Document 3GNBOjbyp94vjxKgj7k7qY2E

FILE NAME: Metropolitan Life (ML) DATE: 1945 Dec DOC#: ML048 DOCUMENT DESCRIPTION: Journal Article by Dr. Lanza - Industrial Health Recent Developments in Pneumoconiosis Vif '&*'l'X' ifl U THE JOURNAL or ms Missouri State Medical Association The Official Organ of the State Association and Affiliated County Societies Issued Monthly .under direction of the Publication Committee COPYRIGHTED, 1945, BY MISSOURI STATE MEDICAL ASSOCIATION. ALL RIGHTS RESERVED. 'Volume 42 DECEMBER, 1945 N umber 12 RALPH L. THOMPSON. MJD., E ditor HELEN PENN, A ssistant E ditor i|:3 Missouri Bldg., St. Louis, Mo. Telephone, Newstead 0404-05 _ iaucAnoN *5. O K M IT T E E RALPH L. THOMPSON, MX*., Chairman W. A. BLOOM. M.D. ROBERT MUELLER, M.D. J. WILLIAM THOMPSON. M.D. L INDUSTRIAL HEALTH f t REGENT DEVELOPMENTS IN .P N EUMOCONIOSIS S ^ T l ANZA, M.D. . NEW YORK Thirty years ago one thought of pneumoconiosis in terms of silicosis and the two words are often carelessly used as though their meaning were iden tical. From 1914 onward, silicosis received an in creasing amount of attention and it was the general feeling among investigators in this field that silicosis was the only form of pneumoconiosis which was of prime importance. It was a clinical entity in it self, could cause disability and death and was fre quently associated with tuberculosis which acted to expedite a fatal outcome. In 1927, the term "asbestosis" first appeared in ^connection with a claim for workmen's compensa tion in Massachusetts, but this occupational dis order was not investigated until seven years later.2 Here was another definite type of pneumoconiosis i with a pathology distinct from that of silicosis and which also could produce disability and death. During these thirty years a great deal of lab oratory research and field study has been car ried on in this country seeking to clarify the eti ology and pathology of these two diseases. Abroad there is the outstanding work of the South African authorities and that of the English, the Canadians and the Australians, as well as similar investiga tions in France, Germany and other countries. Field studies have crystallized ideas pn etiology and the work of Gardner and his colleagues in Saranac have given a great deal of knowledge con cerning the pathology of these two diseases. The roentgenologists, pioneered by the late eminent authorities, Pancoast and Sampson, have made their contribution to diagnosis. Also, engineering Read before the St. Louis Medical Society, October 16, 1945. Associate Medical Director, Metropolitan Life Insurance Company. studies and experimentation have developed meth ods of controlling the dust exposures which are their underlying cause. Some of the earlier con cepts have had lo be changed but it is still evident that silicosis and asbestosis, to which must be added silico-tuberculosis, are the important fqrm of pnumoconiosis from both the industrial and public health standpoints. It is not entirely certain how silica produces .its effects in the lungs, but the evidence is that the re action is a chemical one. Likewise, the evidence indicates that asbestosis is produced mechanically. The tendency of the silicotic person to become tuberculous has been recognized -in every country in which this disease has been prevalent. Silicosis definitely predisposes to tubercle infection, the mortality from this cause ranging from ten to twen ty times that of nonexposed prsons. The nature of the relationship between these two conditions is not clear, but it has been generally thought that tuberculosis was a terminal condition. Of late, Dr. Gardner believes that tubrculo-silicosis in its chronic phases is neither tuberculosis nor silicosis, nor a mere superimposition of one condition upon the other, but that the two irritants act together to produce something that is entirely new and differ ent.3 This observation may have an important bear ing on the attempts that are being made to clarify the pathology of other industrial dust-borne dis eases mentioned later. There have been no special recent developments with respect to asbestosis. The number of workers exposed was and is but a fraction of that exposed to silica. Mostly associated with textile processes, asbestos exposure could be and was controlled. It is a serious disease and must always be watched for where asbestos dust is present. With respect to tu berculosis and asbestosis, the two diseases may co exist, but there does not appear to be the causal relationship th a t exists between silicosis and tu bercle infection. E arly ideas on silicosis w ere based upon experi- 766 INDUSTRIAL HEALTH--LANZA T M issouri M A D ecember, 1945 ence obtained in the hard rock mining ' ndustry in which the causative agent is quartz, S i02, and sili cosis