Research - Mechanical and Physical Hazards

appropriation bill, to help as outreach
efforts.

To date, our consultation people have not
had a rush of requests from the agricultur-
al industry or community and the farmers
and ranchers to conduct on-site consulta-
tion visits. Obviously, we need to find
ways to reach those people. We have not
found those ways yet.

 

In the OSHA history of writing rules,
regulations and enforcement, we have
found that the people who are interested

in trying to correct these problems need
to be on board and in support of the
process.

We need to find ways to evaluate injury
intervention strategies to promote those
that are found to be effective and work.
We need to have the farmers and ranchers
actually involved in helping with the eval-
uation.

326

 

In the OSHA history of writing rules, regu-
lations and enforcement, we have found
that the people who are interested in try-
ing to correct these problems need to be
on board and in support of the process.
They need to find that these kinds of solu-
tions work. Then, we can carry the mes-
sage to the non-believers or the
"stick-in-the-mud" types who need to be
pulled along a little harder.

OSHA is looking forward to the day when
the Congress no longer considers riders on
its appropriation bill to be necessary.
OSHA hopes to be a full-fledged partner
in the outreach and consultation efforts
that help the farm community, the agricul-
tural community generally, with assistance
so that the injury and trauma problems can
be brought to a much more acceptable
level.

We want to see this assistance given in all
50 states, territories, and the Common-
wealth of Puerto Rico to reduce trauma
and tragedies.O

Papers and Proceedings
Surgeon General’s Conference on Agricultural Safety and Health

FARMSAFE 2000 ¢ A National Coalition for Local Action

Convened by the National Institute for Occupational Safety and Health

April 30 - May 3, 1991, Des Moines, lowa

FARMING METHODS AND SYSTEMS ANALYSIS

By Gary Erisman, Ph.D., C.S.P.
Private Farmer

 

Dr. Erisman:

 

Dr. David S. Pratt: The first speaker today is am very pleased, harkening back to some of the
comments we heard this morning—someone who is involved as a stakeholder and a person directly
involved in agricultural production. Gary Erisman was born and raised on a family farm in Stanford,
lilinois. He got a bachelor’s degree and master’s degree, both from Illinois State University, one in
agricultural education and the other in traffic and safety education. He went on to receive a Ph.D. in
health and safety from the University of Illinois in Urbana, and then has gone on to become a
Certified Safety Professional. He has had numerous experiences and has taught and been involved
in occupational safety and health at the university level for a number of years. At the present time,
and since 1980, he is an active farmer and also serves as a safety consultant in farming.

 

 

As I view it, my primary task as lead-off
man for this session is to establish a per-

spective on the topic. It has been conclud-

ed for many years that accidents are a
particular problem to those engaged in
farming.’ This conclusion has resulted
from intuition and the use of epidemiolo-
gy, the scientific method of studying epi-
demics in a particular population.

PROBLEMS WITH THE
EPIDEMIOLOGY APPROACH

Epidemiology is a staple method of investi-

gative evaluations of health problems.
However, there are some problems with
epidemiology when used to investigate
accidents.

1. In epidemics, the agent (germ) is usual-

ly a constant, a single, identifiable or-
ganism with predictable properties.

That finding is not true with accidents.”*

For example, all cases of chicken pox
result from one organism. However,

not all tractor accidents result from the
Same organism (tractor). Tractors vary

in size, weight, ballast, age, etc.

2. Little can be done to change the germ.
In epidemiology, most success has been
achieved by reducing the human’s sus-
ceptibility to disease through vaccina-
tion, administration of drugs, or educa-
tion. However, data has consistently
shown the most success in preventing
accidents is achieved through changing
the agent or environment through
redesign.**°

3. In epidemiology, the illness must mani-
fest itself. It is an “after the fact" meth-
od of problem solving. When compared
with alternative methods, it is an ineffi-
ciency.

4. Perhaps the biggest problem with epide-
miological studies of accidents is that
they rarely tell us the most crucial infor-
mation. Epidemiological studies answer
the questions "who," "what," "where,"
"when." They do not answer "why."

We have to resort to other techniques to
answer the latter question. For example,
we may find 70 percent of all farm acci-
dents in Iowa occur between the months
April and October.

Surgeon General’s Conference on Agricultural Safety and Health - 1991 327
Intervention - Worker Protection from Environmental Hazards

However, that may be because of chance
alone; that is the time span during which
most farming activities are conducted.
When we pool data from different states, it
produces even more uninterpretable data;
April has a different significance to farm
activities in Iowa than it does to farms in
Georgia.

The output of such studies is data, which
serves as the basis of conjecture. It is little
basis for scientific, effective counter-
measure development.

Epidemiological studies of accident prob-
lems already in existence are of value to
isolate problem areas that justify more in-
depth investigation.

THE SYSTEMS APPROACH

A more proactive, modern technique to
use with accident and injury control is
referred to as the systems approach. It is
the approach to accident control that has
been used with considerable success in
areas such as highway transportation sys-
tems, air travel and traffic control, and the
space program.

We need to define some terms as we go
along. I will use the systems method to try
to establish a perspective on farm acci-
dents. A system is defined as an orderly
arrangement of components that act and
interact to perform some task or function
within a given environment.’

1. Note that a system is defined according
to some task or function it is to per-
form. Examples include the digestive
system of a human, the postal system,
or an air traffic control system.

2. A system is made up of components
that act or interact (the components are

328

related); each component affects the
function of other components, and ulti-
mately, the output of the system.

When using the systems approach, the first
consideration is to identify the purpose of
the system. What is the system supposed
to achieve? What is the system’s output to
be?

The second consideration is the develop-
ment of a thorough understanding of how
the system functions. How do the com-
ponents or activities relate to each other?
What happens to the system if one compo-
nent fails? For example, it would be im-
possible for a physician to competently
practice medicine unless he or she knows
the systems of the body, the components of
the systems, and how the systems interre-
late. Extending this example, it is impossi-
ble to effectively use the systems analysis
technique, without first gaining a thorough
knowledge of the system in question.

Systems are designed and maintained on a
two-priority basis. The first priority of a
systems designer is to produce a system
that will do the job for which it is intend-
ed. The second priority is to determine if
the system will work within an acceptable
degree of safety.

Systems can be evaluated using two types
of criteria, systems criteria and human
criteria.’ I would like to use these two
criteria in an evaluation of our American
farming system.

Systems Criteria

Following the procedure set out, I must
ask the question, "What is the purpose of
the U.S. farming system?" From a national
perspective, the purpose is to insure a
reliable supply of food and fiber for our

Papers and Proceedings
citizens and other people abroad. It can
be argued that America’s greatest natural
resource is its capacity as a food factory.
The climate, soil types, water supply, tech-
nology, distribution system, economic sys-
tem, and creativeness of the farmers and
workers, when put together, comprise the
best collection of agricultural resources
(components) in the world.

1. Each farmer in Japan produces enough
food to supply himself and 3 others; in
Russia, 11 others. But each American
farmer produces enough to support
himself and 114 others.*

2. The reliability of the American food
machine is so high, it is largely taken
for granted in this country. We have
never known the starvation experience
of European, Russian, and Asian coun-
tries during and after World War II.
Nor do we know the famine that exists
in a host of countries today.

