Using the geologic setting of talc deposits as an indicator of amphibole asbestos content

Asbestos in commercial cosmetic talcum powder as a cause of mesothelioma in women

“…These three mines all contained asbestos fibers; anthophyllite, and tremolite. [11][12][13][14][15][16][17][18] The Val Chisone talc from Italy was studied by Pooley in 1972. 18 Mine sample had intergrowths with serpentine-type, chrysotile asbestos along with tremolite and anthophyllite asbestos.…”

“…The talc used by this cosmetic company that manufactured and distributed the talcum powder was from three distinct regions: the Willow Creek mine in Southwest Montana, the Regal mine near Murphy, North Carolina, and imported talc from the Val Chisone region of the Italian Piedmont. [11][12][13][14][15][16] The specific geology of talc is an important indicator of whether a talc source may be contaminated with asbestos. These three mines all contained asbestos fibers; anthophyllite, and tremolite.…”

Pneumoconiosis and malignant mesothelioma in a family operated metal casting business that used industrial talc from New York state

“…The resulting deposits consist of fibrous to platy talc, and tremolite and anthophyllite in habits ranging from blocky to fibrous. Amphibole-rich talc deposits were reported to occur in: the Death Valley region of California; western North Carolina; the Gouverneur district of upper New York State; Vermont; Soapstone Ridge, Georgia; east-central Alabama; and central Texas [Van Gosen et al, 2004].…”

“…Scientists at the U.S. Geologic Survey investigated the geologic settings of American talc deposits as a predictor of amphibole asbestos content [Van Gosen et al, 2004]. They reported that a number of U.S. talc deposits of commercial size were formed by processes driven by regional metamorphism and that these large bodies consistently contain talc intergrown with amphiboles such as tremolite and/or anthophyllite.…”

An Experimental Study of the Formation of Talc through CaMg(CO3)2–SiO2–H2O Interaction at 100–200°C and Vapor-Saturation Pressures

“…Some researchers view talc as the initial metamorphic mineral for the CaMg(CO 3 ) 2 -SiO 2 -H 2 O system (e.g., [4][5][6]). However, serpentine minerals, like lizardite and chrysotile, are also likely to form at low temperatures during metamorphism of the CaO-MgO-SiO 2 -H 2 O-CO 2 system, especially in contact or regional metamorphic settings [65][66][67]. Some researchers have even pointed out that serpentine forms at lower temperatures than talc during metamorphism further introduction of SiO 2 will make talc stable relative to serpentine [70][71][72][73].…”