Document 3NEz6bvjmE1x7dkOrXjZDvQ0x

I Asbestos Exposure, Smoking, and Neoplasia Irving J. SelikofJ, MD; . Cuyler Hammond, ScD; and Jacob Churg, MD Asbestos insulation workers,- as a group,- have a high due to chance, the number of such deaths being risk of dying of bronchogenic carcinoma (about seven or small. During the latter part of the study, we ob eight times expected). V.'e have observed 370 such work* tained information on the smoking habits of most men from Jan 1, 1963 to April 30, 1567. Our findings of the survivors, but we could not obtain reliable indicate that asbestos exposure alone is not the entire information on the smoking habits of those who explanation. Of 27 noncigarette smokers, none died of had died at an earlier date. Therefore, w could bronchogenic carcinoma. Of 203 workmen with a history not at that time investigate death rates in reia- ol regular cigarette smoking, 24 died of bronchogenic tion to smoking habits and exposure to asbestos carcinoma, although only three were expected to die of dust which were considered both separately and this disease. Calculations suggest that asbestos workers jointly. who smoke have about 92 times the risk of dying of There is abundant evidence that cigarette smok bronchogenic carcinoma as men who neither work with ing leads to a high rate oi death frem lung cancer asbestos nor smoke cigarettes. V.'e conclude that asbestos""*! in the absence ot occupational exposure to asbestos exposure should be minimized, that asbestos workers who j dust.ai Our findings outlined above susgested (but do not smoke should never start, and that those now ! did not prove) that exposure to asbestos dust may smoking should stop immediately. - lead to a high rate of death from lung cancer in the absence of cigarette smoking. If the latter be T 1564, we reported on deaths occurring between JL Jan 1, 1943. and Dec 31, 1962, among 632 so, then the. combined effect of both types oi ex posure might or might not be equal to or greater members of the International Association of He3t and Frost Insulators and Asbestos Workers.1 All of these men had been occupationally exposed to asbestos dust for many years. Their death rate from lung cancer was found to iie 6.S times as high as that reported for the general while male popu lation of the United States during the same years, with age taken into consideration. Three of the men died of diffuse pleural mesothelioma and one died of a neoplasm histologically suggestive ot peri than the sum of the two effects. On.the other hand, it was possible that exposure to asbestos dust in creases the risk of lung cancer among cigarette smokers but does not lead to lung cancer among' r.onsmokers. The present study was undertaken primarily to investigate these possibilities. In addition, wo wished to obtain more information on the occur rence of mesothelioma and gastrointestinal cancer among asbestos workers. tonea! mesothelioma.' This was of interest since mesothelioma is a very rare disease in the general Material population but is reported to be associated with From records of New York Local 12 and Newark, exposure to asbestos duSL.J In addition, their death NJ, Local 32 of the International Association of rate from cancer cf the stomach, colon, and rectum Heat and Frost Insulators and Asbestos Workers, was higher than expected; but this may have been a list was made of every man who was a member From Ihe Dc;virinv*n( of Community Medicine. Mourn Sin.ii School of Medicine tlirs. S.-likoiJ and C)ur;j. Mnd ihr Dr pari* of either one oi these locals on Dec 31, 1942. or who joined between that date and Dec 31. 1962. men*, of Kpuicir.joiecy *.:! J*U;;s!its. Amerumn Canter Society No one was omitted regardless oi his subsequent tr>r. New York. Svf'in* a jowl iiHt'imc <? the St't'uon on of (he O.fM v.iv*. she i n J'rrvi ntivv M* i.*-ir.e anti tnc American work history. Personnel data from union records indicated that Co'Jcc:* of ChiM .11 tin* Ilolh annua) convention of (he Ar.t riv;f) Nieiiiul A"c.i.iiM*r.. Al!;intir l`s:v. NJ. Jum* U*. r.**7T. Str^ri and i<? S'li-u N. !*! of Avcivu*. New Yack I\rh'j iDr. &V2:;:o). of the G32 on the union rolis on Jan 1, 1913. 33': ci; the men had first been occupation ally expos.-d to asbestos dust prior to 1922, ar.d an additional A i 7937 JAMA. AprJ C. J?*? Vcl 77*. l-f? 3 4U, 223 men had first been ex posed between the be Table 1.--Subjects Classified by Are as c! Jan 1. 