was thought to be a disease distinctive of the mining industry. Eventually, it became evident that many industries contained processes which in volved exposure to silica dust and that frequently there was also exposure to other dusts associated with the silica. Different clinical patterns were de fined. These substances present as dust along with the silica modify its action, the general tendency being t o .retard the action of the silica. It was thought; some, substances, notably free alkalies, might intensify the action of silica but it is doubt ful if there is known at present any occupation in , which the action of silica is enhanced by the pres ence of other substances. Fortunately, the general action of these mixed dusts is in the other direc tion, Such retardation has been described; in the granite industry; iron oxide and coal dust likewise change the Mlicotic reaction. Furthermore, the presence of substances like gypsum and iron may cause aggregations with silica particles in the at mosphere so that they tend to fall out of suspen sion.* When crystalline silica is heated in certain in dustrial processes, two other forms of silica are produced--crystobalite and trydimite. These con version forms of free silica are very active and toxic and will produce silicosis more rapidly than ordinary quartz. This may account for the clinical picture seen occasionally in some industrial expo sures. There has been much conjecture and dispute about the effects upon the lung of silicates--dusts containing silica in a combined form. I believe it was Badham of Melbourne who first coined the term "silicatosis." Marked exposure to a silicate dust will, in some instances, produce roentgen ray evidence of change--exaggerated linear markings. These may tend to clear up after removal from exposure. They are not associated with symptoms or disability, although a study of the tremolite talc industry in New York State showed in some of the individuals exposed a roentgen ray appearance re sembling early asbestosis both in fineness, diffuse ness and ground glass appearance. Two fibrous sil icates were present, tremolite and anthrophyllte, which the investigators concluded werecapable of producing a disabling pneumoconiosis. Triese cases also showed lung plaques varying from small linear deposits to massive deposits of variable outline and density situated on the visceral pleura, including the regions of the diaphragm and pericardium.5 Dreessen, investigating the talc industry in North Carolina, found roentgen ray evidence of dust re action but no disability. From the medical and public health point of view, exposure to silicate dusts does not imply the hazards associated with silicosis. However, in any given case in which a roentgen rav change can be demonstrated follow ing exposure to any type of dust, a medico-legal hazard may exist. From time to time, attention is called to some in dustrial group which presents roentgen ray films showing nodulation and a general appearance re sembling silicosis in which the evidence rules out silica exposure. These occurrences are troublesome and confusing both to the industry and the physi cians, as well as to the individuals concerned. Siderosis is a term that has been much used re cently. Electric arc welders, in a number of in stances, show on roentgen ray films an appearance that is so like silicosis that diirerentiation is diificult, if not impossible, by this means alone. Apparently the inhalation of fumes from the welding process over a period of from six to ton years may cause in ert iron pigment deposits in the lymphatics without fibrous tissue proliferation. There is no progressive change in these cases after exposure has ceased, nor does this condition predispose to tuberculosis or other infection. There are no symptoms and this pseudosilicotic condition has little, if any, clin ical significance.6 It may have a considerable medico-legai significance. Similarly, a group of lime burners in one of our industrial states showed -i generalized nodulation. Iron, carbon and alumi num were identified as present in the fumes to which they had been exposed. There was no clini cal significance in these cases. Both of these groups properly could be classified as having pneumoconiosis. This type, as well as that produced by the silicate dusts, has been called be nign pneumoconiosis which is a satisfactory term, at least in the present state of knowledge, based upon both clinical and pathologic studies. Doubt less other dusts associated with other working con ditions will be found from time to time, which may cause similar manifestations. All the factors in volving working conditions, length and intensity of exposure,- the composition of the dust, and the previous working history have to be considered before arriving