Document 2jqYvyX1qz10pjBjbq664Ox7p

FILE NAME: New York State & NY Times (NY) DATE: 1950 Apr DOC#: NY100 DOCUMENT DESCRIPTION: NY Dept of Labor Monthly Review - Occupational Causes of Cancer The material on this page was copied from the collection of the National Library of Medicine by a third party and may be protected by U.S. Copyrightjaw. NewYork State Departm(oeoncutkh: a b o r MONTHLY REVIEW iene &SafetyStandards M rnir-Ai April, 1950 No. 4 m ^5O c c u p a t i o n a l c a u s e s o f c a n c e r * . _ L I tS R A P* ' ay R. Mayers, M .D .** * Chief, Medical Unit The most intereltiMg^thifig'about occupational causes of cancer is how little we know about them. On the other hand, what we do know is truly pro vocative in that we can actually produce cancer at specific sites in the body, by known chemical a gents, as a result of exposure in industry. This is particularly remarkable in view of the continued lack of knowledge of the basic causes of cancer, in general. It should some day fall into its appropriate niche in the large mosaic now being built up piece meal by independent contributions from the re search work of scientific investigators in many fields. Furthermore, the problems involved in de veloping new data are sufficiently complex to pre sent a major challenge to any research worker with sufficient curiosity and imagination. In New York State, the Division of Industrial Hygiene has had considerable experience with many facets of this problem, including the control of known carcinogens in industry and an attempt to develop new data. But before going into this, it might be well to survey, briefly, what is actually known and what is being conjectured at the pre sent time with reference to occupational causes of cancer; and to bring to your attention the need for further evidence in the case of many sub stances or conditions in the occupational environ ment which are now suspect, but concerning which all too little is known. As background material, it might be well to con sider briefly the nature of the occupational envir onment as a whole; the abnormal elements in this environment which may give rise to occupational diseases generally, including occupational cancer and some of the techniques for their evaluation and control. ' The more one knows about the industrial en vironment, the more one is impressed with its complexity. It is, after all, a man-made environ ment in which each worker is exposed to chemical substances and conditions peculiar to his work- * Presented at Graduate Course on Industrial Med icine under auspices of Academy of Compensation Med icine, University Hospital, New York City, Mar. 3, 1950, CommitteeTMan' NCW Y rk State 0 ccu Patinal Cancer 13 room; an environment which is quite different from that of his family or his neighbors. Aside from dangerous machinery, which contributes by far the highest toll of injury to health in the form of industrial accidents, there are the more subtle health hazards which arise from exposure to a variety of special circumstances, such as the pres ence in the working environment of atmospheric contaminants in the form of dusts, gases, fumes, vapors or mists; radiation; excessive noise; im proper illumination; continual vibration; abnor malities in temperature, humidity or air pressure and so forth. ' Has it ever occurred to you that inhalation of dust is not necessarily associated with pneumo coniosis? When industrial dusts are being consid ered, one usually thinks only in terms of such substances as silica or asbestos, which give rise to characteristic lung pathology; and attention is us ually focused, therefore, upon x-ray diagnosis, par ticle size, dust counts and dust counting techniques. That these considerations do not apply to a great variety of the dusts to which workers are exposed m mdustry, is often overlooked. When lead dust is inhaled, for example, it is dissolved in alveolar fluids and carried in the blood , stream to all parts of the body, producing the rather complex systemic disease known as lead poisomng. Fiour dust, on the other hand, acts as a sensitizing agent, which in extremely minute am ounts is capable of producing asthma or other manifestations' of allergy in susceptible individu als. Zinc fumes are precipitated on mucous sur faces as fine particles of zinc oxide, and as such give rise to transient anaphylactic reactions In the case of other so-called "non-specific" dusts such as wood, fertilizer, methyl methacrylate plasties and so on one is dealing primarily not with lung pathology but with irritation of the upper respir atory passages, or interference with normal ciliarv Q?5TMHhyi 10I giCal function f mucous membranes. Standard dust counting techniques are not ap plicable to most of these dusts and standards for permissible dust counts do not exist, excepting in the most general terms. p8 Among the gases, the colorless, odorless, taste less