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FILE NAME: Hercules Chemical (HERC) DATE: 0000 DOC#: HERC012 DOCUMENT DESCRIPTION: Journal Article - Pleural Plaques and Asbestos Further Observations on Endemic and Other Nonoccupational Asbestosis 234 Annals New York Academy of Sciences 8. Hall, A. L. 1930. Asbestos in the Union of South Africa. Geological Sn Memoir No. 12. Union of South Africa, Department of Mines am! dustries. Pretoria, South Africa. 9. South African Council for Scientific and I ndustrial Research. P moconiosis Research Unit. 1964. Field Survey in the North Western ( and in the Transvaal (Asbestosis and Mesothelioma). Report No. i Pneumoconiosis Research Unit. Johannesburg, South Africa. 10. McCaughey, W. T. E., O. L. Wade & P. C. E i.mes. 1962. Exposure bestos dust and diffuse pleural mesotheliomas. Brit. Med. J. 2: 139T. 11. Selikoff, I. J., J. Churg & E. C. Hammond. 1964. Asbestos exposure neoplasia. J. Am. Med. Assoc. 188: 22. 12. E nticknap, J. B. & W. J. Smither. 1964. Peritoneal tumours in asb<-.-". Brit. J. Ind. Med. 21:20. 13. Hourihane, D. O'B. 1964. The pathology of mesotheliomata and an are of their association with asbestos exposure. Thorax 19: 268. t PLEURAL PLAQUES AND ASBESTOS: i FURTHER OBSERVATIONS ON ENDEMIC AND OTHER NONOCCUPATIONAL ASBESTOSIS Raimo Kiviluoto j Tam pere Central Hospital, Tampere, F inland i Association betw een exposure to asbestos and neoplasia, increasing world production of asb esto s and the possibility of en v iro n m en tal an d other, nonoccupational exposure to asbestos, have caused an increased in te re st of m edicine in th is m ineral. In th is connection, asbestos m ay g a in con siderable fam e as a new discovery. However, it had th a t thousands of years ago. About 4500 years ago, asbestos was generally used in F inland as a cem enting a g e n t in th e p re p a ra tio n of clay p o tte ry . A sbestps ceram ics, according to archo lo g ie finds a F in n ish inv en tio n, w as usejd d u r in g a period of 3000 year's. A pproxim ately 500 A.D. th e use of asbestos ceram ics in F inland and its n e ig h b o rin g co u n tries slowly ceased to be reu sed first about 1,000 years la te r.1 T housands of years ago, asbestos was in everyday use by fam ilies a n d consequently th e Stone A ge m en " geologically" well knew w here asbestos could be obtained. Anthophyllite-asbestos is a fairly common m ineral in Finland and trem olite-asbestos is especially ch aracteristic of the K arelian fo rm atio n s in Northern Karelia. A nthophyllite has been mined since 1918, the annual output being around 15,000 m etric tons. N ear two open asbestos mines several hundred cases of pleural calcifica tion w ere found in people not employed in the m in in g industry.'- C o rre sponding observations have been reported in E ast Germany."-4 P leural plaques, as described in these reports, were sim ilar to those jcharacteristically seen in a sb e sto s w orkers. R egardless of th e ty p e oi' d eg ree of pulmonary reaction or fibrosis, these cases may be called cases of endem ic asbestos is, until a b e tte r specification is found (p leu ral asb esto sis ? ). P ulm onary Fibrosis in Endemic Asbestosis The m ajority of endem ic cases of pleural calcification showed no sub jective symptoms of a resp irato ry distress. Slight pulm onary fibrosis was lu"AciU n lvf rgru iiri)nu liAo rgriirctoa i1iLjr urlwncfun<r_ fi .<1a Kw ii nu ji,xnx aoukuou ni <f 1 .~Ax AVI cAunn i of n-P x1uCuA oncot oocnircej . TxVnca ca vitao Ii u u oa - tion in vivo of the d eg ree of fibrotic changes and th e ir possible connection to asbestos d u st is v e ry complex and difficult. As a re s u lt o f pathologic lung changes, the h e a rt also may be affected. To study this, the follow ing comparison was d ra w n : A roentgenologic volume m e a su re m e n t(o f th e h e a rt was made in 130 p le u ra l plaque cases by u sin g th re e rig h t-a n g le d h e a rt diameters, two horizontal and one sagittal. Control m aterial was g athered by tak in g the cases n e a re s t to the plaque cases in th e ro en tg eji file. T hus, 235 236 Annals New York Academy of Sciences the age distribution in both groups autom atically was sim ilar, since the files are kept according to th e b ir th n u m b e r (y e a r, m onth, day) and the control m aterial was purely incidental. H e a rt volum ina of the plaque group were 18 per cent g re a te r th a n th o se of th e controls. In a group of 38 plaque cases and 23 control cases, pulm onary function tests were performed. H ere only th e vital and diffusing capacities are taken into consideration. The diffusing capacity m easured by CO-method using rebreathing technique, was pathologically decreased in nine cases of the m aterial