1S53. and by Years From First Occupational Cxooscre to Asbestos Dus: uo to Jan 1.1963 ginning of 1923 and the end of 1942. All of these men were successfully traced through Dec 31, 1962, and 262 of them were found to have died up to that time. Of the 262 deaths, seven oc curred prior to the 20th anniversary -of the man's first exposure to asbestos Act. Tr 1W 1C44 ISO 5054 55-59 SO** 95-69 70-74 75-79 80*94 Taul * Suaiccii 2 IS 32 109 SO 42 49 31 21 4 370 r 20.24 2 12 .1.7. ............ ...... 31 Ho. of Ttan Smct First Capoture to Asbestos 2M9 ... i 2 1 1 1 .m.m. 3.0..-.3..4 13 to 1C 3 1 . mm 113 3.5.-.3.9 21 34 11 10 3 ... . 1C 4044 ... c 19 1C 12 1 1 59 45-49 * 1 1* 5 1 39 NO. Ot ...so**. 52 M. 1 *. 2 16 ... 11 16 2 17 17 16 IS 6 23 36 94 dust and 255 occurred after the 20t'n anniver sary. Thus, of the 632 men, 370 were still living on Jan 1, 1963. These 370 men were the subjects of the pres ent investigation. Table V shows their age distribu tion as of Jan 1, 1963,and the lapsed time from first exposure up to that date. All of them have been traced, and 24 of Table 2.--Subjects Classified by Age and by Smoking Habits on or about Jan 1.1963 35-39 40-44 45-49 50-54 55-59 6064 65 49 7074 75-79 E044 Tot,! . Total No. 2 13 32 109 60 42 49 56 21 4 370 Never Smoh.d Regularly 1 2 2 12 ^ 6 7 6 7 3 2 48 Ccr Only ... i 6 5 4 6 7 7 1 39 cigarette Smokers* -i 2 S 26 16 IS 17 12 6 1 101 Current Cigarette Smokers* 1-9 a Day ... ... .3.. 1 ... .1.. ... 1019 a bay ... 5 3 -4 4 1 20-19 a..O.ay 5 12 33 20 11 9 4- 3 04 . * 40+ a Coy A 4 12 24 10 4 $ 3 l ... s 17 97 63 them were found to have "Induces cigarette imokri who Km smoked pipes or ci|irt. died during the four-year and four-month interval from Jan 1, 1963, to April 101 were excigarette smokers, five currently smoked 30, 1967. one to nine cigarettes a day, 17 smoked 10 to 19 Beginning in October 1952, we made arrange cigarettes a cay, 97 smoked 20 to 39 cigarettes a ments to examine these men periodically, once day, and 63 smoked 40 or more cigarettes a day. every six to twelve months; the interval depended The smoking habits of the 370 subjects were upon age and physical condition. The examinations compared with the smoking habiis of a large num-. include chest x-ray films as well as physical ex ber cf men selected from the general population.' amination and cover pas: and present smoking There were proportionally more cigarette snickers habits, occupational history, medical history, and among the 370 subjects than were found in the current physical complaints. Altogether, we have general population sample; age was taken into examined 33S (91.4 = ) of the men at least once consideration. and have repeatedly examined most or those who Causes of Dealh.--A copy of the death certificate arc still living. was obtained for each of the 94 deaths. In addi Information on smoking habits was obtained by tion, we examined hospital records, postmortem persona! interview with the 336 men who were ex findings (41 cases), as well as the surgical and amined. Of the 32 men who were not examined, pathologic reports when surgery was performed (39 six told us their smoking habits by telephone and cases). We also reexamined histologic specimens. five gave us the information by mail. The local It was found that the death certificate was inac union secretaries (who personally knew these men curate in 14 instances. However, this did not alter well) ascertained the smoking habits of IS men, the picture as much as might have been expected and family members' supplied the information on since there were several compensating errors. For the remaining throe men. This accounts for all of example, in one instance the death certificate in the 370 men. Table 2 shows their smoking habits dicated bronchogenic carcinoma as the cause of on or about Jan 1, 19G3, the men being classified death while a review of the histologic specimen by their ages on that date, even though some showed that death was due to pleural mesothe changed their smoking habits between 1963 and lioma: but in another instance exactly the reverse 1257. was found. Likewise, review in one instance re Of the 370 men, 4S never smoked regularly, 39 sulted in changing the reported cause of death smoked or had smoked pipes or cigars but never from bronchoecnic carcinoma to cancer ot the smoked cigarettes regularly, and 263 had smoked stomach with metastasis to the tunas while review cigarettes regularly, dame ni those \.ith history of ir. another instance resulted in exactly the cigarette smoking also smoked pipes or cigars. Of change. The 94 deaths were ascribed to the billow the 253 with a history o: regular cigarette smoking, ing causes: bronchogenic carcinoma, 21; pleural JA'.'A. A-ril 3. 