at a diagnosis. This is particularly true when one encounters an individual patient, either in a hospital or away from his usual work ing environment. When a group of men are being studied in connection with their work and all the factors are known with reference to both working conditions and their physical condition, an investi gator is able to weigh all the evidence and to ren der an opinion with a high degree of accuracy. But with an individual patient who presents a roentgen ray film that looks like silicosis or pneumoconiosis and who may have other organic disease and where the nature and extent of dust exposure is unknown, caution is most advisable and it is essential to back track on the wrork history as far as possible. At this stage of the discussion of pneumoconiosis, it might be well to consider just what is pneumo coniosis. In 1942, Dr. Gardner of the Saranac Laboratory stated that the pneumoconioses include all chronic changes in the lungs induced by prolonged inhala tion of dust with no implication as to the type or severity of tissue reaction. The latter may vary 1fbw s 42 `'OioeB 12 INDUSTRIAL HEALTH-LANZA 767 simple phagocytosis to progressive fibrosis. / Excluded from this category are the responses to rs living bacteria and fungi which occasionally are iphaled as dust.7 i Definitions are frequently unsatisfying as any- pne will appreciate who has tried to compose one. ' The foregoing definition is a good one although it is possible more recent experience may lead to ques tioning the words "chronic" and "prolonged." It has been the general experience, that the develop ment of pneumoconiosis was a matter of years rather than of months. Also, it is not always easy to determine when a condition becomes chronic. I have not mentioned fungous infections and will do so only in passing. Coccidioidal disease has be come quite troublesome in some localities and is caused by inhaling dust in certain areas in which this fmigus inhabits the soil; It would not common ly be thought of as pneumoconiosis although the "method of causation is similar. There is an occupational disease peculiar to the cotton textile industry known as byssinosis, pre sumably due to the inhalation of cotton dust, and which may or may not be a pneumoconiosis. The fibrosis is not mai'ked, cotton dust has not been detected in the lungs of affected workers and the disease is not progressive after removal from ex posure and it appears to have no tendency to cause tuberculosis. Byssinosis is more prevalent and has received more attention in Great Britain than in this country. In England, it is compensable and is credited with the ability to cause total disability and presumably death. It develops slowly over a period of from ten to twenty years and the roentgen ray appearance is not characteristic but corre sponds to chronic bronchitis. It remains to be seen whether or not byssinosis has any appreciable significance in this country. It should not be confused with the infectious illness found among workers in low grade stained cotton, an acute infection due to a gram-negative organ ism, Aerobacter Cloacae, which has been the sub ject of two or three reports by the United States Public Health Service.9 Another disease which has been reported recent ly in this country is bagassosis. Bagasse is the pro duce remaining after the extraction of sugar from sugar cane. This is baled and workmen who later open these bales may present the symptoms o f ! bagassosis, namely, cough, sudden severe dyspnea, occasional hemoptysis, night sweats, chills and fe ver. Prolonged weakness is characteristic and there is usually leukocytosis of the polymorpho nuclear type. The sputum is scanty and mucoid. The roentgen ray film shows a diffuse mottling throughout both lungs. Recovery takes place over a period of a few months and the roentgen ray pic ture clears. The short time of onset and the duration do not correspond with a pneumoconiosis; it is possibly an infection or of an allergic nature. There are two other diseases recently reported which apparently are due to the inhalation of dust or firmes. They are not only very serious but quite distinct from any industrial disease so far recog nized. Fortunately, the cases are few and the con ditions which produced one of them at least ap pear to be no longer in operation. Some employees of certain industries concerned in the manufacture of fluorescent lamps were found to have a pulmonary disease which had the appear ance of sarcoid. There have been about twenty or twenty-five cases of this disease with, I believe, about five deaths. Intensive study, both in the plants and the laboratory, have failed to bring out any clarifying information with respect to expo sure, thopausative agent or the true significance of this condition. It would