3. Americans spend a smaller percent of
their disposable personal income for
food than in any other country in the
world,’

4. American agriculture is big business. It
makes up about 18 percent of all the
nation’s jobs (20 million jobs). Howev-
er, only 19 percent of that 18 percent
(3.8 million) are actually involved in
farm production—farmers, hired labor,
and workers in forestry, fisheries, and
agricultural services.

5. The American production system has
evolved from the hunter-gatherer system
of our Native Americans, through slash
and burn systems, largely through no-
madic systems, and through the subsis-
tence form of farming that
predominated well into the 1950's.

Surgeon General's Conference on Agricultural Safety and Health - 1991

Farming Methods and Systems Analysis, May 1, 1991

Since then, economic demands have
brought a major shift from subsistence
farming to a specialized, commercial-
ized form that predominates today.

6. U.S. farmers produce a variety of com-
modities for domestic and export mar-
kets. The 1987 Census of Agriculture
lists more than 200 different commodi-
ties produced in the U.S. If a single
word were chosen to describe U.S.
production, the best word would be
"diverse".’

7. Each commodity produced represents a
specific subsystem with specific opera-
tions equipment, timetables, labor, and
marketing demands.

In addition, a majority of farms still com-
bine two or more subsystems—one superim-
posed on the other—that usually have syn-
ergistic effects. Examples are hog-corn
farms; cattle, corn, bean farms; etc. Each
farm represents a unique subsystem of
activities and risks, with no two exactly
alike. Perhaps the greatest strength of the
overall system is the creativity of the com-
ponents; each farmer tries to build a better
mousetrap.

It is important, at this point, to make a
distinction between the system’s purpose
from a national perspective, and the pur-
pose of the system from the producer’s
perspective. From the farmer’s perspec-
tive, the purpose of the system is a means
of earning a living, or supplementing in-
come.

True, there are many secondary motives—
pride of ownership, a way of life, per-
petuation of the heritage, etc. But the
primary purpose, to earn a living, should
never be allowed to become obscured.

329
Intervention - Worker Protection from Environmental Hazards

1. Farmers seek to bring about an opti-
mum mix of land, labor, and capital
inputs to maximize output, which is
ultimately measured in dollars.

This technique of mixing inputs is the basis
of doing business in America. It is
referred to as entrepreneurship, "the ability
of one to organize, manage, and assume
the risk of a business or enterprise” (dictio-
nary). Thus, to enter farming is to volun-
tarily expose ourselves to risks, economic
and personal. There is evidence to suggest
that people psychologically differ in their
willingness to expose themselves to risk.”

That does not make them "bad" people. It
adapts them to the demands of the job
others could not perform successfully or
happily. Other occupational groups of this
type would include such people as astro-
nauts, pilots, stock and real estate brokers,
athletes, police officers, and fire fighters.

2. The most telling single statistic that
depicts the system’s performance for
producers was released by the USDA
recently.

In the middle 1970's, $0.34 of every food
dollar was returned to the farm level.
Today, that figure has been reduced to
$0.24. The margin of profit per unit of
operation continues to shrink. There is
only one way to maintain or increase prof-
itability under those conditions, operate or
produce more units.

Usually, for one operator to increase in
size, another must shrink. This may sound
like Darwinism, but it is not that simple.
A farmer may be extremely efficient.

With no opportunity to expand, however,

i.e., no additional land to rent, he can be
economically reduced to the point that his

330

primary income must shift to off-farm
sources. The enterprise is taken up by
another, who remains economically viable.
The result is that the big get bigger. There
are more and more part-time farmers.

The middle-sized operations continue to
disappear.’

3. The trend in farm size leads to another
finding with implications for safety.

 

The trend toward fewer, larger farms
has reduced the number of family work-

ers, but it has increased the average
farm’s hired-labor requirements.

 

Today, 50 percent of the hours worked on
farms are worked by farm operators; 16
percent by unpaid farm workers, such as
family members; and 34 percent by hired
farm workers.’ The trend toward fewer,
larger farms has reduced the number of
family workers, but it has increased the
average farm’s hired-labor requirements.

4. The trend toward fewer, larger farms in
not necessarily a healthy one either for
those engaged in farming or those de-
pendent on the U.S. food system.

There is a point where concerns about
quantity override concerns about quality.
For example, one operator may operate
more acres, but may do a poorer job per
acre. Yields per unit may begin to dip a
bit. These events are insidious and some-
times hard to measure.

The ultimate result is a detrimental effect
on total system output. The system, in
total, reaches a point of diminishing re-
turns. It is not a situation of the operator’s
choosing, making, or desire. It is some-

Papers and Proceedings
thing the economic system is imposing on
them. It is an event that ultimately will
have to be addressed.

To summarize, based on an evaluation of
systems criteria, the U.S. food production

system is found to be extremely productive.

It is also found to be changing toward
fewer, larger components, which, in turn,
threaten continued capacity to increase
production.

Human Criteria

A second group of criteria can be used to
evaluate systems. They are referred to as
human criteria, and as identified by
McCormick and Sanders,’ are made up of
4 subcriteria.

1. Human Performance Measures elements
such as individual demands on sensory,
mental, and motor activities.

It is obvious, due to increased mechaniza-
tion and specialization, that physical
demands on farmers and other workers are
being reduced. It is equally obvious, due
to economic demands, that mental stresses
are being increased.

The luxury of being able to survive a sea-
son of bad weather or inaccurate business
decisions no longer exists for some opera-
tors. It resembles playing in a poker game
with increasingly high stakes. Each year
more and more producers find they have
their whole stack of chips in the pot.
There is no acceptable alternative to being
correct. That is stress!

2. Physiological Criteria indicators of the
effects of the work load on people.

Examples might include blood pressure,
heart rate, respiration rates, chronic health

Surgeon General’s Conference on Agricultural Safety and Health - 1991

Farming Methods and Systems Analysis, May 1, 1991

problems, and others. I am unaware of
studies that have attempted to compare
the fitness to work of today’s farmers and
other workers with those of the past. I
would postulate farmers today are less
physically fit as a group than those 20
years ago.

¢ The average age of an American farmer
today exceeds 50 years of age.

¢ Farm work has become more erratic.
The subsistence farms of the 1950’s re-
quired work every day year around.
Today, with specialization, the physical
demands are much more seasonal.
Nevertheless, farmers today try to oper-
ate units that fully use their capacity
(equipment). This trend tends to pro-
duce more pronounced periods of un-
derwork and overwork. Partially offset-
ting are contributions from industry that
reduce physiological demands, i-e., air-
conditioned cabs, power assists, etc.
Nevertheless, farming still remains
among the most physically demanding
of all forms of work.

3. Subjective Criteria: This critically impor-
tant area refers to people’s evaluation
of the system.

 

Thus, design is the most critical stage
for the prevention of hazards and haz-

ardous products.

 

It is often inaccurate. However, it is the
perspective that drives decisions. From a
national perspective, farming may appear
to have the characteristics of farming 30
years ago. The public perception is often
that of the farm when they left it. Little

337
Intervention - Worker Protection from Environmental Hazards

public understanding of the true dynamics
of modern farming exists.’

By contrast, those directly involved in
farming are acutely aware of the realities
of modern activities. The opinion of many
is that it is not as much fun, nor as enjoy-
able as it used to be. It is approached
more as a cold-blooded, demanding, unfor-
giving business.

