Research - Mechanlcal and Physical Hazards the many other exemptions caused because agriculture is a protected class. STUDIES IN OHIO Some of the studies that we are doing in Ohio, I will briefly present to you. We have a project now with a special agricul- tural population, the Amish. Buggy Safety If you were to view Ohio highway safety statistics, you would find there are three classes of agricultural highway accidents. One is tractors, the second one is farm machinery, and the third one is buggy accidents. Are buggy accidents part of the agricultural problem? The answer is probably, because the Amish really only use buggies for two things: 1. To do some activity concerning the farm. 2. To go to church. So buggies can be a potential agricultural problem. We are embarking now on an effort to work with Amish youth in their schools on safe buggy operation. Highway Safety We are conducting a second project in cooperation with our Highway Safety Of- fice. In the fall, we will be conducting a survey of 1,200 farms in an effort to get the farmers' perceptions of the hazards of operating agricultural equipment on the state and county highways in Ohio: 1. What type of equipment is actually being operated on the roadways? 2. What are the conditions under which farm machinery is moved on the road- ways? 3. What are the major problems with op- erating farm equipment on roadways? 4. What is the road worthiness of farm equipment? RECOMMENDATIONS Although there are many that could be made, the following are some recommen- dations for research and action, 1. We need to continue efforts in research on human sensors and automatic shut-offs. If a person is too close to the tractor in a given situation, it should not start or con- tinue to operate. 2. Research on roll-over protection on older tractors should continue. 3. There should be aggressive inclusion of safety in all of ASAE and other standards. 4. There should be research conducted on the lighting and marking of agricultural equipment. 5. There should be some consideration for a uniform motor vehicle code on farm tractors and machinery used on the high- ways, including set definitions of types of agricultural equipment. This would pro- vide a model for states to consider in fu- ture legislation. 6. There should be continued studies on agricultural safety educational techniques that work.0 276 Papers and Proceedings Farm Machinery and Vehicles, May 1, 1991 REFERENCES 1. Jewell, JR; Farm and Home Accidents: Their Cause and Prevention. Extension Circular 5578, University of Nebraska (1931). 2. Ottey, Audra and Charlene Finch; "Farm Journal Survey Shows Road Travel Tops List of Safety Concerns." Farm Journal, Volume 115, Number 3, February 1991. QUESTIONS John Hahn: I am with the Iowa Division of Labor. Regarding the ROPS, the rollover protection on the tractors, I have heard no mention about the need to use a seat belt or a safety harness to keep from being thrown out of the tractor on to the ground where you can be crushed by the crush-proof cage as it rolls over. Dr. Thomas Bean: Deftitely that is a problem. We-1 say we-a lot of us know that that is a problem. I can go to any farming group, and I ask how many have rollover protective structures-&her cabs or poles-and get a good many hands. Then I ask the next question, "How many use their seat belt?" You will probably find zero or very few. We realize that it needs to be addressed as a behavioral problem. Farmers tell me the reason is because they get off and on their tractor so many times. Something has to be designed or implemented or there has to be education about what is acceptable to that group as far as belting them in on the tractor. Often I try to use the example of highway safety and ask them, "Do you use it when you ride on the highway, at least ?" Still the answer is very, very low. John Hahn: With seat belts on things like tractors-I once looked into seat belts on forklifts, and there is a big controversy on forklifts, and there is something that they call the fly swatter effect. That is, when you fall off an elevation on a forklift, is it better to be fastened in there so that when you hit, your head goes bump, bump, bump against the pavement, or is it better to be unrestrained ? There probably is some of that in agriculture also. (inaudible): I am back. One thing on your comment on the forklift. Generally, other construction equipment works with a seat belt. What some companies have done to keep the guy's head from being pounded into the ground is just to take metal screening or expanded metal and put it on the side and that way he can just cut his head up once against the screening when he goes. John Hahn: I was talking about forklifts. I just might add, I know that there are a lot of problems on the issue of seat belts, when you put a screen or that type of thing on. I know it is more of an issue in logging than it is, maybe, in farming, but the idea is that once you put that screen in, you have now taken that person, and if he has the seat belt on, he can become a human pincushion. The point I was trying to make is, this whole issue of seat belts is a very tough one because, depending on what industry you are working in, there were a lot of complaints when NIOSH talked to OSHA and recommended seat belts on skidders in logging. The main complaint we had was you had screening devices on those skidders to provide something like a cage for that person whiie he is in the skidder. When it rolls or rolls over or while he is moving through the woods, if sticks, and that kind of thing comes in through that mesh, he cannot get out of the way if he has his seat belt on. I have not heard that complaint yet from farmers, but at the same time, these are the types of issues that you have to learn to resolve when you start talkiig about the use of seat belts on this type of equipment. There are other factors that we have to be aware of and we cannot make just a blanket statement that seat belts are the best until we start getting some good information and look at some of the other types of alternatives, such as possibly a seat bar. We are not sure what is going to work. (inaudible): I just have a comment on the seat bar versus seat belts. In Canada, log skidders are being equipped with seat bars, and it looks like they are getting very popular. Surgeon General's Conference on Agricultural Safety and Health - 1991 277 Surgeon General's Conference on Agricultural SaMy and Health FMMSAFE 2000 o A Nafional Coalition for Local Action Convened by the National Institute for Occupational Safety and He&h April 30 - May 3, 1991, Des Moines, Iowa MUSCULOSKELETAL HAZARDS By David Cochmn, Ph.D. Industrial Engineer, U.S. Occupational Safety and Health Administration Good afternoon. I feel a little out of wa- ter in that my specialty is not in agricul- ture. I have been asked to talk about ergonomics, musculoskeletal disorders, and agriculture. As I started thinking about the agricultural environment, I realized that I see it as a hostile environment. It is about as hostile an environment as we have in this country. We have chemical and dust hazards, ma- chines that can take your bodily parts rather easily, slips and falls, amputations, death, noise, and temperature hazards, including cold stress and heat stress. We also have whole body and segmental or limb vibration, explosions, and infectious diseases. Lastly, on my list, we have musculoskeletal hazards. Quite honestly, I think most of you and most people in agriculture do not consider musculoskeletal disorders or musculoskele- tal hazards very much. If you do, you think of back injuries. Back injuries prob- ably are far and away the biggest problem that my discipline, which is ergonomics, deals with. There are, however, cumulative trauma disorders of other sorts. I consider back injuries cumulative trauma. In many cases it is a one-instance