Document p37XwZJMKaxBzNqqVnLmd1YB

- L UA A Occupational and "iS"o)i-occup:ition;d" Asbestos! $ in Finland Ll'.O XOIIO, M.D. Institute cj Oecubador.cl Health. Hr:<:rr:.i, Fin'end Leo Soto, M.D., Director of the Institute Yant Award for ifido by your inrrn'.niiom.ily of Occut'r.tlonal Health, Helsinki. Finland, is esteemed associa tier,. I verv much no;:reciatc the recipient of the 195S William P. Yant this honor also because 1 feel myself to oe a Memorial A.ward. This award is presented scholar irorn the American industrial hycienc V. ' the American Industrial Hy g^iene Associa- school, in wiiicn William Van: has been one Von to comrncrnorr.se the leadership and of the great pioneers. . I am wry glad, too, breadth of contributions of Dr. William P. to see among litis very dislineuhhed audience Yant in the field of industrial hygiene. The many of my tcacheis and. friends front the award is sponsored also by the Mine Satrty time exactly twenty-one years ago when I was Appliances Company with which Dr. Yant tite first Finn after Wo: id War II to be s-t.; was so long end so prominently associated. as a Rockefeller-Fellow to the United States Suitable to Dr. Yard's great interest and ac to study industrial hygiene and medicine for c tivity in carrying industrial hygiene to other countries, the selection of recipients is made from persons who arc not resident in the the purpose of setting-up an occupational health institute and moctcrn occupational health services in my country. United States and who have made outstand ing contributions to industrial hygiene. Dr. NorOj a native Finn, was born in 1915 and received his medical degree from the University of Finland m 19-rl. Immediately following IVarid U'ar 11, he came to the United Stales as a Roel.efellcr-Fcllow to study industrial hygiene r.nd occupational medicine. He returned to Finland to become - leader in these fields and to achieve hilcr' .utionci recognition. He has been Director of the institute of Occupa. iorie.1 Health at Helsinki since 1950. llis publications include topics in industrial hygiene, air pollution, public health, arid epidemiology. He is a member cf the American Academy of Oeeuputional Health and he has bct,n active on international committees of WHO, 1LO, and other such orgait'cations, Asbestos cis c Health Problem I have chosen asbestos:? as tite subject r: tills lecture because in recent years ashe.-ms dust has become an object of cie.v. inteies: a 1 over the world not only as the cause of , o occupational disease, Iinowr. since ilvO. b.:i also as a potential hazard in die health of tite entire 'population. In publicity .wen `'kotTcrpropngnncia" lias appeared In newspapers and on television and ladio orrahcnsis. Ir. the London Sum,ay Tin.es on Oetifner a'., ifto. Dr. A. Byrne " rote; A c.sc:t:tel:ntt licit1 oce.mr.uv'i.a. .use..:.' capable of killing not only the eyu-s.h workmen but a ho periiuo. i,,s women fo.n and even people living i.rai hi- p.,.ee if work is tite subject of inict.-ts e behind-thescenes actnitv bv Ik.tis.i s.~.en;>;~. exiteiis on industrial health and op; event.itu cs v! at least two goverrmier.t ;u.m>ti:es. ' Introduclion Tins concents asbestos ai.ti p.euial ir.O'.'iiy. JT IS A CHEAT honor for me to have liotua. My good lrier.d liei.rv Dmie kindly been selected as the winner of the William sent me another clipping nctrt the American fOaus- iWru VU8 1 BB 0015866 1 196 May-Jur-.e. I5S newspaper Washington Post, December 23, proximatelv 1,000 scientific articles on asbes- 1967, in which Thomas O'Toole considers: tosis. A list has been complied at the Institute "A fatal cancer of the chest and abdo of Occupational and Environmental Health, minal cavities is cropping up among the Montreal. Already three special international nation's asbestos workers. So rare that congresses have been held concerning the twenty years ago it wasn't even in the subject "Asbestos and Health" (Caen 1954, medical textbooks, the cancer is called Xew York 1965, and Dresden 1953) and , mesothelioma and seems almost peculiar to many national meetings. The Canadian as people exposed to asbestos. But oddly, bestos industry lias twice invited a group of those stricken with the deadly disease in experts to discuss tile problem at Antigua, clude a nurse whose father worked in an West Indies. The interest is great1. asbestos plant and a man who handled Dr. Gilson describes very well the develop asbestos for no more than a month while