Document 58bzzOLLOeY3kjkVdeRODVKV

FILE NAME Household Contact HC DATE 1949 Jan DOC HC066 DOCUMENT DESCRIPTION Journal Article - Cancer and Environment 4/29/83 wo ve | tf an ANUARY 1949 SCIENTIFIC AMERICAN VOL 180. NO 1 CANCER AND ENVIRONMENT 4 Scientific and technological progress have exposed man to new physical physical and chemical agents Some are believed associated with the rise of cancer as a cause of death by Groff Conklin F HE industrial era its full expan T is barely two generations old yet during that short period literally thousands of entirely new chemical and physical constituents have been added to . ruman environment Few of these con- estments have been exhaustively analyzed analyzed for their range toxic effects on man They are now being studied however as possible contributors to the rise of cancer The growth in the relative importance ol canere as a catise ik death is me uf the outstanding medical facts of the past 50 years The disease has moved from eighth to second place in the U. S since 1900 and today only heart ailments sur- it The reasons customarily given for -- this improved diagnosis and the ezing of the population not entirely explain it They provide no satisfactory wer to the fact that approximately seven and a half per cent of the known cancer deaths in 1911 decurred in age groups undir 40. There is evidence more* that the disease is not an inevitable consequence of bodily degeneration due to ag aithough the changes of senescence nader certain conditions may be con- tributing factors it seems certain that thee is a net increase in true cancer deuthis if only because fewer people die trom other diseases than in the past An explanation of this increase and of the causes of the disease is therefore being sought our environment so much INS complex than was in 1900. Thi alivestigation is focused on carcinogente agents as lite substaners that produce Cueer are calleil ami in the general questiny ' ut at the eam extent extent to which whicwhhich the ins may be nused by agents ,, , 10 environment ni nave Inthente been considered comparatively harmless It has been established that certam agents to which people are exposed in in- dustrial occupations cause cancer if the exposure to them is sufficiently intense and prolonged As an example over 15 per cent of the miners the Sehneeberg uranium mines of Germany die sak lung cancer nuire than 50 per cent of those in the Joachimsthal uranium mines across the border in Czechoslovakia dir Alpha rays Bata roys Gamma rays Ultraviolet rays : rays . Arsenic , . Asbestos . : Chromotes : Nickel carbonyl Beryllium $2 i Ca Anthrocane oil reba ae . Aromatic amines Benzol Carbon black Creosote Mineral oils Paraffin oil . Polycyclic hydrocarbons Shale oil Soot Tar and Pitch Aniline Azo dyes . Estrogens rt , a TS Schistosome Virusas hematobium hematobium Clenorchis sinGASIS PY on wee ne of the same cause In the 18th century st was learned that among chimney sweeps exposed to intense concentrations of snot e deaths from cancer were between three and four times as high as those in the gen eral population It is known also that certain common substances in concen trated doses can pr^>sluce canevr for ex- 4 ample mouth cancers are uncommunis frequent in tribe in India wharti sunkes eigars with the lighted end in the muuth This causes them to suffer frequent burns and to receive a concentrated dosage of tubacen tars Although these are special cases nt ; intense exposure they naturally suggest speculation as to whether the average human being's relatively mild but long- continueil exposice to new sulistances in a contaminated atmosphere in prierssed funds in cosmetics and in other elements of our environmert may be a contributory cause of cancer We have as yet no cos elusive evidence for or against this pussie bility We have mis accurate estimate of how many of the artificial substances comniou to our lustrial civilization may ' be carcinogenie unuer special circum stances stances nor low any seemingly harnd- - substances interacting with others tral appear to be espially utnicuous mas jo duce carcinogenic results CARCINOGENS known to be pre- pre- ent in human enstonment enstonment are clasin classin hed Less certain agents are in stahes There are < Ce ere MJNA Thecertet alinancer alinancer ^ 143505 143505 curelye Teottatieerss pte thee lants chan_vs chan_vs ota 130 Celi wee ne ere vy A esate, oe os metabolism tissue degeneration viruses . and on Most of these theories how ever deserile mechanistis rather than . . . . moo. . 7 ; -? 4 . aeOe on Mle! ote ey t wend 4 . . 7 . a LAL "owe . . . . . . 4 SINUS Nickel corbonyl * --o < * on ee we 7 ee eins 4 MOUTH Betel nut and tobacco chewing ~ THYROID Jodine q deficiency oot ad ye . iad we . . 