Document Qo5vbdOL54qwG0MBda2v72x4

Jtft/ /hf0J5*r-f P^ (C- 6 (/y 1968 Yant Award Occupational and "Non-occupational" Asbestoaia in Finland O a> o ro * LEO NORO, MJ>. Institute of Occupational Health Helsinki, Finland Preprinted from AMERICAN INDUSTRIAL HYGIENE ASSOCIATION JOURNAL Volume 29, May-June, 1966 IST0 0 1603 Yant Memorial Lecture Occupational and "Non-occupationaJ" Asbestosis in Finland LEO NOftO, MJ). Institute af Occupational Health, Helsinki, Finland Lao Soto, M.D., Director of the Institute of Occupational Health, Helsinki. Finland, is the recipient of the 1968 WUUam P. Yant Memorial Award. This award is presented by the American Industrial Hygiene Associa tion to commemorate the leadership and breadth of contributions of Dr. William P. Yant in the field of industrial hygiene. The award is sponsored also by the Mine Safety Appliances Company with which Dr. Yant was to long and so prominently associated. Suitable to Dr. Yant's great interest and ac tivity in carrying industrial hygiene to other countries, the selection of recipients if made from persons who are not resident in the United States and who have made outstand ing contributions to industrial hygiene. Dr. Horo. a native Finn, was born in 1915 and received his medical degree from the University of Finland in 1941. Immediately following World War ll. he came to the United States as a Rockefeller-Fellow to study industrial hygiene and occupational medicine. He returned to Finland to become a leader in these fields and to achieve inter national recognition. He has been Director of the institute of Occupational Health at Helsinki since 1950. His publications include topics in industrial hygiene, air pollution, public health, and epidemiology. He is a member of the American Academy of Oc cupational Health and he has been active on interncuional commtttees of WHO, ILO. and other such organisations. Introduction IT IS A GREAT honor for me to have been selected a the winner of the William Yant Award for 1968 bv vour internationally esteemed association. I very much appreciate this honor also because I feel myself to be a scholar from the American industrial hygiene school, in which William Yant has been one of the great pioneers. I am very glad. too. to see among this very distinguished audience many of my teachers and friends from the time exactly twenty-one years ago when I was the first Finn after World War II to be sent as a Rockefeller-Fellow to the United States to study industrial hygiene and medicine for the purpose of setting-up an occupational health institute and modem occupational health services in my country. Asbestos at a Health Problem I have chosen asbestosis as the subject of this lecture because in recent years asbestos dust has become an object of great interest all over the world not only as the cause of an occupational disease, known since 1900. but also as a potential hazard to the health of the entire population. In publicity even "horrorpropaganda" has appeared in newspapers and on television and radio broadcasts. In the London Sunday Times on October 31, 1965. Dr. A. Byme wrote: "A disquieting neu. occupational disease capable of killing not only the exposed workmen but also perhaps his womenfolk and even people living near his place of work is the subject of intensive behind-thescenes activity by British scientists, experts on industrial health and representatives of at least two government ministries." This concerns asbestos and pleural mesothe lioma. My good friend Henry Doyle kindU sent me another clipping from the American 195 0011604 196 newspaper Washington Post, December 25, 1967, in which Thomas O'Toole considers: "A fatal cancer of the chest and abdo minal cavities is cropping up among the nation's asbestos workers. So rare that twenty years ago it wasn't even in the medical textbooks, the cancer is called mesothelioma and seems almost peculiar to people exposed to asbestos. But oddly, those stricken with the deadly disease in clude a nurse whose father worked in an asbestos plant and a man who handled asbestos for no more than a month while he insulated the plumbing in his own house. Any attention the disease gets might come none too soon. More than one million tons of asbestos is consumed annually these days in the United States, with more than 3,(XX) separate uses being reported for the fiber. There