Document v113Y1YrZJbzBL19005aG5DG6

FILE NAME Insurance Industry INS DATE 1957 DOC INS101 DOCUMENT DESCRIPTION Report - Survey of the Occupational Environment - Health Hazards Author Herbert Walworth worked for Lumbermen's Mutual The survey of This report was prepared by the subcommittee to revise Plant Hygiene Studies of the Committee on International Relations Council on Industrial Health American Medical Association The following persons are the members of the subcommittee Warren A. Cook Chairman William G. Hazard Herbert T. Walworth Irving R. Tabershaw M.D. and Jerome K. Brash Introduction This treatise is intended primarily for those physicians who serve industry on call those physicians whose private clientele includes industrial employees and those to whom industrial employees come for placement periodic or other types of physical examination diagnosis or treatment Its purpose is to promote greater interest knowledge and activity in occupational health on the part of all physicians who are or should be concerned time industrial medical directors and staff physicians presumably are well acquainted with the matters discussed as are most physicians occupying such positions part time However they might find in this treatise worthwhile reminders The physician may gain much through a personal survey of the occupational environment of persons who are under his supervision or of those who are or may become his patients Increasingly in the large plant and especially where there is a organized medical department the industrial physician observes operations and the conditions under which the employees are working This practice should be adopted by the physician who has an call relationship with industrial plants After each survey the physician should discuss his observations with management with particular recognition of the fact that the assistance of several disciplines is usually necessary to control a given situation General practitioners whose patients include industrial workers can and should acquire some knowledge of the industrial operations of the area through organized plant tours or invitational house arrangements between the industries and the local medical society SERRE EERIE betta hl 38 cupational environment an essential of industrial medical practice Manifold advantages are to be gained from a survey of the occupational environment The information obtained may permit the physician more adequately to diagnose and treat disease affecting his patient As an example a persistent hepatitis may fail to respond to treatment Inquiry into the patient's occupation may disclose exposure to a chlorinated hydrocarbon solvent vapor as the possible cause Only after this exposure is evaluated and brought under satisfactory control can the patient's hepatitis be alleviated and of equal importance development of hepatitis in other workers at the operation be avoided Similarly the survey permits the physician to become familiar with the physical and mental demands of the job It gives him the opportunity to see the people at work in circumstances in which they are much more likely to be at ease than in his office In addition he can become acquainted with materials and operations the nature of exposure to substances and conditions that may affect health and the physical conditions that may be the cause of accidents It is important however at this point to caution the physician against hasty and unsubstantiated conclusions The physician is thus in better position to help in matching the physical abilities of a prospective employee with job requirements He has a better understanding of the industrial health hazards as they actually exist in a given plant and at a specific operation This knowledge of the environment permits him to take a more effective part in the prevention of occupational diseases and in accident prevention What then is the first approach in making an initial survey of a plant and what should be looked for Preliminary to the Survey Arrangements for an initial plant survey should be made invariably with management or an appropriate representative of management Where the plant is small there should be a discussion of the purposes of the survey with the head of the concern and the physician serving the plant If the plant is a division of a larger organization inquiry should be made through local management as to whether there is a medical director or consultant who supervises occupational health throughout all plants If so the physician should communicate with him Both management and med- ical advisors would be expected to welcome such interest in plant conditions on the part of a general practitioner or call physician In preparation for the survey the physician should acquaint himself with the workmen's compensation act and the industrial health and safety regulations of the state In the actual conduct of the survey management should designate someone familiar with the plant to accompany the physician through the various departments In the larger concerns the safety director or the industrial hygienist would be the logical selection since he would be well informed as to operations and potentially hazardous conditions and as to the means of safeguarding workers against them Prior to making the trip through the plant the physician should discuss conditions with the person who is to accompany him A review of plant dispensary records should be made with special reference to minor complaints and injuries as well