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