Document X7nQbnjq1ZoaapK3J1px6Xm9g

stats Mining Snglneer, Mines Department, PERTH KAlOOORUB 2od fereaber, 1991. Aobootom Be*d - Tittoaaom Qayaa Za reply to year latter 818/51. Zt la of latereet te knew that the upper peruieeeble Halt of asbestos duet for a working ataoapbere la 178 p.p.o.e. Zt baa baaa understood tbat tba peruieeeble Halt of elllea duet for a working atmosphere la 500 p.p.o.e. Z <t* -- that tbla llmt atlil holda. Aa average of tba eaapleo taken both la tba traataeat plant aad underground giree a duet count of 507 p.p.o.e. which la juet over tba peralesable Halt. If tbe partlelce are all .silica. Tbla high count aay be accounted for by tba feet tbat ventilating eppliaaeee were not belag oorraetly seed aad tbat broken ore see not belag watered. . By report etatee. *0a examination of tbe duat eaaslee, both froa underground aad tba treetaent plant, tba aaount of flbra risible la wary anall. Sons sables appear to bare no fibre preaeat, and aa eetlaate of tba flbra treeeat in tba air would bo vary difficult to nako.* X paid particular attention to the eeuplaa eraulnod la order to arrlra at aa eetlaate of tbo aaount of fibre preaeat. but ease to tba uaaalnaloatbat tba greater proportion of the partidee were elHoe. Bjwever, &r. Heasell atataa tbat saay long flbrau aay bare baaa excluded froa tba count boonuaa of their raluetaaaa to enter a aachine of tba Vataoa Eoalaeter typo. Tbla aay account for tba abeeaoe of fibre la tbe aaaplee, but It mold be adrlaablo to taka a anker of easplee of the air, aadargreuad aad la tba plant, to detoraiae tba percentage of flbra preaeat. Zt aay be possible to aake tbla aaapl* by aoaaa of tba auger tuba teat or a tuba packed altb cotton wool. (Tbo do manat Aealyiat abeuld bo able to adrlao oa tbla aattar. ) Or peeelbly tba filter fapar eanpler aa aead far Alonlnlaa powder coaeentratloa. could bo uaod for tbla purpose. A aaapla of tba air could b# drawn through tbo Sample* end tbe fibre aad duat retained oa tbo filter piper which could be submitted for analyela. There le certainly little, if any, boring dona la tba fibrous aaterial, but after the face baa been fired aad begging and scraping operations are la progreea mob fibrous aeteriel could enter the ventilation systea. The enforcement of tbe uee of plenty of water in the mine and the conaeouent need for a fibre-drying proeeeo in the trsstneot plant is an urgent necessity. ASSZSTAIP CTILATIOg IgPBCTOR OT HS,