as time injuries It is to be hoped that there may have been some analysis of these data relative to major causes of injury preferably in accordance with the code of the American Standards Association.,,Special note should be taken of symptoms or complaints reported particularly if recurrent in the same person or in different persons in the same department If periodic physical examinations have been made positive findings that may be associated with occupation help to point out those operations especially to be noted in the survey The Survey Several types of surveys that vary in their purposes and thoroughness are well discussed by Patty. He not only notes the information that should be gained in these sur- veys but also includes pertinent comments on proper con- duct within the plant on the part of the person making the survey Conditions to be watched for are described briefly in the following paragraphs Where such conditions are found the physician should become more completely informed through references such as are listed by the Council on Industrial Health of the American Medical Association.3 FREER EEE TERRE EEE EEEEE TERE EERE EEE EEE EERE EEE EEE EEE ey 39 POTENTIAL HEALTH HAZARDS Injurious Materials Dusts Pneumoconio.sTihse hazard presented by dust in an occupational environment is dependent on a number of factorIst is necessary first to know something of its composition Abrasive blasting may involve free silica in the form of quartz if a flint or sand abrasive is used In this case the dust exposure of the worker must be kept at a low level if silicosis is to be avoided On the other hand where steel abrasive is used to remove scale from steel forgings the dust contains no silica and consequently need not be kept under as meticulous control as in the former instance The maximum amount of dust that can be considered acceptable depends not only on its composition but also on its particle size and the duration of exposure Generally dusts present in work atmospheres include appreciable proportions sufficiently small to reach the alveoli The exceptions are rare In regard to duration of exposure not only to dusts but to other hazardous materials an operation may be observed to be brief but inquiry should be made as to whether it is repeated during the day and how often Where production involves a number of diverse operations it is well to inquire whether activity at other periods during the day or week may involve exposures greater than those observed The dusts most likely to produce disabling pulmonary involvement are those containing free silica that is silicon dioxide not chemically combined with other elements Such dusts occur frequently in industry Inquiry should be specific in regard to this component especially since the presence of free silica may not be readily apparent For example soapstone powder widely used to keep layers of unvulcanized rubber from sticking together may contain from 0 to 17 of free silica depending on its source The most common form of free silica is quartz which occurs widely in nature Natural materials widely used in industry that should be regarded as potentially productive of silicosis because of their high silica content are granite flint sandstone sand tripoli and diatomaceous earth Dusts containing asbestos should also be noted because prolonged exposure to asbestos dust in excessive concentration may result in a type of pneumoconiosis known as asbestosis which may be disabling In coal mining and handling attention should be given to the possible development of coal workers pneumoconiosis a recently recognized but incompletely explored clinical condition due to exposure to coal dust per se as well as to the possibility of silicosis from exposure to free silica in the rock associated with the coal in certain areas Metals and Their Compounds large number of metals and their compounds are used throughout industry As a potential industrial health hazard the most prominent of PEER ERE IER 40 these is lead which may be present alone or in a wide variety of compounds The chief mode of entry is inhalation of dust or fume Percutaneous absorption of metallic lead and inorganic lead compounds is insignificant but tetraethyl lead and a few other organic compounds of lead may be absorbed through the skin under suitable conditions Molten lead ordinarily does not present a hazard unless its temperature is well above its melting point Special attention should be given to operations where lead may be subjected to temperatures above its boiling point as in the welding of leaded steel It is wise to have persons who work regularly with lead checked periodically for the extent of their lead absorption by determination of lead in blood or urine Lead compounds may be known by a number of names not including the word lead Litharge the common name for one of the oxides of lead is found in the paste of lead storage battery plates in a cement for attaching glass to metal in doctor solution in petroleum refining and in the manufacture of chrome yellow pigment Although the specific gravity of this compound is high litharge is often so fine that when dispersed into the atmosphere it will persist long enough to cause excessive exposure if adequate control measures are not in effect In most industrial oper- ations where dusty lead compounds are used or produced it is desirable to have an evaluation of the exposure made with the aid of laboratory analysis of the air or of samples of the blood or urine of