Document 9jZQ26qK1nEEX9N7j7wRn9D7

/7ZS C f JUcS/MJ Dr. 3. Gaaderiav Associate Professor in Thoracic Hedicine, University of Hew South Wales, The Prince Henry Hospital, 2nd September, 1965 LITTLE BAY. ff.S.V. Dear Bryan, Thank you for your letter* The party's appreciation of the Tltteaoaa trip was ample reward for whatever effort went into the organis ation and the opportunity to discuss the occupational * health problen was a welcoae bonus* If I was perhaps too forthright, I apologise* I can only plead over-enthusiasm* I did not bother to ash you to add ay question to Janet Elder's paper but feel that some note should be taken of the fact that the so called atypical asbestosls X-rays and sections she showed are probably due to com plicated silicosis. I have. checked my information in regard to the rock formation at Wittenooa and conflated that there is a high quartz content in the ore* 1 sample collected underground near the main mine exhaust contained %,particles ranging up to 12 ap in size, average 1 ap, and the approximate composition was magnetite 7 hematite 33i chalybite dolomite 15^ quartz, 42,3, asbestos 3^- A sample collected near the mill exhaust system contained 22;4 quartz and 22 asbestos* The question was framed as follows : vi* aight any atypical X-ray and histological changes described be due to the associated high free silica content of the wittenooa ore, causing a mixed disease, silicosis/asbestosia? I don't think so* Careful examination revealed very l e~ doubly refruetile particles* Cent. 2 Dr. 3 G-andevia 2. the white asbestos mine I visited at Marble Bar was interesting. It '.?as fairly dusty and posed a fresh proolea on which I would appreciate your advice. The ore body in which the white asbestos is inter laced is mainly serpentine. It is a soft rock. Mechanical teeth which would wear out in a week at ffttteaooa last for years at this mine. There seems to be a certain amount of confusion geologically in regard to distinction between serpentine and chryaotile. However, for my purpose, the chrysotile is the fibrous asbestos and the serpentine la the soft rook which pulverises to dust and not to fibre. Is it safe to assume that the serpentine la safe and in dust sampling, counting fibres Is all that ie necessary? I know this is not exactly your field, but any help you could give will be greatly appreciated.- Don Letham would be very happy to have me spend some time in your unit* Unfortunately, it would be some time before I would be able to travel. In the meantime, I accept your offer gratefully and will keep in touch. Sind regards. fours sincerely, J. McHulty FHTSICIAJf OCCUPATIONAL H3ALTH ej