and non-irritating carbon monoxide may cause MONTHLY REVIEW of the DIVISION OF INDUSTRIAL HYGIENE AND SAFETY STANDARDS NEW YORK STATE DEPARTMENT OF LABOR 80 CENTRE STREET NEW YORK 13, N. Y. Industrial Commissioner EDWARD CORSI 1st Deputy Industrial Commissioner THOMAS F. MOORE, Jr. Deputy Industrial Commissioner in Charge EDWARD A. NYEGAARD Deputy Industrial Commissioner ABRHAM H. GOODMAN The Division LEONARD GREENBURG, M.D., Director R- MAYERS, M.D., Medical Unit WILLIAM J. BURKE, Chemical Unit GEORGE P. KEOGH, Code Unit ARTHUR C. STERN, Engineering Unit T . Industrial Hygiene LEONARD A. PERRIN, Engineering Unit Building Plans death by tissue asphyxia; or in lesser concentra tions, it will give rise to varying degrees of an oxemia, depending upon the amounts of oxygen displaced from the hemoglobin molecules of red blood cells. Hydrogen cyanide also causes tissue asphyxia, but by a totally different mechanism-- its interference with their oxygen receptors so that, while ample oxygen is available, tissue cells cannot utilize it. Highly irritant gases, such as ammonia, do not often present a serious health azard because no one will usually remain in its presence long enough to be injured. When a pipe line breaks accidentally, however, and workers PdPmi i f va?uated fast enough, pneumonia or edema of the lungs may ensue. It is the nitrous fumes, however, from welding operations in en closed spaces which are peculiarly insidious. For while they appear to be entirely innocuous during pdpma^nf r l e,XpC)SUre' sudden death from acute edema of the lungs may occur quite unexpectedly after a latent period of 8, 10 or 12 houre during fWeeiCsick.me 6 Wrker USUally d0es not' usually Among the volatile solvents are those which have LTenzai l ^ w yp fV u e hemaPetic system, such injury to the liver,WshulCchu ams acyarbcoaunsetetcrahcahralocrteidriestoicr aaffffpepctthtHh?erinnaetrevdoudsipshysetnmy,ls;sutchhosaes twrihcihclhorpetrhimylaerniley which m ordinary use may act merely as a nar- cceennTtrraattifoonn3 i^s capable of cauwshinicgh ainbnsourfmficailenbtehcaovn ior patterns largely indistinguishable from non- Swhethertherewm SS /l Jf aa mmaattttPer?Cioff0 Hdeo4sra0gSeeSwhnatd thpseyctohxoisceosl-ogIticaisl *n skm contact with chemicals, equally complex and varied mechanisms are involved. Some chem icals are caustic or act as primary irritants. Others such as paraphenylene diamine, a common fur s u c h ^ f n k o tin ? ? Sensitizin agents. Still others, thrioouuggnh ttnhee sskkimn tton pnrvondnuacmeplsGy's,temmaiyc bdeiseaabsseo. rTbehde 4 cmonnatea naphthalenes produce typical acnet form lesions of the skin; certain heavy oils ani tars are carcinogenic. J For purposes of control, maximum allowable concentrations have been developed for exposure to chemical substances or abnormal* environmental conditions in industry; and techniques have beer developed for evaluating these exposures to de termine whether safe limits have been exceeded m a particular workroom or plant operation. Un fortunately, such standards are not a guide to the control of carcinogenic agents in industry, since there is no known relationship between the. tox icological properties of a substance and its carcin ogenic potentialities. Beta naphthylamine, for ex ample, which is a well established carcinogen, even in small amounts, has not been shown to produce systemic disease generally. Control of carcinogenic agents in industry, moreover, is difficult because cancer takes so many years to develop that control measures must be operative for a long period of time before their effectiveness can be evaluated As a means of illuminating the occupational can cer probiem from still another angle, it might be profitable to consider some of the other charac teristics of the occupational environment, and some of the special medical problems to which they give rise. First of all, exposure is such as to rarely cause acute illness or death. The more usual sit uation is that of continuous or intermittent expos ure to relatively low concentrations of toxic chem-f lcals or low dosage of other adverse environmental I conditions for relatively long periods of time. Med ically therefore, the situation may be puzzling One does not necessarily see clearly defined chem ical disease entities or frank disability in most cases. Often they carry no earmarks whatever of then* occupational origin, as in the case of hepatitis aplastic anemia or bladder cancer. Delayed onset' after the pertinent exposure has ceased, not only m f0nn^ction with occupational cancer but as well fUnd m aplastic anemia due ^ benzol The fact that labor is mobile, and workers go from job to job where environmental exposures differ, creates further difficulties for the physician, rhis is true especially in the older worker who in the course of a long life, has developed many* path ological and functional changes in various tissues