exposed employees or by the combined investigation of the environment and the personnel Other toxic metals to which the physician should be particularly alert include antimony arsenic beryllium cadmium cobalt manganese mercury and phosphorus Exposure may occur in mining refining fabrication and cleaning operations Welding or temperature cutting on cadmium surfaces can be particularly hazardous The toxicity of beryllium is so extreme that it is in a category of its own Mercury is of special importance because hazardous concentrations of vapor are released from the liquid metal even at room temperature The dust of various mercury compounds is also toxic Chromium in the form of chromic acid mist is commonly found in chromium electroplating or as salts of chronic acid in the form of dust and may cause ulceration of the skin or the nasal septum Zinc in the form of fresh zinc oxide fume such as may arise from a bath of molten zinc at a galvanizing operation may cause the temporarily disabling illness known as metal fume fever Excessive exposure to iron dust or fume as produced in welding gas cutting or grinding may cause sufficient retention in the lung to show as nodulation on chest films but the condition is not regarded as disabling These changes are somewhat erroneously interpreted as silicosis Whereas the pneumoconiosis dusts usually require prolonged periods of exposure years to produce bbb EEE IER EE EE their effects very brief exposures to toxic metals solvent vapors and gases can cause illness Thus it is important that the physician be alert to the possibility that operations of brief duration may entail exposures more severe than those observed at the time of his survey Solvents observing operations involving solvents the physician should consider the possibility of absorption through the skin in addition to absorption through the respiratory tract Contact of these materials with the skin not only provides an avenue of introduction into the body but also presents the possibility of dermatitis There is a wide range of hazard potential among the many solvents used in industry This is governed by the volatility of the solvent as well as by its toxicity The exact chemical name of the solvent should be obtained This need is illustrated by the two solvents tetrochloroethylene and tetrachloroethane There is only a slight difference in their names but the toxicity of the former is indicated by a maximum acceptable concentration in the atmosphere of 200 parts per million as against 5 ppm for the latter they are of essentially the same volatility One of the frequent uses of solvents in a great variety of plants is in equipment known as the vapor degreaser This is essentially a tank in which a solvent often trichloroethylene is vaporized by heating and metal parts to be degreased are placed in the hot vapor Such equipment can be used without excessive exposure to the operator but a considerable number of poor practices as listed by Horowitz can result in exposure beyond the recommended limit Benzol benzene carbon tetrachloride carbon disulfide and methanol are other industrial solvents that may cause serious illness if not used under properly controlled conditions Gases general potentially hazardous exposure to gases is not obvious in occupational environments For example a visit to a gasoline engine test room may fail to indicate the presence of a moderate carbon monoxide hazard Where carbon monoxide may occur by leakage from a pipe line or by impingement of a gas flame upon a cold surface with resultant incomplete combustion or by its use as a reducing gas in a treating department inquiry should be made into the occurrence of headache among the employees such as would result from moderately elevated concentrations over a number of hours or throughout the day In addition the possibility of accidental liberation of high concentrations that may result in asphyxiation should be kept in mind These two elements of hazard apply to exposure to a number of other gases The more prominent symptom from moderately excessive exposure to hydrogen sulfide is irritation of the eye rather than headache but the danger of rapid asphyxiation is even greater than that from carbon monoxide Experience has shown that odor of hydrogen sulfide is no safeguard against excessive exposure because even brief exposure to sufficiently high concentration results in the loss of the ability to smell this gas A number of gases are brought into plants in cylinders in the form of liquids under pressure These include hydrogen fluoride used in certain refining processes and in the chemical industry hydrogen cyanide and methyl bromide both used for fumigation and for other purposes and chlorine widely used for bleaching in water treat- ment and as a bactericide Other toxic gases include ozone nitrogen dioxide and sulphur dioxide Dermatitis Materials phase of the sur- vey dealing with producing materials may best start with the industrial nurse who probably will be well informed of the incidence of dermatoses For example if no cases from cutting oils and compounds have come to her attention this source of dermatoses may require no further investigation but if numbers of minor cases with an occasional serious case have occurred this situation should be thoroughly investigated Attention should be given to washing facilities soaps and cleansers used and the availability of hot water Personal washing procedures as well as other measures such as protective creams and