Document OZbavJbjznO9Y726Q4DLOvJe

OCT 11 2005 15:40 FR C.STI 1CIST 348 613 952 9303 TO 12145201181 P. 03/16 SCF-FA-6506 Chrysotile Asbestos in the Lungs of Persons in New York City Arthur M. Longer, PhD; Irving J, Setikoff, MD; and Antonio Sastre, New York , , i ( When inhaled, chrysolite tends to split into unit fibrils 200 to 400 Angstroms in diameter, invisible with optical microscopy. Further, it Is altered chemically and physically In vivo. Therefore, at* tempts to identity unaltered chrysotile in the core of "asbestos bodies" have many pitfalls, especially when such attempts are limited by optical mi croscopy. High-magnification electron-microscopic examination ol representative small samples of lung unequivocally showed chrysotile asbestos to be present in 24 of 28 consecutive New York city autopsy cases. Our data demonstrate that chrysotile fibers and fibrils are present in the lungs of New York city residents. Similar obser vations have been made in London. We antici pate that what is now known for New York and London will bo found In other cities as well. Asbestos Bodies: Their Nature and Occur rence.--Soon after the recognition of asbes toses, examination of lung tissue obtained from individuals with this disease demon strated the presence of coated fibers which were first termed "curious bodies"1*2 and, subsequently, "asbestos bodies."3 Since these first individuals had been heavily exposed to asbestos at their work, it was assumed, un doubtedly with good reason, that the central fibrous core of these unusual structures was asbestos. Submitted for publication May 22, 1970; accepted June 26. From the Environmental Sciences laboratory. Mount Sinai School of Medicine of the City Univer sity of New York. Reprint requests to Environmental Sciences Labor atory, Mount Sinai School of Medicine, Filth Ave and 100th St, New York 10P29 (Dr. Selikofl). When what appeared to be identical structures were next found in lungs of people not known to be occupationally exposed, the "asbestos-core" assumption was applied to these as well. It is of interest that the first descrip tion of such nonoccupational bodies in 1929 was made after examination of the lung tis sue of a person who had lived across the road from an asbestos plant.4 In recent years a number of investigations, starting with the Capetown study of Thom son et al,5 have demonstrated the presence of what appear to be "asbestos bodies" in the lungs (both in tissue sections and in ex pressed tissue fluid) of a large proportion of urban dwellers who had no recorded occupa tional exposure to asbestos. The percentage of instances in which they are found varies with the technique used in the investigation,6 the amount of lung tissue examined, and the diligence and persistence with which they are sought. The percentage of positive findings has been reported to be as high as 97%T or 100%.* The question whether the cores of the "asbestos bodies" observed in these nonoccupationally exposed individuals are neces sarily asbestos has been revived. Although "asbestos bodies" occurring in the general population appear morphologically identical to asbestos bodies observed in asbestos workers, this does not guarantee that they necessarily have the same core. For epidemiological studies it would be useful to have unequivo cal identification of the fibrous core. This has not been easily accomplished because of technical factors.10 | j i Arch Environ Health--Vol 22, March 1971 RECEIVED TIME OCT. 11. 2:43PM P-EXHIBIT-249 'a: as! lor esp do* tifi (" gk do* bo< scr "ft th< fib ha: the als tht asl fui in' fir rei mi tic un lo\ m; lir sir Ui ha SO' in< ex qr wt ui th W; ar to to as ta at aj si* lu e I