4 BRONCHI Nickel carbonyl Radioactive substances Q LUNGS Asbestos Chromates 2s * ee Nickel carbonyl ~~ Radioactive Radioactive Radioactive substances . to. Tar fumes eet oS q LIVER Dietary deficiency ao 4 KIDNEYS Aromatic amines 74s ete . - wey 4 BLADDER Aromatic amines Schistosoma hematobium rm - se a wer f Take te a + 4 URETER Aromatic amines hirst causes ladeed with two or three ex- ceptions all of them seem to require the presence of a triggering agent Possibly the most fruitful current theory is the one that attributes cancer to muta- tions in body cells causing muta- tions it has been demonstrated by experi- ments may be produced by ultraviolet radiation rays radioactive substances and a number of chemicals While more than 99 per cent of all cancers are still of unknown origin nearly all of those for which a proved cause has been found arise as the result of external agents The seem to mutate the cells into a state which is or can become cancerous The methods by which these external agents act upon the body vary considerably depending on the substance in- volved Some carcinogens may cau cancer directly Examples of these are tar the mineral nil- and certain dye intermedi- ates known as aromatic amines Tars generally affect the skin Mineral oils may cause cancer of the lungs through inhala tion The aromatic amines strangely cun- centrate on the bladder no matter what their route of attack Whether they enter the body through the respiratory system the mouth or the skin they gravitate to the urinary system and there build up a concentration that eventually causes 4 act : 4SCROTUM Soat a 7 - ote cancer Other agents seem to cause cancer by altering gans so that the organ elf produces a carcinogen resulting in a cancer The mechanism of this transformation is little utiler It is known that some radiations and certain metallic compounds including the chumates the arsenicals nickel carbonyl and possibly ashestus can cancer in this relatively roundabout way . iu f) 4 a . , mre Te eae ra FY ' 2 3 re . ae we ~ ine t . wT t A rn t ae . . - 4 t t a > meev. \ inant . 7, zFy gf e . nathatnens ia pers erry woe a 5 f see ate q SKIN Radioactive substances vd Soot tar and oils ip rays * 3 Ultraviolet i acteuh : . . Do = pee a aee. , . : Ae BONE BONE MARROW , -Benzol -Benzol mE . OR Radioactive substances , - +. 8; te pe ORIGINAL SITES of malignant growths due to carcinogens in the ene vironment are scattered among almost all the organs of the body Saime agents such as the aromatic amine dye intermediates regularly affect the same organs even though they may use any one of many routes for attack ADIO ACTIVE materials are less spes eralized in their effects they can produce a wide variety of cancers Thiev may cause skin cancer by direct attack un the skin and lung cancer in people who inhale radinactive dust When expo- sure is intensive and prolonged ^ in the ease of the women wlt worked in the radi- min watek and clock dial imlustre some 25 years ago they produce bone cancer And a light but very prolonged exposure to penetrating radiation can result i leukemia s cancer of the blood cells The fatter kind of cancer is ntten found among radiologists whose whole protessional lives have been spent in theoretically safe and protected dealings with rays or radioactive radioactive materials Most subtle of al carcinog are thause helt is canse general metabolic disturbances that produce cancers in youndalmit way Thus the liver may pro- duer calcinogens that can cause or sonie other tissue to turn malignant Among the agents thought to have this effect are the 12 and Sendves . Sendves and certain chlorinated aliphatic hydrocarbons But the mechanism ins velvoel in non absentee that the carenogen metabolic metabolic differences were completely un- derstood derstood human beings might be endowed with resistance to rertain types of cancer men wit are employed in these plants Obviously such investigations present dillicult profilem- and demand a high or- jeity of these sulistaners has not been com- by modifying the individual's metabolic der of judgment It has often been said | Vetely proved One aspect of such indirect causation processes Such ideas are still beyond the realm of practical application in man li that statisties can be used to prove hith sides of a question Environmental car- however is susceptible of proof Among Among some Negro tribes working in the gold munes of Vtrica an excessive incidence of experimental animals however however cancer susceptibility susceptibility or resistance to certain external carcinogens such as several of the einogenesis is no exception An example in American experience is a study which was made some time ago af cancer of the bladder has been traced to azo dyes may lie created at will by the the incidence of lung cancer among U1000 deficiencies in the workers diet It was omission or addition of certain vitamins in workers in an industry suspected of pros found that most of the Negroes had lived lur years on deficient diet of pap and sour milk Only recently South Afric can research workers have succeeded in producing cancer of the liver in rats fed just this diet IN view of the relative novelty of the con- cept of environmental cancer and of the small amount of organizand research in this field it not surprising that must of the known carcinogenic agents have been found in industry Here workers suffer exposures many times more concentrated than the average citizen en- the diet Witlunt animal experimentation seiens tific proof of the carcinogenicity of various substances and radiations would he nearly impossible On the other hand laboratory experiments alon^'cannot prove definitely that such agents are dangerous to man Other methods must be used and the principal instruments so far available tave been statistical studies and medical rec ords In large unselected population groups variations in the incidence of one kind of cancer are usually not sufficiently marked to be significant