equipment should also be checked In addition to solvents innumerable other primary irri- tants and sensitizers cause skin infections Wherever there is skin contact with primary irritants which may include not only strong acids and alkalis in an electroplating department but even dishwater in a plant cafeteria there may be some incidence of dermatitis Skin contact with such materials should of course be avoided though this is difficult in some operations Among the many sensitizers exposure to those involved in the preparation of synthetic resins and in the manufacture of plastics is worthy of note The effect on the skin may be caused by contact either with dust or with gases liberated during these processes Where waxes are used for impregnation of electric con- densers or for wire and cable insulation inquiry should be made as to whether these are chlorinated naphthalene or diphenyl compounds If so suitable precautions listed by the producer should be followed often Pathogenic Organisms number of occupations involve exposure to pathogenic organisms through their incidental introduction into lacerations In packing houses measures to avoid brucellosis and psittacosis should be noted In plants that handle imported animal products such as hair bristles wool and hides investigation should be made of the need for sterilization of these materials and if in order the method used Workmen in these plants should be told what an anthrax pustule looks like and impressed with the need for immediate medical attention for such a lesion EEE EEE EEE EEE EEE EE bt 41 Other Materials other than those falling within the foregoing classifications should not be overlooked Examples of such materials are those capable of inducing cancers including chromium compounds lung naphthylamine and benzidine urinary bladder and certain polycyclic hydrocarbons that may be present in coal tars and in certain boiling catalytically cracked oils skin Surveys of industrial exposure to the cancerogens should be supplemented by epidemiological investigations A single case of cancer hardly proves a effect relationship where exposure to a suspected cancerogen is involved but incidence of such cases significantly in excess of that occurring in the general population would point to the occupational exposure as a possible cause Hazardous Conditions In addition to hazardous materials observations should include hazardous conditions These may be covered under the following headings Excessive Exposure particularly of long dura- tion to excessive noise levels may cause diminished acuity of hearing Although sufficient data are not yet available on which to specify a precise level of sound of a given frequency that can be taken as a maximum acceptable level certainly those noise conditions where one must shout within an inch or two of the ear to make oneself heard should be noted in a survey of potentially injurious conditions The physician upon finding such conditions should recommend that a study be made of the noisy environment to determine whether the intensities at existing frequencies are excessive and if so to determine whether practical reduction measures can be taken He might also rec- ommend that an audiometric examination program be instituted Extremes of Atmospheric Extremes of atmospheric pressure include the high pressures encountered in foundation and tunnel construction and in diving operations and the low pressures of flying at high altitudes Foundation and tunneling operations under pressure tend to be among the more hazardous It is likely that a time or time physician will be connected with such construction operations Other physicians in the area may be called upon because of some temporary unavailability of the physician normally responsible or in event of an accident causing a number of serious injuries Also their patients may be engaged in such work Accordingly it is desirable for physicians in the area to visit the project become informed on compression and decompression schedules and become familiar with the physical examinations given new workers and with instructions to workers such as checking with the physician before going under pressure in case of a coryza or ear block Particularly where high pressures are used the physician should become completely informed on operating condi tions before he decides to enter a pressurized area It would appear prudent for only the younger physician to do so In aviation medicine it is now generally accepted that physicians should be familiar with the effects of low pressures and of too rapid subjection of the body to pressure changes Low pressures from altitude construction or mining operations are not ordinarily within the purview of most physicians It is assumed that physicians at operations in such locations will be informed about the physiological aspects of working and living under low pressures about the decrease in maximum acceptable concentrations of gases dusts and toxic materials as larger volume of the thinner air must be respired Extremes of Temperature Heat many plants the problems of heat in summertime are no different from those in nonindustrial environments generally Since the evaporation of perspiration causes cooling of the skin usually the better the air movement the greater the comfort Although high humidity in itself creates no harmful effects it does limit the rate of evaporative cooling of the skin and can be expected to intensify the effects of high temperatures Many plants have