1?CC Vol got. Mo 2 Ai7933 105 , t.;cc;cC Mum:*' 11 Arr.org 370 Asbestos V.'sr-sri During tne 2-f-'cntn 'mod C*utc >f Dutli TSut cancer (all sites) cf piewra. bronchus. #A0 ircchcc Bronchogenic carcinoma Pleural mticihclioma Ftfitoniil misoiniliomi Cancer cf stomach C*nctr of colon end rectum Cancer of lt other sites combined Asbestesis Heirt end sircvletory dtseese including Sirota . All other causes of death Total, alt causes Observed Oeeihs a* Caoecieo Deaths' 44 27 2-3 24 t 3t 72 3 04 5 L2 7 4J 15 22 :u B 104 77 < 'Based uoon US monaitr euu Citrtgaroing imoiirj nasns. luni-.td States can net avaitaeic. cut u(uit snouie a* only slightly less than 2.3. tUmlee Styles data net available, but these are rare causes of death in general population. mesothelioma, three: peritoneal mesothelioma, sev en; cancer of the coion, four; cancer of the rectum, one; cancer of the. stomach, three: cancer of the pancreas, two; cancer of buccal cavity and pharynx, two; cancer of bladder, one; cancer of undeter mined primary site, two; asbestosis, 15; cor pul monale, one; comary heart disease, 17; congestive heart failure, one; cerebral vascular lesion, two; aortic aneurysm, one; cirrhosis of the liver, three; bronchopneumonia, one: encephalopathy, ' one; acute pancreatitis, one: Wegener's granulomatosis, one; and accidental fall. one. Expected Deaths.--?or purposes cf comparison, we wished to ascertain how many of the 370 sub jects would have died curia." the 52-rr.or.:h period (Jan 1, 1963, to April 30. 1967) if their age-specific death rates had been exactly the same as for the general white male population oi the United States. For this purpose, we made use oi the United States 1964 life table for white males; this provided the roost stabh basis ior comparison. It should be noted that for white males total death rates and death rates from respiratory cancer were slightly higher in the industrial states of New York and Kew Jersey than in the United States as a whole.1'* On the other hand, respiratory cancer death rates in white men aged 20 to G4 are reported to ire a trine lower than average among laborers, not elsewhere classified employed in construction wo:!-:.* . From the life table we determined for each of the 370 men the probability oi his dying within a pe riod of 52 months, considering his age on Jan 1, 1963, and assuming that the life table probability applied to him. Summing these probabilities for the 370 men yielded an estimate of the "expected'' number of deaths under the null hypothesis that the agc-specinc death rates of these asbestos work ers are the same as for United States white males in general. The computation indicated that 47.5 deaths would have been expected. Next, we wished to estimate the expected num ber of deaths from each oi several causes. For this, we made use of the percentage distribution oi deaths by cause oi death among United States white males of various ages during the yea as reported hv the National Center for Heal tistics. These percentages were then stand: for age according to the .age distribution a of the 47.5 expected deaths. The resuits are in Table 3. Expected vs Observed Dccths.--.\s sbo Table 3, there were 94 observed deaths tie, the 370 asbestos workers died) as comparec ' 47.5 deaths expected on the basis of the age-s death rates of all white males in the United . in 1964. Thus, there were 94 minus 47.5 excess deaths. The excess deaths were cue to chogenic carcinoma, mesothelioma oi the : and. peritoneum, asbestosis, and cancer o stomach, colon, and rectum. Cancer o{ Lung, Pleura, end Trachea.--In lished mortality data for the United States ing deaths each year from various causes b> sex, and race, the following diseases are comb cancer of the lung (including sarcoma oi tne 1 cancer oi the bronchus, cancer of the pieura cancer of the trachea. For this group of cis*. there were 27 observed deaths and only 2.. peered deaths, a ratio of neatly 12 to 1. It is well known that, for the United Sra: a whole; all except a very few of the death ported in the combined category are cue to 1 chogenic carcinoma. Thus, it may be assumed there were close to 2.3 expected Heaths from cause as compared with 24 observed- deaths, a of over 10 to 1. Mesothelioma.--Ten oi the 4 observed de were due to mesothelioma, three ware cu*. pleural mesothelioma, and seven were clue to ; tor.eal mesotheliomas. This is such a rare' cis th2t if the 370 subjects had been selected : random sample from the general population, would not have expected any of them to db mesothelioma within a period of 52 mentns. All three of the men who died of pi-rural m ihelioma had a history of regular cigarette smox Oi the seven who died of peritoneal mcsotheiic one never smoked regularly, one smoked only r: and cigars, and five had a history oi regular c rette smoking. Cancer of Stomach, Color., and Rectum.