injury, but in most cases we strongly believe that they are cumulative. The more times you lift exces- sive weight, the more times you stress your back or strain it, the more likely it is that 278 you will have a back injury. It is a cumula- tive problem. In addition, we have problems of the up- per extremities. I am going to go into that in a minute. I thought, that problem is probably not present in agriculture. I was talking to a friend of mine, Barbara Silverstein, who was with the University of Michigan and is now in the state of Wash- ington. She was telling me that the top oc- cupational category suffering from tendini- tis in the state of Washington is farmworkers. They do not have the foggi- est idea why or where it is occurring. Ergonomics and cumulative trauma do exist in agriculture, and probably a lot more than we realize. CUMULATIVE TRAUMA DISORDERS Now, being a professor I have to educate a bit, just in case you do not know some of the things that I think are important. I am going to talk about some of the cumulative trauma disorders. These can be of the upper extremity or the lower extremity-not necessarily concentrating on the back. Tendon-related Disorders First, tendon-related disorders usually occur by overuse of, or stretching of, or excessive forces exerted by these tendons. The most common is tendinitis, inflamma- tion of the tendon tissues. Another very Papers and Proceedings common illness is tenosynovitis, separate or concomitant inflammation of the tendon and its sheath. I normally think of it as the sheath. I do not know how good your anatomy is, but we have tendons. Tendons really are ca- bles in the body. Around those, in strate- gic locations, we have soft tissue that pro- tects the tendons, called sheaths. They are a lubricated tissue. As the tendon slides around a corner or moves past bones, it is protected by the tendon sheath. When the sheath becomes inflamed, it is normally called synovitis. Sometimes when the tendon is involved it is tenosynovitis. This is common in normal manufacturing operations. It probably is common in farming or in agriculture, but we do not have much data. Carpal Tunnel Syndrome Second, carpal tunnel syndrome gets all the press. It is a problem in the wrist. One of the nice things about this one is that all the reporters are suffering from this. Since they are suffering from it, they write about it. There is nothing like hav- ing an interest in your own preservation. Carpal tunnel syndrome is indicated by a numbness or tingling on the palm side of the first two fingers, part of the third fin- ger, and the thumb. It is the damage to the median nerve that goes through the carpal tunnel. The carpal tunnel is in the wrist. It is bordered on three sides by bones and on the fourth side by a strong ligament. None of these give very much. So when you use your tendons a lot, you get tendinitis or tenosynovitis. swell. When you do that, things Musculoskeletal Hazards, May 1, 1991 When they swell in a confined space, they compress on each other. You get a circu- lar problem in that the more they swell, the more they are damaged, the more they want to swell, the more they are damaged, and it keeps going around and around. It gets worse and worse. The best thing to do is quit doing whatever you were doing that made it happen. It is like the dentist I went to one day. I said, "You know, my teeth hurt when I do like this," and he said, "Well, do not do that." It is the same way with carpal tunnel syn- drome and all of these things. If you back off and do not do whatever is causing it as much, frequently it goes away, and you do not have to end up in very expensive surgery. You do not have to end up disabled. Raynaud's Syndrome Third, Raynaud's syndrome, or occupation- al white finger, is a shut-down of the circu- latory system. It is caused by exposure to vibration in the hands. I am not familiar with this disorder in the feet, but it might happen there. So segmental vibration or arm and hand vibration can bring this on. I have not driven many tractors, but the ones I have driven vibrate. Old tractors are the only ones I have ever driven, be- cause I do that kind of work you are talk- ing about. I have a farm. I am a city boy, but I bought a farm. I have an old Ford tractor, and it does vibrate. There is a lot of vibration out there. There is also non-occupationally caused Raynaud's syndrome. Some people get if without being exposed to vibration; mostly it is women who acquire it this way. Surgeon General's Conference on Agricultural Safety and Health - 1991 279 Research - Mechanical and Physical Hazards Let me go back-there are just a few of the agriculture-related cumulative trauma disorders. There are twenty-some repeti- tive motion related disorders of the upper extremities. There is rotator cuff, pronator teres syndrome, cubital tunnel syndrome, and epicondylitis. These are just examples. Do not get the idea that there are just a few of these disorders. What do you do about cumulative trauma? First, I am getting the cart before the horse, but you have got to work on what is causing it, and so you work on the tools and the work station. Normally I deal with a fixed work station, and in agriculture that is not necessarily true. So the problem is more difficult to deal with. We work on the methods: how people do their job, how they do the tasks. I put training and monitoring in there. It is hard to deal with changing behavior; because I do not have a lot of faith in training if it is easier to do something one way than the other. I do not think we have a problem with work pace in agriculture, certainly not in the farming part of agriculture, maybe in other places. I am going to skip idle time; that is production-line-oriented. RISK FACTORS There are six risk factors that we look for in cumulative trauma. Repetition First is repetition, high repetition. If you are doing something highly repetitive over and over again, it tends to cause these problems. Repetition is rampant in things like processing of fish, meat packing, and luggage making. Is high repetition present in farming? I do not know. I do not think anybody knows. My guess is that repetition is not where the major problem is. At the other side of the curve, statically maintaining muscles causes problems. Statically loading muscles causes them to be exerted. They build up metabolic by-products. A lot of the time the circula- tion is cut off so that nutrients are brought into the muscles and the by-products are not carried off and you get rapid fatigue. Very static operations are a problem and very dynamic or repetitive operations are a problem. High Force The next factor, high force, is probably present in spades in agriculture, especially in maintenance-type things. Farmers and agricultural workers are notorious for ig- noring good sense and picking up things they should not pick up. They exert high forces. Things that require pinch grasp go along with that. Anytime you start using the tips of your fingers to exert force, you are not mechanically effective. It puts the body at a bigger disadvantage than normal. So we have pinch grasp, we have static grasp, and what I call a press grasp, any- time you are pressing with hands. In in- dustry when you are boxing things or when you are folding boxes or you are pressing down on tape, you start getting incidences of carpal tunnel syndrome. Those motions tend to be highly repetitive and with a press at the end of them. Gloves cause problems. Gloves cause people to overexert for two reasons: they interfere with the grasp, and they interfere 280 Papers and Proceedings with the feedback, so people tend to over- grasp. Gloves are worn a lot in agricultur- al work. Posture First, let us talk about shoulder posture. Anytime you are reaching down and be- hind or you are putting your elbow up in the air, you are doing something