are at least 100,000 asbestos workers in the United States." It is true that asbestos is a dangerous ma terial. But how dangerous, for example, when compared with radioactive substances, and in which circumstances? This question should be answered scientifically before the people become frightened and the existence of the asbestos industry is placed in jeopardy or at least greatly disturbed through incompetent knowledge and propaganda. Every industry has health hazards of its own. but they can be controlled at the atomic energy industry has v ery well demonstrated. The asbestos industry is ready to eliminate their health hazards too. if we occupational health people can only say liow to do it. N'ow I want to make some general remarks about asbestosis before going on to the Fin nish experiences concerning this ntbject. The world production of asbestos is at present more than four million tons a year, half of it being Russian. According to the American estimation at least 400.000 workers are ex posed to asbestos in the world, but there are no estimates of how many people are exposed non-occupationally to very small amounts of asbestos dust in their everyday living environ ment. Present Knowledge of Asbestosis Until now there have been published ap- May-June, 1968 > pioximately 1,000 scientific articles on asbes tosis. A list has been compiled at the Institute of Occupational and Environmental Health, Montreal. Already three special international congresses have been held concerning the subject ''Asbestos and Health" (Caen 1964, New York 1965, and Dresden 1968) and many national meetings. The Canadian as bestos industry has twice invited a group of experts to discuss the problem at Antigua West Indies. The interest is great! Dr. Gilson describes very well the develop ment of our knowledge of asbestos and health. The modern asbestos industry started in 1878. Asbestosis was described for the first time in 1900. Asbestos and lung cancer came into the picture in 1935. Mesothelial tumors from asbestos-producing areas were first written about in 1955 by C. A. Sleggs from South Africa, and up until now a few hundred cases of pleural mesotheliomas have been discussed in texts from the United Kingdom, South Africa, the United States, Canada, and other countries. In addition to this, Dr. Wagner has elegantly shown in his experiments how easily mesothelial tumors of the pleura can be produced by some asbestos dusts. The incidence of asbestosis cases has dropped, however, in many countries during the last twenty years. Dr. Knox mentioned some time ago that thirty yean ago the incidence of asbestosis among workers was 89% after 25 years of exposure and that ten years ago it was only 3%. This is due to the better dust control. But how far should we go with dust control, if even very small amounts of asbestos dust might cause a fatal disease like mesothelioma as the newspapers and some in vestigations have told us? Are we at all able to prevent in this case asbestosis by industrial hygiene measures which are still economically acceptable? These are the questions which are of interest to those of us who are working in the field of occupational health. History of Asbostos in Finland Finland is one of the oldest asbestos pro ducers in the world. Our asbestos is the rather rare anthophyllite asbestos, which is quarried in eastern Finland close to the Soviet border. Archeological studies have shown that as early ST0011604 American Industrial Hygiene Association Journal 197 IST0 0 1605 a* 2500 B.C. or 4,500 yean ago people in Finland knew how to add fine asbestos fiber to raw material for pottery. The techniral lignificance of this discovery is obvious. In the same way that asbestos is now used to improve tensile strength (in the armoring of cement products, for example) to it was once used to strengthen the tides of lightly fired pottery. When the material had been strengthened, the sides of the veaels could be made thinner. In this way cooking utensils were produced which were not only lighter in weight but in which food could also be cooked more quickly. This surprisingly mature tech nical invention found also a practical adapta boo which commands respect for the eco nomic instincts of those forefathers whom we often regard as very primitive people. Asbes tos potterv was not limited to being a pro vincial specialty of eastern