presence or absence of any adverse effects. There was a uniformly similar strong aversion to any intent under OSHA for medical surveillance to be rejected or in anyway downgraded or disallowed in instances where it is known to be the most reliable means of assuring worker protection. As might be expected, there was great emphasis that in no instance should we condone its being used per se as the device or instrument for assessing the existence of a hazard or measuring its magnitude. Indeed, such an abuse of the individual would be inhuman and intolerable. In all instances, therefore, the intent and object is to achieve a final check upon the adequacy of the program designed to prevent harmful exposure. To eliminate medical surveillance, for whatever reasons of advantage that it might afford OSHA, would be a tragic error leading to measuring only the "health of the air" or working environment with disregard for protecting the health of the individual. One authority commented, "the intent of the act is not protection of the health of the air; it is protection of the health of the individual... the measurement should be of the health of the workers and not (just) of the health of the air." This is equally true of any work environment influence of a potentially harmful nature. In no way do I wish to imply or even suggest that industrial hygiene analytical and related functions are in any manner less important than we have always considered them. They are, in fact, the cornerstone and basic foundation of our planning to prevent ill effects from toxic and other harmful effects in the work environment. In my judgement, purely industrial hygiene measures have contributed more than have purely medical activities in reducing the effects of toxic substances, radiation and other forms of energy, noise, heat and cold stress, excessive work effort and many other potentially harmful influences on our working people. Nevertheless, the most diligently applied industrial hygiene programs are inherently beset with the possibility of failure in that they cannot possibly provide absolute assurance that the worker is safe. Even if TLV's are observed scrupulously, there is no assurance that the individual adheres to practices that preclude excessive exposure. Breaks in techniques of safe working practices, such as unplanned skin exposure or handling contaminants just prior to meal time or smoking can totally invalidate the most exactingly careful precautionary plans. Newer methods utilizing personal sampling monitors which continuously measure the individual's actual environmental exposure may help greatly, but they do not take into account transdermal absorption or any failure based upon sudden, brief exposures at high levels beyond the capability of the instrument to cope. If fail-safe, continuous personal monitoring equipment capable of handling all levels of exposure with reliability are developed, then, except for dermal and oral exposure possibilities, medical surveillance might no longer be needed for routine industrial health control. However, as Stokinger' has indicated, air-borne concentrations as an index of exposure are also unreliable in situations of mixed exposures with metabolic interaction, individual peculiarities of work habits leading to abnormal intake and additive exposure off the job. By reflecting all of the possible variables, medical surveillance can provide both an index of exposure and an index of response. Accordingly. only medical surveillance techniques, if available for the specific exposure, could ascertain that the individual worker is completely safe and has incurred no adverse effects. JOM/Vol. 15, No. 10/October 1973 The complexity of health evaluation is a very real problem and is growing with the passing of time. Simple tests and observations of the past years have been supplanted by vastly more complicated and technically involved methods. The report of the "National Commission on State Workmen's Compensation Laws" states: Technological advances have produced unfamiliar and often indeterminable physical and toxic hazards. Occupational diseases associated with prolonged exposures to unsuspected agents or to fortuitous combinations of stresses have undermined the usefulness of the 'accident' concept While advances in medical knowledge have facilitated the treatment of many injuries and diseases, they have also enlarged the list of diseases that may be work-related. Simple cause/effect concepts of the past have yielded to an appreciation of the many interacting forces that may result in impairment or death. In addition to genetic, environmental, cultural, and psychological influences, physicians must consider predisposing. precipitating, aggravating, and perpetuating factors in disease. Etiologic analysis, estimates of the relationship to work, and evaluation of the extent of impairment have become accordingly complex for many illnesses Thus, it is readily evident that our medical task is difficult A basic predicameni in occupation medicine is a limited technological capability for medical surveillance analytical methods. When one considers the large number of chemical substances in use in contrast to the few for which we have established and confirmed ability to assess absorption reliably. the magnitude of the problem is readily apparent. Although I have made no attempt to cite all of the substances which are fully recognized as having valid medical surveillance indicators of the degree of exposure or bodily intake, it is appropriate to mention some well known examples: heavy metals such as lead, cadmium, chromium and nickel; the various cholinesterase inhibitors; carbon monoxide; methemoglobin formers such as aniline and nitrobenzene; toluene, benzene