seem that these resulted from exposure during 1940 and 1941, that thy be gan to manifest themselves in 1943 and that th manufacturing procedres have been changed and that there is no evidence of further trouble. Various hypotheses have been advanced by the physicians and research workers who have been studying these cases. The disease may be an atypi cal silicosis due to the inhalation of exceedingly fine particles. Also, it may be due to the inhalation of fluorescent powders activated by some form of radiation; and it may be due to the toxic action of some substance present in the process. Suspicion has fallen upon beryllium. The factor of infection may. be present; possibly a combination of two or more of these suggested causes may be respon sible.10 Beryllium has not previously been considered toxic11 but the Saranac Laboratory states that beryllium is a potent irritant and capable of pro ducing chronic disease. More information will be forthcoming as the present studies develop. Another disease has been detected in a group of workers who process bauxite a t a high tempera ture. This process, by no means new, has never previously involved any health hazard as far as is known. In some plants in Canada, several cases : were detected which presented the following sj niptoms; cough, dyspnea, cyanosis, to the point of dis ability and a distinctive roentgen ray appearance characterized by bilateral spontaneous pneumotho rax. There have been from twelve to fifteen cases with four deaths so far. The postmortem examina tions showed massive extreme fibrosis and emphy sema. There was no evidence of tuberculosis. . I am indebted for my information about these cases to Dr. Andrew Riddell of the Health Depart ment of Ontario who has kindly enabled me to ob tain a film and lantern slides of one of these cases. Here, again, it remains to be seen whether this condition can be classed as a pneumoconiosis. The fatal cases lived about a year or a little longer after disability occurred. There are certain definite implications with re spect to the subject of pneumoconiosis and other air-borne occupational diseases. While silicosis and asbestosis are the two most important industrial -"r-^... ,rsir ft' >, INDUSTRIAL HEALTH--LANZA 1-H J. MissooM Mj t Decimbeb, dust diseases, knowledge regarding them is still far from complete or thorough. It is being realized more and more that all,industrial dusts are poten tial sources of trouble and that new.types of expo sures and new types of reactions are being dis covered. Combinations involving active chemical substances, rare metals and radiant energy imply harmful possibilities, and even a dust commonly considered harmless may under certain circum stances or in ^Combination with other substances, also.-in themseltves considered innocuous, become actually or potentially dangerous. Any dust which can `produce roentgen ray changes, even though classed as benign pneumoconiosis, must be consid ered seriously. With any dust, not only does there , arise the question of its specific reaction but of its relationship to tubercle infection. And here, one moves from the medical and scientific field to that' of medico-legal action. ' Prevention of these dust diseases is entirely posfaible. Engineering skill and engineering methods aa'^eT&|ipUed to control or remove the dust at its soir; liis is often expensive, but po is the pro vision of safe drinking water. People have been educated in this country to spend enormous sums of money to proyide safe drinking water but they have not learped yet to be as intelligent about the pollution of afijas about the pollution of water. Hand in hand with dust control in industrial es tablishments goes medical supervision. One of the lessons learned in war plants is that competent med ical supervision and competent engineering control guarantee sound preventive medicine. Both are es sential and satisfactory results cannot be obtained with one alone. It is essential that industrial physicians^ roent genologists and other physicians who may come into contact with industrial workers be,alert to detect and follow up unusual cases. Ih e two dis eases mentioned before were detected early in plants having a good medical service. One thinks of the possibility of individual cases in which the significance of the findings and the relation to oc cupation are apt to be overlooked. One of the phases of the pneumoconiosis situa tion which has attracted a great deal f attention in the last few years is the use of aluminum dust both for the prevention and treatment of silicosis. It is almost ten years since Denny, Rgtbson and Irwin of the Banting Institute in Toronro demon strated that by administering finely divided alu minum dust to experimental animals they could in hibit the action of silica. This