local hot spots such as ovens heattreat baths and furnaces that cause excessive exposure to radiant heat as contrasted with heat carried by convection or hot air In the steel glass foundry and other industries where processing is built around large melting operations control of radiant heat is a major problem A given amount of heat transferred to a man will have the same effect regardless of the means by which it reaches convection conduction or radiation But the control of radiant heat is totally different from the control of the others If a man is subjected to radiant heat air movement over the man will not reduce his heat load Shielding with some reflective material such as aluminum may be required The physician should become acquainted with the hightemperature occupations in a plant Workers with certain circulatory defects should be placed elsewhere Since longterm physiological effects of working in heat do not seem to be serious and acclimatization is a very real factor the physician would ordinarily refrain from recommending the alternating of workers between hot and temperature operations An increase in the body temperature and pulse rate results from exposure to extreme heat Since these effects are alleviated fairly promptly on removal to cooler areas the physician should note whether such areas are available and utilized as required If an conditioned rest room can be provided recovery is considerably more rapid When the pulse rate does not decline sufficiently during a rest period in a cooler area more effective control measures should be recommended IRIE REI RR 42 III ER eee In hot occupations the physician should observe whether an adequate water supply with salt is available for the prevention of heat cramps and exhaustion Salt is usually taken in tablet form Several varieties are sold but the enteric or impregnated type seems the most satisfactory A cooled salted water supply is sometimes used One teaspoonful of table salt per gallon of water is ade- quate Thirst is not an accurate indicator of how much water a man needs when working in extreme heat His fluid loss will usually exceed the replacement induced by thirst It has been said that one benefit of salt tablets is that they result in a man's drinking more water than would otherwise be the case Extremes of Temperature Exposure to extreme cold may occur in packing plants in freeze food producing and storage operations and in flying at high altitudes Provision of proper clothing is the principal fac- tor to be noted It has been stated that acclimatization to cold has not been satisfactorily demonstrated An investigation of a group of 66 workers engaged many years in preserved manufacture in cold rooms maintained at 0 to 2C showed a high incidence of chronic muscle and joint pains and of upper respiratory tract involvement Inquiry should be made of these possible manifestations of the effects of cold by the physician concerned with such exposure Ionizing Radiations radiations are finding increasing applications in industry Inqury should always be made as to whether radioisotopes or ray units are being used or whether it is contemplated they will be introduced Some years ago industrial radiology was limited principally to the use of radium or ray for making radiographs of welds and metal castings for detection of flaws Today a considerable number of radioisotopes are employed for a variety of purposes Cobalt a powerful gamma emitter may be used instead of radium for radiography or it may be the source of gamma radiation in recording devices for liquid levels or in a thickness gauge Beta emitters such as phosphorus may be found in thickness gauges for application of rubber coating or in milling of aluminum foil Even alpha emitters have an industrial use where polonium bars remove static electricity from printing press rolls and other machinery where static inter- Write Dept. B8 hme samme products TOT sugar beet products co the washwof oindrustdry saginaw mich los angeles calif toronto canada The famous SBS upside hand picture first appeared about a year ago It dramatically illustrates how SBS Cream Deodorant Soap is almost im- possible to waste . . . and why it has solved literally thousands of soap headaches in hundreds of nationally known organizations What is your soap headache 8 soap powder spilled all over your washrooms 8. bar soap wastefully dissolving on the shower room floor e o liquid soap dispensers either dripping or all clogged up constant work keeping dispensers filled and in order complaints about your soap from both men and women whatever your soap headache SBS can help Write and we'll send complete information that tells you just how SBS Cream Deodorant Soap cures most of today's soap headaches Write us today We'll rush the details to you SBS research developed SBS after years of study This new type of soap is proclaimed the successor to liquid and bar soaps 43 feres with production or safe operation Radium also con- tinues to be used for this latter application The risk of inhalation or ingestion of radioactive materials particularly alpha emitters should be checked Radioactive sources and devices utilizing ionizing radiations can be used with safety where adequate precautions are observed The physician need not be an expert in the intricacies of ionizing radiation but he should inquire into the schedule of monitoring exposure to radiation and review the records of radiation levels within occupied areas and of personal monitoring