that a meatpacking company I have dealt with calls winging of the elbows. When they look at any kind of a task, they look for that. That causes problems with the ten- dons and the nerves. Repeated inward and outward rotations, especially when you are going from the maximum of one to the other, is called pronation and supination. Inward and outward. Think about rotating the fore- arm. If you do that frequently, it causes problems such as cumulative trauma disorders. When tasks are highly repetitive or are highly forceful and involve bending the wrist, they cause the tendons to wrap around a corner. They are pressing against those soft tissues that are supposed to lubricate their movement. Sometimes they press against the median nerve and do damage. We want to keep the wrist in a neutral posture as much as possible. Mechanical Stress Concentrations Anywhere on the Skin If you have somebody who has to maintain a pressure on the hand or anywhere else, it is a problem. Resting their arms on sharp edges or lack of a good armrest can cause nerve damage. It can cause circulatory or circulation damage. Musculoskeletal Hazards, May 1, 1991 If they use their hand as a hammer, like banging hubcaps on, banging things loose with the palm of their hand or the base of their hand, this causes nerve and circula- tion damage. Mechanical stress concentra- tions anywhere on the skin can cause prob- lems. A lot of the tools we use-pliers, screwdriv- ers, things like that-press right in the palm of the hand where you have the tendons and the nerves running, and they do dam- age. Vibration There are probably people in this audience who know a lot more about vibration than I do. We have whole-body vibration, and we have segmental vibration. Dealing with each is different. The frequencies that cause problems are different. As far as I can tell in reading the literature, there is no good number as to what is excessive and what is not. There are some guidelines. NIOSH put out a publication on this with- in the last year.' It is pretty good, but as far as I could tell there is no magic num- ber that says, "When you start exceeding this number, you have got problems." Cold Now, when you throw in cold with any of these other factors, it accentuates it. When you throw in vibration with any of these other factors, it accentuates it. If you put cold in the environment and you get cold hands or cold muscles and ten- dons, it accentuates the problem. If you are doing some of these things and your body is vibrating, it accentuates the prob- lem. Surgeon General's Conference on Agricultural Safety and Health - 1991 281 Research - Mechanical and Physical Hazards If any of you are familiar with industrial hygiene or familiar with chemical hazards, you know that OSHA sets permissible exposure limits (PEL's). Those are based on single-chemical exposures or single-agent exposures. She was telling me that the top occupational category suffering from tendinitis in the state of Washington is I farmworkers. No one knows what the combined pres- ence of toluene, gasoline, and carbon mon- oxide does to you and at what concentra- tions that combination is a problem. WORK DESIGN It seems to me in agriculture that we have a problem of work design. We have the task that people are doing. We have the machinery and equipment they are using. We have the products that they are pro- ducing and the products that they are us- ing. All of these combine to be potential problems. One of the things that I am interested in is packaging. Things that people use on the farm are packaged in anywhere from 5- to loo-pound quantities. I have seen people picking up 50-pound containers or loo-pound containers and standing in pre- carious situations and pouring them into hoppers or whatever. The same thing in ergonomics occurs. We have repetition here. We have force. We It is no surprise that we have back injuries. have posture. We have mechanical stress- It is no surprise that we have slips, trips, es. We have cold and vibration. All of and falls. In fact, if these were in regular these things combine in some way to cause industry-if I were not working for OSHA problems. at the moment-I would say, "OSHA might shut them down." It is hazardous. One of the main questions I get is, "How many repetitions are too many reps? How much force is too much force?" We do not know because the problem is almost al- ways in combination with something else. You cannot isolate them. We know that almost no force is required if the repeti- tions are high enough, because we have people that sign for the deaf that get car- pal tunnel syndrome. This is far and away the easiest to read and best book on cumulative trauma of the upper extremity.2 It was originally put out by NIOSH, and it is now available from Taylor and Francis for about $23. There is an 800 number. They are located in Phila- delphia. RESEARCH NEEDS I could not find data or anybody who knew of any data out there relating to cumula- tive trauma disorders, and there is not much relating to back injuries in agricul- ture, which I see as the number one re- search need. We have a dearth of data. My understanding is NIOSH is beginning to act on this and that there are several programs. I think there are about three programs that may start to collect more data. I will admit that I may be ignorant of some of the data that has already been collected. 1. From my point of view, we need to determine the nature and the extent of the 282 Papers and Proceedings Musculoskeletal Hazards, May 1, 1991 problem. We also need reporting. It is my understanding that most farmers have never heard of an OSHA-200 log. 2. We are going to need epidemiological studies. 3. We are going to need studies on pack- aging and how to repackage things. 4. We need studies of what are the high- incidence tasks out there. Now some of them you know, but I would venture to say that if we ever arrive at cumulative data, if it is out there, we will find some tasks we do not know about now. 5. We also need to research what can be done in machine and equipment design to minimize cumulative trauma disorders, if that is what is causing them. 6. We need to figure out what the costs and the benefits are. 7. Lastly, and not necessarily least impor- tant, we have to come up with things that are acceptable to the people doing the work. You know as well as I do that there is no more independent group than farmers. Maybe truck drivers challenge them, but farmers are very independent. You put guards on machinery, you do things that are supposed to be for their benefit, and they blow it off. We have to come up with solutions that are acceptable to this com- munity.0 REFERENCE Putz-Anderson, Vern; Cumulative Trauma Disorders: A Manual for Musculoskeletal Diseases of the Upper Limbs. New York: Taylor & Francis, 1988. QUESTIONS Ronald Schuler: I am from the University of Wisconsin, Madison. Dr. Co&ran, have you heard of milker's knee, and is that a cumulative disorder? Dr. David Cochran: I have heard of it. I am not familiar with it. My guess is yes, but I do not know. Tom, do you know? Dr. Thomas Bean: It is very similar to miner's knee. It is a bursitis, an inflammation of the bursa of the joints, because of the constant bending, and the repetition, and the force as you are kneeling against the ground. Dr. Wesley F. Buchele: I am Wes Buchele from Iowa State University, retired. Dr. Co&ran gave a list of things you ought to conduct research on. I would like to add to that list, if I might, putting a screen over a wagon to permit people from sinking in the grain when they happen to be on grain. I happen to be one that thinks we should put extra seats on the tractor, with seat belts, because people are going to ride tractors and are going to have more than one person on the tractor. Therefore, we ought to start taking care of the problem as they do in Europe. I