Finland: it spread over a wide area of Finland, Scandinavia, and Russia. The asbestos pottery as found in Finland and in neighboring countries is unique--nowhere else have discoveries of that kind been made! This use of asbestos also illustrates that ex posure of man to occupational asbestos in handicrafts has at least a 4,500-year-old his tory in Finland as well as the non-occupational exposures in asbestos areas. But only since 1918 have we had a modern industrial exposure of workers in quarry, mill, and fac tories. Our eastern neighbor, Russia, started the production of asbestos as early as 1712 during the reign of Peter the Great. Their production at present Is already approxi mately two million tons per vesLr, half the total of world production per year and twice as much as the United States annuallv uses. Finnish Asbestos The present production in Finland is only 11,000 metric tons per year of anthophvllite asbestos. The asbestos dust in the quarry and mill mineralogicallv contains: Anthophvllite Talc Chlorite 30-75% 20-60% 3-13% The theoretical chemical composition is (Mg. Fe!M: ((OH): (Si.On);]. There are small amounts, perhaps maller than in Canadian asbestos, of some metals such as Ni, Cr, Co, which might have some cancerogenic interest Levels of Exposure to Asbestos Dust Unfortunately the exposure levels at plants have been systematically measured only dur ing recent years. Twenty years, ago, before the management of the quarry and mill changed, the dustiness was, especially in the mill, rather great One could only tee a few meters ahead. The level of dust was surely many times higher than what our threshold limits indicate it should be. This great expo sure reflects in the frequency and severity of our asbestotis cases, which will be presented later. The present situation of dustiness will be reflected in the morbidity of the next ten to twenty years. In the entire asbestos industry approximately 225 different jobs have been examined. In three-fourths of them the level of dust is under the threshold limits, but it is higher in the remaining one-fourth. We have used: (a) gravimetric samples taken with electrostatic precipitators (MSA) and/or with membrane filter field monitors (Millipore Filter Corp., Type AA), and (b) breathing zone samples taken with an impinger (MSA! for particle counting and siz ing under the microscope. X-ray diffraction methods are used also. In the mill and quarry the total quantity of dust varies from 7.5 to 100 mg/m*. In other working places the level of dust vanes from 0. 3 to 10.6 mg/m* or 11 to 2,400 particles/ cm'. Only 1% to 5.4% of the total dust f impinger-method) has been fibrous particles, 1. c., 5 in length, the length being three to four times the width. In this connection I would like to mention that in eastern Europe (the Soviet Union, East Germany) the thres hold limits are somewhat lower than the western ones: 2 mg/m' or 100 to 150 particles/cm1. The level of industrial hygiene in Finland is not yet satisfactory, and unfortunately we must expect still more asbestosis cases. Medical Findings The first medical survey in our asbestos industry was made in 1946 by C. Wegelius. 198 May-June, 1968 The remit* of this x-ray itudy tell about the health effects of rather heavy exposure dur ing the first twenty active yean cif the asbes tos industry. From 476 asbestos workers (in dustry included) 126 cases (26.5%) of asbestosis were found. However, 73% of these were of stages I or I-II, in which diagnosis was not easy because at that time only x-ray film rise 24 x 36 mm was used. Pleural and pericardial thickenings were present in 36% of all cases and in connection with stages IIIII and III in 100%. Since 1954 the asbestos workers have been examined roentgenologically rather regularly. Until 1967, altogether 144 cases of asbestosis had been diagnosed in the asbestos industry, which employs approximately 500 workers. In all these cases the exposure time has been more than two years. Among insulators 35 cases of asbestosis have been determined until now. No meso theliomas have been found. There are ap proximately 400-500 insulators in Finland. At present (1968), we are again studying the up-to-date situation in the quarry and the mill. Our preliminary study shows: --During the last thirty years approximate ly 400 workers have been exposed to asbestos dust for more