4. Accident Frequency: It should be noted
that accidents are just one of several
criteria used to evaluate a system.

The value of any system is contrasted with
the cost to operate it. That statement may
sound insensitive. It is an accurate as-
sessment of the way the world works.

When viewed in the systems concept, an
accident represents one form of system
failure. When the system breaks down,
output is reduced or stopped. Systems are
designed to minimize or eliminate break-
downs in any form.

Farming ranks at or near the top of the list
of accidental deaths per 100,000 workers
exposed to risks.””” These findings have
been documented by more than one
source.

Translated into system terms, this docu-
ments a system that breaks down more fre-
quently because of a specific reason (inju-
ries) than most other systems. Further, it
documents that consequences of this sys-
tems failure are more serious than others.
The breakdown involves a death or serious

injury.

The question is, "Why?" That is a question
for which we do not have a definite scien-
tific answer. In my evaluation, we have a
great number of opinions, conjecture, and

332

over-generalization. We do not have de-
fendable data. That finding is the direct
result of the inadequacy of the
epidemiological methods primarily used to
study the problem.

HAZARD EVOLUTION

Perhaps the greatest single value of the
use of the systems approach is the preven-
tion of the problem before the problem
manifests itself in the form of an injury. I
will discuss one example of its use.

When we view the development of any
device, i.e., hammer, screwdriver, or trac-
tor, we find that in each stage of move-
ment, an opportunity for degradation from
design criteria exists. Examples are incor-
rect assembly, repair, and wear.

It has long been recognized that the safety
of a device can be no better than it is
found to be at the design stage. Thus,
design is the most critical stage for the
prevention of hazards and hazardous prod-
ucts.**?

When products are found to have prevent-
able hazards resulting from design inade-
quacies, it suggests that two further evalua-
tions are in order:

1. The academic preparation of the engi-
neers and the content of the curricula
through which engineers are or have
been prepared, and

2. The degree to which administrative
environments encourage or reward
contributions toward sound systems and
human factors design.

Papers and Proceedings
SUMMARY

The U.S. production system is a model of

productivity when viewed from the outside.

Economic trends have left much to be
desired to producers and others who work
in the system and make the system work.

REFERENCES

Farming Methods and Systems Analysis, May 1, 1991

Accident frequencies suggest a high fre-
quency of system breakdowns that must be
addressed. System approaches should be
used to evaluate why these breakdowns are
occurring. What system modifications can
be made to reduce the system failure
rate?0

1. National Safety Council. Accident Facts - 1990 Edition. Chicago: The Council, 1990.

2. Halsey, Maxwell; Editor. Accident Prevention. American Public Health Association. New York:

McGraw-Hill, 1961.

3. Jacobs, Herbert, et al. Behavioral Approaches to Accident Research. New York: Association for the Aid

of Crippled Children, 1961.

4. Klein, David and Julian Waller. Causation, Culpability, and Deterrence in Highway Crashes. U.S.
Department of Transportation, Washington, D.C.: Superintendent of Documents, 1970.

5. Marshall, Gilbert. Safety Engineering. Monterey, California: Brooks/Cole Engineering, 1982.

6. Waller, Julian. Injury Control. Lexington, Massachusetts: D.C. Heath, 1985.

7. McCormick, Ernest, J and Mack S. Saunders. Human Factors in Engineering and Design. 5th Edition.

New York: McGraw-Hill, 1982.

8. Meyer, Don. McLean County Cooperative Extension Service, University of Illinois, 1991.

9. Americans in Agriculture - 1990 Yearbook of Agriculture. Washington, D.C.: United States Department of

Agriculture, 1990.

10. Erisman, J. Gary. "The Relationship Between Emotional Immaturity and Accident Involvement of
Illinois Male Farm Operators." Research Report No. 7, Safety and Driver Education Laboratory, Cham-

paign-Urbana: University of Illinois, 1971.

11. Master, David. Conceptual Aspects of Human Factors. Baltimore: John Hopkins University Press, 1989.

Surgeon General's Conference on Agricultural Safety and Health - 1991 333
Surgeon General's Conference on Agricultural Safety and Health

FARMSAFE 2000 ¢ A National Coalition for Local Action

Convened by the National Institute for Occupational Safety and Health

April 30 - May 3, 1991, Des Moines, lowa

ERGONOMICS

By Professor Stephan Konz
Department of Industrial Engineering, Kansas State University

 

that is very popular, Work Design:

 

Dr. David S. Pratt: We have another presentation that | think is going to shed some important light
on agriculture from a perspective that we, unfortunately, seldom hear from very much, and that is
ergonomics. Dr. Steve Konz is going to speak next. He received his Ph.D. in Industrial Engineering
from the University of Illinois. He has been at Kansas State University since 1964. He has been a
prolific writer and contributed to the scientific literature with over 170 publications, and he has a book
Industrial Ergonomics," which is currently in its third edition
and was just recently re-offered in 1990, and it is used at more than 25 American universities. We
are, Indeed, delighted to have Dr. Konz with us today to talk about Ergonomics. _ Dr. Konz:

 

 

SUMMARY

Ergonomics deals with the interaction of

man and machine in a physical and social
environment. For agricultural safety, two
ergonomic recommendations are:

1. Focus on unsafe conditions, not unsafe
acts.

2. Redesign rather than use training or
warnings.

ERGONOMICS
Overview

The word ergonomics was coined by Pro-
fessor Murrell in Wales in 1949 from the
Greek words erg (work) and nomos (laws,
tules).' Thus, it referred to the study of
work. Over the years, the meaning has
broadened to the study of the interaction
of people and their environment. The
work environment is just one possible envi-
ronment.

One aspect of ergonomics that has
received considerable attention is the study
of the characteristics of the individual per-
son. When focused on a person’s dimen-

334

sions and strengths, this is called anthro-
pometry. When focused on the cardiovas-
cular and muscular systems, this is called
work physiology.

Information flows from the man to the
machine through controls. Information
flows from the machine to the man
through displays.

Thus, it was logical that much of the early
work in ergonomics focused on controls
and displays. Note that displays include
not only instruments (active displays) but
also letters and number arrangements such
as text, tables, and graphs (passive dis-

plays).

The man and machine are in a physical
environment (visual, noise, climate, chemi-
cal). Therefore, ergonomists also study
these variables.

Most ergonomists attention has been fo-
cused on the visual environment. Ergo-
nomists’ interest in noise and climate
(temperature, humidity) has focused on the
degradation of performance due to noise
and climate.

Papers and Proceedings
Finally, this activity occurs in a social and
organizational milieu. The person inter-
acts not only with machines but with other
people. This area presents many challeng-
es as people are much more difficult to
modify than machines.

One of the basic philosophies of er-
gonomics is the primacy of people over
machines. The idea is to adjust the ma-
chine, not the man.

This is in contrast to a common en-
gineering philosophy of designing a
machine, then assuming the personnel
department will be able to find someone
to be able to run the machine. Thus:

¢ Adjust the machine to the man, not the
man to the machine.

An alternative statement is:

¢ Adjust the procedure to the person, not
the person to the procedure.

PROFESSIONAL BACKGROUND OF
ERGONOMISTS

As might be imagined, the professional
background of ergonomists is very diverse.
As a very broad split, ergonomists are
divided into those interested in product
design and those interested in occupational
ergonomics.

The ergonomists interested in product de-
sign, however, usually are not designers or

engineers but staff consultants to designers.

Very commonly, they will have a

background in psychology— usually a MLS.
or Ph.D.