also think that we should think about putting floor boards on tractors to eliminate people being run over by tractors, which they are from time to time-run over by either a front wheel or a back wheel. We no longer put planters and cultivators in that area. I think we also ought to put a seat bar like on a ferris wheel or on forklifts. They have taken care of the forklift problem by putting a Surgeon General's Conference on Agricultural Safety and Health - 1991 283 Research - Mechanical and Physical Hazards seat bar on the skid steer loaders. We should have seat bars on tractors. We should also promote the use of guards by retrofitting. I think that we need to retrofit roll bars on tractors, guards on power take-off shafts, and guards on augers. Mark Veazie: I am from the Johns Hopkins Injury Prevention Center. Dr. Co&ran, have you done or are you aware of any assessments that have been done on cumulative trauma risk with manual harvesting typical of migrant and seasonal farm work? Dr. David Co&ran: I am not aware of any, but there may be. 284 Papers and Proceedings Surgeon General's Confrmnce on Agricultural Safety and Health FARMSAFE 2000 9 A National Coalition for Local Action Conumed by the National Institute for Occupational Saristy and Health April 30 - May 3, 1991, Des Moines, Iowa ELECTRICAL POWER By Robert McLymore Extension Safety Specialist, North Carollna State University Dr. Glen Hetzel contributed a lot to this presentation, as well as some of my other colleagues. In the event that I did not call you to get some background information, do not feel bad. When they have the pan- el presentation tomorrow, you can answer some questions. Electrical safety areas of concern are elec- trical wire components, electrical wiring systems, overcurrent protection, ground- fault interrupters, and grounding. These terms may not be important to you now. Maybe as you think in terms of what you do at your home, these terms can have some significance. ELECTRICAL WIRING SYSTEM The reason why I am talking about electri- cal wiring components is that we need to know where power is coming in on an operation. We know that it is coming in several plac- es-at the service entry riser and the meter. You may have a meter on your home. Think about it. There are meters on farms. Farming is not like that picture that you saw-that poster-where you see them out in the fields smiling, laughing, carrying on, and having fun. It is much more. There is power somewhere on that farm: overhead power; there is underground power coming to that farm. It all has to go through a certain code. Figure 1. An Example of a Wiring Box. For these components, you should only have licensed electricians install that elec- tric wiring, and it has to be inspected. This may be what one of those wiring boxes looks like (Figure 1). You have never opened one up, have you? You have never opened your fuse box up Surgeon General's Conference on Agricultural Safety and Health - 1991 285 Research - Mechanical and Physical Hazards at home, have you ? It does not look like that. It has circuit breakers in it, has it not? This assures that the wiring will meet the requirements of the National Electric Code (NEC), as well as local safety codes, which may be in your home or in your state. There are requirements for agricultural buildings in Article 547 of the NEC that specifies the type of materials to use for safety and protection is the environment in which this wire is contained. Dusty or damp conditions exist in agricultural build- ings, which may create explosive atmo- spheres or corrosive conditions for electri- cal metal fixtures and equipment. Did you ever think about that? These things, in themselves, may be explosive. That explosion may be in the form of a fire. That is what those conditions may be. Figure 2. The Atmosphere of a Chicken Barn. How many of you know about poultry. You ate it today at lunchtime. Was it good? Those are dusty, damp, dirty condi- tions-if you did not catch it in the last slide, that is what dust looks like when it is in suspension in the air (Figure 2). This is what dust looks like when it is coming out of that vent that is adding air into that house (Figure 3). It is collecting particulate matter. Will that dust bum? Is it truly just dirt, or is there partially dry material in with that material? OVERCURRENT PROTECTION The next part is overcurrent protection. There are specific types of overcurrent devices. You have the plug, the cartridge fuses, and the breakers. Figure 3. Dust on an air vent from a Chicken Barn. Fuses This is what they look like (Figure 4). There is the fuse (right, center in Figure 4). You have seen this type at home be- fore, a screw-in fuses. That is another type of cartridge fuse (also in Figure 4). Some are delayed so that when a surge of power goes through them-too much electricity-they are de- layed. They protect the conducting wire. You are probably more familiar with breakers in a box at home (Figure 5). The fuses and breakers are installed to protect the circuit, not the appliance. 286 Papers and Proceedings Figure 4. Examples of Fuses. Figure 5. Examples of Breakers. There are special fuses that are available to protect the electrical equipment, and it is important that we realize that overcurrent devices are sized to carry no more current than the circuit wire is rated to carry. Is that important to you? Is it important to that farmer? Yes, it is important because he has some expensive equipment that he is using, and overcurrent protection is needed to protect it. What about for his own personal life? Electrical Power, May 1, 1991 Think about you and the overcurrent de- vices that may be in your home. You have wires like this that are made to carry a specific amount of electricity. If contact is made with a live part, will the overcurrent device trip and protect human life? No. Well, I used to work at a funeral home, so I have seen it, too. The human body will receive a lethal shock if the current that flows through the body is 0.01 amperes or greater. A fuse or breaker will not provide protection to the human body. The wire protected by the proper size of the fuse or breaker will not allow the temperature of the wire to exceed safe operating condi- tions and cause what we have on some farms-explosions in bins and fires where material may be stored, like hay or dry feed. GROUND-FAULT INTERRUPTER The ground-fault circuit interrupter (GFCI). Are you familiar with that term? Do you know about it? You have seen it a lot? You buy devices, appliances, that have GFCI's on them. It is the most re- cent device that is used and designed to protect human life from shock. It is designed to detect minute amounts of current, 0.005 amperes or greater leakage, from the circuit. It is supposed to trip the circuit off. The overcurrent power and the conven- tional tripper turn the circuit off when there is a current flow that is in excess of the rated value of the breaker. The GFCI may be a separate device or it may be incorporated within a breaker. It is de- signed to give protection from that lethal Surgeon General's Conference on Agricultural Safety and Health - 1991 287 Research - Mechanical and Physical Hazards shock in a fraction of a second. It can be used on any 120-volt circuit. It is also required in places at home by NEC. These places are in the kitchen, in the bathroom, in the garage, and exterior sockets on the house. How many of you use extension cords outside to, perhaps, vacuum the car? Has the circuit ever tripped off for you when you were outside ? Be thankful that they invented the GFCI. You would not be here at this conference without its protec- tion. Think about farmers. Are they always in dry locations when they are utilizing some of their appliances, some of their tools, like a skill saw or maybe a hand grinder? There is one particular person who was