Soper River, near Kimmirut, Baffin Island, Nunavut, Canada, (K0.24Na0.73) 0.97 (Ca1.86Na0.14) 2.00 (Mg4.15Fe0.07Mn0.01Al0.71Ti0.06) 5.00 (Si6.45Al1.55) O22 [(OH)1.25F0.63O0.12] 2.00, a 9.8814(6), b 17.967(1), c 5.2927(4) Å, 105.263(5)°, V 906.5 Å3, C2/m, Z = 2, has been refined to an R index of 2.9% using 1506 observed intensities measured wit...