--in earlier study of asbestos workers,1 there were m deaths than expected from cancer of the stem: coion, and rectum (9.4 expected, 2D observed), compared with a total of l.S expected deaths i: these causes, there were eight observed deaths this study, due to cancer oi the following si: stomach, three; colon, four; and rectum, one. . though this bears out our earlier finding;, the r.u ber of deaths from these causes was so srr.aii we still retrain from drawing any conclusion this time. As bes t osis. -Asbestosis accounted for 15 of *- S-l deaths. While it is not surprising that i-vr.t from this disease occur among men cxp^t-ii asbestos dust, attention must be caiieti to me fv \ 7 9 3 3 100 JAMA. April . 10C ` Vet Z0 `. ** i.' *. J ( i t wv cAr ^wrvc---d&uiKOFF ET AL 1W that these subjects were primarily insulation work Taoie A.--Estimated Numbtr of Lur- Cancsr CeatM Expected to Occur Dunn; a Fensa Of 52 Months per 10.000 Men Livir^ at the Start of Period: by A' and by Srnokm-r Habits* ers. V/hile all of them were occupationally ex posed to asbestos dust, their degree of exposure was light as compared 'with the degree of ex posure of asbestos miners, processors, and weavers in earlier times. Bronchogenic Cardnomo.--Bronchogenic car. dnoma accounted for 24 deaths while only about 2JJ were expected on the Currtftl Ce*r*ttt Sffl*rtT A<, Vr (Jan 1.1963) 35-39 40-44 45-49 50-s* 55-59 60-64 65-69 70-74 75-79 >0-64 $moM& Rtgularly 0 2 2 7 6 16 14 12 21 25 Ciar Ctcitarattt 19 Only ......t ... ......2 Smnkars; 5 7* 10 a Oay ... 22 26 IS S3 ...n 71 to 32 97 52 100 103 5) 109 ...32 ]4( 10-19 4 . .O.a.y 44 .9.1. 157 206 1*15. 20-39 a .O.a.y IS 39 69 117 190 305 286 3.4.1. 404* a ^Oa_y . 15 46' 99 165 256 350* 450* 3.2.9. ueefi dm from a oratsastiva stud/ t* for u$ monsuty *dertenc*. rCihOst* >rtdiciu rm omitue for ca?t<sries with no suoiasta n tn* $aa Taota 2. :inefufl*s eier*:x amohara ne i.`*o srro*9 919a or cigar. Man with a History of only ci|mui amount Hava Mgntr long eanear r;tn than noA nara. (Rms abUtnad by smootnmf tf* oau. basis of general United States mortality data for divided into many five-year age groups, some of the white males. However, as previously mentioned, subgroups contained only a smail number of men. evidence at hand suggests that there were propor In consequence, the lung cancer death rate was tionally somewhat more cigarette smokers among statistically unstable in some of the very small sub the 370 subjects than among white males in the groups. In three instances where the observed rate United States as a whole, age being taken into in a small subgroup appeared to be badly out of consideration. This might have partially accounted line, we arbitrarily made an adjustment to bring it for the high bronchogenic carcinoma death rate of more into line with adjacent figures in the table. the subjects. For this and other reasons we made These adjusted figures which are indicate^ with estimates of the expected number of bronchogenic symbols in Table 4 carry very litrle weight in the carcinoma deaths, the smoking habits of the men final calculation. All of the rates were then ad being taken into consideration. This was done as justed as follows: follows: Lung cancer death rates in the United States Data are available on lung cancer deaths in re have risen steadily year by year and were higher lation to the smokir.2 habit; of 440,000 men en in 1964 chan during the period i960 to 1964 as a rolled by American Cancer Society volunteers in whole. Furthermore, in the study described above, a prospective epidemiological study between Oc we avoided enrolling seriously ill people ana. ss oi tober 1939 ana March 125G and traced through the cui-ca date for preparing the computer tape, Sept 30,1964. Causes of death were ascertained from we had not yet received death certificates for ail death certificates. but whenever cancer was men of the men now known to have died during the tioned on & death certificate inquiry was made of specified period of time. For these reasons, lung the physician who signed the certificate. In case cancer death rates in the study population were of disagreement between the two sources of infor appreciably lower than those reported for white mation, the physician's statement was