was confirmed by other investigators, notably by Dr. Gardner of the Saranac Laboratory. The Canadian group Used metalic aluminum and Dr. Gardner also used amor phous hydrated alumina. Several of us who are in terested visited the Silicosis Clinic in Porcupine and were greatly impressed by what we saw. There is no question but that a number of the silicotic employees who had undergone this treatment expe rienced considerable relief of their symptoms, no- tably cough and dyspnea. It should be noted, how- i ever, that in other instances no improvement was noted and, in other localities, it has been difficult at times to induce the men who were receiving this treatment to continue with it. It is natural that the novelty of this type oi ad ministration of a therapeutic agent would cause some hesitancy with respect to its adoption. There also has been a natural reluctance to try this mode of therapy on silicotic patients who are also tuber culous. At the present time, this whole matter has been the subject of discussion by the Council on Indus trial Health and the Council on Pharmacy and Chemistry of the American Medical Association and it is the intention of these two councils to issue a joint statement relative to the status of this sub ject at an early dat. While there is naturally some divergence of opinion on various points among those concerned with the demonstration of this method, { believe that there is a general agreement with respect to basic considerations. Silicosis is essentially a chronic disease and takes years to develop and, once the disease is well ad vanced, the general outlook is not very good, par ticularly with respect to the possibility of tube rcle infection, Consequently, it is going to take a con siderable length of time to demonstrate whether in human beings this method of treatment by the in halation of aluminum dust or of amorphus hydrated alumina will fulfill the expectations raised by the results in experimental animals. It is apparent that where this form of therapy or prophylaxis is being tried, it is necessary to maintain careful and accu rate medical supervision if permanent and worth while restilts are to be demonstrated. All who are active in endeavoring to develop the use of alum inum are agreed that it is in no way a substitute for engineering control of the dust hazard and for med ical supervision of workmen exposed. It is appre ciated that in some instances it is difficult to control entirely the escape of silica dust into the atmos phere but, in any event, it is insisted upon that engi neering control and medical supervision be ade quate before aluminum treatment is initiated. As far as is known now, metallic aluminum is nontoxic. In response to an inquiry in The Journal of the American Medical Association, January 20, 1945, the statement is made that American medical literature contains no convincing evidence of pul monary or bronchial injury from exposure to alum inum dust. There is considerable literature on the action of metallic aluminum on the lungs and some of the German investigators have claimed that aluminum is capable of producing a pneumoconio sis. This has been denied by other observers. There have been some reports that amorphous hy drated alumina may have an unfavorable effect upon tubercle infection. It is obvious that careful supervision of this inhalation method of treatment is obligatory. There also arises the question of pos sible medico-legal complications with respect to INDUSTRIAL HEALTH--HILLEBOE infim therapy and, again, only time will give us "iSe^nal answer, ' v V I' BIBLIOGRAPHY ffiL :Lanza, A. J . : Miners Consumption: A Study of 433 Cases Zinc Miners in Southwest Missouri, Pub- H ealth Bull. __(January) 1917 (out of p rin t). . . . . 2. t a n , McConnell and Fehnel: Effects of Inhalation, of l-ijAsbestos Dust, Pub. Health Rep. 5 0 :1 (January) 1935. SrWiC e. personal communication. !> H i 4. G ardner: Interim R eport of Silicosis Experim ents a t the e Saranac Laboratory, (October) 1937. ' s. Segal, Sm ith and Greenburg: D ust Hazard in Trem olite ^"tTalc'Mining, Am. J. Roentgenol (January) 1943. 1 6. Sander: J. Indus. Hyg. i t Toxicol. (M arch) 1944. 1 7, M. Clin. North America 6 (July) 1942. ; j.'Heal. Paul: National Institute of Health, personal com munication. 9. Neal, S c h n e lte ra n d Cam anita: J . A .M . A. 1 1 9 (August) [-. 1843: Pub. H ealth Rep. (Ju ly 30) 1943. , . . 