or organs of his body. His doctor is usuaUy capabL' Of evaluating the usual signs of aging or of inter Zwhno ThasdlsSpeeanSft -mHaonwyeyveear'rs^ otfhheiscalsiefe* oefxapowseodrketor even a single toxic chemical, such as lead1 for ex ampie the medical practitioner finds himself put t d ah along the line to dissociate those elements ln. *be ptcture which may properly be at tributed to the lead, from those which are due to th Tn Process or ther unrelated conditions. In industry one may be dealing with cumulative poisons such as lead or mercury; or w i t h TM la tive pathology, as in the case of a liver which has been exposed to repeated insults by hepatotoxic substances until its regenerative powers have been overwhelmed and evidences of liver insufficiency begm to make their appearance; or acute yellow atrophy causes the death of the worker ThfliveT chneeimmcaSis,' iinn thSat i8t is^ t,h?e fde-etoxxpiofsv^ins?t onTrefoanx ticn the body. One can raise an interestinf question) The material on this page was copied from the collection of the National Library of Medicine by a third party and may be protected by U.S. Copyright.law effectiveness of different research techniques. One approach is the use of death certificates, noting the occupation given. Social Security rec ords--which now cover the last ten years--make it possible to check back on previous occupations for this ten-year period. One can take a suspected industry or plant and try to follow back, by means of social security numbers, workers who had left the plant and subsequently died of cancer. One can compare the cancer incidence rate of com munities in which suspected carcinogens are pres ent in the industries with that of similar commun ities not having such plants. One can study the effects of air pollution by industrial plants in a community or in a given geographic area upon the cancer incidence in that area. One can interview cancer patients and get detailed occupational his tories going back to each patient's first job. Each of these methods has merit. Each also has its limitations. Interviewing cancer patients for the purpose of obtaining reliable occupational histories and accurate technical data as to the oc cupational exposures associated with each job is not only time-consuming, but requires an indus trial hygiene valuation of each interview. Official records, on the other hand, are notably lacking in precise and pertinent information with reference to the occupational exposure. And yet, there are many situations where there is no alternative, since they provide information which cannot be obtained in any other way. The use of death certificates, for example, is limited primarily by the fact that only the last oc cupation is given, whereas occupational cancer is more apt to have been caused by some previous occupational exposure, perhaps ten or fifteen years earlier. Moreover, death certificates indicate only those persons who actually died of cancer. They do not include patients who had recovered, and who subsequently died of one or another unrelated condition, such as diabetes, coronary thrombosis, and so forth. In any study of occupational causes of cancer, the patients who were cured are obvious ly quite as important as the ones who died of this disease. And finally, the occupation is usually stated in such general terms that it is extremely difficult, if not impossible, to know what the per son's environmental exposures really were. Un fortunately, official records, generally, fail to give sufficiently precise data as to either occupations or occupational exposures. Even hospital records are no better, in most cases. The seriousness of this situation from the standpoint of any study of occupational cancer cannot be overemphasized. Information that a man was a garage worker, for example, provides very little indication as to what he actually did there, or the kind of garage it was. If he worked in a garage where cars were merely parked and stored, his exposure was pri marily to carbon monoxide gas in varying concen trations. If, however, he worked in a garage which housed commercial buses carrying diesel engines, his exposure to carbon monoxide gas was relatively less important than was his exposure to aldehydes in the exhaust gases. Aldehydes, though not as toxic as carbon monoxide gas, are highly irritating to the upper respiratory passages. Or, he may have been working in a garage which did repair work. In that case, if he did welding on car bodies, his exposure was very different from what it would have been had he done spray painting. ;5 Similarly, to say a worker is a "foundryman"--f a very common designation, by the way--is not| sufficient. It makes a great difference whether het is a moulder who handles foundry sand and part OQ . 