Document bajN2w0RZrVDYavNej52GN9j0

American Journal of Industrial Medicine 19:701-704 (1991) RESEARCH ARTICLES Translocation of Inhaled Asbestos Fibers From the Lung to Other Tissues Y. Suzuki, mo, and N. Kohyama, PhD To Investigate translocation of asbestos fibers, tissue samples from 13 North American insulators were examined, using electron microscopy. Of the two major types of asbes tos, chrysotile and amosite, chrysolite was found to be much more active in the trans location than amosite, being the fiber mainly detected in mesotheliomas and hyaline plaques. Key words: chrysotile, amosite, tang tissue borden, mesolhcttonta, hyattne ptaqUcs INTRODUCTION Asbestos Fibers are known to be durable and not easily digested or dissolved after being inhaled into the lung. Some are cleared from tire lung {Wagner et al., I974J; this clearance is greater for chrysotile than for amphiboles. The fate of asbestos fibers cleared from the lung has nol been completely explored. If they are totally cleared to outside the host's body, the risk of asbestosrelated diseases will be correspondingly low although initial cellular and nuclear changes might have long-term consequences. However, such an optimistic assump tion may not be entirely .warranted, since translocation of intrapulmonaty asbestos Fibers (particularly chrysotile) from the lung into the parietal pleura has been indicated by the tissue burden studies of LcBouffant et al. [1973] and Sdbastien et al. [1980]. Numerous short chtysotile fibers were found in pleural hyaline plaques in the former, and the latter detected asbestos fibers in both the lung and the fibrotic parietal pleura in a patient with asbestosis who had been exposed to both chrysotile and amphiboles. Long amphibole fibers predominated in the lung, while short chrysotile fibers were seen exclusively in the fibrotic parietal pleura. We have also seen asbestos fibers in "Zuckerguss" (a type of peritoneal fibro sis, histologically identical to hyaline plaque) of the hepatic and splenic capsules obtained from people who had been occupationally exposed to both chrysotile and Division of Environmental and Occupational Medicine, Mount Sinai School of Medicine of the Citv University of New York (Y.S.). New York. National Institute of Industrial Health, Ministry of Labor, Kawasaki, Japan (N.K.). Address reprint requests to Dr. Yasunosuke Suzuki, Division of Environmental and Occupational Med icine, Mount Sinai School of Medicine, 1 Gustave L. Levy Place, Bo* 1037, New York NY 10029 6574. ' Accepted for publication September 24, 1990. t- s ) v 702 Suzuki and Kohyama TABLE I, Demographic and Pathological Feature) in a Study of 13 North American Albertos Insulation Worker! '" ' Asbestos exposure Case no. Age a( death Sex Smoking history* Age and year of onset Duration*' n. ' JDiagnosis6 Pathological features* i 67 M Ho data 25 C4I) 42 Asb IF (s) 2 54 M No data 21 ('52) 34 Asb IF (m) 3 58 M 40 PY 21 ('47) 37 Asb IF <m). PC 4 63 M 100 PY 20 ('39) 44 Ash + LC IF (s). Sc-C 5 62 M 15 PY 20 ('43) 4t Asb + LC IF (s), Ad-C 6 70 M 25 PY 31 C40) 40 Asb + LC IF (s). Lc-C 7 52 M No data 18 ('43) 34 PI. Meso IF (n) 8 67 M No data 24 ('39) 44 Pt. Meso 1F(!) 9 55 M Ex-smoker 27 ('48) 29 Pe. Mcso IF (m) 10 56 M 35 PY 24 ('50) 32 Pe. Mcso IF (s) 11 62 M No data 24 ('36) 38 Pc. Meso IF (s) 12 7! M Non-smoker 18 ('30) 53 Pc. Meso IF (m) 13 45 M 40 PY 19 ('54) 27 Pe. Meso IF (s) *PY. pack years. kYean from first exposure to death. cAsb, asbestosis; LC. lung cancer, PI. pleura; Pe. peritoneum; Mtio. mesothelioma. rfIF, interstitial fibrosis; (s), severe; (m), moderate, in), none; PC, pancreas cancer, Lc-C, large cell carcinoma; Sc-C, small cell carcinoma. amphibole asbestos (unpublished data). The asbestos fibers detected in "Zuckerguss" were overwhelmingly chrysotile. Questions have been raised as to whether the translbcation of inhaled asbestos fibers from the lung to the pleura and/or the peritoneum occurs commonly and whether chrysotile has a strong potential to translocate into these serosal tissues from the lung. MATERIALS AND METHODS To explore the problem, we have compared the