1962
NEW HORIZONS OF ENGINEERING IN ENVIRONMENTAL HEALTH
Colonel Alvin F. Meyer, Jr, P. E.
Senior Biomedical Engineer
Office of the Surgeon General, USAF
Before we talk about new horizons, perhaps we need a starting point, and the starting point might well be the discussion of some basic philosophy. We can then enter into a discussion as to what the new horizons are, and how we might undertake approaching these horizons. One of the first things that one needs to know and which applies to both research and development, as well as to progress of a. scientific discipline, is the present state-of-the-art, or established order of things. This is the starting point.
Now, as the tide of events moves on, one will develop some facts which are perhaps (in a manner of expression) to the left or to the right of the known state and which seem to establish a new pattern. At the initial time that this “omen” or change is occurring,, it may be difficult to discern exactly what is happening..
As an example of this, let us take the question of establishment of threshold limit values or permissible exposures, as discussed by Dr. Thomas yesterday. In the early days of the use of a new material you may not know how dangerous a substance it is. You have certain determinations which may make you think, “Yes, this will require very restrictive requirements and yet, on the other hand, maybe we are overstating the hazard”. You have a lot of doubt. As shown in Figure 1, there is a widespread of initial results of tests.
As you proceed further along in time, perhaps Figure 2 is the picture that begins to develop. As a matter of fact, it is rather difficult even after some further studies, in some circumstances, to determine just exactly in which direction you are heading because of the overlap in findings which can occur.
Ultimately the stream of events and findings begin to indicate one way or the other as to what the true situation is, (See Figure 3), in regard to new horizons of engineering in environmental health, something very similar to this exists as in the continuing evolution of our professional discipline. As new demands result from a changing society and technology, we reach new starting points, or base lines of knowledge and endeavor.
One of the things one must keep in, mind is that in the dynamic technological society of today, the corporate body of technical details
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becomes outmoded about every ten years. There may be those of you who disagree with this. A little reflection will indicate, however, some of the areas of concern in which we are vitally interested, such as noise and radiation.
The problems and gaps in knowledge of ten years ago are really “old hat” and out of date today. The problems that we are dealing with today as great new exotic problems are going to be quite simple to handle and deal with ten years from now. As a matter of fact, it has been estimated that the basic knowledge available to us expands several orders of magnitude every 10 years, and as these sources of basic knowledge expand, so then we develop new specializations. This is one of the big problems with which we are faced. The amount of knowledge available in the field of acoustics alone, to cite an example, is such that these can develop a completely unique specialization in the field of noise and noise control. The same is true of many other areas of concern, to the engineer in environmental health work.
This also presents a problem to the generalist. Most of us in this room are generalists. There are, also, a few easily, identified, highly competent specialists. A generalist can also be a highly competent general practitioner, with some degree of specialization in certain areas of practice. This is the inevitable result of an expanding base of knowledge. This situation affects every branch of the engineering profession.
Perhaps some definitions and some postulation of theorems are in order. General Jennings’ paper contained a definition of “engineer”. One can also define the engineer as one who practices the art and science of controlling forces of nature for man’s well being. One must make the distinction between an engineer and a scientist. The engineer uses intuitive Judgment, whereas the scientist, tries to find new knowledge. The engineer in turn uses this knowledge in arriving at decisions and judgment.
The borderline, however, between the two is often fuzzy and indistinct, especially in the area of concern for health protection, health promotion and human effectiveness. These require art and science as well as engineering judgment. Some further generalizations may also be of value. It has been said that science, which is the study of the behavior of materials and forces including man, can move no further and no faster than the art of measurement.
Measurement involves the language of mathematics. Engineers are users of scientific knowledge, and also are trained in measurement techniques, and the language of mathematics.
In the fields of medicine and the effect of environment on man, a major
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opportunity exists for new activity and new contributions by engineers. The engineer possessing a knowledge of biology and ecology, a knowledge of (sp) uration techniques and an understanding of physiology, now has the opportunity to make many contributions • In the health professions and life sciences there is an interesting area of activity of which we must be aware and further prepare ourselves to meet. new responsibilities for professional practice.
There are some new definitions affecting our profession, such as biomedical engineering. This is defined by the Engineers Joint. Council as the application of engineering knowledge and technique, in conjunction with an understanding of biological science, to the improvement of medical art and science and for the promotion of health and efficiency. It includes, among other things, the application of electronics to medical diagnosis and treatment, and in a broad sense the detection and control (in the environment) of physical, chemical and biological stresses on man, It is the direct application of engineering science to medical technology.
Those of us who are practitioners in the field of industrial hygiene know that we are engaged in a science and art devoted to the recognition, evaluation and control of stresses arising in or from the occupational environment. These may cause sickness, impaired health and wellbeing or cause significant discomfort and Inefficiency among workers or members of a community. In the past we have primarily oriented our efforts and our special competence toward the production lines and the occupationally exposed worker. We are equipped, however, by virtue of our background and our training to undertake activity in the broader area of biomedical science.
