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

Journal Article · Tue Nov 01 04:00:00 EST 1983 · Environ. Health Perspect.; (United States)

DOI:https://doi.org/10.1289/ehp.8353143· OSTI ID:5260554

Seshan, K

Various tests and techniques were used to study the effect of exposure to simulated gastric juices as well as the effect of long term storage in water on asbestos fibers. Changes were noted in the physical, chemical and surface properties of chrysotile asbestos as a result of exposure to water, strong acids, and simulated gastric juices. The charge on the surface (the zeta potential) was changed from positive to negative; the surface became silica-like; and the magnesium was lost from the asbestos fibers on exposure to water and acid. The smaller the fiber diameter, the faster the loss of the magnesium. Notable among the changes in physical properties is a change in the refractive index. Asbestos exposed to acids or water may not be detectable using the dispersion staining techniques that identify asbestos based on the refractive index. Other physical property changes include the destruction of the gross crystallinity of the fibers. The x-ray diffraction signal disappears when fibers are exposed to acid. The fibers may still be detected by electron diffraction. Upon acid exposure, the magnesium ions are leached out, leaving a magnesium-free silica network. A positive ion, possibly the proton or the hydronium ion, replaces the lost magnesium ion. 20 references, 11 figures, 2 tables.

• Research Organization: Univ. of Arizona, Tucson
• OSTI ID: 5260554
• Journal Information: Environ. Health Perspect.; (United States), Journal Name: Environ. Health Perspect.; (United States) Vol. 53; ISSN EVHPA
• Country of Publication: United States
• Language: English

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63 RADIATION, THERMAL, AND OTHER ENVIRON. POLLUTANT EFFECTS ON LIVING ORGS. AND BIOL. MAT.
ALKALINE EARTH METALS
ASBESTOS
CHEMICAL COMPOSITION
CHEMICAL REACTIONS
COHERENT SCATTERING
DIFFRACTION
DISSOLUTION
ELEMENTS
HYDROGEN COMPOUNDS
INORGANIC ACIDS
LEACHING
MAGNESIUM
METALS
OPTICAL PROPERTIES
PHYSICAL PROPERTIES
POTENTIALS
REFRACTIVITY
SCATTERING
SEPARATION PROCESSES
SURFACE POTENTIAL
X-RAY DIFFRACTION