he ment of our knowledge of asbestos and. health. insulated the plumbing in his own house. The modern asbestos industrv started in 1373. Any attention the disease gets might come Asbestosis was described for the first time in none too soon. More than one million tons 1900. Asbestos and lung cancer came into of asbestos is consumed annually these days the picture in 1935. Mesothelia! tumors from M-' in the United States, with more than 3,090 ' asbestos-producing areas were first written separate uses being reported for the fiber. about in 1955 by C. A, Sleggs from. Sou tin There are. at least 100,000 asbestos workers Africa, and up until now a few hundred cases in die United States." of pleural mesotheliomas have been discussed It is true that asbestos is a dangerous ma in texts from the United Kingdom.. Booth terial. But how daiigeious, for example, when Africa, the United States, Canada. ;u:d other compared with itullnac.live substances, and in countries. In addition to this. Dr, \Vaguer which circumstances? This question should has elegantly si town in his experiments how be answeiecl scientifically before the people easily mesothciial tumors of the pleura can become frightened and the existence of the be produced by some asbestos dusts. The - asbestos industry is placed in jeopardy or at incidence of asbestosis eases has dropped, least greatly disturbed through incompetent however, in m:mv countries during the last knowledge and propaganda. Every industiy twenty years. Dr. Knox mentioned some has health hazards of its own, but they can be time ago that thbty'years ago the incidence controlled as the atomic energy industry has of asbestosis among workers was 89'T after very well demonstrated. The. asbestos industiy 25 years of exposure and that ten years ago is ready to eliminate their health hazards too, it was only Zc/c. This is due to the better if w-e occupational health people can only dust control. But how far should we go with say how to do it. dust contiol, if even very siren 11 amounts cf Xow I want to make some general remarks asbestos dust might cause a fatal ci'ease like about asbestosis before going on to the Ein- mcsotliclioma as the newsormers ar.d some in nisli experiences concerning this subject. The vestigations have told us? A:e we at all able world production of asbestos is at present tc prevent in this case asbestosis bv industrial more than four million tons a year, half of it hygiene measures which :ec still economical!-, being Jlussian. Accoiding to the American estimation at least -100.0C0 workers are ex posed to asbestos in the world, but tiiere are acceptable? These arc the questions which are of interest to those of us who ate wet king in tire field of occupational health. no estimate1 of .bow many ncopic arc exposed non-occupat:ona!!v to very small amounts of History c: Asbestos in Finland asbestos dust in their cvervdav living environ Finland is one of the oldest asbestos nro- ment. ducers in 'due world. Our asbestos is the tether Present Knowlecoe cf Asbestosis rare a.nthophv kite asbestos, which is cur.rricd in eastern Finland close to the Soviet h:-rd'-r. Unt'l now' there have been r ibhshrd an- Archeological studies have shown that asw.rlv | BB 0015867 | American Industrial Hygiene Association Journal 197 ' a* 2300 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 tiic same way that asbestos is now used to improve tensile strength (in Use armoring of cement products, for example) so it was once used to strengthen the sides of iighilv fired jKUtery. When the. material had been strengthened, the sides of the vessels could be made thinner. In this way cooking mensiis were produced which were not only lighter in weight but in which food could also be cooked more quickly. This sui prisingiy mature tech nical invention found also a practical adapta tion which commands respect for the ccotpir.ic instincts of those forefathers whom we Vm'tcn regard as very primitive people. Asbes tos pottery 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-occupationa! exposures in asbestos areas, but only since 101 ft have we bad 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 minion tons per year, half the \ atal of world production per year and twice as much as the United States annually uses. Finnish Asbestos The present production in Finland is only 11,000 metric tons per year of anthophyllitc asbestos. The asbestos dust in the quarry and mill mineralogically