Document 2NQMZEd3z6jb1GabbvEK5KYyR

V.)U lul xarylhn' .scnce, In the lung m' hi wlutt >>r>|ntt.tun of the iMrtIUe* in the residue* wore In fct recognir.abli'a* fiber*. ' a---------------------- . .variety nd tried'.; *Uered chrysolite', [ -'iSr , desttie end Knot;,; (/lands. und pleur* bryiotlle. for pro!' _ <l, non*. miftlm^.if Several year* Ago a preliminary study had been made in the Safety in Mines Research Establishment of the dust in the lungs of tome 20 case* of ssbantonis. Most of the lungs had been supplied by K. "M. McGowan of the London Pneumoconiosis Medical Panel, other* by the Pneumoconiosis Research Unit In Cardiff. The grade of aabestosis had been assessed as minimal, moderate, or severe by the pathologists concerned, using the cri teria given by Beattie and Knox (1961. p. 420). (eral dust obtained ' one-trnth norm*! as mg./gm. dried lit 'most case* whole lungs (right, left, or both) were available, and representative samples of one or both lung* were used for analysis. The umple* were minced, dried, and ground. Between 20 and SO gm. of dried ground lung were ashed at 380*0., and total silica and iron oxide were determined chemically on part of the ash. Another sample of ash wa* ex tracted with 0.1 N hydrochloric acid, washed with water, and dried to give t> Knox (10G1) s mineral residue for examination by light and electron microscopy and X-ray diffraction. tetteals Tbe object of the acid treatment was to remove endogenous lung salts S* completely as possible and at the same time to attack the asbestos a* oderate Severs' little as possible. Experiments with a fine chrysotile sample from Southern e u -<b 'tft: 6.9 j. ``U ' | Rhodesia (previously used by Smith cf of., 1981 and referred to a* 26 p ample), and with normal lung ash, were' made with different buffers snd : hydrochloric acid at different concentrations, and 0.1 N hydrochloric acid was Anally used as s compromise. It leftabout 20 per cent of the ash from % -/ * ' i.. .. Vhich are auA^f fj.it average, luaf" lie lung* with (period betw**|a; |sd dust aecumcj b :.' PRODUCED RY poo n