The ergonomists interested in occupational
ergonomics include consultants. More
commonly, they include industrial engi-

Surgeon General’s Conference on Agricultural Safety and Health - 1991

Ergonomics, May 1, 1991

neers, medical practitioners, and safety
specialists. These occupational er-
gonomists tend to have a small amount of
training in ergonomics (50 to 100
classroom hours) grafted onto a basic
specialty such as industrial engineering,
industrial hygiene, occupational medicine,
ete.

The occupational ergonomists tend to have
BS degrees. (During the 1950’s and
1960’s, ergonomics was the province of the
Ph.D. In the 1970’s, it changed from a
science to a technology. Ergonomics
knowledge was obtained by those with
M.S. and B.S. degrees. In the 1990’s,
training materials are beginning to appear
for blue-collar workers.)

There are many professional homes for
occupational ergonomists in the USA. The
largest ergonomics society, the Human
Factors Society (HFS), has "technical inter-
est groups” for Safety (582 members as of
January 1, 1990) and Industrial Ergonom-
ics (506 members). They are the second
and fourth largest of the seventeen interest
groups in the HFS.

The Institute of Industrial Engineers has
an Ergonomics Division of about 1,050
members. The International Foundation
for Industrial Ergonomics and Safety has
about 300 at their annual meetings. There
is considerable interest in ergonomics in
other organizations (National Safety Coun-
cil, American Society of Biomechanics,
etc.).

Ergonomics is widespread outside the
USA. There are 18 countries that have an
ergonomics society belonging to the Inter-
national Ergonomics Association (IEA), as
well as some countries that have not yet
joined the IEA. Total membership is
about 15,000.

335
Intervention - Worker Protection from Environmental Hazards

AGRICULTURAL SAFETY AND HEALTH
CHALLENGES

As a broad generalization, safety and
health problems can be divided into three
categories:

1. Injury: An accident causes an injury.
The time frame is short~a "sudden event."
An example would be a hand mangled in a
power takeoff or a burn from a grass fire.
It enters government statistics for deaths,
lost worktime, medical treatment other
than first aid, loss of consciousness, restric-
tion of work or motion, or transfer to an-
other job.

 

2. Cumulative trauma: The body (mus-
cles, ligaments, joints) suffers "insults" over
a time period usually measured in months
or years. Examples would be carpal tunnel
syndrome, back injuries, or hearing loss.
In general, the problem is due to a
"physical" agent (weight, noise, vibration)
or motion of the human body itself. In
government records, cumulative trauma
(also called repetitive strain, occupational
over-use syndrome) is considered an
illness. Back problems, however, are con-
sidered injuries.

3. Illness: An organ of the body is
injured, generally by a chemical or a bio-
logical agent. The time period is variable,
with times of minutes (acute) for skin ir-
ritants and allergies to years (chronic) for
silicosis and occupational cancers.

Note that the present government statistics
do not have this division into three catego-
ties. Present statistics are divided into
injuries and illnesses.

Most of the cumulative trauma problems

are in the illness category although back
problems are considered injuries. Figure 2

336

shows how cumulative trauma has become
a larger percent of reported illnesses.

Table I gives, for agriculture, injury and
illness statistics for 1988 (last data
available). A key point is that, although
cumulative trauma is increasing in impor-
tance among illnesses, total injury cases
(per 100 workers) are about 20 times more
frequent than total illness cases.

ERGONOMICS FOR AGRICULTURE

As pointed out in the previous section, the
major problem of safety and health is
safety. Although ergonomics has a broad-
er orientation than just safety, two ergo-
nomics concepts will be discussed in rela-
tion to safety.

Table |. injury and illness statistics per 100 full-
time workers for agriculture in 1988.”

Agricultural. Forestry
Production Services

4 Vv v
Injury
Total cases 11.7 9.2 11.9
Lost workday cases. 6.1 5.0 6.3
Non-fatal cases with-
out lost workdays 5.6 4.2 5.5
Lost workdays 108 91 136
ilIness
Total cases 0.54 0.45 0.47

ES

Focus on unsafe conditions, not unsafe
acts. Most accidents and injuries can be
considered to be a result of either unsafe
acts or unsafe conditions. For example:

¢ A farmer is injured when a tractor tips

over on a Slope. The injury could be con-
sidered to be from the tractor having a

Papers and Proceedings
Ergonomics, May 1, 1991

 

  
 
    
   
  
 
 
 
   
  
 
 
 
 
 
   
   
  
 
 
 
   
 

McCarthy et al.*, after reviewing 400 papers, reported that there is very little evidence that
warnings work—that is, change behavior. Any cigarette smoker emphasizes this point. There are
literally thousands of warnings about the dangers of smoking. Yet, people continue to smoke.
The acronym Present, Read, Understand, Memory, Act, Effective (PRUMAE) points out some of
the challenges.

P (Present): The warning must be present. If the warning is in an instruction manual, which
has not been seen, the warning cannot work. If the warning originally was a label on a machine
but the label is gone, there is no warning.

R (Read): The next problem is to get the warning read. People find many excuses not to
start reading material. (If all else fails, read the instructions.) If they start, they often skip many
parts of the text. We are surrounded by a barrage of messages in newspapers, TV, billboards,
etc., and learn to filter them out. Most injuries concern rare events so there is no reinforcement
from not following the warning. (Remember how in “Peter and the Wolf," Peter ignored repeated
warnings about the wolf and nothing happened to him for a long time until the last time.) Try to
make the warning “stand out" of the background.

U (Understand, comprehend): The reader may not understand the warning language
(e.g., a Mexican reading English). Even if the reader "knows" the language, the words may be
‘too big." Pictographs are an attempt to reduce this problem. Unfortunately, some of them are
as intelligible as written Chinese. That is, pictographs are another language that you may not un-
derstand. Understandability can be improved with grammar and layout of the message. The
warning can be divided into four statements: signal, hazard, consequence, instruction. For
example: "DANGER, HIGH VOLTAGE WIRES CAN KILL, STAY AWAY*: or "WARNING, CON-
TAMINATED WATER, ILLNESS MAY RESULT, DO NOT DRINK." The “hazard” statement is the
most important. The “Signal” word and the “Consequences” may be redundant information to
informed users.

M (Memory): Once motivated to input the information to the brain, the person now must
commit it to long-term memory. Then, upon need, retrieve it. Easier said than done.

A (Act): Upon retrieving the information from the brain, the person now must translate this
into action. An important point is the cost of compliance. For example, complying with a
warning "Don’t use broken door” was 94 percent if another door was adjacent, 6 percent when
another door was 50 ft. away, and 0 percent when another door was 200 ft. away. Reducing the
cost of compliance (reducing the cost/benefit ratio) should improve compliance.

E (Effective): The person then needs the necessary ability to do the desired behavior and
then the skill and training to do it effectively.

 

For a warning to work, all six steps must succeed.

 

 

Box 1. Warnings.

Surgeon General’s Conference on Agricultural Safety and Health - 1991 337
Intervention - Worker Protection from Environmental Hazards

high center of gravity or from an unsafe
act of the farmer (farmer makes too sharp
of a turn).

¢ A farmer is injured on a power takeoff.
The injury could be considered due to an
inadequate guard or an unsafe act (farmer
fails to maintain the guard).