accepted. males in the United States in 1964. To compensate For the purpose at hand, we only made use of data for this, we raised the rate of each individual smok covering the 52-month period beginning on June 1, ing category so that the total lung cancer death 1S60, and ending on sept 30, 1964. The number of rate (disregarding smoking habits) in each five- lung cancer deaths occurring during the 52-mcn:h year age group would be the same as that of all period was divided by the number of men alive at United States white males (based upon the 1964 the beginning oi the period. This was done by five- life table and the 1964 distribution of deaths by. year age groups for men in each of the following causes of death). The results of these computations smoking categories: (1) never smoked regularly are shown in Table 4. (It should be noted that (nonsmokers and occasional smokers being com Table 4 shows only such rates as were required ior bined); (2) history of regular pipe or cigar smok iurther calculations.) ing, past or present, but never smoked cigarettes The rates shown in Table 4 were then applied to regularly; (3) excigarctte smokers (including those the number of asbestos workers shown in each of who had smoked or currently smoked pipes or the corresponding internal cells of Table 2. This cigars); and (4) current regular cigarette smokers yielded an estimate of the number of lung cancer (including those who also had smoked or currently deaths expected to occur during a 52-month period smoked pipes or cigars). The last of these cate* among the 370 asbestos workers classified by their gozies was further divided by current number of smoking habits. 3y 'expected" number, we here cigarettes smoked per day: 14a) one to nine ciga mean an estimate of the number of lung cancer rettes a day; (4b) 10 to 19 cigarettes a day: (4c) deaths which would have occurred under the null 20 to 39 cigarettes a day; and t4d) 40 or more hypothesis that asbestos workers do net diner from cigarettes a day. Since the men were divided into other men in respect to their lung cancer death raven groups by smoking habits and further sub rates, both age and smoking habits being taken A. r^t,\ s. 19C-3 voi CM. No 2 A :794C !57 T2ble 5.--Ci*er/ed *nC Exrcttcd Brenchojesic C?rcmema Deaths by Smckin? Habits' for 370 Asbestos Workers Smoking HkH Never amehed rcfularty History of pipe, csgar smohmc only History of ictvltr c.sircttt smokmgt ODbesaetrhvsed CO>peexetnletd 0 0.05 0 0.13 24 2.98 T*Ut 24 3.16 11Bnactlueddeuspeonnspratrt.**smTooksetr*s2onaendaTltoasstem4o.ked pipe or Otar. Table 6.--Expected and Cbss rved Cea;t!S Among 632 Asoes to* Worker* Exposed to AsOesto Oust 20 years or Longer ToLtaalpd*CtsUlhds: all causes Observed ToEtaxlpceicwteidn; an sitae Observed CaEnxcpeercotef dlung, trachea, pleura Observed Cancer of stomach, colon, rectum Expected Observed CaEnxcpeercatelldether sites combined Observed AsbE>epsteotstelsd Observed AllEextpheecrtecdauses Observed 1943-1962 203.5 255 353 95 Total 1963-1967 1943-1967 475 94 251 349 *.6 4SJ 49 144 6.6 45 25 27 85 72 9.4 15 1U 29 37 205 21 -. 0 12 45 14 *. O 15 25 35 O 27 167 38.9 2055 14* 30 179 into consideration. The results are summ arized in Table 5 which shows t!r.e expected and observed number of lung cancer deaths in each of three smoking categories. Taking smoking habit; as well as age into con sideration (Table 5) a total cf 3.2 bronchogenic carcinoma deaths were expected whereas taking only ago into consideration 2.3 deaths were ex pected irom this cause (Table 3). Thus, perhaps one of the excess bronchogc-nic carcinoma deaths might be attributed to the fact that there appear to have been proportionally somewhat more ciga rette smokers among the 370 subjects than among men of the same ages in the general population. The following statements are based upon the data shown in Table 5. Twenty-four deaths irom bronchogenic carcinoma occurred among the 370 subjects compared with oniv 3.16 expected, a ratio of about 7.6 to ]. This is siighriy Jiicher than found in our earlier study which indicated a ratio of o.S to 1 (not taking smoking habits into considera tion). It should be noted in this connection that the 370 subjects in this study had been exposed to asbestos dust somewhat longer titan the subjects of our previous study (the present 370 subjects are survivors as of Jan 1, 1963, of subjects in the previous study). Of the subjects who never smoked regularly and (hose who smoked only pipes cr cigars, none died of bronchogenic carcinoma whereas 0.1S of these men v.ite expected