7-0 ing compounds; whether he pours the molten met CO al, and if so, whether the metal he is pouring con tains lead or other toxic materials; whether he _Q sandblasts the finished castings or whether he TO operates the crane in the foundry. Thus, data as to a worker's occupation must be very precise and &OO very specific in order to provide useful informa Q_ tion. Frequently the worker, himself, is unable to provide all of the necessary data because of his CO lack of technical knowledge--particularly where E industrial chemicals are concerned. 03 For these many reasons, the New York State Occupational Cancer Committee has undertaken TO Q- to work with live cancer patients, as they come into the hospital for diagnosis and treatment rather than with official records of any kind. Each patient TO is interviewed in the hospital, and a very long and detailed occupational history taken, starting with JD CTO his present work and going all the way back to his o first job; inquiring how long he worked at each one of his jobs, and the environmental conditions under which he worked, insofar as he can recall. Because of the technical nature of the information to be obtained, it is clear that the patient will not always know the names of the chemical substances he handled in the course of his work; nor will he be able to describe his many occupational expos ures in technical terms or interpret dosage. How ever, if one gets from him very precisely the type of work he was doing in each occupation, it is pos sible for those who are specialists in the field of industrial hygiene to know, from their experience the chemical and other environmental exposures usually involved in this type of work. And so, in New York State, the Occupational Cancer Committee has been supplementing the The material on this page was copied from the collection of the National Library ol data given by each patient, with reference to each of his occupations, with information as to the en vironmental exposures known to be associated with those occupations. A statistical analysis of this data by the use of tabulating machines, is expected tc provide leads which can then be studied more in tensively in the field. Clearly, in this type of approach, one is introduc ing a great many variables--the many jobs helc by individual workers; duration and intensity o: exposure in each job; the great number of indus trial chemicals and other environmental factors; and necessarily the degree of professional inter pretation where the patient's information is lim ited. But these variables, troublesome as they art to the statisticians, are not created by this methoi of approach. They are inherent in the material under investigation, and one cannot close one's eyes to them. In order to obtain data which may be considered statistically significant, however, under these circumstances, a large series of cases is re quired. In the present study, an effort is being made to interview 6,000 patients at Roswell Park Memorial Institute in Buffalo. Out of this number, it is anticipated that there will be approximately 1,000 "Normals", i.e. patients who come to the hospital,thinking they have cancer but who turn out not to have it. (C ontinued in the May Is s u e ) here, as to whether, in th$ conjugation of chemical substances by the liver, a particular metabolite in a particular situation may not actually turn out to be more toxic than the original exogenous sub stance from which it was derived; or can it even turn out to be carcinogenic, perhaps, where the original substance was not? In cases of non-oc cupational aplastic anemia of unknown etiology, the possibility has been seriously suggested that benzol poisoning of purely endogenous origin may occur in a particular person as a result of meta bolic disturbances. Dr. Hueper,1 in his classic volume on Occupa tional Cancer, presented known and suspected causes of occupational cancer, giving such sup porting data as was available at the time. From this, the New York State Occupational Cancer Committee compiled the tables which appear in the Occupational Cancer Manual2 which was dis tributed to you at the beginning of this session. You will observe that they include: A description of selected lesions which may be associated with occupational cancer-producing agents and an al phabetical listing of recognized and suspected occupational cancer-producing agents, with sites characteristically affected. With this material before you, I shall discuss very briefly a few of the better-understood car cinogenic agents responsible for occupational can cer. Aside from scrotal cancer in chimney sweeps, recognition of the role of beta naphthylamine and benzidine in the production of bladder cancer is perhaps the most important, historically speaking. Dr. Gehrman,3 who did much of the early work in this field, has been largely responsible for the de velopment of present methods for control, both of the manufacturing processes and of the disease itself. The latter includes periodic medical