* A farmer falls from the second floor of a
barn. The injury could be considered due
to an inadequate railing or an unsafe act
(farmer tripping over tools on the floor
near the edge).

To reduce future accidents and injuries,
the best approach is to consider all acci-
dents as due to unsafe conditions. That is,
the "machine" is at fault. The "machine"
should adjust to the "man," not the con-
verse. If the man had "problems," then the
"machine" or procedure should adjust, not
the man.

Psychologically, the "machine is at fault"
approach results in a positive approach to
solving the problem. If a "man is at fault"
approach is used (i.e., the accident was due
to an unsafe act), the problems of chang-
ing human behavior seem so overwhelming
that often nothing is done.

There is a need for research on how to get
people not to commit unsafe acts. Why do
people do things that they know are un-
safe? And, an even more difficult problem,
how can their behavior be changed?

FOCUS ON DESIGN RATHER THAN
USE TRAINING OR WARNINGS

A safety challenge can be reduced by
warnings, training, or design. For example,
a farmer could fall into a silo. One possi-
bility is to warn the farmer against falling
into the silo. The second possibility is to

338

train the farmer not to fall into the silo.
The third possibility is to redesign the
procedure or machine to prevent falls.

¢ Warnings

Box 1 discusses warnings in more detail?
The key point is that warnings do not work
well. Many things have to occur for the
warning to work.

Another problem with a warning is that it
is a temporary solution, not a permanent
solution. That is, each person exposed to
the danger must be warned and the warn-
ing must be repeated over time, or it is
forgotten.

¢ Training

Training can be effective, but it is expen-
sive since everyone exposed to the danger
must be trained. It is difficult to give
training to "visitors" and "bystanders."
Another problem of training is that it is
temporary and must be repeated over
time, or it is forgotten.

¢ Design

Designing out the problem is the best
approach because it is a permanent solu-
tion. For the silo problem, design solu-
tions might be a safety harness or railings.

It may help acceptance of design solutions
to focus on the annual capital cost rather
than the initial capital cost. For example,
railings may cost $500 but then last 25
years. Give the cost as $20 per year rather
than $500.0

Papers and Proceedings
Ergonomics, May 1, 1991

REFERENCES

1. Konz, S. The Rise of Ergonomics, Proceedings of the Int. Ergonomics and Safety Conference. Cincinnati,
London: Taylor and Francis, 1989.

2. Occupational Injuries and Illnesses in the United States by Industry, 1988 (Bulletin 2366). Bureau of
Labor Statistics: Washington, Supt. of Documents, August 1990.

3. Konz, S. Work Design: Industrial Ergonomics. 3rd edition, Scottsdale, AZ: Publishing Horizons, 1990.

4. McCarthy, R., Finnegan, J., Krumm-Scott, S. and McCarthy, G., Product Information Presentation, User
Behavior, and Safety. Proceedings of the Human Factors Society. 84—85, 1984.

Surgeon General’s Conference on Agricultural Safety and Health - 1991 339
Surgeon General’s Conference on Agricuttural Safety and Health
FARMSAFE 2000 ¢ A National Coalition for Local Action

Convened by the National institute for Occupational Safety and Health
April 30 - May 3, 1991, Des Moines, lowa

PERSONAL PROTECTIVE EQUIPMENT

By Richard A. Fenske, Ph.D, M.P.H.
Associate Professor, Industrial Hygiene Program
University of Washington

 

Dr. David S. Pratt: The next speaker Is Dr. Richard Fenske. Dr. Fenske received both his Master's in
Public Health and his Ph.D. from the School of Public Health at the University of California at
Berkeley. Following his preparation there, he spent six years on the faculty at Rutgers University In
New Jersey and worked with the Agricultural Experiment Station in New Jersey. Recently, and i must
say to the lament of the agricultural community of New Jersey, Richard has left and Is now with the
University of Washington, School of Public Health and Community Medicine. Dr. Fenske is going to

 

talk about Persona! Protective Equipment. Dr. Fenske:

 

 

I am going to talk about—and I was a little
daunted by being the only person to talk
about a subject this broad—personal pro-
tective equipment. I have done research
in this area, but as all of us who do re-
search know, we know a lot more about
the particular problems that we have stud-
ied than the general issues that might be
raised by all of the farming activities in the
United States.

As a result, this talk is going to focus more
or less on applicators and, perhaps, field
workers and their exposure to pesticides
and the use of protective equipment under
those circumstances as opposed to, say, the
use of such equipment in silos or in swine
confinement and all the other kinds of
activities that are involved.

The pesticide application problem and the
residue problem with harvesters tend to
be, in some sense, generic—not that there
are not differences across the regions. The
processes have some similarities, and we
are able to make some general statements
about the use of personal protective equip-
ment during these kinds of activities,

340

WORKER PROTECTION STRATEGIES
IN THE AGRICULTURAL WORKPLACE

I am going to start out by discussing a lot
of options other than personal protective
equipment. In industrial hygiene and in
occupational health in general, we tend to
talk about controls of exposure or hazards
in terms of a hierarchy that involves engi-
neering, administrative controls, and per-
sonal protective equipment.

This hierarchy is actually explicitly ad-
dressed in the Occupational Safety and
Health Act, and this point has already
been made earlier—that the best solution is
to engineer the hazard out of the process,
if we can do that. Increasingly, regulators
have turned to personal protective equip-
ment because given the kinds of risk as-
Sessments that are being produced for
pesticide applicators and field workers,
under current practices, it would appear
that many compounds could not be
registered if we were not using personal
protective equipment.

I am going to be a little bit critical of this
point of view, but at the same time sympa-
thetic to the dilemmas that are faced by
regulators and by farmers who have a

Papers and Proceedings
pressing need for certain chemicals to be
registered at the present time. Let us go
through these options before we get into
our main subject.

Engineering Controls

Regarding engineering controls: we have
already had some examples of closed mix-
ing and loading systems. I think this is an
understandable concept. If we can avoid
direct contact of the worker with chemi-
cals, we are going to reduce the hazard.

We can have applications conducted with
closed tractor cabs. If these types of sys-
tems are used properly, they do tend to
reduce exposure among the workers. We
can also have changes in the way in which
we conduct the applications.

Quite a bit of research is going on in the
way of agricultural engineering, attempting
to get more of the material on the target
and less as drift and on areas of the envi-
ronment where we are not interested in
having the compound. We can also make
innovations in formulation.

Microencapsulation comes to mind as a
good example of a formulation technology
that gets the active ingredient out there,
but in a much less hazardous form. So
there are many opportunities, if we are
creative, to reduce the hazard before we
ever have to worry about personal protec-
tive equipment.

Administrative Controls

In terms of administrative controls, I think
one that is given a lot of lip service but, I
know from my own experience, does not
get much funding is integrated pest man-
agement. That is selective use of agricul-
tural chemicals and the use of other kinds

Surgeon General's Conference on Agricultural Safety and Health - 1991

Personal Protective Equipment, May 1, 1991

of pest management processes. This, obvi-
ously, reduces the hazard of chemical ex-
posure.

I might add to this list alternative cultiva-
tion practices. One of the interesting
points in the earlier talk had to do with
the evolution of farming practices, from
subsistence to specialization. With that
specialization comes the need to use in-
creased amounts of chemicals, given mono-
cultural agricultural systems.