That is why environmen ducing a carcinogenic agent It was known front -tudies in other countries that lung cancers were exceptionally frequent in this industry and there was no eviience that American manufacturing methunds differed in any majur respect from those abroad Yet this study reported no lung caneers at all In any group of 4038K adult mules several cases of lung canevr are bound to occur merely in the basis of the incidence of the malignancy in the population as a whole The results of tlse study surely suggest a lack of thorough- ness in the collection and evaluation data , om counters in a industrial environment environment Fully 90 per cent of the known carcinos genic agents are industrial and a similar proportion of cancers of known cause arises from carcinogens of industrial im- portance These known agents are listed in the chart on page 11 The difficulties in the scale study il carcinogenic agents are formidable The modern environment is so ramified Chat efforts to evaluate it in terms of long- range carcinogenicity may appear nearly hopeless Nevertheless the techniques already developed in the study of necupational carcinogens may be of some value in analyzing the environment as a whole even though more refined methods may have to be developed if such a program is to be successful The two principal methods now used to uncover the more obvious occupational ancer hazards are animal experimentation and statistical analysis Cancers have been produced in experimental animals by most of the known physical and chemical carcinogens Hundreds of other sulistances have been and are being tested Some that have been shown to be carcinogenic in ammals have not as yet been proved dangerous to man or else they do not form a part of his normal environment Among these substances are urethan ergot sele- suum and diethylene glycol One aspect of the work on animals that is important in considering human cancer the phenomenin known as species spechcity Many carcinogens that cause cancer in some sn^>m^lspecies have thus for proved harmless to others For example certain tars when currectly applied produice skin cancer in mice rats rabbits and diggs but not in monkeys Rats and mice get skin cancer from ultraviolet rays but rabbits do not The probability is that specialized metabolism is at the bottom of this species speciheits for cancer If such tal carcinogens are usually difficult to detect Up to half century ago indegil exis dence of specite extrinsie causations of cancer was discovered largely be clinical observation Physicians practseing in urban or manufactming areas began to notice a remarkably high incidence of cer- tain types of cancer among workers in individual trades Such was the case in the diagnosis of cancer of the scrotum in chimney sweep Discoveries by direct ab- servation continue to be made as in the case of radium and ray cancers that nes vurred with alarming frequency among people working with these agent in the most distant past T observation has its limitations Un- less very carelul tnedival recent. are kept or unless workers remain in a car vinogenie jak for many years the fact that the job is carcinogenic may escape escape notire Characteristic of environmental cancers is the long period between the beginning of exposure the carcinogen and the actual appearance of a tumor A worker win leaves a dangerous job before the cancer appears may later develop a malignant tumor without realizing its origin The process of traring cancers to their source through medical verorils amil healthhealth statisties has livcome a work of skilled des duction When a given community is found on careful examination of its illness and mortality statistics to have an unusual number of cases of cancer in certain sites the biometrician at once suspects the pres ence of an active environmental carcini gen The chances tiilas are very great that it will be traced one or more factories in the area since so few industrial car einogens have been trunil Conversely if it is known that certam plants are pro dueing or using known carcinogens the statistician searehus for evidence of au abnormal incidence of caneer Lrtherey es CLEAR example of the intelligent use ul statisties as tool in uDCOV environmental caremogens is the way in which cancers of the bladder were identi- lied as an recupational hazard in plants using the aromatie amine dve intermes diates mentioned earlier The following composite composite description based on a numilwer of European and American investigations of this problem illustrates the methal The people in certain industrial reginn have a frequency of bladder cancer that is a slight traction higher than nor- mal The variation is well within the range of random probability but the fact that several cases of this not too eonimoa ma- lignancy have been found in single community leads to a further study of the region It is found that the incidence of bladder cancer jumps from .02 per cent in the provmee as a whole too per cent in the particular community under study an increase of 400 per cent On further investigation it is fearned that among the workers in a particular dye plant in the town 5 per cent are suffering from or have died from bladder cancer- nearly a 5.000 per cent increase Fullus ing this elae every operation in the plant is studied and one particular job is found in which