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RECORD NUMBER: 430 OF 826

Main Title How Are the Physical and Chemical Properties of Chrysotile Asbestos Altered by a 10-Year Residence in Water and up to 5 Days in Simulated Stomach Acid.
Author Seshan, K. ;
CORP Author Arizona Univ., Tucson. Dept. of Metallurgical Engineering.;Health Effects Research Lab., Research Triangle Park, NC.
Year Published 1983
Report Number EPA-R-807000; EPA/600/J-83/263;
Stock Number PB85-104974
Additional Subjects Asbestos ; Gastric juice ; Serpentine ; Physical properties ; Chemical properties ; Reprints ; Drinking water
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NTIS  PB85-104974 Some EPA libraries have a fiche copy filed under the call number shown. 07/26/2022
Collation 8p
Abstract While there are many studies concerning the ingestion of chrysotile asbestos, there are a few studies concerning how the chrysotile asbestos itself is altered by the exposure to the acid stomach environment. It is shown that the charge on the surface, the Zeta potential, is changed from positive to negative; that the surface becomes silica-like, i.e., depleted of Mg++ ions; that Mg++ is lost from the fibers of asbestos upon exposure to water and acid; that the loss of Mg++ is more rapid, the smaller the fiber diameter. Notable among the physical properties, the loss of Mg++ causes the refractive index to change. This means that asbestos exposed to acids or water may not be detectable using the now popular dispersion staining techniques which identify asbestos based on refractive index. The physical property changes include the destruction of the 'gross' crystallinity of the fibers. The x-ray diffraction signal from acid treated fibers disappears. This means that x-ray diffraction cannot be used to identify chrysotile which has been exposed to acid.
Availability Notes Pub. in Environmental Health Perspectives, v53 p143-148 1983.
NTIS Title Notes Journal article.
Title Annotations Reprint: How Are the Physical and Chemical Properties of Chrysotile Asbestos Altered by a 10-Year Residence in Water and up to 5 Days in Simulated Stomach Acid.
PUB Date Free Form c1983
Category Codes 6T; 57Y; 68D
NTIS Prices Not available NTIS
Primary Description 600/11
Document Type NT
Cataloging Source NTIS/MT
Control Number 503219661
Origin NTIS
Type CAT