than one year. --One-half of these workers have died from various causes, which are under study. --One-fourth of them have had asbestosis (90 cases). In 1967, 135 workers (24 pensioners in cluded) were examined, and among them 37 cases of asbestosis were found, of which 13 were new. In four cases exposure time was less than ten years, in 17 cases it was less than 20 years, and in two cases more than 30 yean. No lung cancer or mesotheliomas were found among these cases. When comparing the asbestosis cases and the roentgenologically normal people among the 135 examined, the following observations were made in connec tion with the clinical examination: In asbestosis cases the following data were significantly present more often than in the non-asbestosis group: --older age --longer exposure time --longer time of residence in the district --longer and heavier history of smoking --more pneumonia (highly significant) --more production of phlegm --more shortness of breath --worse lung functions (FVC, FEV, ,, and AS). Smoking history is always important in connection with all occupational lung dis eases. If lung cancer is an average of ten times more common among heavy smokers than non-smokers (in some age groups even 60 times more common according to some authors I, this fact should always be taken into consideration when discussing lung cancer as a complication of asbestosis. The two environmental factors, smoking and asbestos, simultaneously make the risk of cancer greater too! ^ ^ _ t__, ___ ___ _ _ These epidemiological studies indicate that asbestosis is still a rather important occupa tional disease in Finland. Whether or not anthophyllite asbestosis is more dangerous or more caneerogenic than other asbestos types, chrysotile, crocidolite and amotile, is an inter esting question, which it being studied at pres ent. We might have the answer to this ques tion in a few years. "Non-occupation*I" Asbestos The Finn, Raimo Kiviluoto, in 1960 pre sented his observations on the unusual, "Pleural calcification as a roentgenologic sign of non-occupatkmal endemic anthophylliteasbestosis," at the XHIth International Con gress on Occupational Health in New York. He had collected approximately 800 cases of special-looking, mostly bilateral pleural cal cifications among the population in an asbes tos area. Dr. V. Raunio continued the study and collected approximately 1,300 similar cases, visible in 70x70 mm AP-x-ray pic tures, in the population of the same district. His study was based on more than 600,000 RP pictures taken in thirteen Finnish towns and 106 rural communes, which together cor respond to approximately 20% of the Finnish imputation over the age of fifteen. In the Tuusniemi commune, where the asbestos quarry is located, this kind of peculiar pleural calcification was found in 9% of the popula- ST0011606 L American Industrial Hygiene Association Journal 199 tioo ovtr fifteen yean of age. Under the age the entire population. Already in 1884 Cursch- of 40 yean they were rare, but in penoeu mann described them as "sugar icing"-- over 63 yean of age the calcification* were "Zuckergu**"--at the time when the asbestos obeerved in almost 30%. In the rural popu industry was only starting in some countries. lation eltewhere in Finland only teven cam Asbestos bodies--if they are all asbestos (?) -- were found in the 265,223 people examined, are rather frequent in lungs: in Finn:sh mate but in two larger town* they were more fre rial in 57.6%, in some oth-r material between quent, 0.7% of the examined. Kiviluoto ha* 5 and 30%. (It deoends on what kind of later found 77 ca*e* of calcification* in 33,000 method is used and in what detail the lungs cheat x-ray picture* from the population of are studied.) This does not mean, however, f . -our second largest city Tampere. that thev are "asbestos1* cases." as Chemical J Bilateral thickening of the parietal pleura Week (Sept 10. 