over 90 per cent of the workers have bladder cancer or have died from it Obviously the focal point of the disease lias liren established It is from just such relatively slight statistical anomalies that much of the original evidence of rareinogenesis en me dustry arises Of course as muce carcniver gens become known and are added to the list the statistical techminuischange techminuischange Witle the enoperation of the minstries involved medical and public health experts go ales reetls into the plants and stins the mora tions and the workers Otten However publir mertical mertical and death recuriks aller aller the- 13 only reliable source of information Many jadustries actually do not know obthe ex- jstene of carcinogenic lizards in their y futories The study is so new that only Frants in which the incidence of specific cancers is mudurimsly high are aware of the problem A few industries do know of the existence of carcinogens in their plants and probably some of thein have developed their own methods of coping with them The reluctance of industrial manage ments to publicize the existence of a carcinogenic hazard is understandable for it could easily become difficult for plants MI labeled to recruit workers or even to self their commodities To make factories emi- ploying carcinogenic materials safe to work in furthermore sometimes requires extensive and costly alterations If one firm makes such alterations and others du not the competitive position of its product is endangered Generally speaking however employers are no more responsible for the lack of information about industrial cancer than are the many thousands of physicians w have cancer patients in industrial areas or who actually are associated with factories It is an unquestionable fact that an appreriable number of occupational cancers slip through the hands af doctors unidentified This is due in a great degree to a general ignorance of the occupational as pects of cancer Physicians have never been adequately informed of the basic symptomatic and sociological factors invalved in identifying occupational carcino ggeneesisnegensesis igenessis T HE medical profession should be better educated abwut the need for ex: haustive case histories which carry the individual's juis record in detail hack as far as 25 years about the urgency of cheek- ing medical suspicions of industrial cancer hazards against careful epidemiological studies of all the workers in a plant and almout the paramount importance of impressing plant management with the seriausness of the proliteni The standard protective and hygienic measures currently used in industry to combat industrial poisons and other health hazards are not always adequate for the kontrol ol occupational cancer The fol lowing case history is a compelling illus- tration Some 30 years ago workers in one at the newer metal industries began to develop lung cancers At that time the cancers were found to remain latent from 10 to 15 years The incidence was umust- ally ligh in certain operations where the careimigenie careimigenie tanee was prosent in parneularle lugh concentration as an air- Inrue dust An effort was made to safe- guard these operations date equip ment for reining dust and fumes was installed and a standard industrial liv- zene program was inaugurated including including protective clothing But this suitrome W81 exactly exactly the opposite of what had been ese perter The incidence of lung cancer did not diminish in fact soon afterward eanvers began to appear among workers who had been exposed fne jess than six years a nuch shorter period than had been pre- viously observed What had happened was that at the time when the protective meas ures were adopted the factory had also begun to use a hinre finely ground materia to improve production The finer dust though present in a much lower contentration than the original material pene- trated farther within the bronchi of the lungs Thus despite the installation of the latest in protective devices and pro- cedures the cancer hazard was actually increased T is obvious therefore that the control of nccupational carcinogenesis even to a great extent of cancers stemming from more indefinite environmental elisset that the community be protected by the prevention of the discharge discharge of cars cinogenic wastes that factories be li censed and inspected that workers be provided with protective clathung erup- erupiment and medical supervision mchaking frequent and thorough physical examina- tions The Environmenial Cancer Section of the Institute which is a part of the U. Public Health Service is preparing an immediate comprehensive campaign of education and information the purpu ni which is to bring physicians to a realization the existence of the problem Plans are also under way to make exhaustive surveys of major industrial areas in the nation These studies are essential preliminaries to the institution of the controls that Dr. Ineper has suggested Many of the control recommendations admittedly are reaching in their nupli- . City Percent of total possible sunkigar Skin cancers per 100,000 population Boe eae . . _ Ee Ae ot TPs oars RA Bt DALLAS :, 7 Ff *. 