contains: Amhophyi'iic Talc Chlorite 30-75% 20-60% 3-13% The theoretical chemical composition is (Mg, Fr*)T f(OH);. (Si,0,i);). There are small amounts, perhaps smaller than in Canadian asbestos, of some metals such as Xi, Or, Co, which might have some canccrogcnic interest. Levels ef Exposure fo Asbestos Dust Unfortunately the exposure levels at plants have been systematically measured only dur ing recem years. Twenty tears, ago, before the management of tire* quarry and mill changed, the dustiness was. especially in the mill, rather' great. One could only sec a few meters ahead. Tire level of dust was surely marry times higher titan 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. ,,Tiu* present situation of dustiness will be reflected in the morbidity of the next ten to twenty years. Tn 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 taker* witii electrostatic precipitators ;MSA) and/or with membrane niter field monitors (Millipore Filter Corp., Type AA), and (b) breathing /one samples taken with an impingcr (MSA) for panicle counting and siz ing under the microscope. X-iny diffraction methods are used also. In the mill and quarry the total quantity of dust varies from 7.5 to 100 mg/nv". In oilier working places the level of dust varies from 0. 3 to 10.6 mg/m3 or 11 to 2.400 panicles/ cm3. Only 1% to 5.4% of the total dust (impinger-method) has been fibrous panicles, 1. c., 5 fi in length, the length being three to four times the width. In this cornwcilon 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/m3 or ICO to 150 particies/cm3. The level of industrial hygiene in Finland is not yet satisfactory, and unfortunately we must expect still more asbestosis eases. Medical Findings The first medical survey in our asbo.-tos industry was made in 1946 by C. Wegelius. | BB 0015868 | J 93 ;r/~? The results of this x-ray study tell about the --longer time of residence in the dh".!:.'t h.eahli effects of rather heavy exposure dur- --longer and heavier history of smoking ins the first twenty active years of the asbes . --more pneumonia (highly significant) tos industry, From 476 asbestos workers (in --more production of phlegm dustry included) 126 cases (26.5qb) of asbes- --more shortness of breath tosis were found. However. 73fb of these --worse lung functions (FVC, Fe,Y,... and were of stages I or I-II, in which diagnosis AS). was not easy because at that lime only x-ray film si/c 24 x 36 mm was used. Pleura! and pericardial thickenings were present in 3647 of all cases and in connection with stages IIIII and III in ICOfo- Since 1354 the asbestos workers have been examined roentgcnologically 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 lias been more than two years. Among insulators 35 cases of asbestos's have been determined tint'll now. No meso theliomas have been found. There are ap proximately 400-500 insulators in Finland. At present (I960), 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 titan one year. Smoking history is always important in connection with all occupational h.tr.g dis eases. If lung cancer is an average of ten times- more common among heavy smokers than non-smokers (m some age greens even 60 times more common according te some authors), this fact should always be taken into consideration when discussing lur.g can cer as a complication of asbestosis. Tae two environmental factors, smoking anc asbestos, simultaneously make the risk of cancer greater tool These epidemiological studies indicate that asbestosis is still a rather importer.: orctmatiottal'.disease in Finland. Whether or not antbophyllite asbestosis is more dangerous or more cancrrogetv.C than other asbestos tvees, chrysotile, crcckioiitc and amostte, is aa inter esting question, which is being studied at pres ent. Wc might have the answer to thh ques tion in a few years. --One-half of these workers have died "Non-oecupaiional" Asbestos from various causes, which aie under The Finn, Raimo Kiviiuoto, in I960 're study. sented bis observations on ih.c v.ttt's- -- One-fourtli of them have had asbestosis ``Fieural c.deibeation as n roentgerr-'ogic sign (90 VMM'S) . of non-oeeupntional endemic au'.no; hvllitv- In 1967. 135 workers (24 pensioners in asbestosis," at the Xlll'.h International Con cluded) were examined, and among them 37 gress on Occupational Health ir. New York. cases of asbestosis wetc found, of which 13 He had collected approximately CCD cases of were new. In four eases exposure time was special-looking, mostly bilateral ph.