1966) seemed to tlvnk wh-n [i is, however, a verv common finding at autop- it stated. "Forty per cent of all Americans ' ties in all of Finland, as Dr. Metirman stated have mild, chron'C cases of asbestosis." We in his study in 1963. He found them in do not even know yet what materials are a 39.3% of his cases, equally in eastern and part of the needles, fibers, bodies, etc. which western Finland. In 70% of the cases the have been found in the human body. plaques were bilateral and in 72% the find ings were in men. They were more common in the urban population (32.2%) than in the rural areas (31.8%). In the asbestos area the incidence and calcification of plaques were higher. Asbestos bodies were present in 57.6% of the 264 lungs studied, in men 60.1% and women 54.3%. Other findings were: In the Finnish asbestos area, however, cal cifications, visible in x-ray pictures, are much more common than in other parts of the country. Air pollution is not the only cause of exposure. We have made some investiga tions and noticed that calcifications ar> found outside of the area where asbestos dust spreads. Of course, the local exposure to dust --The frequency of asbestos bodies in the (asbestos ovens, asbestos stones !n the sauna, lungi is higher in urban than rural popu agricultural exposure from dust in fields, etc.) lations (70%-49%). could be a cause. But also the entire eeo- --The frequency of asbestos bodies in the micrological comoosition of the soil is differ lungs of persons in the asbestos area was ent. In our preliminary studies in this area greater (however in 5 cases of 15 no ue have noticed great differences, for ex asbestos bodies could be found). ample. in the Mg-content of the drinking --In farmers asbestos bodies were found in water, which might influence the calcification 47% and in building workers and work processes. The study, however, is not yet ers of corresponding trades in 67%. finished. It, nevertheless, seems that asbestos --Asbestos bodies could not be detected in in the air or soil has something to do with plaques. calcification of plaques, because also in occu --There was a positive correlation between pational asbestosis cases pleural calcifications the occurrence of asbestos bodies in the are rather frequent symptoms (in our mate . lungs and of pleural plaques. In cases of rial of advanced cases in 100% of them). bilateral plaques 85.7% exhibited asbes What then is the prognosis of plaques and tos bodies in the lungs, but, on the other calcifications? Does one part of them develop hand, approximately 40% of the cases into mesotheliomas and whv? This is an in I showing asbestos bodies in the tunes were teresting question. Our Finnish experience free from pleural plaques. does not as yet prove it to be so. t --The plaques did not have any correlation You might ask, "If you find this kind of with emphysema, heart disease, pulmon peculiar pleural changes in even 9% of the ary stasis, or pulmonary tuberculosis. population, then what is the situation in re Chronic bronchitis was not studied. gard to pleural malignancies and mesothelio Perhaps the most important finding is that mas in this area which alreadv has a 4.500- pleural plaques are a verv common disease in sear historv of endemic exposure." The Fin- S TO O I1607 IST0 0 1608 200 May-Junt, 1968 nish Cancer Register shows that the incidence exposed workman but also perhaps his of cancer of the lung and malignant pleural womenfolk and even people living near his and peritoneal tumors is not higher in the place of work." If so, the population in "calcification area" than in the other rural the asbestos area of Finland would already districts of east Finland during the yean be dead and nobody could live there. Still 1953-62, as Dr. Raunio has stated. Kiviluoto at present in the asbestos area the mortality came to the same conclusion. Only one case rate from cancer and other malignancies is of pleural or peritoneal mesothelioma has equal to the other rural areas of the coun been detected during autopsies from this dis try, although in the worker population the trict (Kiviluoto). Twelve cases of meso frequency of lung cancer might be some theliomas of the pleura have been recorded in what higher. Finland, and not one of these was from this area. Knowing that the area has had 4,500 years of endemic exposure, which in the last 50 years has been rather heavy in occupa tional exposures and hat been increased among the neighborhood population .y in dustrial air pollution and knowing that every third man over the age of 65 has pleural plaques, one could already expect more meso theliomas in this district! Or should we wait still some twenty years longer and see what will have happened when the population has (3) As industrial hygienists we, however, have to continue our work to reach