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Aqueous Surface Chemistry of Asbestos Minerals.

PB90100942

Publication Date	1973
Personal Author	Smith, R. W.
Page Count	20
Abstract	Physicochemical study of the manner in which hydroxyl and other ions leave the surfaces of asbestos minerals as a function of aging time in water is presented. In relatively pure water systems a parallelism is noted between magnesium dissolution and pH change for all asbestos minerals studied. The magnesium and hydroxyl dissolution reactions are diffusion controlled. Silica is more readily dissolved from crocidolite than from either chrysotile or amosite. Electrokinetic work shows that chrysotile placed in water initially has a surface approaching that of pure magnesium hydroxide, but after long aging in water the surface approaches that of nonasbestiform serpentine. Attempts made to relate pretreatment of asbestos fibers to carcinogenicity and fibrogenicity indicate that chrysotile appears more likely to induce tumors in rats than acid-treated chrysotile or other asbestos minerals.
Keywords	Surface chemistry Asbestos Minerals Physicochemical properties Electrokinetics Grants Water Adsorption Electron microscopy pH Laboratory animals Ions Silicon dioxide Magnesium hydroxides Dissolution Reaction kinetics Carcinogens Occupational safety and health Aqueous solutions Hydroxyl radicals
Source Agency	National Institute for Occupational Safety and Health
NTIS Subject Category	99F - Physical & Theoretical Chemistry 68G - Environmental Health & Safety 57U - Public Health & Industrial Medicine
Corporate Authors	Nevada Univ., Reno.; National Inst. for Occupational Safety and Health, Cincinnati, OH.
Supplemental Notes	Sponsored by National Inst. for Occupational Safety and Health, Cincinnati, OH.
Document Type	Technical Report
Title Note	Progress rept. (Final) 1 Sep 69-28 Apr 73.
NTIS Issue Number	199002

Aqueous Surface Chemistry of Asbestos Minerals.

Aqueous Surface Chemistry of Asbestos Minerals.
PB90100942

Publication Date	1973
Personal Author	Smith, R. W.
Page Count	20
Abstract	Physicochemical study of the manner in which hydroxyl and other ions leave the surfaces of asbestos minerals as a function of aging time in water is presented. In relatively pure water systems a parallelism is noted between magnesium dissolution and pH change for all asbestos minerals studied. The magnesium and hydroxyl dissolution reactions are diffusion controlled. Silica is more readily dissolved from crocidolite than from either chrysotile or amosite. Electrokinetic work shows that chrysotile placed in water initially has a surface approaching that of pure magnesium hydroxide, but after long aging in water the surface approaches that of nonasbestiform serpentine. Attempts made to relate pretreatment of asbestos fibers to carcinogenicity and fibrogenicity indicate that chrysotile appears more likely to induce tumors in rats than acid-treated chrysotile or other asbestos minerals.
Keywords	Surface chemistry Asbestos Minerals Physicochemical properties Electrokinetics Grants Water Adsorption Electron microscopy pH Laboratory animals Ions Silicon dioxide Magnesium hydroxides Dissolution Reaction kinetics Carcinogens Occupational safety and health Aqueous solutions Hydroxyl radicals
Source Agency	National Institute for Occupational Safety and Health
NTIS Subject Category	99F - Physical & Theoretical Chemistry 68G - Environmental Health & Safety 57U - Public Health & Industrial Medicine
Corporate Authors	Nevada Univ., Reno.; National Inst. for Occupational Safety and Health, Cincinnati, OH.
Supplemental Notes	Sponsored by National Inst. for Occupational Safety and Health, Cincinnati, OH.
Document Type	Technical Report
Title Note	Progress rept. (Final) 1 Sep 69-28 Apr 73.
NTIS Issue Number	199002