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)RS D., F.A.C.P. B.S.Enc. D.Sc. .. Ph D. M.D. ., MJ). M.. D.Sc. J.. , >.D.rr m.p.h .A C.P. S.M. :h g., a.b. >, M.D. E., M.S.P.H. Ph.D. .. B.S.. R.N. MANUAL OF INDUSTRIAL HYGIENE AND MEDICAL SERVICE IN WAR INDUSTRIES Issued under the Auspices of the Committee on Industrial Medicine of the Division of Med ical Sciences of the National Research Council PREPARED BY THE DIVISION OF INDUSTRIAL HYGIENE, NATIONAL INSTITUTE OF HEALTH. UNITED. STATES PUBLIC - HEALTH SERVICE WILLIAM M. GAFAFER, D.Sc. Editor W. B. SAUNDERS COMPANY PHILADELPHIA AND LONDON 1943 OF DISEASE IN INDUSTRY of the flat bones of the skull, fractures, and osteogenic sar- 1 to 2 micrograms may produce ie amount of radium a worker is 0.1 microgram, as revealed by i change of his occupation and :rapy or other mode of therapy <ed is recommended.*7 Curtiss3* led air is found to contain more iter, it indicates that at least 0.1 sts in the body. omatic. The decalcifying therapy .ionium chloride, as used by Aub lown to increase the excretion of >duce the total deposition of radium are-** is possibly of value early in coi. ned in the trabeculae rather , thorough medical and dental exed before employment. The comle of preemployment examination subsequent blood counts. Periodic luding hematologic studies should ine month and particular attention ve blood counts. Many authorities air radon test, which is made at year, because a dangerous radium in this way before it has had tin# lood picture. Leucopenia, relative anemia calls for careful investiga.'cupation for the worker concerned onary Fibrosis, Pneumoconiosis) sis is a broad generic term applied | ungs. In a more restricted sense, /til duced by inhaled mineral dust s of the American Public Health "a disease due to breathing air coo*j :terized anatomically by generalisedj velopment of miliary nodulation sho-*ness of breath, decreased Vj rn.uoi.fcM or OCCUPATIONAL DISEASE expansion, lessened capacity for work, absence of fever, increased susceptibility to tuberculosis (some or all of which symptoms may be present), and by characteristic X-ray findings." Classification.--On the basis of the structural changes induced in the lung and the type of dust, the pneumoconioses or pul monary fibroses may be classified as follows (compare refer ence 43): 1. Simple benign pneumoconiosis, which is virtually a deposi tion of dust in the pulmonary tissues usually accom panied by pigmentation, and includes, for example, anthracosis induced by coal dust and siderosis induced by iron. It does not incapacitate and roentgenologically shows as a maximum change only an exaggeration of linear pulmonic markings and is of clinical interest only by way of differential diagnosis. Such cases should never be diagnosed as silicosis. 2. Silicosis, which is a pathologic pulmonary reaction due to free silica; for example, sandblasters' silicosis. This type of pneumoconiosis results in a classical nodular fibrosis of-both lungs, demonstrable both in the X-ray and at post mortem. Massive fibrosis, varying degrees of pig- ' mentation, atelectasis, emphysema, fibrous pleurisy, bronchitis, cavitation,, and pneumothorax are among the concomitant pathologic changes.44 S. Mixed forms, that is, silicosis resulting from the inhala tion of mixtures of varying amounts of free silica and more inert pneumoconiogenic dust constituents, for ex j aoa/mf -sp.i'lliei;c,--o-a-s1nis-thurna__d_c_VooOusUbiliJtceLoUdsdlyiibsicoaiUmnUdeMusinCdSdeSeror sthiliicsocslias.ssMifiocsattiocna.ses i^Asbestosis, a characteristic diffuse, interstitial fibrosis u of the lungs induced by fibrous minerals which, according to animal experimentation, is due to the mechanical ac tion of the asbestos, producing a ground-glass appear ance on the X-ray. It may cause disability and a few fatal cases have been recorded. j-JTtioiopj/--Silicosis is incurable and large numbers of work*i are potentially exposed to conditions favoring the developi of the disease. The majority of cases of this chronic ry disease occur among workers engaged in mining,47, --.lag, ceramics industry, tunnel construction, sandblasting. Ifccsdry work. stion of siliceous dust almost invariably results in sili- - ............... * -ii,.. i -^v.. MSEASE IN INDUSTRY prevailed during the work' ng these silicosis-producing ible size (usually 0.5 to 3 ie atmosphere at the breathconcentrations exceeding 5 oot. number of years, a free state, such as quartz. >n of high concentrations of ces disabling disease in a lation of low concentrations t. ites, which include the 11 rage, either list silicosis in or make certain provisions nia, Connecticut, Delaware, . Maryland, Massachusetts, York, North Carolina, North Wgshington, West Virginia, ii? on the basis of the 1930 100.000 workers are exposed ns, including X-ray studies, at from 8 to -26 per cent of y disabling pneumoconiosis; in these dusty trades would e. This resistance of some t than real47 if consideration ^ t period required before the lly or even by X-ray study, evelop after at least 7 years 3 lave developed in as short a .3 ther extreme, with exposures j more than 30 years may bar* to a stage when it can bfi"j ker showing X-ray evidence f simple silicotic involveme*di