Document qkKrdbRXJRO1MxQB1q7yGOr6E

1 O I to the biosubstratum. In particular the adsorption and bonding or albumin on active centers (Benson, Castle, 1958). The major value of the surface conditions and Its activity can be Judged from the results of several series of our experiments with asbestos-bearing dust. The asbestos content In them varied from 20 to SOf. They all, however, were distinguished by the fact that the surface area of the fiber was more or less covered by any bonding agent: polycondensed Bakellte, vulcanized rubber, hydrated cement, magnesia and calcium carbonate. Such powders are formed during the machining of asbestos-Bakelite, asbestos-rubber, asbestos-cement and sovelite articles. All these powders revealed a very moderate fibrogenic nature In spite of the Increased hardness and acicular form of some of them and the Increased solubility of others. A. . -V-'" ` .v-. v -tOV - The hydroxyprollne content In animals Into which the dust of sovelite was Introduced (2200 yg.) Is substantially less than in those receiving a mechanical mixture of 85X magnesium carbonate and calcium and 15X chrysotile-asbestosi i.e., in the same pro- thls despite the fact that after 4 months the quantity of duBt of the' fibrogenic action of these artificial mixtures confirm i.'i Recently under our supervision "there was conducted ah -v; l6v?Btigati6n''of. the fibrogenic nature of faollte,' a material whichvV'-V'b; contains 60X anthophylllte, and as a bonding agent phenol- 7* 12 ft COO 0ft75 PRODUCED BY FORD