type, number, and size distri bution of asbestos fibers in lung parenchyma with those of fibers in tissues other than the lung parenchyma, such as lung cancer tissue (the primary site of bronchogenic carcinoma), fibrotic parietal pleura (mainly hyaline plaques), neoplastic pleura (the primary site of malignant pleural mesothelioma), and neoplastic peritoneum (malig nant peritonca`1 mesothelioma). This is a preliminary report of (he study; additional details will be reported (Kohyama and Suzuki, 1991]. Tissues were collected from 13 North American insulation workers. These 13 cases included three of asbestosis, three of lung cancer, two malignant pleural me sotheliomas, and five malignant peritoneal mesotheliomas. Table l shows age, sex, smoking history, history of exposure to asbestos, classification of the disease, and histopathologic findings. North American insulators are known to have been occu pationally exposed to an admixture of chrysotile (mainly Canadian) and amosite (South African) [Selikoff ct a!., 1979]. It was noteworthy that, histologically, pulmonary asbestosis was seen in all but a single case (case 7; pleural mesothelioma). Translocatfon of Asbestos Fibers 703 Characterization of the asbestos was accomplished using analytical electron microscopy of digested bulk tissues obtained from various sites, such as the lung, pleura, and peritoneum, as described above. RESULTS Chrysotile (15-196 x 10s/g dry lung; 63.1 x lO'Vg dry lung mean value) and amosite (7.27-415 X 10s; 150.2 x 106 mean value) were the major asbestos types seen in the lung parenchyma of all 13 cases. Amphiboles other than amosite were also seen in the lung; crocidolite fibers were,seen in the lung of 7 of the 13 cases but the numbers were much smaller (1.28-86.4 x 10s; 11.4 x 10s mean value) than either chrysotile and amosite. A small number of anthopbyllite fibers (2.83-3.50 X lO'Vg dry lung; 1.86 x 10s mean value) were identified in 3 of the 13 cases. A small number of tremolite or actinolite fibers were also seen in another three (3-11.3 x 10s; 2.45 x 10s mean value). ' The proportion of asbestos types seen in either the pleural tissue (hyaline plaques or primary pleural mesothelioma tissue) or peritoneal tissue (the primary peritoneal mesothelioma tissue) was very different from that seen in the lung. In the pleural tissue, (IJjamples from 10 cases: 10 samples of hyaline plaques and-l-ofthe-------- primary_plw.raLrnesothelioma) ,-the number ofintrapleui al aingsheflbets-fdry weight)------waTdramaticallv less (0-6.81--X. 10s; 2.18..X. 10-/g,.mean.value) than the intra-___ plcutai chrysotile (12.1--89.7 x 10s; 46.3 x 10*/g, mean value). In thcjreritoneal tissueTsixiampies_from.f3v.e.peritoi)eal.mesothelioma.tissues)..amosite.xvaZo^Tl4.2: x' 10s f3.05 x 10s mean value) and chrysotile was 12.5-89.6 x 10- (37.9 x 10s. mean value). Unlike in the lung parenchyma, amphiboles other than amosite (croc- idolite, anthophyllite, tremolite, and actinolite) were not detected in either the pleural or peritoneal tissues. DISCUSSION These findings,indicate; th,atjJ).inhaled.asbestos fibers were translocated from the luffgTmo the pleura and the peritoneum; and 21 the mreri?iSri7Tr-nan<ii;U.!.rw^ different for cbtysotile and amphibole asbestos fibers,_chrvsntilp. canity greater ferjitehLlo translocate'.~combired with amnsiir~ ' The size distribution (length and width) of the detected asbestos fibers was compared among three sites; lung (non-neoplastic lung parenchyma and the primary site of lung cancer); parietal pleura (hyaline plaques); and peritoneum (peritoneal mesothelioma tissue) in three cases (a lung cancer, a pleural mesothelioma, and a peritoneal mesothelioma). No significant differences of the size distribution of as bestos fibers were seen in the three tissues. ' It was noteworthy that long (> 50 p.m), and thick, (> 0.25 p.m) asbestos fibers were rare in the lung, suggesting that such fibers do not easily reach the lung paren- . chyma through the respiratory tract. " CONCLUSIONS The present study has led us to the following conclusions: 1) translocation of inhaled asbestos fibers from the lung to other organs, such as the pleura and the ti, seemed to occur frequently among asbestos insulation workers, although IV 704 Suzuki and Kohyama American Journal of Industrial Medicine 19:705-713 (1991) the route of the translocation has not been completely investigated; 2) in insulation workers (occupationally exposed to asbestos, mainly chrysotile and amosile), chrysolile seemed to be more actively cleared from the lung and translocated into extra pulmonary tissues, compared with amosite; 3J ehrvsjtilc fibers cleaned from the luna were not later eliminated from.the.host.