There is a need for engineers to have a better appreciation of the complex forces and stresses in the environment and man’s response thereto. If one wants to draw a typical engineering chart of the relationship between environmental stress and. human response, you get a picture similar to Figure 4. We can define environmental stresses rather finitely. We can even specify by engineering means the stresses which we will allow in the environment. As an example, we can say this room should have so many air changes per hour and is to be controlled by certain relative humidity and temperature. This we can do, and further we can make fairly precise measurements to ascertain if our design criteria have in fact been met.
Man’s responses, on the other hand, are rather variable. Man Is a variable both physiologically and psychologically from day to day, as well as from year to year. But, be that as it may, certain general response characteristics can be stated and defined. In an environment
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in which there are minimal stresses, man will respond, depending upon the variation in individuals, as being In a “comfortable” situation. If the stress is mild, the response may be one of “irritation”. If we have moderate stress, the result may be degraded performance, or even disability. Depending on the degree of increasing severity of stress, the response may be delayed, or it may occur in a short time or even be immediate. If severe enough the result Is illness or death.
Now, at first blush, It would appear that there are enough challenges in the traditional areas of concern of the Industrial Hygiene Engineer and other scientists engaged In health protection and health promotion resulting from new techniques, new problems such as highly toxic chemicals, ionizing radiation, and so on. It would appear that there is enough to absorb all our effort. However, in the aerospace environment with which we are vitally concerned in the Air Force, there are a number of problem areas to which our techniques, our skills and our competence can and should be applied.
Among these there is the problem of acceleration. There is the problem of weightlessness and the problem of vibration, shock and noise In aerospace vehicles. There are problems of isolation, confinement and fatigue. There are problems relating to microwaves, visible light and the interesting and challenging field of lasers, in which the Air Force has a definite and tremendous interest and which, I might point out, are also very Interesting’ problems from the industrial veiwpoint. We have new problems of radiation, all the way from fission product containinatlon through nuclear power and propulsion devices.
In the field of closed environments there is a wide variety of areas of activity and concern for people with engineering training, coupled with physiological and biological knowledge. This includes atmospheric composition, temperature and pressure phenomena, the requirement for the provision of water and the removal of waste products, and toxicity. (As a matter of fact, one of the more interesting toxicity problems is the outgaslng of paints and materials inside a closed environment). . Not just in space vehicles, but in industry and in the rest of the aerospace environment, such as the launch control center, we have closed-in areas in which these problems exist. I could go through a whole host of other areas, but I think I have cited enough to at least stimulate your imagination.
Now, what should be the role of the engineer in this? His first work with his colleagues in medicine, and those in the “life sciences” is to apply his skills and special competence to do the following: First, to analyze what the problems are. As engineers we are analytically trained. We should find out where the exposures may occur to any of the possible stresses and we need to develop better means to measure
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and define these stresses. Knowing the stress factors, the engineer determines potential severity, and the location and numbers of exposed populations. We should have the competence to determine possible courses of action, to evaluate them, and to make recommended solutions. We must also have the capability of following-up to see that our judgment was right.
Now, to these, we must add the need for greater application of specialized engineering skills in relation to human performance and health protection, and this in the USAF brings us into a greater association with those concerned with research and development of operational Air Force systems. We must, indeed, have a bridge between those concerned with hardware and those who are responsible for technical area management. This is an area in which we must do more.
At the same time, while we are concentrating on these so-called “newer horizons” (which are merely extensions of our existing capability and performance requirements) one cannot overlook the fact of the need for greater application and effort in applying new knowledge to some old basic environmental health and industrial hygiene problems. When in civilian life one can have one of the richest counties in the United States with $65, 000 homes rendered uninhabitable because of septic tank back-up, one cannot help but face the fact that we have not solved all of the b4sic problems yet.
There also are some traditional problems in the aerospace age. As an example, it has been brought to our attention that we are still having difficulty getting potable water in certain of our missile installations. While we are concerned with new problems, perhaps in the broa4ening of our capability of basic science and basic knowledge we may discern better ways of attacking these fundamentals.
It is apparent, as Colonel Boysen and I suggested ten years ago in a paper entitled “The USAF Physician-Engineer Team- -An Evaluation of the Future,” there are new education and training approaches required, if we are to provide the proficiency necessary to meet. these requirements. In addition to engineering and the environment per se, there Is now arising a need for engineers with the capability to work with physicians on the problems of application of engineering techniques to diagnosis and treatment, as well as medical facility and hospital design. In these areas we are devoting a great deal of effort to broadening out our career field.
It is recognized that the competence of the engineer in meeting the needs described above may not be thoroughly recognized either by ourselves or our physician and scientific colleagues. The solution in this lies in a greater effort, on our part, to develop the ability to intercommunicate within the varied disciplines.
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In conclusion, I have discussed with you some general philosophy and cited some needs. In essence, it. boils down to this: The engineer is well grounded in basic science and applied engineering. If he has proceeded through the proper educational pattern he is gifted with an inquiring mind. He also has the ability to communicate in the language of mathematics. If he will add to this the ability to speak the language of his colleagues in the health promotion and health protection area, he will find that his horizons are limited only by his initiative, imagination and willingness to explore new areas. This is no easy road. There are many problems ahead, but the importance of the contribution of engineering competence in some of the areas discussed above Is of such a nature that we must, indeed, beseech each one to apply himself to undertake this task diligently. There are new horizons. They are restricted only by where we want. to go.
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