to die of ium: cancer. Tin's sug gests that exposure to asbestos oust docs not in crease the :i'k ci Lucnuhogcnic carcinoma among 103 n7941 men who never smoked cigarettes regularly. ; ever, considering the small number of such sv.h in this study, we only conclude that expose asbestos dust does not greetly increase the r. bronchogenic carcinoma among men. who : smoked cigarettes regularly. Twenty-four of the men with a history of re cigarette smoking died of bronchogenic card: whereas only 2.9S were expected to die of it. a of S.05 to 1. From this it appears that exposu: asbestos dust greatly increases the risk of cancer among cigarette smokers. Now we may ask how greatly is the risk of t chogenic carcinoma increased by the combine* fects of cigarette smoking and exposure to asb; dust. To answer this question, we applied ; shown in Table 4 for nonasbestos workers never smoked 'regularly to the number cf sub; with a history of regular cigarette smoking as sh in Table 2. This indicated that only 0.26 of subjects with a history of regular cigarette srr.o. would have been expected to die of bronchos carcinoma if they had never smoked regularly' had never been occupationally exposed to asbc dust. Since 24 of them actually died of this ca the ratio of observed to expected deaths is 92 (ie, 24 divided by 0.26-92). This appears to aicate that cigarette smoking plus occupant exposure to asbestos dust increases the risk bronchogenic carcinoma by a factor :r. the orcie magnitude oi 92 to 1. It should be noted that estimate does not take-current amour.: oi cigar, smoking into consideration. Comparison With Earlier Findings.--As exploit we started with a cohort o: 632 asbestos insula*, workers, the entire membership oi the union Ic* on Jan 1, 1943. We have now traced each n through April 30, 1957. Table 6 shows the ebser and expected number of deaths ior each oi t periods (the first. 1943 to 1962, being previcu reported') and for the entire period. In Tespect respiratory cancer (lung, trachea, and pleura) : in respect to cancer of the stomach, colon. : rectum, the findings in the two periods are in ci agreement. Comment The increased risk of neoplasia (mainly brcr.c: genic carcinoma and mesothelioma) among ir.su tion workers reported here should be evaluated the knowledge that these men have comparativ light exposure as asbestos trades go. Primarily c ployed in construction work, many of the mater: they use contain little or no asbestos ana c:h< have only 5Fc to 15>. Conditions of work va: these men often work outdoors unlike operators in factor.' work. Comparatively i\w iiu exposure surveys have keen made in this irr.de their results have generally been wr.inn the 3 n lion particles per cubic foot permh.-ih-e ii.n;t* c really accepted by the American C -; ' Governmental Industrial Hygieniita. 'Mur hr. JAMA. April 5. Vc.l T. m ' additional potentially carcinogenic substances been 40 years ago. Youngsters who start smoking now identified among the other materials used.1* Heavier or even lighter exposure may result in different decrees of risk of neoplasia. Heavy factory have a much greater chance of having both ex posures simultaneously. Significance of Findings for Asbestos Workers.-- exposure in the past has in some instances resulted The import of the data reported here seems clear. in considerable lun? cancer risk." In others, para There is an extraordinary risk of developing and doxically, little lung cancer was seen because as- dying from lung cancer for asbestos workers who bestosis was so common and so severe as to cause smoke cigarettes regularly.. In the group studied, death of the exposed workers before they could live the combination of asbestos exposure and cigarette long enough to develop lung cancer. Once exposure smoking increased the risk approximately 20 times was reduced by improved industrial hygiene prac compared with men who neither work with asbestos tices, early death from asbestosis sharply dimin nor smoke! ished and lung cancer became common.'