Document 0gVB17Rr22wL8K8JxemDxM88J

c collected In water but loioi studiea^^ have shown that counto of implnger sam- y'pies of asbestos dust tr.kon In water aro not reliable. Ethyl alcohol instoad of in all subsequent experiments. water was ueod aa tho collootlr.g fluid xcosaisxxjuiuctxucpm-i^ Results of tho investigation, briefly summarised In table 4, show that in halation of King's floatu asbestos dust produced a typical peribronchiolar fibro sis In guinea pigs but not in rabbits or rats. Ronotlon in Korcal Guinea Pigs. Guinea pigs inhaling this dust for porloda up to 33 months developed a characteristic fibrosis occurring in conical patohoa about tho reapirntory bronchioles. During this exposure the peripheral alveoli wore not involved. Tho particulato oloments In the dust wore transported through tho lymphatic system to tho bronchial nodes, causing no significant roaotion in aithor alto; tho fibroua elements remained fixod at tho points of original looaliiation and woro seldom dotoctod in the lymph nodes. Aftor expoauro of approximately a yoar, a small amount of collular reaction had been produced about many respiratory branohioles (fig. 4). Aa more duct was inhalod. It continued to accumulate In the s&mo location and lator stageo of tho disosflo (fig. 6) oonaistod of extensions of tho original losions. Apparently, tho inhaled fibers woro oeught In tho pocket-like alveoli that are given off from tho lateral walls of tho respiratory bronchioles. There they woro phagocytirod and many of thorn wore oarrlod into tho wall by migratory colls. Uononucloar louccoytoo attracted to tho aroa caused an appreciable thiokening of the bronchiolnr wall. Aftor / 10. Fulton, Ifl.D., Ilouts, R.L., Dooley, A. and Uathowa, J.L.t Asboetocis. Part I. Tho Collection and Counting of Asbestos Dust. Spoo. Bull. 37, Penn. Dopt. of Labor and Industry, 1934. -10- L