-era! on.'V less than ten years, in 17 ca*es it was less titan eifientions among the population in :m asbes 20 yeais. am! in two cases more than 30 wars. tos area. Dr. Y, Rauttio continued th.- s No lung earner or mesotheliomas were found among them cases. When compaiing the asbestosis rases and '.ho )oentgenologicaliy normal people among the 135 examined, the following observations weie made in connec tion with the clink.d. examination: In asbesiosis < ases the following data were .md collected auproximatelv 1.3C3 .-uttilr- casrs, visible in 70 x 70 mm. AP-x-tav tttr- tmes, n the population of the same di-trii:. IPs study was based on mere '.hart fH.i'l.? RP pictures taken n thetern Finnish towns and 106 ru ml coninu'rv-A wi: :u}i c "***- lespon.d to np;5roxi!'J.v*,_!y 23r`c of the Fiarh , sigmlirnmlv present mote often than in the pyeiatiue ovci tliv of nftcc-. In non-asbestosis group; Ti.".:sni":n' comjirir.c, icV'h V; ;:v,- ;'S-v. - --older age quarry is io ctitcu. i;;U cfjit: urc'i!..::- r; --longri '-xposuie time calcification was found ::i l'r c of t;.c * vr-;.- I BB 0015869 1 American Industrial Hygiene Association journal * 09 tion over fifteen years of aye. Under the age of 40 years they were rare, but in persons over 65 years of age the calcifications were observed in almost 30 77. In the rural popu lation elsewhere in Finland only seven cases were found in the 265,223 people examined, hut in two larger towns they were more fre quent, 0.777 of the examined. Kiviluoto has later found 77 eases of calcifications in 35.000 chest x-rav 'pictures from, the population of our second largest city Tampere. Bilateral thickening of the parietal pleura is, however, a very common finding at autop sies in all of Finland, as Dr. Meurman stated in his studv in 1965. Kc found them in 39.377 of his eases, equally in eastern and ,--stern Finland. In 7077 of the cases the '(,,aques were bilateral and in 7277 the find ings were in men. They \\ere more common in the urban population (52.2771 than in the rural areas (31.877), In the asbestos area the incidence and calcification of plaques were higher. Asbestos bodies were present ;n 57.67c of the 264 lungs studied, in men 60.177 and women 54.377- Other findings were: --The frequency of asbestos bodies ir. the lungs is higher in urban than rural popu lations (7 077-49 77). --The frequency of asbestos bodies in the lungs of persons in the asbestos area was greater (however in 5 eases of 15 no asbestos bodies could be found). --In farmers asbestos bodies were found in 4777 and in building workers and work ers of corresponding traces in 6777. --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 eases of bilateral plaques 85.7"77 exhibited asbes tos bodies in the lungs, but, on the other hand, approximates 4077 of the cases showing asbestos bodies in the lungs were free front pleural plaques. --The plaques did not bas e any correlation with emphysema, hca:t disease, pulmon ary stasis, or pulmonary tuberculosis. Chronic bronchitis was not studied. Perhaps the most important finding is that pleural plaques are a sen' common disease in the entire population. Aheady in 1804 Curschmann described them as "sugar icing"-- `'Zuckcrguss"--at the time when the asbestos industry vaa only starfing in some countries. Asbestos bodies--if they are all asbestos (?' -- are rather frequent in bungs: in Finnish, mate rial in 57.677, in some other material between 5 and 5077-. (It depends on what kind o: method is used and in what detail the iur.g1 arc studied.) This does no; mean, however, that they rue "asbestosis eases." as Chemical Week (Sept. 10, 1966) scented to think when it stated, "Forty per rent of all Americans have mild, chronic cases of asbestosis." `.