7 Keo 60-80 perpceentrcent 140 | |. NEW ORLEANS 62-64 percent 129 [ ee Sk ; . r ef ee , - PITTSBURGH AneOC * 50-57 percent 37 | ra fo DETROIT 25-40 percent 24 . f - eye CARCINOGEN IN NATURE is sunlight Such natural carcinogens however are few An abnormally high concentration of arsenic in drinking water has been shown to ratise cancer of the skin and internal organs Inbee- tions of certain parasites have also been found to lead to malignant growths agents and when they are discovered is a public health problem al considerable magnitude This is made even more ap- parent by the scope n^> a control program that has been propused by Dr. Wilhelm C. Hueper head of the new Environmental Environmental Cancer Section of the National Cancer Institute Dr. Hueper une at the world'sworld's leading experts nu occupational cancer has studied the problem in the l S. and elsewhere for many years Several of the elements of his program bake ahrady been put into effect in EuropeaEuronpean cintillajes The program proposes that calemogeme agents be eliminated from industriak miti tary and civilian ose as far as is pussible audi pracneal that manufacturing manufacturing pilve esse es winch must use such materials ell rations Years of work will he required to put them into petas tice watli maximal eec- tiveness This is particularly true of the recnummendations for social contril- On the Techmeal nie some at the elements can be instituted once and without great expense management and labor can be persuaded to agree to them For example effective medical and sam- Lary supersasi^n supersasi^n it exposed workers can be undertakunedertnaken immediatletimsediatlets This su uryas con simuld meinde ray examinations at frequenfrtequent intervals intervals varchui varchui clinieji stay ut suspicions suspicions destas preparation preparation nl nye haustive and neta n^job analyses Ami TANK TEN~"RULES TEN~"RULES vesti^n sputarteris sputarteris or sem4- annual physical physical examinations examinations of all wisten wisten crs who might pressibly sutic exposure exposure to . A he carrinogenic agents a constant review of dangerous plant operations to enforce 2 constant goosek housekeeping and tri clieck fe the level of carcinogenic dusts fumes id mists Raa one hel iar ea A ee eee oa oS at, ea ne ato UT aEt ASg oe SSmt cae wee en s ge Sy TS MR val ee Rte wera ws . we ase . Protective measures for the workmen themselves are also simple and relatively a inexpensive although the enforcement of their use is sometimes made difficult by the discomfort they cause They include the regular wearing of respirators and sealed clothing whenever exposure to a carcino { genic hazard is likely daily showers for all persons working in or near the hazard- t ous operations use of separate lockers for street and work clothes and adoption of work techniques that will minimize the dangers of expomire Other and more important technical measures are likely to involve heavy expenditures for management In some in- stances entire factories would have to be rebuilt Others would require costly ; control equipment such as elec tronic dust precipitators and extensive remodeling to enclose carcinogenic opera tions and keep the workers from any contact with dangerous agents Few plants could afford the necessary changes unless Ww 4 on 4 4 ot, +EF: + B43 =p POPULATION STATE IS aI=N WHICH LOCATLOCEATDED ' > 2":0.02 percent affected +... 22 POPULATION OF COUNTY ey IN WHICH PLANT IS LOCATED : 0.71 7 0.1 percent affected all other plants in the same industry were required to make the same improvements at the same time ; ; N some instances such changes might ae an ter & ; WORKERS EMPLOYED IN: TH 7. E THE ENTIRE PLANTS PLANTS possibly be undertaken as a result of industry agreement In others Megislative and administrative enforcement : might be essential Such action would in- a clude factory licensing and inspection by government improved compensation laws revnenizing occupationally acquired can- 2 cers as compensable and revision of the health codes to make nccupational cancers , \ notifiable just as are many other diseases These measures would require coordinated and carefully planned action on the part of management labor the medical profession state public health and labor deportments and state and Federal legislatures A precedent for such a program has already been set by the successful control of communicable diseases through public : health laws and through the organized comperation in their enforcement of both private and public agencies How effective these controls would be in diminishing the hazards of still undiscovered environmental carcinogens is a question that only time can answer Meanwhile the known causes of occupational . cancers would be placed under technical and social restraint and patterns would be established for the future contrul of new carcinogens as they are found in our ws wie OO : Me. Si a v4 5 - ss ela . . a WORKERS IN DEPARTMENT WHERE 3 | ~ CARCINOGENIC prev ey; ACTIVITY TAKES PLACE ~ 20-50 percent affected am Hor Uw f 2 thas on WORKERS DIRECTLY INVOLVED 7 IN THE CARCINOGENIC ACTIVITY 90-100 percent affected i 3 : L oo | ; environment Gro^ f Conklin is a sci- ence writer and a former consultant with the Nu tional Cancer Institute fee -- . EXTREME CASE of environmental cancer is represented by record of aro- matic amine plant in Germany OH workers directly in contact chenueal 90 to 100 per cent developed cancer of the bladder Running from top to hottom is illustration of statistical analysis used to jocate such bazar~-ls 15