Document wEwbpagD1O1RqzOq7aeMbOE4

2/12/2003 WED 10:32 FAX 312 896 1899 UIC LBS CHICAGO @004 Table III. Test results try electron micrograph. Test Product Brand Method Presence No. of Conditions of Free Free Samples of Test-F Fibers Fiber* 1. Automablle A Friction drum brakes 6 500 - 800 Few <1 2. Automobile B Friction drum brakes 6 230 - 900 None 0 3. Automobile C Friction drum brakes B 300- 700 Few <1 4- Automobile C Friction drum 1 700 - 900 Numerous -10 brakes 5. Automobile D Friction S 300- 900 Few <1 drum Fiencb brakes 6. Automobile E Friction drum brakes S 300-700 Few cl 7. AufamobBe F. Friction s 300- 800 Few <1 i; drum German brakes 8. Automobile G Friction drum brakes 2 100-800 Few <1 9. AutomobPe G Friction drum brakes 1 600-700 Numerous --15 10. Automobile H drum brakes Friction 2 100-600 Few <1 U. Automobile J dutch Dynamometer 1 Normal None driving 0 12. Automobile K Dynamometer 1 Normal Few disk driving breko <5 15. Bus drum L Dynamometer X City None brake driving 0 M- Bus drum M Friction brake 2 480 - 350 None 0 16. Truck drum F Friction brake (light) 10 200 - 800 Few <1 Weight oitlmiM from fiber volume- Some independent experiment* done at b broke Siring research laboratory11 have shown that all of the magnesium present in the chtyaotile asbestos orig inally in the fining can be accounted tor in the deecunpoaitioA products. How ever, the characteristic X-ray difiraction pattern of chiysotile asbestos had vanished. Thus, it is apparent that under conditions in which asbestos is worn from the fining of a brake, the asbestos isdestroyed- Conclusion Only a very small proportion of the asbestos worn from brake finings is released as free fiber; the remainder is converted into same other mineral aa a result of the extreme temperatures gen erated at small spots on the lining sur face. Thus, although urban air con tains a fewfreefibers oa a result otbrake lining wear, they represent a very small 828 proportion of the total asbestos used in manufacture of brakes. Many sources of respirablo fibers not associated with asbestos products have been identi fied,11 and free fibers from brake fining wear seem to be an inconsequential health factor in urban air pollution. References 1. Cooper, W. O., "Asbestos as a haeaxd to health." Arch, tf Bna. Htahh. IS: 285(1987). 3.Thomson, J. CL, TTmafnila, R. 0. CL, and MnDonald, R. R.. "Asbestoafs as a modem urban haierd," & Afr. Mid. J. 37:77(1963). 3. Cauna, D., Totten, R. g., and Grow, P., "Asbestos bodies in human limn at autopsy," JAMA, 192 : 87J198G). 4. Webster, X, in (Sdousabo of Thomp son, 8. F., "Physiological effect of DiU in memmals," Aiuu N, Y. Acad, Set, 84:786 (I960). 5. Meurman. X, "Asbestos bodies and pleural plaques in a Finish aeries of autopsy eases," Ado Path MicnbicL Ucond Supply 181:107 (1966). 6. Aryilrel, L- end Thuribook. W.( 'The inadeaee of asbestos bodies us the Kings of randan autopsies In Montreal Canada. Med, Aooc. J., 93: 1)79 (I960). 7. Thomson, 3. G, "Asbestos and the ur ban dweller/' Ann. N. Y. Acad, So,, 132: )96 0965). 8. BeBkofl, I. J.,Churg, J, end Ham mond, E- 0~ "Asbestos expesww ad neoplasia,''.MMA, 188:220964). 9. Buell, P. and Sunn, J. JSL "Relative impact of umpiring wed bb paUntHU on lung eenoer," Aral, ofBus. Heauh, 15:291(1987). 10. Entwilne, P. E. and Kendrick, M. A-, "Asbestos dust exposures at vsnou* lends end mortality," And. * Htahh, 15:181 (1967). 11. gfaelair, D., "Study of wear dust from brakelining," Johna^AwvUlftBisiuul Eng Otr., personal communication (19B7). 12. Oraflqr, X1., Keenan, R. 0-, Lynch. J. K. end Lainhart, W. 8., `ouro* and identiftoattan af respirable nbert, Amer. Ind. Hyg. Assoc. J., 29: 129 noftftl Journal of the Air Pollution Control Aseoristlon I 3