better and better hygienic conditions and dust control in places of employment as well as in the environment of factories and mines to safeguard the workers and general popu lation. There is enough evidence already to cause us to pav more attention to this health prob lem. Many questions have not yet been answered: aged and incubation time has been long enough and also other cancerogenic factors like cigarette smoking, exhaust gases, zinc in the drinking water, etc., have had a combined influence great enough? At present we still know too little about the danger caused by asbestos to the general population. (1) What is the health significance of fibrous foreign bodies found in the lungs, and are they all asbestos? (2) Does a small amount of asbestos dust, caused by construction activity, asbestos material in houses, the brake linings of motor vehicles, etc., really have any influ Summary ence on the health of the population in the i In summary of the Finnish experiences concerning asbestos, we feel that: urban living environment? Does this kind of minimal exposure have any cancerogenic effects? What is the role of aibeitos among (1) Asbestos is a rather dangerous mate the hundred other environmental cancero rial to workers' health, just as hundreds of genic agents like cigarette smoke, exhaust other agents are if they are not properly gases of motor vehicles, food additives, controlled in industrial use. We, however, viruses, etc.? are at present able to control it and make the use of it as harmless as the use of other dusts or toxic materials, even radioactive substances, might be. Every occupation lias its health hazards, so also docs the asbestos industry; as a part of the total health of workers, asbestosis can be reduced by mod (3) How far should we go in dust control to prevent totally the development of new asbestosis cases and what should the thres hold limit be? Or is it impossible to reach the safety limit of 100% with only moder ate expenditures? ern industrial hygiene to a very small haz These are some questions which still are ard. waiting for answers, but I am convinced that, (2) We cannot agree with the recent "hor with the proper collaboration of industrial ror propaganda" such as was written in the hygienists, whom you are representing here, London Sunday Timet by Dr. Byrne that and medical experts, these kinds of problems asbestos is, "Capable of killing not only the will be solved in the future. ST0011608 American Industrial Hygiene Association Journal 201 Finniih Bibliography on AsbartoMf ____Kij: AAaitM--------- 1 ImliHf Woafcsei is FmIm4. frt. .IT 1st. C*lr' Ortmp. Mrriik, Vienna <I9M>. Aunts. t.. sad A. Vaussls: Cbv da* Aibmri--w FisaUa* sad ihre ircfcaacfce \reriuan. Crsfefurkr Cf<r*auA# i'trifdtbekmmtdm Sr 34 UtSdT Fiaab Misseil (Cariuaa I: TAe Wtid't Fin* .Ukrtti A|tr. Karilaaes. ft.: FIwmsI Caiciiatisa m s liwmsoiwif In rd NesasBepsosnal Mwmir Aatb--bsflits AtbsunsAtu AaduJ. iSsdtatal Sappi. 1*0; IW (1*0). KivOsw. ft.: Ptearal Plaque* sad AabsMu; Farther b* --nuiw s esdesuc sad otfccr nos wwninl n bmmm. Arm4* S. Y Acmd. Ut. 132. 03 <l*5). Kiwdsoto. R.: PWsisI r>lnftrsiKs< and AabsMsaa. Bni. f RtdfUfy ' 1*7). Lassuses. A., sad V Ratasaa: ObarvtisM so ^snibrr r Air Psiluoo* Caused be Asbucss. iitui Aaron ikf /uriiu i Otcnpmmtud Hr4tk 1944, Kebiafc U964I f sen. A.. Leo Noro. sad V Reusio Observation <* Viawplsnt Air PolNation Caused bv Ubntn. .<- U*d Sn. 132. 240 (19651 Meunaaa. L.. AabsMsa jodn asd ftrural PUawa m a FtsnsN Sns oi Auteprv Cura. Am Feta Srtmei. Sui>s< Itt<l96b` Smrm. Lsa: uOs*uliwiHHiadnsiTkmit A Nan. Ur. Km. k AIImdO. rAn..ttljaii* at*. W: IT* (IW). N-- ^ A. O. Atm fat. Mr ut M. VuUn. /at. Aftk. CfM llaa tl Mm Dnafca IML Rsssis, V.: Oswum aI I'wuul fW Calriftrsiaia in Fbibad IsKisr ss dfsapArrie FrAntmm Cm*4 h Arkmm. Iff ililalri (IW). Sthuua. C.: Irdmrtnd Nmmm Aiputi so Xtadiet W 4dma Oso * (^srdia# PUr. tVA. liethbalu ami). Sdtears. C.: Oksana nan oa tbs AAau Dm Milan sms. Cassbsdasnk ffmiddk Fianab SeupOMSi os PsosnoesoMM. Pnpse. June 11-17. 19*7. Wpdiw. C: Ckssf is tbs Leap* is !* Casa mi A#bssHM ObwroJ is Fialsad. Arts JtadM. fSasskhstBl Jt: 199 (1*7). Viikan. 54.. sad K. Ahiaua- Redastoyical Csaafinosa si Caan itb Psesnocasaoaa is tbs Liibi oi a Crons Sndr. SLL 19: 811 (Fiaaab) (1904). Vliken. M . at W.. llrraahall Fasaiisssuas is Aabmws. To be i IST0 0 1609