I think a lot of farmers actually are taking
a second look at this. Mixed cultivation,
rotation of crops and such, is a means of
reducing the use of chemicals. It is
cost-effective in some cases, and it certain-
ly reduces the hazard.

 

So there are many opportunities, if we
are creative, to reduce the hazard before

we ever have to worry about personal
protective equipment.

 

Product substitution: EPA is trying to find
safer substitutes for the kinds of com-
pounds that we use in the agricultural
work place, but given the review process
and the complexities of the regulatory pro-
cess, we know this is very difficult. Also,
at this stage in the game, to create a new
chemical, a chemical manufacturer has to
invest literally tens of millions of dollars
prior to that compound coming onto the
marketplace.

It is a very risky game at this stage for
chemical manufacturers, and we have seen
a thinning out of the industry. A number
of agricultural chemical companies have
disappeared from the scene in the last five

341
Intervention - Worker Protection from Environmental Hazards

to ten years because of this kind of pres-
sure,

Of course we have worker education and
training, something I think is being dis-
cussed quite a bit in this (conference). We
are going to talk a little bit more about
how important that is for personal protec-
tive equipment. It is a control that can be
exerted to reduce hazards that can be
quite effective. Of course, when you are
talking about agricultural field workers,
people who enter fields that have been
treated and may come into contact with
the residues, we do have a formal ad-
ministrative control called a re-entry inter-
val. I believe, EPA is changing the name
of the reentry interval to restricted entry—a
period of time during which no one is
allowed into a field so as to allow residues
to decay to an acceptable level as judged
by a risk assessment process.

Personal Protective Equipment

Our third and, one should say, final resort:
In general in industrial hygiene, it is con-
sidered that personal protective equipment
is the final resort and also a temporary
resort.

No one may consider that temporary may
mean years of time to bring a new engi-
neering control into the marketplace to
avoid the use of these things, but I think
philosophically we need to treat personal
protective equipment as a stop-gap mea-
sure, however necessary it may be today,
and try to look beyond the use of this
equipment to some process that does not
require the need for this equipment.

The first question to ask about personal

protective equipment is, "Can we make
equipment that does the job?" I think the

342

answer is—with American ingenuity behind
us—yes, we can. We have seen it done.

For workers conducting some mechanical
operations on the moon, their protective
equipment is doing a very good job of
protecting them from absolutely nothing.
In this sense that is profound, for without
these suits there would be a hazard, in-
deed.

We put these same kind of suits on work-
ers right here on earth. If you can imagine
yourself working for eight hours a day
under these circumstances, I think you can
immediately see some of the problems
associated with protective clothing. Cum-
bersome, etc. We will detail some of
these.

Now, in the agricultural work place, unfor-
tunately a farmer’s view of farm work is
this. I point out this fellow who is dressed
like a true westerner. This is a picture in
South Dakota. (Slides are not illustrated.)

My experience in working with farmers
throughout the United States is that this is
their image of themselves, not of the previ-
ous slide of a hazardous waste worker or
some other kind of specialist in chemical
hazards, because the use of agricultural
chemicals, which are acutely or chronically
toxic, is only one relatively small part of
the job of being a farmer. I think we have
some farmers in the room who can attest
to that.

These workers would much prefer to be
dressed like this during their work, or with
short sleeves, or whatever and leather
boots: all the things we tell them they
cannot do when they are working with
pesticides. That is the reality, and I think
it is quite a legitimate point of view. I

Papers and Proceedings
would rather work like this than work in
the kind of gear that I showed you before.

Now, we can dress workers up to wear
equipment, and they can use it properly.
That is clear. We have gloves; we have a
nonwoven coverall; and we have a mixing
process here going on. But we know that
lots of workers would rather dress like this
when it is 90°F, 90 percent relative humidi-
ty in Florida, in July.

You can see the open shirt, no gloves, no
rubber boots—just jeans. Mixing. Loading.
Exposure under these conditions with an
open loading system like this is inevitable.
The issue is a balance between protection
and comfort. It is very hard to persuade
workers in these environmental conditions
that protection is more important than
comfort.

We can get workers to put on suits, but
sometimes they do not wear their gloves.
In some cases we can get people just load-
ing, putting on their respirator but seeming
to be totally oblivious to the fact that some
of these compounds go through the skin
and the dermal route of exposure is a very
important one.

Here we have someone dressed in his
street clothes with no gloves, loading
50-pound bags of an organophosphate
insecticide—I might add with the propeller
blade running. I use this in class. How
many things are wrong with this picture?
So we do have problems in education and
communication, in awareness of hazards.

Here we can have someone who looks like
he is dressed up just about as well as we
are going to do it: rubber gloves, a full
coverall, respiratory gear, some kind of cap
anyway—but then we find him doing some

Surgeon General’s Conference on Agricultural Safety and Health - 1991

Personal Protective Equipment, May 1, 1991

strange things. He only wants to use a
portion of his bag.

He has ripped open the bag, measured out
a wettable powder in the breeze, and
turned out to be the highest-exposed per-
son in the study we were conducting, de-
spite all his protective gear on. He is
doing something that he should not be
doirig, but no one is going to go there and
enforce any regulation on him.

Then we have people right here in the
state of Iowa who will tell me that since
they are just mixing an herbicide, and it is
not toxic—and they mean acutely toxic, of
course—that they do not need to wear
gloves or protective clothing.

Then we have people out on the bean
buggies spraying herbicides in the soy bean
fields who are dressed without a thought to
personal protection. Here we have to
consider that this young woman is a pesti-
cide applicator who is trying to get a sun-
tan at the same time, working quite a bit
at odds with our idea of personal protec-
tion from skin exposure.

We have a wide range of people to consid-
er and to protect, and we shduld remem-
ber—I think it is obvious from this confere-
nce’s emphasis—but these children are
pesticide workers. They are agricultural
workers too, exposed to pesticides in the
fields behind them.

They are ready to go out and do some
harvesting and will inevitably come into
contact with pesticide residues. All of
these people in some way or other have to
be helped, and protective clothing is not
necessarily going to do the job.

343
Intervention - Worker Protection from Environmental Hazards

PERSONAL PROTECTIVE EQUIPMENT
Limitations

Here are some of the limitations that I see
as important for using protective equip-
ment. In general, whatever it is gloves,
Tespirators, or these whole-body gar-
ments—it is uncomfortable. That decreases
your ability to do and enjoy the work that
you are supposed to be doing.

If you are wearing a respirator, it puts
Stress on your respiratory system, which
can be a problem. You lose dexterity
when you use gloves.

A whole-body garment that is nonwoven
cannot breathe, and can cause heat stress.
All of these things are very well known,
but I am recounting them because I think
they are all important to keep in mind.

Use Requirements

Some people would argue that it is easier
to use protective equipment than to do the
administrative or engineering control. In
fact, if you have a good protective equip-
ment program, it is not easy at all. You
have to deal with training your personnel.
That is not a one-time thing. It is a con-
tinuous process.

You have to determine that people are
using the equipment you have given them,
using it properly. The equipment has to
be maintained.

Somebody has to be made responsible for
the maintenance. Is it the worker? Is it
the employer? Who takes care of this?
Equipment has to be replaced.

A judgment has to be made about when it
is replaced. That judgment is often made

344

on the basis of economics rather than on
the basis of safety. We have a whole host
of things where is unclear whose responsi-
bility it is for all of these items. That is a
problem in itself.

