Document VJROkrM44N2rYL7MOrxn7by1g

STOOI I 602 J&t/ /v AT/Z i, (/"^ 1968 Yaut Award Occupational and "Non-occupational" Asbestosis in Finland By LEO NORO, MX). Institute of Occupational Health Helsinki, Finland Preprinted from AMERICAN INDUSTRIAL HYGIENE ASSOCIATION JOURNAL Volume 29, May-June, 1968 PLAINTIFF'S EXHIBIT STOO11602 S T 0 0 I1603 Yant Memorial Lecture Occupational and "Non-occupational'* Asbestosis in Finland LEO NORO, M.D. Institute of Occupational Health. Helsinki. Finland Leo Soro, M.D., Director of the Institute of Occupational Health. Helsinki. Finland, is the recipient of the 1968 William 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 teas so 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 is made from persons who are not resident in the United States and who have made outstand ing contributions to industrial hygiene. Dr. .Voro. a native Finn, was born in 1915 and received his medical degree from the University of Finland in 1941. Immediately following World War II, he came to the United States as a Rockefeller-Fellow to study industrial hygiene and occupationalr medicine. He. returned to Finland to become a leader in these helds and to achieve inter national recognition. Hr has been Director of the institute of Occupational Health at, Helsinki since 1950. His publications include topics m 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 international committees of WHO, ILO. and other such organizations. Introduction TT rS A GREAT honor for me to have: been selected as the winner of the Williami Yant Award for 1968 by your 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 tny 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 modern occupational health services in my countrv. Asbestos as a Health Problem I have chosen asbestosis as the subject of this lecture because in tecent rears 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. Byrne wrote: "A disquieting new 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 oi at least two government ministries.'' This concerns asbestos and pleural mesotheliorna. Mv good friend Hemv Doyle kindly sent me another clipping from the American ! 95 ST0011603 196 newspaper Washington Post. December 25, 1967. in which Thomas O'Toole considers: "A fatal cancel of the chest and abdo minal cavities is cropping up among the nation's asbestos workers. So rare that twenty vears 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 3.000 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 lease greatly disturbed through incompetent knowledge and propaganda. Every industry has health hazards of its own. hut they can be controlled as the atomic energy industry has very well demonstrated. The asbestos industry is ready to eliminate their health hazards too. if we occupational health people can only say how to do it. Now [ want to make some general remarks about asbestosis before going on to the Fin nish experiences concerning this subject. 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-occupationallv to verv small amounts of asbestos dust in their everyday living environ ment. Present Knowledge of Asbestosis Until now mere have been published np- May-June. 1968 6 pioximatelv 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, N'ew York 1965. and Dresden 19681 and many national meetings. The Canadian as bestos industry has twice invited a group of experts to discuss the problem at Antiguaj/y West Todies. The interest is great! ___| Dr. Gilson describes very well the develop-CD ment of our knowledge of asbestos and health.CD The modern asbestos industry started in 1878.-- Asbestosis was described for the first time in----- 1900. Asbestos and lung cancer came into cn the picture m 1935. Mesotnelial tumors from CD asbestos-producing areas were first written -JT" 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 :n 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 years ago the incidence of asbestosis among workers was 89cr after 25 years of exposure and that ten vears ago it was only 3C/c. This is due to the better dust control. But how far should we go with dust control, it 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 oi us w ho are working in tlie field of occupational health. History of Asbestos 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 Archeoiogical studies have snown that as early ST0011604 STOOI!605 American Industrial Hygiene Association Journal 197 as 2500 B.C. or 4.500 years ago people in Finland knew how to add fine asbestos fiber to raw material for pottery. The technical significance 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) so it was once used to strengthen the sides of lightly fired pottery. When the material had been strengthened, the sides of the vessels 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 tion 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 hat e 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-vear-old his tory in Finland as ueii as the non-orcupational 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 vear. half the total of world production per vear and twice as much as the United States annuallv uses, Finnish Asbestos The present production in Finland is only i 1,000 metric tons per vear 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-'): [(OHV. fSiiOu . . There are small amounts, pe: luifts -mallei than m 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 see 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 asbestosis 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: (ai 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 impinsjer (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/nr1. In other working places the level of dust varies from 0.3 to 10.6 mg/m1 or 11 to 2.400 particles/ cir. Only 1% to 5.4% of the total dust (impinger-inethod I has been fibrous particles, i.i'., 5 js. in length, the length being three to four times the width. Tn 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/nr or 100 to 150 par ticles/cm !. 