and two cases of the control. S ta tistic a lly the difference is insig nificant. The mean vital capacity was 3600 in the m aterial and 4000 in the control series. The reduction in vital capacity was statistically significant at 95 per cent level (analysis of v arian cy , F = 4 .7 6 ). Because reduction in vital capacity m ay occur in m any diseases and re garding to the statistical insignificancy of th e difference in diffusing ca pacity, positive conclusions are im possible. In endemic asbestosis, the possibility of pulmonary fibrosis m ust nevertheless still be taken into account. Pulmonary and Pleural Neoplasia and A sbestos in N orthern Karelia Pulmonary and pleural neoplasia occur in a high percentage among asbestos workers, as is already well know n. A close relationship has even been stated between environm ental exposure to asbestos and pleural mesotheliomas. Two hundred and sixteen cases of histologically proven lung carcinoma, found during 1958-61 in the C entral H ospital of N o rth ern K arelia, were used as a m aterial for studying the asbestos-neoplasia problem. The areal distribution of all 216 cases did not show a h ig h er incidence round the two asbestos mines, but corresponded to th e areal distribution of pulmon ary tuberculosis and cardiac insufficiency. Coincidence of endemic asbes tosis and pulm onary carcinom a w as observed in 21 cases. A comparison between the la tte r m entioned an d c a rc in o m a ta w ith o u t asbestosis, as to the site of the tum or (u p p er or lower lo b e), w as draw n. In 67 advanced cases locating the tum or was not possible because of diagnostical d if ficulties. The tum or site in coincidental cases was on rig h t 7 upper 6 lower lobe and on left 2 u p p e r/3 low er lobe, an d in o th e r cases 48 u p p e r/21 lower lobe on rig h t a.nd 43 u p p e r/1 9 low er lobe on left. Four esses occurred w ith a tumor penetrating the thoracic wall. These showed signs of endemic asbestosis. During 1959-62, the C entral H ospital paid special attention to the pos sible occurrence of pleural mesotheliom a. However, only one case was recorded. Prelim inary clinical diagnosis was cholecystitis and chest roent genogram showed pleurisy on rig h t. A fte r an tib io tic therapy without success and increase of rig h t chest pain, pleural tum or was suspected. Kiviluoto: Pleural Plaques and Asbestos 237 Thoracotomy revealed tum or infiltration in the basal pleura and histology proved a pleural mesothelioma. Lifelong environm ental asbestos exposure occurred in this case. Compared to the high incidence of benign pleural lesions .or plaques among population environm entally exposed to asbestos, pulm onary and pleural neoplasia are rare. Especially the vague areal distribution of pul m onary carcinoma in N orthern K arelia counteracts a positive! conclusion concerning causal relationship betw een endemic and pulm onary carcinoma. It should also be noted, th a t in th e series o f 216 cases th e d istrib u tio n by sex was 216 male, 0 fem ale. No explanation fo r th is was detectable. Cases of Pleural Plaques F ound in Central Finland ' A m ong 35,000 ro u tin e ch est ro e n tg e n e x am in atio n s d u rin g 18 m onths in 1963-64, 77 cases of p leu ral plaques w ere fou n d . R oentgenologically th ese were sim ilar to those seen in endem ic asbestosis. Of the 77 cases, 68 w ere questioned concerning a possible occupational or other exposure to asbes tos an d mixed dusts. T he re su lts a re p re se n te d in table 1, also show ing the occurrence of roentgenologically detectable pulm onary fibrosis in these cases. In cases w ithout any detectable exposure to dusts, pulm onary changes were slight or absent, and the p atien ts showed no subjective symptoms of respiratory distress, w hereas e.g. th e bricklayers had various degrees of dyspnea and showed roentgenologically definite pulm onary fibrosis associ ated w ith local em physem atous a re a s . In m ost cases w ith pulm onary fi brosis, visceral pleural adhesions, directed from the plaque to the lung, were discernible especially using fluoroscopically aimed various oblique projections. This phenomenon was not found in plaque cases w ithout pul m onary fibrosis. T he discovery of an asbestos d u s t ex p o su re in case h isto ry isi o ften very difficult. A 50-year old wom an h ad been tre a te d over a periocj of several years for an unspecific dyspnea. T he clinical diagnoses werej asthm a or cardiac insufficiency. The p atien t show ed typical bilateral pleliral calcifi cation. However, she denied any possibility of asbestos exposure or even having ever visited the m ining area. Two years later the patient came upon the following inform ation. As a five-year old child she had spent th ree