10. Fifty-ninth and Sixtieth A nnual R eport of th e Trudeau ' !: Sanitarium, 1943-1944, t s : 1J. FairhaU: Physiol. Rev. 2 5 (January) 1945. u TUBERCULOSIS IN INDUSTRY .i HERMAN E. HULEBOE, M.D. ` WASHINGTON, D. C. lf L Control of tuberculosis in industry in the past- r` was often hampered and made ineffective by costly roentgen ray procedure. The standard 14 by 17, inch film, universally regarded as the most accu rate plate size for the detection of lesions in early tuberculosis, was too expensive in matrial and per sonnel for large scale use, and was not practicable for the further important reason that any consider able number of workers could not be handled in. desirably short periods of time. ! Now, however, tuberculosis in industry can be controlled effectively by the application of a new and relatively inexpensive mass radiography tech nic. Photofluorographic methods employing 35 mm. and 70 mm. roll film, 4 by 5 inch filraj afid 14 by 17 inch roll pper film have given, industry tools for the control f a disease that strikes down the most valuable industrial workers-~men and women be-ft tween the ages of 20 and 4,5. In 1943, newly one half of the deaths from tuber culosis (44.8 per cent) was in this age group of maximum personal .effectiveness. Indeed, from early adulthood to the age of 35, tuberculosis is the chief cause of death. Between the ages of 15 to 49, it is one of the first three causes of death; and be tween the ages of 20 to 34, one out of every six deaths among white persons and one out of every three deaths among nonwhite persons are due to tuberculosis, Recent surveys show that from twelve to fifteen in every 1,000 industrial workers are attacked by tuberculosis, and in consequence.'they may beconie inefficient on their jobs, are often absent and spread the disease to others. The cost to industry is incal culable and the expense in human life beyond all measure. During the war there was no general increase in tuberculosis. Nevertheless there has been a larger proportion of deaths from tuberculosis in urban in dustrial areas than in nonindustrial areas. Chief, Tuberculosis Control Division, U. S. Public Health Service. Industrial communities are spawning grounds for this dread disease. Overcrowding; insanitary living Conditions and unusual fatigue are contributing factors that precipitate the susceptible Into break downs and hinder the already diseased from achiev ing maximum recovery. Tuberculosis control efforts should be and have been concentrated on these areas in anticipation of an expected rise in tuberculosis mortality as ^-con sequence of the war and its contingent Kealth strains and pressures. Soon after war was declared, the United States Public Health Service established a tuberculosis control office for the purpose of assisting state and local health departments in the development of tuberculosiif control programs. Then, in July 1P44, the Tuberculosis Control Division was created. The objectives pjf this Division are as fallows: -(l) case finding, (2) isolation and treatme^f, (3) Jafter-care and rehabilitation, (4) protection of th a family of the tuberculous person against economic distress. The purpose of case finding is fa. discover hidden cases of tuberculosis. Such efforts, in the past, were directed toward the family members of known in fectious cases. Since the introduction of mass'radi ography, however, case finding has had a much larger range. It has been pointed to large popula tion groups. The two sizable portions of the popu lation which can be reached easily by mass radi ography re (1) persons admitted to general hos pitals, and (2) persons employed in the large and small industries of the nation. This second group is at thepresent moment one of the chief concerns of the Tuberculosis Control Division. When Ciases of tuberculosis are found, they must be given tnedical care and be isolated to assist the patient in renewing health and hope, and to pre vent spread of the disease. To be sure, there is a lack of vision in case finding if treatment is delayed by a shortage of sanatorium beds. In every indus trial community in which a tuberculosis control campaign is undertaken, plans must be made for the provision of a sufficient number of beds. Tem porary facilities may, for a time, bjji utilized the people, realizing the seriousness of the* fcom-fi munity's plight will demand the construction and maintenance of the necessary hospitals. After-care and rehabilitation are extremely im portant aspects of the whole fight against tubercu losis. It is well known that tuberculosis is a r t lapsing disease. The industrial worker who has arrived t an arrestment of his case must have help and competent advice, both medical and social, in his readjustment to self-supporting life. This is a large problem which will require the cooperation of private industry and local, state and federal agencies. When the industrial worker is stricken with tu berculosis, his family often is required to depend on public funds for the necessaries of life. Accord ingly, a sound medical program must be comple mented by a generous plan of public assistance. If y. h Of 1 i i riC '% i'* ': 3 f fi .rip a Pm i uu