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. ST0011605 STOOI1606 L98 May-June, 1968 The results of this x-ray study tell about the health effects of rather heavy exposure dur ing the first twenty active vears of the asbes tos industry. From 476 asbestos workers (in dustry included) 126 cases (26.5%) of asbes tosis 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 size 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 roentgenologicaiiv 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 w-orkers (24 pensioners in cluded) were examined, and among them 37 cases of asbestosis were found, of which 13 were new. Tn 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 years. No lung cancer or mesotheliomas were found among these cases. When comparing the asbestosis rases and the roentgenologicaiiv 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 aee --longer exposure tune --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), this fact should always be taken into consideration when discussing lung can cer as a complication of asbestosis. The two environmental factors, smoking and asbestos, simultaneously make the risk of cancer greater too! 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 canceroeenic than other asbestos types, chrvsotile, crocidolite and amosite, is an inter esting question, which is being studied at pres ent. We might have the answer to this ques tion in a few vears. "Non-occupafional" Asbestos The Finn, Raimo Kiviluoto, in 1960 pre sented his observations on the unusual, "Pleural calcification as a roentgenologic sign of non-occupational endemic anthophylliteasbestosis." at the Xlllth 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, r isible in 70 x 70 mm AP-x-ray pic tures. in the population of the same district. H is studv 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 population over the age of fifteen. In the Tuusniemi commune, where the asbestos quanv is located, this kind of peculiar pleural calcification was found in 9cc of the popula- ST0011606 American Industrial Hygiene Association Journal 199 tion over fifteen years of age. Under the age of 40 years they were rare, but in persons over 65 t ears of age the calcifications were observed in almost 30%. In the rural popu lation elsewhere in Finland only seven cases were found in the 265,223 people examined, but in two larger towns they were more fre quent, 0.7% of the examined. Kiviluoto has later found 77 cases of calcifications in 35,000 chest x-ray pictures from the population of our second largest city Tampere. Bilateral thickening of the parietal pleura is. however, a verv common finding at autop sies in all of Finland, as Dr. Meurman stated in his study in 1965. He found them in 39.3% of his cases, equally in eastern and western Finland. In 70% of the cases the plaques were bilateral and in 72% the find ings were in men. They were more common in the urban population (52.2%) 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: --The frequency of asbestos bodies in the lungs is higher in urban than rural popu lations (70%-49%). --The frequency of asbestos bodies in the lungs of persons in the asbestos area was greater (however in 5 cases of 15 no asbestos bodies could be found). --In farmers asbestos bodies were found in 47% and in building workers and work ers of corresponding trades in 67%. --Asbestos bodies could not be detected in plaques. --There was a positive correlation between the occurrence of asbestos bodies in the lungs and of pleural plaques. In cases of bilateral plaques 85.7 % exhibited asbes tos bodies in the lungs, but. on the other hand, approximately 40% of the cases showing asbestos bodies in the lungs were free from pleural plaques. --The plaques did not have any correlation with emphysema, heart disease, pulmon ary stasis, or pulmonary tuberculosis. Chronic bronchitis was not studied. Perhaps the most important finding is that pleura! plaques ate a verv common disease in the entire population. Already in 1884 Cursch- tnann described them as "sugar icing"-- "Zuckerguss"--at the time when the asbestos industry was only starting in some countries. Asbestos bodies--if thev are all asbestos (?)-- are rather frequent in lungs: in Finnish material in 57.6%, in some otfrm material between 5 and 50%. (It depends on what kind of method is used and in what detail the lungs are studied.) This does not mean, however. that they are "asbestos's cases." as Chemical Week (Sept. 10. 1966) seemed to th'nk wh-n it stated. "Fortv per cent of all Americans have mild, chrome cases of asbestosis." We do not even know yet what materials are a part of the needles, fibers, bodies, etc. which have been found in the human body. ,j-j ,--^ t--) ___ ___ (--> 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 am found outside of the area where asbestos dust spreads. Of course, the local exposvire to dust (asbestos ovens, asbestos stones ;n the sauna, agricultural exposure from dust in fields, etc.) could be a cause. But also the entire genmicrologica! composition of the soil is differ ent. In our preliminary studies in this area we have noticed great differences, for ex ample. in the Mg-content of the drinking water. vshich might influence the calcification processes. The study, however, is not yet finished. It, nevertheless, seems that asbestos in the air or soil has something to do with calcification of plaques, because also in occu pational asbestosis cases pleural calcifications are rather frequent symptoms (in our mate rial ot advanced cases