Document 29JK71ynwGM1y0v59rrkjrLN

M. JbMunr mlS--'WSeiiYs 576 ASBESTOS VERSUS NONASBESTOS FIBERS-i-GROSS ET Ah 1 I ASBESTOS VERi or ferruginous bodies isolated f urban dwellers in sufficient nur. statistically significant data. Although identification of th< of ferruginous bodies and of has been accomplished by fraction1 and electron micro sis,11 these techniques are L time consuming. Furthermore, scale investigation necessary t tisticaliy reliable data, extensi above techniques could prove expensive, since it would tend f the costly equipment involved of trained technicians. Also, the need exists for a r would facilitate acquisition data rapidly and economically, mention suggests a means to needs. A procedure, essentiollj method, is described for class fibers and the central filamen nous bodies into asbestos or fibers. The cores of ferruginoi made accessible' for such cla< freeing them from the encru* nous shell by chemical or physi either with oxalic acid or ultr tions. Materials and Meth na 5.--Two psfstlet gists flbsn In opposition which show onesttp profile: P^uejty width of uninterrupted rsctlllneer of eurvillnMr profile Indicate* honssbesto* fiber (x 20.000). 1 Arch Environ Health--Vol SO, May: 7970 The classification of inhaled : from lungs19 is based on the fact fibers are composed of compactly fibrils, whereas nonasbestos fiber neous units. Because of this diffe: lure, the fractured ends of these fibers differ in a very important of on asbestos fiber is irregular : that of a bundle of fragile sticks * broken transversely. As might be fertnt fibers of the bundle break iilTerent points. At an appro) Oration, therefore, (as describee electron microscopy) the froctu ents an irregular profile with r like projections and depressions steps being shallow and others de contrast, inhaled transparent fits asbestos but of similar diameter a homogenous in character, and. b< la fracture so as to present unin tar profiles at the fractured ends Another important difference haled asbestos anti nona*l>e*ti*s i 8600 6437 Arch _JL PRODUCED BY FOtm