devices If exposure should exceed accepted values he should call to the attention of management the seriousness of the injury that in time may develop Factors involved in the proper handling of radioisotopes are outlined in a paper on surveying industrial plants for safe use of these materials Illumination making a survey of any occupational environment the adequacy of illumination should be observed This would include intensity for a given operation and area together with quality of illumination This latter factor includes contrast lack of glare and proper brightness ratios in respect to both artificial and daylight illumination It is not contemplated that a detailed illumination survey will be undertaken by the physician If his general observation indicates that the illumination is inadequate the plant management should be referred to pub- lications on industrial illumination and advised to have an illumination survey made In connection with the relation- ship of illumination to the visual demands of tasks attention should also be directed to an adequate examination program and to suitable protection equipment as well Harmful Operations Repeated Motion may be caused by repetitious movements Attention should be given to operations that may lead to bursitis and synovitis Information may be obtained from the plant nurse as to whether such conditions have occurred and if so at which operations The physician may be able to make pertinent suggestions for adapting the operation to the physiological and anatomic limitations of the human body Vibration Compressed hand tools are widely used in industry In many plants the intermittency of the operation or other factors have prevented difficulty If there has been some incidence of white fingers or if these tools are used routinely reference may well be made to a paper by Dart10 that covers this condition from the viewpoint of a practicing industrial physician Heavy pneumatic tools such as hammers reportedly may cause injury to elbow joints but in this country cases have been few ACCIDENT HAZARDS Operations and Conditions the survey is made in company with the safety engineer more attention may be given to accident hazards A check list of operations and conditions to be noted is given by Blake Unsafe acts of workers account fora greater number of injuries than do environmental conditions and machines but both factors are involvedin the majority of accidents Information on accident hazards and their control can be gained by a review of the accident experience of the plant and through the plant survey and also by attending plant safety committee meetings SANITATION General American Standard on Sanitation serves as a guide to general sanitation facilities The physician should obtain information as to the state and local code requirements Adequate maintenance and proper use of these facilities should be emphasized Where difficult remove materials get on the skin the physician should learn what is provided for skin cleansing and in addition should observe what is actually used Many a case of dermatitis is caused by use of solvents and harsh abrasive cleaners even in plants where proper washing facilities and cleaning agents are provided Food Handling Whether food handling is directly under the plant management or is the function of a catering service the physician should observe the methods utilized If foodstuffs are prepared outside the plant premises the survey should extend to such locations Methods of refrigeration and of keeping hot foods above the temperature of bacterial germination should be noted One should inquire into use of foodstuffs after they have been standing in serving areas during mealtime Garbage disposal should be checked The storage and use of pesticides in and around food handling and storage areas should be inquired into carefully Not only is sanitation of importance in plant food handling areas but also the nutritional adequacy of foods served by the cafeteria and selected by the employees should be checked It is difficult to change eating habits but where food served appears to be nutritionally inadequate this should be investigated and then proper recommendations made to management A threefold approach might be suggested through offering balanced meals mak- ing them attractive and educating personnelin food selec tion particularly those greatly underweight or overweight as well as the diabetics and others who have to watch their diet carefully Hazard Evaluation The general survey of a plant will disclose some operations where hazardous materials are used under obviously safe conditions Other operations may as obviously be hazardous and call for a recommendation to management that control measures be instituted EER EEE EEE EEREE EE ee 44 In many instances potentially hazardous operations may be in progress that may or may not cause injury depending upon the severity of the exposure Control measures may be costly and management may be reluctant to incur such expense just to be on the safe side especially where competitors may not be adding the expense of such control to the cost of their product In such a case the question of whether a hazard actually exists may best be answered by recommending that the plant avail itself of expert pro- fessional survey services which may include tests for atmosphere contaminants or of such biological materials as blood or urine and recommendations for methods of hazard control based on their experience and technical