oms and physical signs are the patient has a silicosis, ** hracosilicosis), or ashest"1* THE PROBLEM OF OCCUPATIONAL DISEASE 163 Symptoms and signs do, however, assist in the determination of disability. Among the symptoms and signs of importance are shortness of breath, particularly upon exercise; cough, usually dry; chest pain, varying from a feeling of tightness in the chest to the sharp, excruciating pain typical of pleurisy; hemoptysis; general complaints such as digestive disturbances, insomnia, and dizziness; decrease in chest expansion; prolonged expiration, especially in association with emphysema; altered breath sounds; rales; and the presence of areas of increased density in the lungs. Infection may complicate the picture at any time and is usually manifested by pleural pain, fever, night sweats, weight loss, aggravation of dyspnea, anorexia, weakness, and a cough produc ing large amounts of blood-tinged sputum. Diagnosis.--In establishing a diagnosis of one of the pneumo conioses, all of the following three factors should be considered.* d 1, An occupational history which reveals definite prolonged * exposure to siliceous dust or asbestos dust. it 2. Symptoms and physical signs which furnish valuable in formation in (a) gauging the extent to which pneumo coniosis has progressed, (b) showing the degree of dis ability, and (c) excluding other diseases. 3. X-ray findings, .which, if classified on the basis of the sys tem recommended by the U. S. Public Health Service, show bilateral ground-glass, nodular, or* a t more advanced type of luhg-field marking... So long as the chest roentgenograms show predominantly ^B&ear pulmonic markings, silicosis or modified silicosis need not tW given serious consideration. It is when the shadows in the lung assume a ground-glass, granular or nodular appearance they become specific and assume more diagnostic characics. Using Irvine and Steuart's analogy,4* the usual linear >nic markings are likened to the branches of a tree and the sular, stippled, or nodular lung-field markings simulate the Complete foliation then means silicosis. Viewed stereolly, the films at this stage will 6how fine nodulation. Some describe a related change in the lung-field appearance as ition.4* Although not definitely determined, this type of J-field marking may result from the inhalation of mixed later stages will show massive areas of fibrosis, and if >n is present the X-ray shadows tend to be asymmetrical. itotis is exceptional from the standpoint that the pul- j. . field of forensic medicine il has been frequently demonstrated studies *~i|] yield essential information. ."' " " -'?'j ' t* *$** ,-* .-*** HAr*.~- ''- vs* #vj '(: 154 PREVENTION AND CONTROL OF DISEASE IN INDUSTRY monarv fibrosis is caused by dust containing little if any free silica. The asbestotic patient will usually show clinical symptoms and signs which are out of proportion to the apparently small amount of pulmonary involvement shown by the chest roentgenogram. Large massive shadows are very rarely seen in the chest roentgenogram except in the presence of a complicating infection. On the contrary, the diffuse interstitial fibrosis is manifested by a ground-glass appearance, frequently with fine pinpoint stippling of the middle and lower lung fields. It progresses to terminal diffuse fibrosis usually without nodular pre dominance in about twenty years.'" A shaggy' appearing cardiac silhouette due to involvement of superimposed lung structures and pleuropericarditis is not infrequent. Asbestosis bodies may be demonstrated in the sputum or the lung tissue. Medical Control Measures.--All applicants for employment in dusty trades should be examined by X-ray. Periodic medical ex aminations at intervals of one year to possibly three years, in cluding X-ray study of the chest, should be made of all workers in dusty trades in order to detect evidence of active pulmonary tuberculosis and early silicotic changes. The length of the inter- val between examinations depends mainly on the degree of haz ard'and the prevalence of endemic tuberculosis. Clinical study of patients suspected of having pulmonary tuberculosis should be.made to determine the dynamic status of such complication. No worker should be rejected on preemploy, ment examination or removed from work, which he is accus tomed to perform, merely because of a diagnosis of simple silicosis, but rather the atmospheric dust in which he works should be brought within safe limits. The worker whose first roentgeno gram shows healed primary tuberculosis should not be denied employment in a dusty trade on this account alone. If the worker has minimal, arrested, or healed reinfection tuberculosis, he should be allowed to continue his work but should be observed with the same precautions as a man with simple silicosis. Close medical supervision is recommended for all silicotic workers in order to control or prevent serious complications of the common respiratory infections. Benzene (Benzol) Poisoning Benzene (benzol) is an excellent solvent for gums, resins, fats, and oils, and as such has found many industrial applica tions. It is used in the manufacture of rubber, rubber goods. > ,, ^vi * r*'i * .**>... ,iii'!-.;l'1;>i} -* y* ~ if' ^'