\V do not even know set what materials are r. part of the needles, fibers, bodies, ctr. which have been found in the human body. In the Finnish asbestos area, "nowever, cal cifications, visible in x-ray pictures, are nv-.ch more common than in ether parts of the country. Air pollution is not the or.lv- cat;-' of exposure. We base made some imestivctions and noticed that calcifications arc found outside of the area where asbestos c.is; spreads. Of course, the local exposure to dust (asbestos ovens, asbestos stones in the sauna, agricultural exposure irom dust in fields, etc. could be a cause. But aiso the entire gvomicrologicai composition "of the soil h dmfvrcnt. In our preliminary studies in this area we have noticed great differences, for ex ample, in the Mg-conient of the drinhhu; water, which might influence the calcification processes. Tire study, however. is not vet finished. It, nevertheless, seems that asbestos in the air or soil has something to do with calcification of plaques, because nl-o in occu pational asbestosis eases pleural calcification; arc rather frequent symptom; (in our mate rial of advanced eases in K10r7 of them',. What then is the prognosis cf plaques and calcifications7 Does or.e par; of them dev-, lor ir.to mesotheliomas and why? This is an in teresting question. Our Finnish experience does not as set prove it to ne so. You might ask, "If you find this kind < peculiar pleural changes in esen 9(7 of population, then what is the situation ir. r gard to pleural malignancies and meso:hr he rnas in this area which already has a 4,:Cdycar history of endemic exposure." The Fin- T15870 200 May-J un15CS1 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. Kivihioto came to the same conclusion. Only one ease of pleural or peritoneal mesothelioma has been detected during autopsies from this dis trict (Kivihioto). Twelve eases of meso theliomas of the pleura have been recorded in 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 lias 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 63 has pleural plaques, one could already expect more meso theliomas in this district! Or should we wait still some twenty years longer and sec what will have happened when the population lias aged and incubation lime has been long enough and also other canccrogcnic 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 ntate. rial to woikers' health, just as hundreds of other agents are if thev arc not properly coniioiled in industrial use. We, however, ate at pre'en: able to control it and make the me of it as haiinlv's as the use of other dusts or toxic materials, even radioactive substances, might be. Every occupation has its heahh hazards, so also does the asbestos industry; :n a part of the total health of woikers. asbe'to'is can be reduced by mod em indum in! hygiene to a verv small hazatd. (2) Me cannot agree with, the recent "hor ror propaganda" such as seas wiitten m the Loiiticn Sumiav Titm's bv f m living mat asbestos is, "Capable of kill:." ' nut only the exposed workman but also perhaps ids' womenfolk and even people living near his, place of work." If so, the population in j the asbestos area of Finland would aireadv be at pdreeasdenat nind mn, oebaosdovcsctoosuladreliavemteherareo.rtaSitiril.l,j rate from cancer and other malignancies :/ equal to the other rural areas of the court-i try, although in the worker population tbm frequency of lung cancer might be some-i what higher. , (3) As industrial hygienists see, however,!1 have to continue our work to reach better! and better hygienic conditions and dusts control in places of employment as well as; in tlic environment of factories and minesi to safeguard the workers and genera! popu-1 lntion. There is enough evidence alrcadv m came, us to pav more attention to this health pro':--J lcm. Many questions have not yet been' answered: (1) What is the health significance of' fibrous foreign bodies found in the kings, i and are they all asbestos? j (2) Docs a small amount of asbestos dust/ caused by construction activitv. asbest'-1 material in houses, the brake linings cl' motor vehicles, etc,, rcallv have ar.v irtflu-j cnee on the health of the population in : 1.e urban living environment? Docs this hi:..! j of minima' exposure nave nnv enncerogoi/r eflects? What is the rede of asbestos antor.: the hundred other env ironmental car.ccrogeme agents like cigarette smoke, ixltau-t gases of motor vehicles, fo'd additives, viruses, etc.? (3) How far should we go in dust rout::'. I to prevent tntallv tec developim-nt of new ` asbestosis eases and what shov'd the times-j hold limit be? Or is it impossible *.- reach j the safety limit of 'Okfl with on.lv m.cthr-i ate expenditures? . ji T hcsc me some cmestmns \C;;:.ch. <.'! er.- waiting fui answeis, pm 1 am cousincm! tii.-.t. t with the pioper ( u.k.`'u:atiou of in 'u = tr : hygienists, wh.i'in you me mpm-e:-`net-/ anti medical experts, tle-e ;,ind< of "i 'b'e;-,, will be solved hi the i.iture. i BB 0015871 J American Industrial Hygiene Association Journal 201 Finr'.isK Bibliography on Asbesiosis M.'