findings Such services are available through official departments of industrial hygiene or occupational health in most of the highly industrialized states and in certain of the larger cities and counties Private sources of these services are available and include a number of the larger casualty insurance companies time consultants and various | professional and research organizations in the field of industrial health including a number at universities RECORDS OF CONDITIONS IN OCCUPATIONAL ENVIRONMENT After the survey of the industrial environment the phy- sician should report to management his observations and recommendations It would also be helpful to the physician to prepare his own record for his use concerning job requirements and health hazards in the plant This record should include the potentially injurious materials used or otherwise present something of the intermittency or duration of exposure to them and whether the exposure was normally under good control obviously requiring control or in need of technical study for its evaluation The operations involving the potentially haz: ardous materials or conditions should be listed A graphic means of associating hazardous materials and conditions | with operations or departments consists of a chart on | section paper with the materials and conditions along | the ordinate operations or departments along the absicissa and notations at the intersections indicating existence of the hazard at a given operation or department Control Methods The survey of the plant should include a consideration of control measures both medical and engineering which are or should be followed in maintenance of a healthy work force and healthful working environment It is not proposed that the physician include engineering control as | part of his activities However an understanding of the | engineering factors involved in the control of health hazards will enhance his appreciation of the over health aspects of plant operation The more common control methods are as follows MEDICAL CONTROL Preplacement Examination The physician should ascer- tain the scope of the preplacement examination of all applicants for work and of special examinations of employees who are to be placed in an occupation involving exposure to some hazardous material For example employees to be placed in occupations involving exposure to pneumoconiosis dust should be given a chest ray and those to be exposed to toxic substances should be given the same clinical tests that will later be used in periodic examinations to provide base values Periodic Examination physician should also ascertain which special procedures are included in periodic examinations of employees in hazardous occupations and the interpretations of the findings If the findings point to possible health impairment inquiry should be made as to what conditions in the plant are to blame The intervals at which these special procedures are conducted should be determined by the severity of the hazard and modified as the hazard is brought under control The interval between chest rays should be related to the period required for the development of detectable changes Where a medical control program has been set up by one physician it is advisable that another making a survey of the plant discuss his observations with that physician ENGINEERING CONTROL Purpose physician making a plant survey has a proper interest in engineering control measures for a number of reasons The decision of the physician in recommending the placement of a worker at a given operation or retaining him at his accustomed occupation may depend upon the engineering control measures The physician may have completed an initial ray survey of a foundry group and among the core finishers noted one man with arrested tuberculosis As foundry work is considered by many a physician to be a laborious hot dusty occupation the first thought on reading the ray may be that this man may better be placed in some other industry Consultation with the safety engineer or industrial hygienist or personal survey of this employee's workplace may disclose that his job is conducted while he is at a bench equipped with welldesigned local exhaust ventilation obviously resulting in no appreciable exposure to dust On the other hand if an employee subject to asthma is exposed to an organic dust to which he is allergic and the only feasible control measure is a filter respirator adequate protection for the man's fellow workers the physician might well recommend that this man be placed in a more suitable location in the plant The interest of the physician in engineering control serves as a stimulus to the production and maintenance departments for provision of adequate control measures 45 The production superintendent is occupied with getting out the product plant maintenance departments have a backlog of work that a foreman or superintendent is pushing to get done Provision for control of health hazards is often deferred to the next day and the next The physician in observing the state of control measures might note that the elbow in an exhaust pipe was eroded and leaking and find an explanation for the recurrent nosebleed of the chrome plater When the physician emphasizes need for repairing the ventilating system through the proper channels it is probable that action will be taken promptly Types of Control Methods number of categories of engineering control measures may be applied to reducing to safe levels exposure to hazardous