* Of 283 asbestos workers who had a history of In any case, heavy exposure is not likely to be cigarette smoking. IS died within a period of 52 the most important problem in the future, unless months whereas only 32.4 would have been ex tbere be sheer carelessness or unconcern. Rather, pected to die within that length of time if their age light exposure, similar to that in insulation work, specific death rates had been the same as for the be much more common, both in direct asbestos general white male population of the United States. working trades and as the result of indirect occupa Of the 78 deaths, 24 (31%) were due to broncho tional exposure, as in the construction and ship genic carcinoma. It is estimated that if these men building industries. had smoked cigarettes but had not beer, exposed to There is another type of "light exposure" which asbestos dust, only 2.9S would have died of bron may ailect many more people than those industrial chogenic carcinoma within the same length of time. ly exposed. In the past several years, it has been If they had neither smoked nor been exposed to demonstrated that asbestos bodies can be found in asbestos dust, only 0.26 would have been expected the lungs of 25% to 50So of adults examined at to die of the disease within a period of 52 months. autopsy in large cities, such as Belfast. Northern Of 87 asbestos workers who-never smoked ciga Ireland, Capetown. Republic of South Africa, rettes regularly, none died of lung cancer within the Ivliami, Fla, Pittsburgh, and Montreal. This is 52-month period (although three died of asbestosis presumably due to "asbestos air pollution" by and one died of peritoneal mesothelioma). This fibers derived from industrial "spillover" (as dust finding, being based upon the experience of only from construction sites or iaciory wastes) or from S7 men, does net prove that exposure to asbestos end-product use. Such community asbestos air dust has no influence cn the risk of lung cancer pollution may be important since there is already among nonsmokers. However, it suggests that ex evidence that in certain circumstances, as living posure to asbestos dust docs not lead to an ex within half mile of an asbestos plan: or in the tremely high risk of lung cancer among nonsmokers. household of an asbestos worker, intimate environ The conclusions are evident: mental contamination can be associated with some 1. Occupational exposurt to asbestos dust should risk oi mesothelioma.13 What is not now known is be reduced to as low a level as possible: but there whether the minimal amounts inhaled by the gen may be an irreducible minimum ievel if asbestos, a eral public carry a similar risk.1* very useful material, is to be used at all. Such Nor do we know whether inhalation of the very reduction in exposure will benefit asbestos workers small amounts of asbestos present in the air oi some oi the future. However, we are also concerned with communities is associated with a special lung workers who have already been exposed at signifi cancer risk in cigarette smokers (or. conversely, cant levels for many years. Asbestos fibers wifi re whether cigarette smoking makes the inhalation of main in their tissues lor the remainder of their lives. very small amounts of asbestos particularly hazard 2. All people incur a great increase in risk or lun2 ous). It will be important to ascertain whether such cancer if they smoke cigarettes: ior asbestos work cocarcinogsnic or potentiating or precipitating rela ers the increase in risk is tremendous. Asbestos tionships exist because, with the rapid growth of workers who do not now smoke cigarettes should asbestos use (5G0.GQ0 tons per year world produc never begin. Those who do smoke, should stop tion in 1230 has risen to over -t.000.000 tons per immediately. We may hope that the decrease in year now), it may be difficult for cigarette smokers risk which results from cessation of smoking among to avoid inhaling air contaminated with asbestos. the general public* will be the good fortune of the It may not be easy to unravel the interrelation asbestos workers as well. ships which might exist between community as This imotu-mon w.is uii.-porlcd ly ihe Health P.cc.neh Coun bestos air pollution and cigarette smoking. Both cil -A the City u[ New York. asbestos cxo>urc and cigarette smoking have a long-lapsed period between on.-et oi exposure and occurter.cc o: rseopitvsia. yet tor current smoke;s these two exposures may not have begun simulta neously; there was much less asbestos used 20 to References I. .SeliiosT. U.: Chars. f.: ami U.uumrttu!. F.C.: fWMirv 1N1I NVo:Civi.. JAMA 1 Apr;i *ii tv*-i V. !-/.: C-hur<. !.: jmf K.r.niw?ui. K.C.. Ii* .i:wu !%?* lv**-**n fv\iH^urv lo A<liv>i' an.I Mesciln-lioiiy, .Vex J ./( f.Marc:i Hi l>*V -V vv.. Ap.nl 8. Vc*l :*C-. Ns 2 A i794 o 103 g 'Hmmond. E.C.: "Fmokin* in Rrlntion to the Dcnih Roes of j f/.O.f'k* Mrn And Women." in tp^f^njniji-ico Study f Cancer and Other Chrome Di>>-ctet. Ueike^di. Mil: Nation*) Cancer lnlit*- ICCu. monofttaph 19. pp K1<CC4. 