months in the immediate vicinity of the asbestos mill. As many others, she had used bunches of asbestos fibers as a playing m aterial. W ith the basis of previous observations on endemic asbestosis; in E astern Finland and fu rth e r exam inations concerning the severity arid duration of exposure, it can be noted, th a t th e plaques develop very slowly. It seems ap p are n t th a t even v ery s lig h t ex p o su re over a sh o rt p e rio d 1m ay cause pleural changes many years or even decades later. The problem presented by the tim e factor, very different to th a t seen in occupational constant expo- i 238 Annals Mew York Academy of Sciences T able 1 Particulars Concerning 77 Cases of P leural P laques F ound in 35,0(m> Routine Chest Roentgen E xaminations at T ampere Central Hospitai. during 18 Months in 1963-64 O ccu p ation N um ber of cases R oentgenological evidence of pulm onary fib rosis N orm al or very sligh t fib rosis E xp osu re Jricklayers 8 6 iuilding 7 2 w orkm en 'actory w orkers, 20 6 etc. 2 In te r m itte n t e x p o s u r e to m ix e d d u sts containi:-.,: 5 a sb esto s. V ery slight exposure t 14 d u s t s w i t h o u t km,* a sb e sto s it random 25 4 - 2 0 - 1 0 - 4 1 21 Not detectable B orninK uusjarvi, r i ' 2 ern F in l a n d . Envir m ental e x p o s u r e t a sb e sto s. H usband e x p o se d t . 4 1 b e s t o s 2 0 -2 8 > a - p r e v io u sly . 3 F ath er exposed to containing asbesu 77 sure, highly complicates th e chances to prove w h e th e r or not there he. a dust exposure and/or any relationship to asbestos. The four (la st) cases in table 1 deserve special a tten tio n . The fu found in routine chest-photofluorograph. The case history reveal' : the p atien t's fa th e r had 50 y e a rs ago been occupationally exposed u dusts. This was the only possible connection to asbestos. For fur1 formation the husband of the patient and her three sisters were r\.. The husband showed no pathological changes in th e lungs or ph-ur all three sisters had b ilateral p leu ral changes, two had very typical plaques. One of them also h ad visceral pleural adhesions and pe::fibrosis. All b u t the last m entioned w ere subjectively symptomles- ; ogy of biopsy material taken by thoracotom y, revealed pulm-e Kiviluoto: Pleural Plaques and Asbestos ! 239 I pleural fibrosis and in fo u r m icron thick paraffin sections no asbestos fibers were visible. i C o m m en ts j In advanced cases of p leural plaques, roentgen diagnosis is easy. |Misin- terpretations as lung or pleural tum ors are possible, especially if relatio n ship to asbestos or dusts is not known. In the literatu re, benign local parietal pleural changes "of obscure origin" consisting of hyaline sclerotic fibrin, a t first m isin terp reted as lung or pleural tum ors, have also been reported.7 To judge from the description of those pleural changes, they seem very sim ilar to those seen in asbestosis. The correct roentgenological observation and interpretation of parietal pleural plaques enables discovery of pneumoconiosis even in cases w hich show no other clinical evidence of an inhalation dam age. Even though not pathognomonic to asbestosis, pleural plaques are of significance for In d u s trial hygiene and may be very helpful in epidemiologic studies. The detection of exposure to asbestos or mixed dusts is often very diffi cult in case histories, m ainly because the interval between exposure and m anifestation m ay range from several years to decades. Also, it should be noted th at asbestos is found w ith g reat difficulty in paraffin sections of ordinary thickness.* In cases of pleural plaques asbestos m ay be found more often if they are specially searched for and if special m ethods are used. R eferen ces 1. Meinander, C. F. 1954. Die Kiukaiskulture. J. Archeol. Soc. Finland 53 : 165. ; 2. Kiviluoto, R. 1960. Pleural calcification as a roentgenologic sign of non- occupational endemic anthophillite-asbestosis. Acta Radiol. (Stjockh.). Suppl. : 194. 3. Wagler, F., H. Muller & M. A n spa ch . 1962. Gibt es eine endemische A s bestose? Zeitschr. Ges. Hyg. 8: 246. ! 4. Anspach, M. 1962. Sind Pleuraverkalkungen pathognomonisch fr eine Asbestose? Int. Arch. Gewerbepath. 19: 108. f 5. Wagner, J. C., C. A. S leggs & P. Marchand. 1960. Diffuse pleural meso thelioma and asbestos exposure in North Western Cape Province. Brit. J. Industr. Med. 17: 260. 6. McCaughey, W. T. E., O. L. Wade & P. C. E lm es. 1962. Exposure to as bestos dust and diffuse pleural mesotheliomas. Brit. Med. J. 2: 1397. 7. Tivenius, L. 1963. Benign pleural lesions simulating tumour. Thorax (Lon don) 18:39. 8. F owler, P. B. S., J. C. Sloper & E. C. W agner. 1964. Exposures to asbestos and mesothelioma of the pleura. Brit. Med. J. 5403: 211. i i