.Ki.m. Kaj: Jam!. PrfiC. {Uv-j,*- A'l* jihwuj In^uiaior Woi^crs in Fin* Ini. Congr, Ore*./. lit chit, Vicmia Atifi'-V E.t A. Vc^riJo: V'bcr oir AOo:vor^oir.ncu K>nit>a.*.G^ unci line U'ctnutn.e \ ciu*riu!us. Gealvgtsslir l' nil r -.*A Ct otrehni^rhr i 'itZjJentiifhungen Sr -*t , Ii`54;. 1" inn-: **' a\ (Cirt^on): The It'-r.'n'j Tint Aihfilot Kivtuioic.. R.; Ricural CA-riUc.Tiin:i at .4 Roentgenologic Sii:n oi N t`rnvCi;*:ittan,i! i.tH.ynue At.riiojrlo 1 .,;e* ,\0>cstci$t Acte ]\-.uio1, (*S;r<Klioiu) Suv>;L Ki\iuio;v*, R.; lMciu.tl i'iar.uc.-. an;' Asbestos; further oh* if,To: o`4 on citcionuc and n;;;rr no*-ocou;>.loa] as- Sei;c>4>. Arad. Sti. 132: 235 (ibjuj). K.: Plural Calcifications and AkbestoLs, Brit. J. }la.U,uOgy ]j3r,i.v\fn. A.* *t<! V. Raunio; Oiioerkrttiofts or. Atmospheric , Air Cljuwd by A'hoii/t. .w.;iur/ Rtf.ort or iht Jr.uiiuU oj Octk. i>sitt*nal Mesh!, 10:*4, Helsinki {Ji'C-4). I.aj:;..Ti.cn, A., Leo Norn. .*11.d V. Rhui.io: Observations On Atu,o*pncfiC A`.r J'oiiuium Caused l>v AiUuios. X". Aeac. Sti. 13J: 240 (JOGS). Mcunr.a.i, L,i Asbestos flixlirs anci Pleural Plagues in a Finnish 5>crie? of Autopsy Cases. Ana Pain, Sreind, . Swm>L iS2 C!4). Norn, Leo: On the !;%:*'r.*> r.l A'hftitV,,, Aeta Path. tMi* lirevioi. Sluin'. 2J: 53 N010. Lo, K. ArJu'in. A. I.a.u*.anrn, ir.o M. VbVefi: A'hc.-imc als Lcr-n'-lsr.inAurc in Ini. Artk. Ceu e`J: i'b (I'Aiyi. Nntv Leo, X, A.`L..... . A- 0. K-hi.oi.cp. T. P.inanrn, 7*. KiniaJa. L. h,.;.-...en and M. Yu*- r : Orru^atiraai Ar.i}u>phvlii;e-A*'.'v*ic#'..> m r*r.l.ir.r, 1 \ ,.re.:n;;.4r> rtort): Second /.net nat.Ohai O'p vrr/.r.* on the S.oiojical EiTccts c>i A>'*.stu*. Dffsr.rn Rannm, V.: Occurre*,re o LniAu.ii I'n* rh,l.ud in A/k'i'.f* rr Annoipnm: AiOcsto;. Iic.*'jui C-a'c.-tciiinn in win'll Ca^uc ty Sillaner., L-: Ind>>r if j : iiyctene A:!'-is h Slucm c` ( &57)4,`1 mcj.'oj huii r.i Wr*t Kir. g j u IVA. StCpc`n Siit.Ti-.cn, F,,: Oh*r\'A.ion on iie A'`-s:o* Oust Me.v^fer.jcr.is. C/i-cho< iO'.a'i.-Svec:sii*Fr n-'i >xT.pos:urr* co Pr-cumoceakies. Prague. June 12-iT, 1^*3. Werc'iu?', C.: ir. the Lunei ir. bninciv O..H<rvec in riniid. Rci- K: :""3 (P.-i:/. rf At* \'ii*.eri, ai,c K. Ahiman: J<adio't*c\*ai cf C-tacs teith ir. t.e Lieut ol a Crv^a? bl"4lO>. $I+L />-' 2Jil (Flfni'.'ij yi?-.-,,. N'iifccri, M., el cl.: Ui;rathaJi V.\aTnir^t:or>s in Asiicstotu. To i*e puiiiished. Hearing Statistics Racial, regional, and urban-rural differences in hearing thresholds o: Amer ican adults are presented in a new report front the National Center tor Health Statistics. These linciir.gs arc based on pure-tone audiotnetric testing at fre quencies of dOO, 1000. 2000, 3000, *5000, ;:;td 0000 cycles per second in the Health. Examination Survey during 19G0-62. For th.e survey a prebabtiity satnple of 7.710 persons was selected to represent the 111 mil.ton adu.ts in tite civilian, noninstiuuionnl population of the United States aged 18-/$' years. Of these, 6,672 adults, or more than Sbr/c, were examined and tested. Hearing threshold levels reported in this study are limited to those for the "better" ear and principally to trends observable at the extremes of the acuity range--those with better titan "normal" hearing (thre.-ho.ds of -0 decibels or more below aucliomctrie zero) and those with presumably some hearing handi cap (thresholds above 15 decibels). The data indicate that, in general, hearing tended to he somewhat le.-s acute among white than Negro adults. I3y region, tite rates for persons with -tetter man normal r.er.rm.g were si: rhtlv greater in the South than cb;w.-.cre. rstitai residents wete found to be somewhat more likely titan their moan counter parts to have better titan "normal" hearing below 48.,,7 cycles per seccr.d. Charts and tables provide actual and expected rates within specuCw ranges for tite better car and in the norma: speech, range; and detailed dtstr.butions arc presented by sex, age, race, and region, as vcii as by tvpe ar.d size of residence area. Findings ir. this report arc compan-d with, those tror.i several previous hearing surveys in this country, ar.d appendices provide tec..meal in fo: manor. on survey methodology and definitions o: c.e.itr'grap;uc term-- t.scd. Conics of Hearing Levels of Adults by Race, Region, and Arrc of K- siclcnee: United States, 1900-1962 (PHS Publication No.`iC03. Series 11, No. 25), 33 pp. may be purchased for 30 cents front the Superinrettuen: o; Docmne.its, U. S. Government Printing Office, Washington, D. C., 20-'io2: | BB 0015872 |