4. Smnhine and Health. Report of the Aivior>* Committee to the Kutseon General of tr.r l'unlic Health Svrsire. poblication 1103. US Dept of Hr.tlih. Etlurauon. anil Welfare. 1904. 5. Hamntsrtd. E.C.. and Garr.nWel. I.: O.jnics in Ccaretle Smokir.g 1P39-1965. Amvr J Public Health oStCiMfi fJim) 1968. 6. Vital Slstisties oi the Untied States, lirn). part A. US Dept of Health. Education, anti Welfare, 1965. vol 2. 7. Death nates From Moiipnent Scoplasms. I960! Public Health Service, publication 1113. US Dept of Health. Education, and Welfare. 1963. 8. Mortality by Occupation and Cause of Death. Public Health Service. US Dept of Health. Education, and Welfare. Vital Sta tistics Division, Vital SuusticvySpecial Reports. 53:323 (Sept) 1963. 9. Heischer. W T.. et al: A Health Survey of ripe-Coverinp 0|e-rations in Conirurunj Naval Vcvelt, J Induttr Hvg Toxic 28:9-16 t Jan) 1946. 10. Kenne* W.T, and Zavon. MJl: Occupational Hazards of Pipe Insulators. Arch Knrtron Heoith 13:171-175 tAupt 19-16. 11. Doll. Ru Murulitv Prom Lun; Cancer in Asbestos Workers. Brit J Induttr Met! 12:S1.`6 t April) 1953. 12. Jacob. G. and An>pch. M- Pulmonary Neoplasia Amort Dresden Asbestos Workers. Ann Aft' Acad Sc lSZiiSo-StS (Dec 31) 1965. 13. Nothoufe. S1.I_ and Thompson. H.: Mesothelioma of Pleura and Peritoneum Following Exposure to Asbestos in the London Area. Drit J Induttr Med S261-2C9 (Oct) 1965. 14. SelikcS. U. et al: Aabvstosis and NeopUsia. Amer J Med 42:457-496 (April) 1967. Ii 110 Many, possibly most, of the words in the dictionary stand there as representatives of a whole family of forms. Not even the timiaost of the linguistically timid will run to the dictionary for encouragement when, for instance, they want to refer to a spell of "hiccuping," provided they are certain that Webster does know "to hiccup." All the tense forms, the participles, the gerunds are assumed to be authorized by implication the moment the infinitive is known to exist The plurals of nouns are similarly taken ior granted, and the iorms of comparison and the adverbial forms of adjectives. This phenomenon is generally covered by the assertion that a dictionary is not a grammar and that each individual entry in a dictionary stands simultaneously for all its grammatically possible forms. (For details, consult your grammar.) But is a gerund a grammatical form? Or is it a sufnx-dorived noun? I am not really looking for an answer. I ask those questions to suggest that the dividing iine between grammatical form ana derived neologism is both hard to do* fine and artificial. If I distinguish--among men--the "hunting" worn the "hunted," I have done r.o more than form (grammatically) two nouns from two adjectives which are forms < grammatically) implied in rite existence of "to hunt" But if "hunting" is implied, why not "hunter"? Why not "huntee" and "huntable" and "huntabilize"? The question of -a hen a new word is a new word and when it is merely an "im plied" form of a conventional term is indeed more complex than is grossly appa-ent Take "Jehairabil ty" r.s an example. Can I e'aim the word is implied in the cx-istence of "hair," or must I assume the responsibility for having spawned a monster? Or take "unequivocably," which indeed was the starting point of all this rea soning and woncerir.g. for it was spotted as a bold neologism in JAMA in the sentence, "Research at the Public Heoith Service Hospital at Lexington, Ky, has unequivocably proven that methadone has all of the euphoric properties of morpltine. ..." Now, clearly, the adverb "unequivocably" is grammatically implied hi the ad jective "unequivocafcie." and this in turn is implied--grammatically of semi-grammatically or otherwise--in "equivocablc." If we grant further that formations in "able" of "-lble" are likewise legitimate without special dispensation, we shall conclude that "unequivocably" is in no sense a bold departure since "to equivo cate" is a firmly established, standard English word. But there is a hitch and a flaw in the argument. "To equivocate" means "to use ambiguous language" and (by extension) "to render ambiguous." Hence, "equivocable" can only suggest the trait of "being apt or able to be made ambig uous." and that, 1 fear, was not intended. Which means, by t nongrammatical) implication, that the discrepancy between the obviously intended meaning of ``un equivocably" and its structutally supported significance was the cause of the un pleasant jolt experienced by the spotting reader. PS.--It is of course possiole, and even likely, that "unequivocably" was just a typo for "cquhocally." Alexander Code, PhD A 17 9 4 3 JAMA. April 8. :9GC t Vol 2C4. No 2 I I