in 100% of them). What then is the prognosis of plaques and calcifications? Does one [tart of them develop Into mesotheliomas and whv? This is an in teresting question. Our Finnish experience does not as yet prove it to be so. You might ask. `Tf you find this kind of peculiar pleural changes in even 9% of the population, then what is the situation in re gard to pleural malignancies and mesothelio mas in this area which alreadv has a 4.500\ear Instore of endemic exposure." The Fin- ST0011607 STOO! 1608 200 Mav-June, 1968 nish Cancer Register shows that the incidence of cancer of the lung and malignant pleural and peritoneal tumors is not higher in the "calcification area" than in the other rural districts of east Finland during the years 1953-62, as Dr. Raunio has stated. Kiviluoto came to the same conclusion. Only one case of pleural or peritoneal mesothelioma has been detected during autopsies from this dis trict (Kiviluoto). Twelve cases of meso theliomas of the pleura have been recorded in Finland, and not one of these was from this area. Know-ing 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 has been increased among the neighborhood population by 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 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. Summary In summary of the Finnish experiences concerning asbestos, we feel that: (1) Asbestos is a rather dangerous mate rial to workers' health, just as hundreds of other agents are if they are not properly controlled in industrial use. We, however, 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 has its health hazards, so also docs the asbestos industry: as a part of the total health of workers, asbestosis can be reduced bv mod ern industrial hygiene to a very small haz ard. (2) We cannot agree with the recent "hor ror propaganda" such as was written in the London Sunday Times bv Dr. Bvrne that asbestos is. "Capable of killine not onlv the exposed workman but also perhaps his womenfolk and even people living near his place of work." If so, the population in the asbestos area of Finland would already be dead and nobody could live there. Still at present in the asbestos area the mortality rate from cancer and other malignancies is equal to the other rural areas of the coun try. although in the worker population the frequency of lung cancer might be somew'hat higher. (31 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: (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 bv construction activity, asbestos material in houses, the brake linings of motor vehicles, etc., really have any influ ence on the health of the population in the urban living environment? Does this kind of minimal exposure have anv cancerogenic effects? What is the role of asbestos among the hundred other environmental cancero genic agents like cigarette smoke, exhaust gases ot motor vehicles, food additives, viruses, etc.? (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 ]00r with only moder ate expenditures? These are some questions which still are waiting lor answers, but I am convinced that, with the proper collaboration of industrial hygienists, whom you are representing here, and medical experts, these kinds of problems wdl be scale ed in the fntuie. ST0011608 American Industrial Hygiene Association Journal 201 Finnish Bibliography on Asbestosis Vhlman. Ka): Asbestosis among Insulator Wotkers in J in land. Pmc. AT* lot. Conge. Occup. Health. Vienna ' 1966). Aurola. E.. and A. Wtasalo: l)ber die .Asbrstvcrkommen Finnlands und ihre irchnische \ rr**ertung. Genlogtschi l ntersvckungsamtalt. Ceotechnnche I'erdffenllichunfieti Xr 54 (1954). Fiimiih Mineral (Carlssonr: The World's fiat Asbrstot At< >* Itanfs. Kiv iluoto. R.: Pleural Calcification as a Roentgenologic 5 gn nf Xonoccupational Endemic Anthophyilite*Asbe*io.is. Acts Radiol. (Stockholm) Suppl. 1960:194 (i960). Kiviluoto. R. Pleural Plaque* and Asbrstos: Further >b>ervauons on endemic and other nan occupational a*bestosis. Annals A'. Y. Acad. Set. 132: 235 (1965). Kiviluoto. R.: Pleural Calcification* and A'be,*tosir. ftril I Radiology i 1967 I Laamanen A . and V. Raunto: Observations on Atm'>*phviv Air Pollution Caused by A'bestos. Annual Report <>i fIn Institute of Occupational Health 1964, Helsinki < 1^64 I. Laamanen \. Leo Xoro. and V. Raunto: Observations < n Xtmospherrc Air Pollution Caused bv Atbesco*. .-1.c< Acad. Set. 132: 240 (1965). Mcurman. L.: Asbestos Bodies and Pleural Plaques in a Finnish Series of Autopsv Cases. Actn Path. S<aml. Sti|>pi. 182 11966). Noro. Leo: On the Histology of Asbestosis. Acta Path. Mi crobiol. Scand. 23: 53 (1946). Voro. Loo. K. Ahlman. A. Laamanen, and M. Viikeri: Asbesiose als BeruUkrankheit in Finniand. Int. Arch. Geustrbepatk. 22: 179 (1966). Noro. Leo. K. .Ahlman. A. O. Heinonen. T. Partanen. E Rintala. E. Silcanen. and M. Viikeri: Occupational AnthophyLite-Asbesiosis in Finland (A preliminary re port): Second International Conference oo the Bio logical Effects of Asbestos. Dresden 1968. Raunio. S'.: Occurrence of Unusual Pleural Calcification in Finland in Studies on Atmospheric Pollution Caused by Asbestos. Helsinki (1966). Siltanen. E.: Industrial Hygiene Aspects on Studies o[ Asbestos Dust at Working Places. IVA. Stockholm (1967). Siltanen. E-: Observations on the .Asbestos Dust Measure ments. Czechoslovak-Swcdish-Finnish Symposium on Pneumoconioses. Prague. June 12-17. 1967. Wegelius. C.. Changes m the Lungs in 126 Cases ol Asbestosis Observed in Finland. Acta Radiol. (Stockholm) 23: 139 (1947). Viikeri. M.. and K. Ahlman: Radiological Classification of Cases 'tch Pneumoconiosis in the Light of a Group Study. SLL 19: 2211 (Finnish) (1964). Viikeri. M.. el ol.: Ultrashall Examinations in Asbestosis. To be published. --] CD e7i CD ST0011609