Selection Criteria

Let us look at respiratory protection first
and then we will go to other kinds of pro-
tection. When a respirator is required on
a pesticide label, a process has gone on at
the regulatory level.

A toxicological evaluation of a particular
compound has been conducted. A permis-
sible exposure limit has been calculated.
To some extent, an estimate of what peo-
ple are actually exposed to has to be gen-
erated. If it appears that one needs a
respirator—that the hazard is sufficient to
require a respirator—then it has to be de-
cided what kind of respirator deals with
the particular associated hazard.

Is it an aerosol? Is it a vapor? Are we
talking about large dust particles? This all
is a complicated regulatory process, but we
have it pretty well worked out.

Respiratory Use Requirements

Now, at the use level, there are some very
important things to remember, and again,
they complicate the use of protective cloth-
ing. When someone is using a respirator
and conducting labor, they need to be
tested in terms of their respiratory capacity
to make sure that that respirator is not
going to put excessive stress on them. The
issue of fit testing, which is commonplace
in industry in a work place that is well-def-
ined and may have an industrial hygienist
on staff, is very problematic out in the
agricultural work place.

Papers and Proceedings
Who does the fit testing? Most farmers do
not know how to do fit testing. Fit testing
actually can become quite a sophisticated
process. My experience is that there is no
fit testing in practice going on in agricul-
tural workplaces. So, if the respirator does
not fit, it is not an effective means of re-
ducing hazard.

Then we have the inspection and
maintenance of this equipment. Most
farmers and farm employees are not ina
position to decide if a respirator is no
longer in good condition.

Finally, one problem with the kind of car-
tridges that are traditionally used on pesti-
cide respirators, for example, is that you
never know when they are saturated. They
have a finite capacity, and a lot of farmers
change them once a season.

Some do it by smell, which is a real prob-
lem because the hazard usually occurs
prior to the odor threshold. We do not
have a good system for that.

All of the responsibility for these things is
placed on people who are very busy doing
something quite different; they are produc-
ing food. They are dealing with crops.
They are mechanics.

They are all the other things that we have
talked about, and here they are also having
to be experts and specialists in protective
clothing evaluation. It is a big problem in
terms of a realistic expectation that we
place on people.

CHEMICAL PROTECTIVE CLOTHING
If we turn to what I am calling chemical

protective clothing, where we are talking
primarily about garments that cover the

Surgeon General’s Conference on Agricultural Safety and Health - 1991

Personal Protective Equipment, May 1, 1991

skin and attempt to put a barrier between
chemicals and the skin.

Regulatory Selection Criteria

We go through a similar kind of regulatory
selection criteria with a toxicological evalu-
ation and exposure scenario, making sure
that the particular material matches the
kind of exposure. There is an infinite
variety of combinations of material and
hazards. One material is fine against one
chemical, but is readily penetrated by an-
other. EPA has worked on a very compli-
cated process in the last few years, but
they would be the first to admit that there
is a lot more that needs to be done.

Cost and availability: A lot of farmers do
not know what is out there. Also, it looks
like it has a pretty high price tag, especial-
ly the nonwoven coveralls that have be-
come popular.

They are supposed to be throw-away gar-
ments. It is very tempting not to throw
those garments away but to use them over
and over again, because they can be ex-
pensive.

Worker acceptance: It is fine to give a
worker one of these garments, but he may
not be wearing it if he is under your super-
vision. Once he is out of sight he may not
be wearing this garment properly. We
have seen plenty of evidence of that out in
the field with zippers pulled down, cover-
alls with the top part tied around the waist
~—all sorts of ingenious ways of keeping
cool under the kind of work that these
workers do.

Testing

If you are interested in research for a
lifetime here is an area where there is

345
Intervention - Worker Protection from Environmental Hazards

plenty of work. We have all agreed that
there is no such thing as an impermeable
garment, and it is a very important concept
to get across.

This breakthrough is a function of time.
Some garments may be impermeable for
days or weeks, but they are not infinitely
impermeable, and breakthrough time has
become a primary criterion for testing
garments.

We have standard laboratory tests, which
are actually quite good for testing break-
through times. Whether this simulates
field conditions or not—actual use
conditions—is open to question. We only
have limited field performance tests, and
we need more of that kind of work if we
are going to say to farmers, "Wear this
garment. It will reduce the hazard that
you face." I think there is a serious ques-
tion at this point as to whether we can
make that statement or not for very many
garments.

FIELD PERFORMANCE EVALUATION
Orchard Applicator Exposure

What I would like to show you is some
work that we have conducted down in
Florida the last few years—a very short
summary of it—that gives you a couple of
examples of why I am expressing skepti-
cism about the use of chemical protective
clothing. We conducted a study under
EPA sponsorship in the citrus orchards in
Florida.

But this is the kind of application process
called an air-blast applicator—a trac-
tor-pulled rig that has 1,000 gallons of
material that is sprayed to basically satu-
rate these trees to provide complete cover-
age. It is a very high exposure potential

346

situation for the worker who is sitting
there in an open cab and can end up tak-
ing a shower.

We were specifically testing a couple of
nonwoven coveralls to see if they could
improve the situation for these workers.
Workers did not like them very much, but
they were willing to wear them for our
half-day study period. We found some
problems with these garments very quickly.

They were not designed to step on and off
tractors. One gentleman, within 30 min-
utes of wearing this garment, ripped it. He
is about 40 minutes from his home base.
So if he does not have any spare clothing,
he has a problem. He has less protection
than he would have had had he just been
wearing his regular clothes.

Another fellow had the same problem. He
was reaching up to work some equipment.
It turns out that these garments do not
have a lot of play in them. They are used
to working in cotton, so maybe this is a
problem that can be addressed eventually,
but it certainly was a startling one for us to
see for these workers.

We use a technique that introduces a fluo-
rescent material into the spray system and
then allows us, under black lights and
darkened conditions, to see patterns of
exposure on the skin. We saw some inter-
esting ones here—and unexpected ones.

Here you can see that this worker was not
wearing gloves and there is material on his
hands. This person was wearing a long-
sleeved garment and look at this material
that goes up here. You can see the mate-
rial goes all the way up to the elbow, and
yet he is wearing a longsleeved garment.

Papers and Proceedings
This person is even more impressive. We
had material on his hands, quite a bit on
the forearm. Here is the elbow. Material
went up the elbow. We actually saw mate-
rial down around the armpit of this work-
er—material that was being blown right up
the sleeve of these garments.

I do not know if you noticed in the previ-
ous slides, but these garments have rather
large sleeves. They are made as
one-size-fits-all.

Of course, having an open sleeve allows a
certain amount of ventilation, since the
garment does not breathe, but it also al-
lows a lot of material to be blown right up
the garment and onto the skin. We also
saw cases of actual breakthrough of these
garments.

You can see here material that went down
through the neck, but here is material on
the upper arm that was quite isolated and
was evidence that the garment had broken
through—and this was in about a two-hour
spraying period. He might wear this gar-
ment for eight hours a day. So the
breakthrough is happening relatively early.

When we use this fluorescent technique,
we develop an exposure score when we
attempt to quantify this. I show you this as
a baseline for four types of garments: a
work shirt, a woven fabric that is a cotton
coverall, and two different types of
nonwoven fabrics that we were testing.