materials Where substitution of a less hazardous material is feasible this should be done for example toluene for benzene as a paint diluent Alteration of method may serve as a control measure This may involve a minor change such as installation of a operated hoist to replace manual handling of baskets at a vapor degreaser or a major change such as replacement of beehive kilns with tunnel kilns for abrasive wheel calcining In the latter case the dust exposure is appreciably decreased and in addition efficiency of operation and quality of product are improved Isolation has application at many operations One of these is the use of radioisotopes in shielded enclosures with mechanical devices manipulated from the outside Ventilation is the most widely used method of engineering control General ventilation refers to movement of air from an entire room or building Local exhaust ventilation is usually more effective since it is designed to capture the contaminating dust or gas before it escapes into the general room atmosphere Wet methods may serve as an effective means of dust control in certain operations This may involve merely the use of garden watering cans to sprinkle the earth floor around a foundry molding area or the installation of a powered water blast for removal of cores from castings in place of the dusty operation of using pneumatic chisels Good housekeeping in itself is an impor- tant control measure Personal protective devices have a real place as control measures Although respirators should not be used as an inexpensive substitute for a local exhaust system they may be recommended for operations where other control meth- ods are not feasible and where there may be a severe exposure for a brief period They may be used also as a supplement to other control methods The type of respiratory protective device selected is extremely important and the physician would do well to learn specifically about the applications and limitations of such devices Where toxic dusts or gases are present or where the atmosphere is deficient in oxygen devices approved for the particular exposure by the U. S. Bureau of Mines and as listed in their reports,,should be used Personal protective devices also include goggles hard hats gloves plastic sleeves as bestos leggings and clothing made of aluminized fabric to ward off extreme radiant heat Conclusions The purpose of this discussion has been to stimulate the interest of the physician in making surveys of plants with which he may be in contact to suggest the manner in which he should approach such a survey and to indicate the nature of conditions that should have his attention during the survey The facts obtained should influence the nature of the medical examination given workers and findings of an examination should be interpreted in the light of such information Care should be exercised in arriving at con- clusions until there has been sufficient examination of all the facts The mere presence of a toxic agent does not necessarily mean that the exposure is excessive or that injury will occur Examples of potentially hazardous materials and condi- tions and the operations with which they are associated have been included but it is urged that the physician consult reference sources for more complete details This will place him in better position to appreciate whahte sees during the survey and help him in constructive dis- cussion with management REFERENCES 1. American Recommended Practice for Compiling Industrial Accident Causes Z16.2-1941 New York American Standards Association Inc. 1941 Patty F. A science Publishers InIcn.dus1t9r4i8al Hygiene- and Toxicology vol 1 pp 29-40 New York hair 3. Selected Publications on Industrial Health the Council on Industrial Health of the American Medical Association Chicago 1933 Vapor Labor 4. Horowitz L. D Check List for Vapor Review New York State Department giene 34 9-11 March 1955 Degreasing Operations Monthly Division of Industrial Hy 5. Brouha L. A Air Conditioning Stress Heating Piping and Air Rest Areas Reduce Physiological 27 92-95 Conditioning Aug. 1955 Physiological 6. Rosenau M. .: Preventive Medicine and Hygiene 1951. 950-954 Maxcy New York Appleton Inc. edited by K. F. pp 7. Troisi F. M Amorati A. and Bonazzi .: Pathological Effects from Work in Cold Environments Indus Med 22 11-13 Jan. 1953 Surveying 8. Cook W. .: Surveying Industrial Operations Involving Radioactive Materials Transactions of the 41st National Safety Congress Chicago National Safety Council 1953 pp 91-93 1952. Recommended 9. American Standard Practice for Industrial Lighting A11.1-1952 New York American Standards Association Inc. Practice of Daylighting Illuminating Engineering 45 107-139 Feb. 1950 Industry Occup Med 315-550 June 10. Dart E. Engaged in the 11. Blake R. .: Effects of High Airplane .: Industrial Safety Speed Vibrating Vibrating Tools New York Prentice Operators 1946 Inc. 1943 12 American Standard Minimum Requirements for Sanitation in Places oIfnc.Employ. ment Z4.1-1955 New York American Standards Association Mines 1952 United 13. Pearce S. J. and Berger L. B List of Respiratory Protective Devices Approved by the Bureau of Mines Information Circular Circular 7636. United States Department of the Interior Bureau of This Committee Report was approved for publication by the Council on Industrial Health B. Dixon Holland M.D. Secretary Reprinted from J.A.M.A. Dec. 8 1956. " PR EEEEEEE EEE EE EEEEEEEEEETEREEEEEEEE EE EEEEEE ETE EEEEEEEE AEEEE E EE 46