using his welder when it was raining. He could not work outside, but he had some welding work that he needed to do. He did not want to use the welder inside his shop because it was too small, too tight of an area, and there would be too many welding fumes. He laid down a piece of sheet metal; he pulled out the piece of equipment he was going to do some weld- ing on, and he hooked it up to the welder. The coroner tells us what happened to him next. He was shocked and killed. It was raining. There was the metal. There was the electrical appliance, with the electrical source coming in through the welder, and the welder was not properly grounded. There are three types of and locations for these devices. We will find that these GFCI' scan be at a distribution box to protect the entire circuit or they can be at a receptacle box. They can also be in an extension cord. GROUNDING Do you see the third leg (Figure 6)? These are designed to give you continuity, to give you the grounding so that you do have a proper ground in that extension cord. That term "third-wire" ground and bonding should be understood for safety. Electrical bonding means to connect all metal parts in the building together and that this be connected to the system of the ground. The proper grounding of the system helps prevent stray voltage, which is a term that a lot of my colleagues know about. It is not voltage that wanders around aimlessly saying, "I am looking for a victim." It is voltage in itself that is not going to a prop- er ground. It provides a low resistance path for the neutral current to go to the ground. That third-wire ground is the conductor in the wiring system that extends from the ground to the main distribution panel to the electric device and looks similar to that (shown in Figure 6). That is what is plugged in for your hot side and cold side. That is the ground that goes in. This is what it looks like on the other side, on the male side. That is the female receptacle and the male receptacle (Figure 7). That is why bonding is so important-I talk about it twice be- cause a lot of injuries and deaths could be avoided if the electrical bonding process was followed. The last slides I have are getting more back to the topic of what to do from an 288 Papers and Proceedings Electrical Power, May 1, 1991 Figure 6. Example of Three-wire Receptacles. Figure 7. Male and Female Receptacles. agricultural perspective, or even from just regular people's perspective. GENERIC PROBLEMS When you start thinking about your uses of electricity, there are generic problems I see that may arise on the farm. Wire Damage One is damaged wire resulting from crush- ing or cutting incidences where wire can be enclosed in a conduit material or exposed. In Figure 8, you see wire that is encased - either a metal case-like conduit or in the hard rubber, plastic, or the other material that you have that wire comes in. When you are working around a farmplace, you are using a lot of equip- ment. Farmers are using equipment that backs onto it. Two-Prong Adapters These are what I call pseudo-outlets (Fig- ure 9). These are two-prong plugs. The significance of these two-pronged plugs is that there are two-prong adapters being used with various equipment that requires that third wire ground; that third leg, so they can properly ground the electricity that is flowing through. Figure 8. Examples of Wiring. How many of you have remodeled your homes lately, or done anything inside the home where you changed a light fixture or maybe have changed a wall socket? They sell what I would term pseudo-outlets for you. They were originally designed for two wire and replaced with a cover for a third wire Surgeon General's Conference on Agricultural Safety and Health - 1991 289 Research - Mechanical and Physical Hazards Figure 9. Two-prong Plug and Adaptor. ground. It looks like it is grounded prop- erly, but it is not. This is what it may look like (Figure 10). You have them there. Who is to say that has just been put into a two-prong outlet or through the wall sock- et. Assume it is not grounded unless you look behind it. I f. i Figure 10. A Three-prong Receptacle. Wire Nuts Do you know whether or not it has been grounded properly ? Can you tell? Can you walk up to and look at the socket and tell that it has been grounded? Some people, when they replace their wire nuts, do not necessarily use the wire cover on the nuts (Figure 11). They may use plastic. They may use tape. They may squeeze them together. But it may call for the wire cover, the wire nut, the yellow cap That is why those 250 fatalities occur. Some of them did it before, some of them did not. This is a term which is not a scientific term, but I like it. Have you heard of a term called "shade tree mechan- ics?" This is what I call the "jack-leg" wire mechanic. That means that he is not fol- lowing codes for the types of materials he uses. This is a faulty method of installa- tion. There is a hot wire that goes through the wire. There is a hot side and there is a cold side. You can hook the hot side through the switch and the cold side through the switch so the wire is running through the white side. When you shut if off,. the switch goes off, but it is still hot. You start working on that socket. You start taking it out of the wall to repair it; it is still connected. The power is still flowing through it. Was it installed using NEC codes? Figure 11. A Wire Nut. 290 Papers and Proceedings to go over that wire where that connection has been made. A lot of jack-leg wiring will go on like this. You have a conduit box there designed to carry only so many connectors inside. They are rated because of the amount of heat that is given off by each connector. They build up additional heat inside. This situation is an excellent point for a fire to occur, unsuspectedly, for the wiring itself to degrade from the heat, causing it to touch the metal casing and the metal conduit around it. A person could then touch it and die. Overhead Wires I would be remiss without talking about what we traditionally think about on the farm where we have equipment that is being pulled around: getting in contact with overhead wires. There are labels. There are safety shields and warnings in place to help people to avoid that situa- tion. Most people, farmers and agriculture workers, do try to obey this. Sometimes, however, they get too busy, and they forget for a few moments. That moment of care- lessness may end up with that piece of equipment getting in contact &th that line. We know how electricity kills. It is going to go through what is grounded the most. A cartoon character can live through it. The human body cannot. CONCLUSION Inspections Need to be Made In conclusion, I would like to offer the following. Inspections need to be made on Electrical Power, May 1, 1991 the farm. They need to be made on a scheduled basis and immediately when things are damaged. These inspections will reveal problems before they become life- threatening situations. Those conduits, if they are bent, need to be checked. How many times have you put down an electric cord and said, "Well, I am only going to use this temporarily here; get some power to do this little func- tion." NEC Codes Should be Followed Five years later you still have that same electric cord in place. Think about it at home. You have an electric cord you have been using someplace, have you not? That moment of carelessness may end up with that piece of equipment getting in contact with that line. We know how electricity kills. The NEC should be followed. It helps everyone on that farmstead or that place. They can have some assurance that there is some safety, that they know that it is supposed to be working like this. You know what kills a lot of people-things that "were supposed to be," (and were not) and sometimes we do not find out until after the fact. Safety