and other hydrocarbon solvents. The control of lead poisoning represents one of the great classics in the history of occupational medicine. In conjunction with good work practices, industrial hygiene control measures and, as the ultimate safeguard, the medical surveillance techniques of accurate analyses of urine and blood lead levels of workers, it has become possible for men to safely engage in all types of work utilizing lead. Another interesting point with respect to lead is that in the new NIOSH criteria for a recommended standard entitled. "Occupational Exposure to Inorganic Lead", there is the specific requirement for medical surveillance (biologic and medical monitoring) of all workers subject to exposure to inorganic lead. The standard sets forth specific procedures for sampling and analysis of blood or urine. It also prescribes the frequency of testing and requirements for environmental sampling and analysis. This is a major step in the right direction for OSHA and represents a reaffirmation of the essential need for testing the man and the inescapable re-introduction of utilizing skilled professional judgement. I hope this is the beginning of the end of the "numbers-in-the-air" game in which TLV's and other standards are arbitrary rigid limits--rather than guidelines subject to professional interpretation. Lord Robens Committee Report on the British System points out its chaos with voluminous provisions and standards for achieving safe and healthy working conditions. It is obvious from this report and 797 more recent.comments from NIOSH that inevitably the only system which can succeed is one which prescribes good work practices based on known standards and guidelines plus appropriate medical surveillance with professional judgement being the most meaningful ingredient necessary for success. Although it is true that we do not have anything like enough reliable human indicators available to meet our current medical surveillance needs, a strengthened research program utilizing the fantastic array of new analytical technology could almost certainly devise means for measuring most of the physiological, functional or chemical alterations possibly created by work environment hazards. Additionally, newer technology being developed will soon permit us to accomplish many things that are impossible today. It is in this area that I believe our greatest emphasis should be placed in the immediate future. I hope such studies will eventually resolve areas in which medical surveillance is now totally unsuccessful, such as in human testing to assure total absence of adverse effects from exposure to carcinogens. However, many recent innovations offer great promise. The work of Stewart3 in developing breath analysis techniques which are consistent with blood levels and correlate with atmospheric exposure levels represents a great advance. His human studies have demonstrated another important aspect of medical surveillance the finding of an otherwise unexpected abnormality—an increase in blood carbon monoxide in instances of exposure to one of the hydrocarbon solvents. A few of the newer developments that appear to offer considerable promise include: atomic absorption spectrometry and other complex means for analyzing finger nails, skin, hair, and other tissues for signs of toxicity; electroneuromyographic and other neurophysiologic methods for studying insidious effects of neurotoxic agents; many developments in enzymology; lyzosomal changes and subcellular (mitochondrial) metabolic changes; chromosomal aberrations and circulating antibodies to agents in exposed persons. Newer procedures in prospective epidemiologic study of industrial populations holds forth great promise. The unique contributions of labor union records and cooperation in both retrospective and ongoing epidemiologic investigations have been clearly demonstrated by Selikoff, Hammond 5 and others. All of these and the coming generations of technologic developments should offer a remarkable opportunity for medical surveillance to become the ultimate in worker protection. I am convinced that medical surveillance alone can provide this ultimate degree of safety. One of my correspondents stated that it provides the only means of having an integrated approach for determining interaction of a potentially hazardous agent with all of the variable characteristics of the individual such as his respiratory rate, size, metabolic pattern, genetic constitution, personal habits, multiple factor etiology, and other aspects of variability of response. In otherwords, the real measure of hazard to the worker is what is absorbed into his system and the physiologic response which this engenders. Inevitably this is related to a dose/effect relationship-a concept which we must staunchly support and promote in contrast to the zero tolerance outlook for which there is no physiologic justification. It is imperative to mention the critically important necessity for developing suitable criteria for all new advances in medical surveillance capability. Without that, such testing would be meaningless and misleading. In conclusion, I wish to emphasize my belief in the success of the historically balanced type of hazard control program consisting of industrial hygiene engineering methods to preclude improper exposure, industrial hygiene surveillance to determine adequacy of the control measures and medical surveillance as the ultimate measure to assure that the individual worker's health is not compromised. Expert professional judgement is the inherently essential ingredient. In my personal judgement, the term medical surveillance is superior to biologic monitoring and should be adopted. Finally, there is a great need for vastly expanded experimental facilities for extensive research on medical surveillance methods-since there is no really better way of measuring man's exposure and its effects. References 1. Stokinger HE: Rationale for the use of biologic threshold limits in the control of worker exposure. Paper presented at Third Conference on Environmental Toxicology, Dayton, Ohio, October 25-27, 1972. 