-BiologicaLeffects lnf[~lhe7rn'sTncatarf 'asbesrorfl^rs-mav lw~significant and translocated chrysotile fibers may play an important rqlc-m'TKe-imfacU'nn ni ppher .malignant, mesothelioma anH/nr hyaline ~~ -plaqqesrlhe^asbcstos fibers delected in.bpth.were mainly chrysotile. ACKNOWLEDGMENTS Tumors of the Urinary Bladder in Painters: A Case-Control Study Zdislaw W. Myslak, md, Hermann M. Bolt, mo, PhD, and Wlnfrled Brockmann, PhD Wc thank Dr. Irving J. Seilikoff for providing the material. The assistance of Richard Ashley, Anna Calderaro, and Steven R. Yuen is gratefully acknowledged. REFERENCES Kohyama N, Suzuki Y (1991): Asbestos analysis in lung parenchyma, pleural plaque and mesothelioma tissues of North American insulation workers. In press. LcBouffant L, Martin JC, Duyif S. Daniel it (197.1): Structure and composition of pleural plaques. In Bogovski P, Gilson JC, Timbrell V, Wagner JC (cds): `'Biological Effects of Asbestos". Lyon, France: IARC Sci. Publ. No. 8:249-257. Sdbasticn P, Janson X. Gaudichct A. Hirsch A, Bignon J U980): Asbestos retention in human respiratory (issues: comparative measurements in lung parenchyma and in parietal pleura. In Wagner JC ted): "Biological Effecls of Mineral Fibers 1". Lyon, France: IARC Set. Pub!. No. 30:237-246. Selikoff U, Hammond EC, Scidman ft (1979): Mortality experience of insulation workers in the United States and Canada, 1943-1976. Ann NY Acad Sci 330:91-116. Wagner JC, Berry G, Skidmore JW. Timbrell V (1974): The effects of the inhalation of asbestos in rats. BrJ Cancer 29:252-269. In a casc-control study, 403 male patients with a diagnosis of "bladder tumor" and (as controls) 426 patients suffering from prostate disease were investigated. The results of this study indicate that past employment as a painter was associated with an excess risk of bladder tumor. The relative risk of bladder tumor estimated for painters was 2.76. The possible role of benzidine-based azodyes (or azodyes based on substituted benzidines) is a carcinogenic risk factor for painters is discussed. Key worth: aromatic amines, azo dyes, occupational bladder tumors INTRODUCTION Some characteristic case observations of bladder cancer in painters {Bolt and Myslak, 1985] have attracted our attention to the occupational causes of this disease. These cases, in connection with material published in the literature and suggesting an increased risk of bladder tumors in painters, have led us to perforin an epidemiolog ical study into this problem. The study reported here is a case-control study on patients treated in the urological departments of hospitals in Dortmund, Germany. Interim results of (his study have previously been presented at annual meetings of the German Society of Occupational Medicine (Myslak et a!., 1987; Myslak and Bolt, 1988a}. t MATERIALS AND METHODS The study was carried out in the East Ruhr Area, a major industrial area of Germany. The cases, treated in the period 1984-1987 for urological tumors, included .403 patients of urological departments of three major hospitals in the city of Dort mund; 290 with a diagnosis of bladder carcinoma and 113 with that of bladder Instilui fik ArbcUsphysiologle at the University of Dortmund. Dortmund* Federal Republic of Germany. Winfricd Brockmann's present address is the Fachbochsehule Dortmund. Dortmund, Federal Republic of Germany. Address reprint requests to Dr. Hermann M. Bolt, lnslilut fdr Arbcitsphysiologre. Ardcystrassc 67. 4600 Dortmund I, Federal Republic of Germany. Accepted for publication October 10, 1990.