Procedures Adopted There are safety procedures that should be adopted. First, if you are going to do your own work, you need to have someone there who can check it over before you start using it. What happens with people Surgeon General's Conference on Agricultural Safety and Health - 1991 291 Research - Mechanical and Physical Hazards doing their own work is that they are al- ways trying to save on budgets. Other problems are putting things up and not checking to make sure that they have been wired or that they have been ground- ed properly. Maybe someone cut down on the materials that are being used because he or she is just going to add some power to a particular room or building on the farm. I have seen places where you have wires extended over here, hanging down-a light bulb extended hanging down from the rafter. That in itself is an accident waiting to happen. They can be avoided. We are trying to get codes followed, in- spections made, and safety procedures adopted. When you work with electricity outside, make sure that you do not use equipment unless it has been properly grounded with that third wire. Make sure that everything has been bonded together so that it is properly grounded. Only then can we address this problem effectively.0 292 Papers and Proceedings Surgeon General's Confetmce on Agticuttural Safety and Health FAR&&FE 2000 o A National Coalition for Local Action Convened by the National Institute for Occupational Safefy and Health April 30 - May 3, 1991, Des Moines, Iowa NOISE AND STRESS By Matthew Marvel, M.D. Attending Physician, Oneonta Health Center It is indeed a privilege to speak to this dedicated and distinguished group. I ap- preciate being invited to speak here. The topic of my talk today is noise and stress. Let me preview a little bit what I am going to talk about. In a few words, I am going to be talking about noise and its potential to cause stress. I am not going to talk about stress to any great extent. Most of my expertise is in the area of noise and noise-induced hearing loss in farmers. I am going to discuss those topics. For those of you who are not familiar with the subject, I am going to define noise and what constitutes dangerous noise. I will be reviewing OSHA guidelines gov- erning noise exposure, show some sample farm-equipment sound levels, and review the characteristics of noise-induced hearing loss. I am going to give an overview of studies that examined hearing loss in farm- ers and finish with suggestions for future research. NOISE AND STRESS First, a few words about noise and stress. Can noise cause stress? Yes. For exam- ple, if this microphone were to start having feedback, I think both you and I would start to have stress after a little while. There are ample studies in animals that have documented the ability of noise to cause stress-related physiological changes. In humans, noisy jobs have been associated with higher rates of various diseases. Noise can cause stress by interfering with communication, disturbing concentration, and acting as a noxious stimulus leading to activation of neurohumoral mechanisms. Noise results in elevated blood pressure, heart rate, and respiratory rate, as well as affecting other systems. All these contrib- ute to increased levels of fatigue and, ulti- mately, injuries. DANGEROUS NOISE Noise is loosely defined as an undesirable sound. It is a subjective definition and one that is a matter of taste. For example, one man's noise is another man's music. Potentially hazardous noise, on the other hand, can be simply defined as something greater than 85 decibels and is indepen- dent of the source. It is a function of the intensity, as measured in decibels, and of the duration of the sound. This governs industrial workers and not, for the most part, farmworkers. It can be used as a guideline and should be used for farmworkers. After all, a hundred decibels in a factory is no different than a hundred decibels in a barn or in a field. Surgeon General's Conference on Agricultural Safety and Health - 1991 293 Research - Mechanical and Physical Hazards Where I am from, Ostego County in New York. Various types of equipment operate above this 85-decibel level. A cab added to a tractor can have a protective effect, on lowering the exposure to sound. Chain saws are loud. Some people might find surprising their including chain saws on this slide, but in my part of the country particularly they are widely used on the farms, in wooded areas for clearing and for cutting firewood. We have heard, at various times in the talks this week, how engineering is improv- ing things for farmers. That is true in the area of sound production as well. Newer equipment is engineered to be quieter, but there is a lot of older equipment still in use. A survey of upstate New York found that the average age of tractors in use on farms is about 20 years. There is quite a bit of equipment out there being used that has not benefitted from this improved engineering. NOISE-INDUCED HEARING LOSS Noise-induced hearing loss can be either permanent (PTS stands for permanent threshold shift) or temporary (TTS refers to temporary threshold shift). Established noise-induced hearing loss is permanent, but moderate exposures to noise may cause temporary threshold shifts. Repeated temporary threshold shifts may become permanent. Noise-induced hear- ing loss is sensorineural. In noise-induced loss, opposed to conductive types of losses that are due to middle ear disease, there is actual damage to the neurological struc- tures of the inner ear. It tends to be bilat- eral but may often be directional, as some of the studies have shown. In addition noise-induced hearing loss presents &ally at higher frequencies, with a characteristic loss that occurs at 4?000 Hz. This is com- monly called the noise notch. This has implications for hearing conserva- tion measures as well. Noise-induced hearing loss develops more rapidly at the higher frequencies, and speech comprehen- sion is affected. Consonants are heard at the higher frequencies, whereas vowels tend to be in the lower frequencies. It once was thought that speech was mostly a phenomenon that occurred between 500 and 3,000 Hz. The work of Alice Suter and others, however, has shown that accu- rate speech comprehension requires the perception of higher frequencies and that we need to be looking at those as well.' STUDIES OF HEARING LOSS I would like to now turn to the overview of some of the studies on hearing loss in farmers. It is not a large body of evidence at this point, compared to a lot of other fields. Again, I am going to give an overview of the different published studies from the scientific literature covering hearing loss in farmers. The first reported study was by Glorig in 1957, who reported the results of hearing tests done on visitors to the 1954 Wisconsin State Fair.2 He found that farmers aged 50 to 69 had significantly more hearing loss in the 2,000 to 6,000 Hz range than office workers of the same ages. The frequencies affected pointed to noise-induced hearing loss as the culprit. Lierle and Reger reported, in 1958, on the adverse effects of tractor noise on the hearing of farmers.' 