2. Major reorganization plan for industrial safety. Dept Employment Gazette 80:611-614, 1972. 3. Stewart RD et al: Experimental human exposure to methylene chloride. Arch Environ Health 25:342-348, 1972. 4. Hammond EC, Selikoff II: Types of prospective studies needed in cancer research. Paper presented at a meeting sponsored by the Princess Takamatsu Research Fund, Tokyo, November 28, 1972. 5. Selikoff II: Toxicological research through labor union cooperation. Paper presented at the 32nd AMA Congress on Occupational Health, Chicago, September 12, 1972. Although many individuals contributed to this paper, I especially acknowledge with appreciation the thoughtful help of: Drs. M. Bundy. B. D. Dinman, R. M. Clyne, R. E. Eckardt, H. H. Golz, H. F. Howe, W. H. Jones, M. M. Key, N. Nelson, N. I. Roberts. I. H. Wolfsie, Messrs. E. E Christofano, R. C. Wands, and Ms. 1. A. Tins, of Celanese, for editorial and other invaluable help. Medical Surveillance in Industry/Dixon Several years ago at an American Occupational Medical Association meeting. I presented a paper entitled "Medical Surveillance in Industry." At that time I thought I knew most of the answers; now I am less sure-but also I am certain that no one else knows all the answers. However, having long been concerned and having given considerable thought to this subject, I envision my role on this program, at least in part, as being somewhat the devil's advocate. I think of health surveillance, especially when we currently view it to be one of the means of assisting in the protection of the health of workers and in meeting compliance requirements of the Occupational Safety and Health Act, as being awesomely complex, limited in its capacity to accomplish what is expected and logistically difficult. In part this is due to extreme problems with our entire system of national health care delivery, and I find myself deeply troubled and concerned with the developments which I have seen of late. Hence, it is my intent in this presentation to share with you some thoughts that are perhaps non-traditional and some differing perspectives. This being our Bicentennial Year, I wish to recall two quotations appropriate to these deliberations: In 1782, six years after the Declaration of Independence, Jean de Crevecoeur stated: "What then is the American, this new man? He is an American who leaving behind him all his ancient prejudices and manners, receives new ones from the new mode of life he has embraced, the new government he obeys, and the new rank he holds. The American is a new man, who acts upon new principles. He must, therefore, entertain new ideas, and form new opinions..." And in 1787, just five years later, that early and eminent physician Benjamin Rush RECORDKEEPING AND SURVEILLANCE wrote: "The American war is over. But this is far from being the case with the American Revolution. On the contrary, nothing but the first act of the great drama is closed. It remains yet to establish and perfect our new forms of government, and to prepare the principles, morals and manners of our citizens for these forms of government after they are established and brought to perfection." What I'm driving at is that much of our traditional approach is of reduced relevance today: that innovation and new methods are desperately needed; and that the regulatory process remains disturbingly imperfect. It is, therefore, my purpose to review some of the problems and to allude to some possible solutions. An analysis of the objectives of health surveillance requires consideration of some of the problems and inherent myths with which we are faced. As each newly proposed standard for a given chemical exposure issues, it has its unique specifications and language of health surveillance requirements for that substance alone. In the ideal circumstance such might be appropriate; but in the "real world" sense, this is very unsatisfactory and an imminent problem for a variety of reasons, prominent among which are the following: Multiple Exposures It is rare for workers to be potentially exposed to a single substance only. Although such may occur at a given moment, over a period of time (days. weeks, or months), the probability of multiple exposures exists in most instances. Perhaps it was otherwise in times past-but certainly not now. Here we encounter the first stricture in the application of scientific principles and methods: when we know that health surveillance presently is incapable in all but rare instances of measuring any impact in the one-cause/one-effect relationship between an agent and reaction to it, how can we expect to realistically assess the multiple-cause/perhaps -more-than-one-effect condition? The application of Koch's postulates would be truly strained. Multiple Effects of Individual Exposures There are many examples of vary RECORDKEEPING AND SURVEILLANCE ing effects from individual exposures to hazardous agents just as there are varying responses to naturally occurring diseases. Variations of response include the categories of acute versus chronic, localized versus disseminated, the reactions in various organ systems, and the impact in healthy versus unhealthy, young versus old. male versus female, and so forth. Good examples are the great imitators, lues and tuberculosis, which present greatly differing manifestations under differing circumstances. Interaction of Occupational and