super vision and physical examinations of workers, with cystoscopy for diagnosis and figuration of lesions for therapeutic purposes. A recent review of the Italian experience by Barsotti4 and Vigliani pre sented in 1948 before the Ninth International Con gress on Industrial Medicine in London has con tributed further data as to the carcinogenic prop erties of these dye intermediates. In this study, 186 workmen were examined cystoscopically over a period of several years; some repeatedly. The interesting thing about these bladder cancers is that they cannot be differentiated either cysto scopically or under the microscope from non-oc cupational epitheliomata of the bladder; and they metastasize just as slowly. A recent study by Dr. Machle,5 indicating an increased incidence of lung cancer in workers in the chromate-producing industry, has led to fur ther investigations both in the field and in the lab oratory. A field study recently conducted in Ohio by Dr. Mancuso,6 reported at the last meeting of the American Public Health Association, appeared to support Dr. Maechle's thesis. Dr. Baetjer at Johns Hopkins' and Dr. Smith at the Institute of Industrial Medicine, New York University--Bel levue Medical Center, are now working on this problem with animals under controlled conditions. The relation of asbestosis to lung cancer has been long suspected. Actually, considerable con firmation has recently been provided by the Chief Inspector of Factories in England,7 in his Annual Report for 1947. During the period from 1924 to 1946 inclusive, there were 235 deaths either caused by asbestosis or in which asbestosis had been established at necropsy. Cancer of the lungs or pleura was found in 31 of these cases or 13.2 per cent, which is very high compared with a general incidence of 1 per cent for cancer of the lungs among all adults examined at necropsy. Moreover, the sex distribution seemed also to suggest the presence of an occupational carcinogen. The his tologic character of the cancers--squamous cell, instead of adeno-carcinoma--and their histogenic derivation, in that the bronchial mucosa was in volved rather than the alveolar epithelium, was interpreted .to indicate the presence of a specific exogenous carcinogenic agent as the etiological factor; in this instance, inhalation of asbestos dust. It has been estimated that 20,000 workers are now employed in asbestos-producing industries in this country and Canada. The development of can cer of the lungs in these workers is believed to be more directly related to asbestosis, the disease, than to the inhalation of asbestos dust per se. Diff erential diagnosis by X-ray between asbestosis .and lung cancer presents all the difficulties one would anticipate. It has been suggested that cytological examination of the bronchial secretions might well be included in periodic examinations of workers exposed to asbestos dust whenever clinical or X-ray evidence suggests the possibility of a pre-cancer ous lesion. Careful histological studies of lung tissue, postmortem, in all such cases would provide valuable data. Recent preliminary studies of male pharmaceut ical workers engaged in the manufacture of estro gens 8>B-10 would seem to provide additional evi dence of a relationship between estrogens and breast cancer. Without being conclusive, these data tend, nevertheless, to add further weight to pres ent concepts that caution is required in the con tinuous use of estrogens, for any purpose, over long periods of time. As everyone knows, there has been a dramatic increase in exposure to radiation in industry in recent years--mostly in fields other than radium dial painting. These include the use of X-ray and radium in foundries for the examination of flaws in castings; the use of fluoroscope not only in shoe stores, but in shoe factories to detect misplaced nails in shoes; or as a means of detecting foreign bodies in any packaged goods, including food; the use of radium-coated bars as static eliminators to prevent fire hazards in publishing houses, the manufacture of plastic fabrics, and the like. These are a few examples of specific chemicals or environmental exposures in industry which, there is reason to believe, could be responsible for the development of occupational cancer unless adequate controls are provided. Are there other substances or other environmental conditions which are not even suspect at present? The National Cancer Institute, by Grants-in-aid to States, is making possible a more intensive in vestigation of the whole subject of occupational cancer than has ever before been attempted. And the various States, through their Divisions of In dustrial Hygiene, have been approaching the prob lem differently--each according t6 its own ideas. A series of pilot studies are thus in progress which, it is anticipated, will not only provide additional data, but will also provide experience with the 15