294 Papers and Proceedings The next reports did not appear until the mid-1970's, when Karlovich tested the hearing of an unselected rural population in Wisconsin', and Townsend studied a similar group in rural central Michigan. Townsend used a mobile van to visit rural communities over an g-week period and tested over 1,300 adults. The purpose of the study was to depict a profile of hearing sensitivity of rural mid- western adults. His findings were that, on the average, hearing loss was greater than could be expected by aging alone. There was no significant difference in hearing, however, between those with a history of industrial work and those with- out. He concluded that in addition to occupational noise exposure another noise exposure, perhaps recreational such as one gets during hunting, boating, or the use of snowmobiles, seemed to be a prime con- tributor. Thelin re-examined what Glorig had found from the 1954 study to see if the discrep- ancy between the hearing of older farmers and office workers could still be shown and if there had been a change, and to deter- mine if younger farmers were also at risk. The sites were the 1979 Missouri Farmer's Association Agri-Fair and the 1982 Shelter Insurance Health Fair." He tested 161 farmers and 75 non-farmers at the Agri-Fair and 130 office workers. His findings were that older farmers were still at risk for high-frequency hearing loss as were younger farmers, which Glorig had not found. Like Townsend, however, he also found a higher rate of hearing loss in non-farmers at the Agri-Fair. The non-farmers' hearing was not as bad as the farmers' but was worse than the office workers. Noise and Stress, May 1, 1991 Karlovich, in 1988, published reports of his testing of 812 visitors over a 5-year period to the Wisconsin Farm Progress Days.' The purpose of this study was to re-evaluate the prevalence and characteris- tics of noise-induced hearing loss in a rural population. The findings were similar to the overall trends that Glorig had found in the 1950's. Males continued to acquire noise-induced hearing loss sufficient to affect their ability to commumcate. It was seen as early as age 20. One out of four of the males had the beginnings of a communication handi- cap by age 30; one-half of them had a communication handicap by the age of 50. Again, both farmers and non-farmers dem- onstrated noise-induced hearing loss, sug- gesting a non-occupational source of noise like firearms use. Only 25 percent of noise-exposed males reported consistent use of hearing-protective devices. Broste, et al., in a 1989 publication, exam- ined an even younger group for evidence of noise-induced hearing loss.8 He studied 872 high school students from Wisconsin to determine whether students engaged in farming had evidence for more hearing loss than their non-farming peers. He found that about twice as many students involved in farming had evidence of early noise-induced hearing loss as compared to non-farmers. Less than one out of ten of the students, however, used hearing protection. The left ear was more severely affected, and for the first time in this series of studies, precau- tions were taken to exclude or to try to control for temporary threshold shifts. I have a study that is due for publication this year. It will be appearing in the Arner- Surgeon General's Conference on Agricultural Safety and Health - 1991 295 Research - Mechanical and Physical Hazards ican Journal of Industrial Medicine.' We tested 49 randomly selected, full-time dairy farmers from Ostego County, New York. Ours is the first study to examine a ran- dom selection like this. We also tested 49 age- and sex-matched rural non-farmers. The purpose of our study was to assess the prevalence and nature of hearing loss in this population. Like Broste, we controlled for temporary threshold shifts, but we used hospital-based equipment. We found an alarming rate of hearing loss in the farmers, while the non-farmers had losses not far from what one might see due to the effects of aging alone. High-frequency ranges (HFA), is an average of the frequencies at 3,000, 4,000, and 6,000 Hz. Sixty-seven percent of the farmers had abnormal hearing as opposed to 37 percent of the non-farmers, at the high-frequency ranges. The PTA4, which measured the mid-frequency ranges of 500, 1000, 2000 and 3,000 Hz, showed somewhat lower levels, but still a big difference. The farm- ers had a 37 percent rate of hearing loss, whereas the non-farmers had 12 percent. As to the results of the subjects who were younger than the mean age of 43 years. At the higher frequencies, where we would expect to find noise-induced hearing loss, we saw lower average thresholds for the farmers. We also found that the left ear was more severely affected, as did Broste. Through correlation regression analysis of the data, we were able to support our hypothesis that the differences found were due to farm noise exposure. I am aware of one other study that is going to be published this year. The preliminary reports were presented at a hearing con- servation conference in San Antonio. This is by {;alle, who is from northern Iowa." Looking at the troubles that some of the studies have had in separating occupational noise exposure from recreational, he sought to select a group of 30 farmers who had only occupational noise exposure. He compared them to a group of age-matched non-farmers who had no significant noise exposure. There were three groupings-age 30, age 40, and age 50. The 30-year-olds had no significant differ- ence at any of the frequencies tested. The 40-year-olds had significant differences in the 3,000 to 8,000 Hz range, again where you might expect noise exposure to start showing. The 50-year-old group had signif- icant differences at all frequencies tested. I was pleased to find that his audiometric data looked similar to what I showed you on those two graphs. Our results look similar. The cumulative summary of the findings, then, showed that farmers have higher-than-expected rates of hearing loss. This is true in all studies. The rates exceed those of the general population, and loss starts in the teen years or before. Farm noise appears to be a major factor. In addition, non-occupational noise may be contributing, as Thelin, Karlovich, and Townsend have reported. This is also something very important to recognize and address. If you are only working on occu- pational noise exposure and people are still losing their hearing while hunting, you are not gaining much. 296 Papers and Proceedings That summarizes the studies that have been done to date. Despite the evidence, some people still have not heard the mes- sage. Therefore, more work needs to be done. FUTURE RESEARCH What are the areas for future research? First of all, we have barely scratched the surface of this problem. There is plenty of room for more research. The number of studies so far is still small, and it is a large and diverse industry with many different risks. We also might find some high- technology solutions like using sound cancellation. I We ought to be testing other regions of the country, other types of farming practices, and other types of farmers. Research should be done for more effec- tive methods of hearing conservation and education. We should be doing dosimetry studies to better define noise risks. I was pleased in looking through the pamphlet showing the poster sessions. It looks like somebody is presenting something on that. Noise and Stress, May 1, 1991 We need more research on the possible synergistic effects between noise and cer- tain agents like carbon monoxide. We need some more research into engineering advancements, greater developments for quieter equipment at the source, ways to improve baq-iers to sound transmission like tractor cabs. This is needed not only for improved new ones, but perhaps more economical ones that farmers could retro- fit. We also might find some high-technology solutions like using sound cancellation. Improvements could be made in hearing protective devices, to improve the fit, the comfort and convenience and, consequent- ly, the likelihood that farmers would wear them. It would be nice to be able to better pre- dict the risk of noise-induced hearing loss from noise exposure levels and early au- diometric changes. Naturally, it would be good to see more basic science research into the anatomic, physiologic, and genetic bases for presbycusis and noise-induced hearing loss. In conclusion, through research, let us continue to look for ways to better de- scribe the nature of the problem so that through the spread of this knowledge those at risk for noise-induced hearing loss may see the ways to prevent it.0 REFERENCES 1. Suter, Lempert B and J Franks; "Real-ear Attenuation of Earmuffs in Normal-hearing and Hearing- impaired Individuals." Journal of the Acoustical Society of America. 