NonOccupational Factors The range of variability in human response is dramatic. In determining the interaction of a potentially hazardous agent, one must consider all of the variable characteristics of the individual such as his respiratory rate, size, metabolic pattern, genetic constitution, personal habits, multiple factor etiology, and other aspects of variability of response. In other words, the real measure of hazard to the individual is what is absorbed into his system and the physiologic response which this engenders. Inevitably this brings into play a dose/effect relationship-a concept which we must staunchly support and promote in contrast to an empirical zero tolerance outlook for which there is no physiologic justification. Complexity of Health Evaluation This is a very real problem and is growing with the passing of time. Simple tests and observations of the past years have been supplanted by vastly more complicated and technically involved methods. The Report of the National Commission on State Workmen's Compensation laws states: "Technological advances have produced unfamiliar and often indeterminable physical and toxic hazards. Occupational diseases associated with prolonged exposures to unsuspected agents or to fortuitous combinations of stresses have undermined the usefulness of the 'accident' concept. While advances in medical knowledge have facilitated the treatment of many injuries and diseases, they have also enlarged the list of diseases that may be work-related. Simple cause/effect concepts of the past have yielded to an ap 60 preciation of the many interacting forces that may result in impairment or death. In addition to genetic, environmental, cultural, and psychological influences, physicians must consider predisposing, precipitating. aggravating, and perpetuating 'factors in disease. Etiologic analysis, estimates of the relationship to work, and evaluation of the extent of impairment have become accordingly complex for many illnesses." Thus, it is readily evident that our medical task is difficult. A basic predicament in occupational medicine is a limited technological capability for health surveillance analytical methods. When one considers the large number of chemical substances in use, in contrast to the few for which we have established and confirmed ability to assess absorption and effect reliably, the magnitude of the problem is readily apparent. Several additional matters of great concern are our actual practices and standards for and inter-relationships between the following: Health Surveillance First, I would issue a plea for universally adopting the term health surveillance. in place of medical surveillance, for all clinical and other measurements of human functions made on industrial workers. Since preparing this presentation, I have had access to Doctor Key's introductory comments. His statement concerning the origin of the term "biologic monitoring has substantially influenced my thinking. He said. "I should point out that the term 'biologic monitoring' originated with the industrial hygienists and is indicative of their ability and intention of carrying out certain health monitoring' procedures-limiting factors being cooperation of the worker and ability to get blood, urine and breath samples." The primary function of all of these measurements is to keep a vigil on the health of the workers. It should be a multi-disciplinary approach designed to protect the health of the workers and one designed to be positive-aimed at prevention, not treat 61 ment. Workers are people and must be treated in the most humane way possible-not as subjects of a scientific study-and for this reason, the term 'biologic monitoring' is not appropriate and too limiting. I am troubled by the emergence of all kinds of new surveillance schemes and differing requirements under new standards. I certainly agree to the importance of allowing judgment and not circumscribing initiative. but lack of any uniformity will create a nightmarish set of problems and utter chaos in any effort to assess the value of surveillance. This is especially true where there are multiple exposures with differing medical requirements. In the latter, differing exposures occurring sequentially over a period of time might require numerous separate examinations as well as new tests relating to each new exposure. Administration within the industry or industries for whom the individual worked would be extraordinarily complex, cumbersome, and difficult to achieve. The physician or physicians charged with the surveillance responsibility would find the task confusing, troublesome. and difficult to coordinate; this is especially true for private practitioners to whom the bulk of the job would fall; indeed, we have already encountered physicians who have long provided good services to industry refusing to undertake surveillance because of its vagarious and capricious requisites. In addition, numerous physicians have indicated reluctance or unwillingness to attest that a worker has or has not encountered adverse effects from exposures, may or may not be physically fit to undertake working with specific agents, and may or may not be physically able to use protective devices, for example, respiratory equipment. For these and many other reasons, it has long been apparent to me that the only reasonable answer is the adoption of a uniform basic core health surveillance scheme where surveillance is deemed essential. This would consist of a standardized medical history, physical examination, and clinical tests such as chest X-ray, pulmonary function, urinalysis, hematology, and blood chemistry tests. To that would be added, as set forth in the standard issued for a given RECORDKEEPING AND SURVEILLANCE |