87 (5): 2114-2117, 1990. 2. Glorig, A; "Some medical implications of the 1954 Wisconsin state fair hearing survey." Trans American Academy Ophthalmology Otolatyngology 61:160-171, 1957. 3. Lierle, DM and SN Reger; "The effect of tractor noise on the auditory sensitivity of tractor operators." Ann Otol Rhinoi Laryngol 67:372-388, 1958. Surgeon General's Conference on Agricultural Safety and Health - 1991 297 Research - Mechanical and Physical Hazards 4. Karlovich, RS, and TL Wiley; "Spectral and Temporal Parameters of Contralateral Signals Altering Temporary Threshold Shift." Journal of Speech and Hearing Research, Vol. 17, No. 1, pp. 41-50, 1974. 5. Townsend, TH, FH Bess, and WA Fishbeck; "Hearing Sensitivity in Rural Michigan." American Industrial Hygiene Association Journal, Vol. 36, No. 1, pp. 63-68. 6. Thelin, JW, DJ Johseph, WE David, DE Baker, MC Hosokawa; "High frequency hearing loss in male farmers of Missouri." Public Health Rep 98:268-273, 1983. 7. Karlovich RS, TL Wiley, T Tweed, DV Jensen; "Hearing Sensitivity in Farmers." Public Health Reports, Vol. 103, No. 1, pp. 61-71, 1988. 8. Broste, SK, DA Hansen, RL Strand, DT Stueland; "Hearing loss among high school farm students." American Journal Public Health. May: 79(5): 619-22, 1989. 9. Marvel, ME, DS Pratt DS, LH Marvel, M Regan, JJ May; "Occupational hearing loss in New York dairy farmers." American Journal of Industrial Medicine, 20(4): 517-31, 1991. 10. Plakke, BL, and E Dare; "Occupational hearing loss in farmers." Public Health Rep 107:188-192, 1992. 298 Papers and Proceedings Surgeon General's ConRmnce on Agricultural Sakty and Heatth FARMSAFE 2000 o A National Coalition br Local Action Convened by the National Institute for Occupational Safety and Heatth April 30 - May 3, 1991, Des Moines, Iowa TECHNOLOGY TRANSFER By Mumy M&en Product Safety Engineer for Agricultural Equipment Deere and Company There are opportunities for inventions, discoveries, innovations, and improvements that will help reduce the traumatic and acute injuries that occur in agriculture. These opportunities exist in both hardware and software technology, and I contend their impact can be achieved more fully and in a more timely manner through better technology transfer. I will explain that as we go. o By hardware, I mean the sheet metal, machines, parts, and gears. o By software, I mean the safety signs, safety messages and operator's manuals, promotional brochures, posters, human factors interfaced with the machine, and much more. o By technology transfer I am talking about not only what moves the infor- mation going from here to there, but also the process that drives it, how the information gets delivered from point A to point B. We are engaged in this conference to help protect the men, women, and children who come in contact with agriculture. I am especially interested, of course, in that part of agriculture that relates to agricultural machinery such as farm tractors. 1 am also talking about the things that plow the fields and turn the soil. I am going to run through some of these quite rapidly to give you a flavor for modern production agricultural equipment. They are the plows that turn the soil; the plant- ers and tractors, combines and other har- vesters; the mowers; the windrowers; the loaders; the manure spreaders, wagons, and much more. That is a grain drill, a minimum-till grain drill, and a corn planter. You might notice there (on the planter) the dry chemical transfer system Deere and Company devel- oped with American Cyanamid, the "lock and load" system. That is a spectrum of some agricultural tractors, one at closer range. A combine is shown in wheat as well as corn. There is a cotton picker, for those of you from the south and west, and you from Arkansas may be more familiar with cotton strippers. You see a self-propelled forage harvester, a rotary cutter, a rotary mower or mower conditioner, a windrower, and front-end loader with a large, round bale. There is a product that probably no one stands behind, a manure spreader. You see a cotton stripper, hay equipment, all-materials transport utility hauler (which distinguishes it from an ATV or all-terrain vehicle), self-propelled high-cycle sprayer, and a blank slide that gets me on to the important part of my conversation with you today. Surgeon General's Conference on Agricultural Safety and Health - 1991 299 Research - Mechanical and Physical Hazards I have a very strong preference for preven- tion before injuries happen, for the lever- age of design over safe practice control. I recognize, however, the need for a compat- ible blend. I am delighted that you are here. I wish that more people could be. I am also extremely impressed with the attendance at this conference and encouraged about the steep learning curve that all of us are on for these few days that we are together. My plan is to move from the broad per- spectives to suggestions for improved tech- nology transfer. I plan to give you some kinds of research that I believe are appro- priate and necessary. I will close with three general directions. BROAD PERSPECTIVES You have all seen the FFA signposts that declare, "Agriculture is more than farm- ing." It is technically farms, dairies, nurser- ies, orchards, vineyards, cranberry bogs, hatcheries, and more, that produce crops from artichokes to zucchini and livestock from Angus to zebra. Agriculture is done in fields, buildings, and under water. It in- cludes agricultural services such as veteri- nary care, farm management, landscaping, tillage, and crop protection. Agriculture includes tree farms, tracts, nurseries, and those engaged in gathering forest products. And it includes commer- cial fishing, hatcheries, preserves, and commercial hunting and trapping. While our typical "mind's eye" picture may run to the serene dairy in Delaware or to the cotton of California, that is only part of the real picture. Yes, there are household products used on farms. There are hand tools, grinders, welders, saws, drills, motors, mills, and much more. There are ATV's, trucks, crawler tractors, and punch presses. My remarks focus on agricultural field and farmstead or farmyard equipment, typically on wheels or mounted to tractors that have wheels. Many farms have a full line of modem production machinery. Others use tractors and machines that are 50 or more years old. Sometimes equipment is in mint condition; other times it is not, or modi- fied, or built from scratch in a local shop. In all cases, new equipment must be com- patible with the old. A great deal has been accomplished through the voluntary standard system, such as the American Society of Agricultural Engineers (ASAE), to achieve the essential level of inter- changeability and compatibility. Each day technology and our understand- ing of it-how to use it; how product users will interface with it-increases. It leads to improved products-products with greater productivity, products with less cost, and products with improved safety. All of those are happening now. We are on the brink of future technology that will dwarf the revolutions of the 20th century. Semiconductors and the associat- ed inventions have led to innovative new products, like computers, and to improve- ments in others, like radios. Mechaniza- tion, electronics, and biotechnology must be considered the technological revolutions of this century. Perhaps photo&s, the gathering and processing of information transmitted by means of light, will join them. I wish that I had the ability to predict what the next inventions will be. But who 300 Papers and Proceedings