We measured the exposure to the head,
and we saw that, more or less, these work-
ers were getting the same type of exposure.
We had controlled the conditions, and we
expected to see this. This more or less
confirms it. This is the head exposure, and
you can see that it is substantially higher
than the exposure to the torso—the trunk

Surgeon General’s Conference on Agricultural Safety and Health - 1991

Personal Protective Equipment, May 1, 1991

of the body. But, again, the exposure in
this region seems to be very similar.

Look what happens when we take a look
at the forearms, which are the white bars,
and the upper arms, which are these other
bars. We have an actual increase in expo-
sure as we move from a work shirt up to
these nonwoven garments. That is simply
a quantitative verification of what you saw
in those slides.

In the cases where people were wearing
these nonwoven garments, sleeve openings
allowed substantial material to move up
and deposit on both the forearms and the
upper arms. You can see the same trend.
So, actually, the woven garments proved to
be more protective under these particular
conditions.

Now, you can seal up the sleeves and you
can prevent these problems, but unfortu-
nately most of the garments are designed
without any kind of seal on them; and
most farmers are unaware of this kind of
problem.

When we looked at exposure to the thighs,
using patches above and below the cloth-
ing, here again we found something very
interesting. Although for the work shirt
material—I guess this was for the tor-
so—there seemed to be a little bit more
penetration. We could not make any dis-
tinction, between the cotton coveralls and
the nonwoven coveralls.

What is important is that all of these gar-
ments were breaking through. There were
measurable residues of pesticides
underneath virtually all of these workers
after a two-hour application period, and
that is a small fraction of their normal
application period.

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Intervention - Worker Protection from Environmental Hazards

The problem that I see, and I am going to
illustrate it with another study, is that the
workers believe, because we tell them, that
they are receiving protection by wearing
these garments. This study at least sug-
gests that under these particular condi-
tions, they were not receiving any greater
protection, and for the arms they were
actually receiving less protection than if
they had been wearing cotton garments.

So our conclusions from that study were
obvious:

1. Nonwoven fabrics tear.

2. The garment design is the problem in
terms of the arm exposure, all of these
garments exhibit penetration.

3. These are important findings in terms
of trying to evaluate these clothing ar-
ticles realistically.

Greenhouse Applicator Exposure

The second study had to do with
greenhouse application and was funded by
NIOSH. We had a problem that we did
not anticipate. We were traditionally look-
ing at the applicator as spraying an aero-
sol. We were worried about the aerosol
deposition. Would it penetrate the cloth-
ing?

We ran into a different problem—that the
foliage in these greenhouses overhangs the
benches. The worker comes into contact
with that foliage, and we knew from other
studies that the clothing gets some contam-
ination on it. Here is a worker spraying in
a greenhouse wearing blue jeans and a
workshirt, and he is brushing up against
that material when he bends over the
bench.

348

We did our fluorescent tracer technique,
and this is a real useful slide for male
workers, when you point out to them ex-
actly where they are getting exposed. It
motivates them to think about what they
are doing.

Also, if they wear this clothing home, this
becomes their lap, and that is where their
child sits. When you tell them this, they
really do think about it, and we have seen
some startling changes in behavior.

I think what we found that was even more
interesting is that when you have a worker
dressed up in one of these garments that is
nonwoven and is advertised as protective,
we see a breakthrough within one hour of
spraying. These are the knees and the
material is clearly associated with the
height of the bench and the foliage where
the contact is occurring.

You can see that it was very extensive,
virtually all the way up to the top of the
thigh, down to the knee, and halfway down
the leg on both the front and the side of
both of the thighs. This is a substantial
body surface area, and when we talked to
the worker about this, he had no idea that
this breakthrough had occurred.

He is wearing basically a plastic garment.
He is sweating underneath that garment.
He is unaware that there is moisture tra-
versing that garment and contaminating his
legs.

We stopped him after one hour. He nor-
mally sprays three or four hours a day and
uses this same garment all day and tends
to use one garment for three days before
he throws it away. This breakthrough is
occurring in less than one hour. We clear-
ly had a problem; the greenhouse where

we did this work has certainly made some

Papers and Proceedings
changes in terms of the protective clothing
that they offer their workers. They were
quite happy to find this out.

Our conclusions were that:

1. There is a particular hazard of contact
with wet foliage.

2. The breakthrough can happen relatively
quickly.

3. Workers are unaware of the break-
through.

Unfortunately exposure is a very compli-
cated issue. Unless we do these kinds of
field studies, which tell us which clothes
perform in what way under what particular
conditions, it is difficult for us to give good
advice to farmers regarding the use of
chemical protective clothing.

AGRICULTURAL WORKER
PROTECTION STRATEGIES

To sum up, I think that we can look at the
problem in two different ways.

Adapt the Worker

We can adapt the worker to the work
place—and in the greenhouse, unfortunate-
ly, given the economic constraints, we
cannot convince greenhouse growers to
move their benches further apart. It is
very expensive to operate a greenhouse,
and they want as many plants in that build-
ing as possible.

So, the worker is going to come into con-
tact with that material. That is an example
of where we cannot adapt the work place.
The worker is going to have to somehow
adapt to the work place.

Surgeon General’s Conference on Agricultural Safety and Health - 1991

Personal Protective Equipment, May 1, 1991

Adapt the Work Place

There are, however, opportunities to adapt
the work place to the worker. I would
suggest as a general strategy that we think
about it in these terms.

I think the commercial applicator whose
livelihood depends on this and who, in a
sense, becomes through practice an expert
at the use of hazardous chemicals, is a
legitimate candidate for requiring protec-
tive clothing and requiring a high level of
training, knowledge about the use of the
clothing and such—all the ingredients that I
talked about that make personal protective
equipment so complicated.

When it comes to these other groups—the
owner applicator, our family farmer whom
we talked about, or the worker who occa-
sionally applies but is doing 90 other things
on the farm, or the agricultural field work-
ers who are walking into a field after
spraying has been conducted and are as-
suming that it is safe because their employ-
er told them they could—we have to devel-
op, long-term strategies to adapt the work
place to those workers to create a safe and
healthy working environment for them.

We are a long way from that, I admit, and
protective clothing can, under particular
circumstances, serve an extremely useful
role. I do not think it is going to serve us
as a long-term strategy.

I am quite hopeful that with the kind of
work that we have talked about in this
conference and the kinds of initiatives that
NIOSH has taken recently, we are going to
see more work directed at solving some of
these problems higher up on the scale—that
is in the engineering and administrative

349
Intervention - Worker Protection from Environmental Hazards

sides—so that we can ultimately reduce our
reliance on personal protective equip-
ment.O

QUESTIONS

George Cook: I am George Cook, University of Vermont Extension System. Those slides showing the
breakthroughs through this supposedly protective clothing—are there any recommendations as far as what
people should use?

The EPA has spent the last five years developing a document for their use in terms of recommending
personal protective equipment to users. I think EPA is going to have a data base that is primarily based on
laboratory data but also a review of field studies. That is going to be our best evidence, Unfortunately, the
answer to your question is that there are no guarantees that the use of this material that has been tested
under particular circumstances may or may not be appropriate under other circumstances.

Thomas Seymour: Could you describe the fluorescent material you added into the material, as to its particle
size and so on? Did it enhance penetration or permeation, or do you know, in looking at some of the
material tests, whether it had any effect one way or the other on the performance of the material itself?

Dr. Richard Fenske: Well, we have not extensively tested that particular tracer compound with materials in
a laboratory setting. We have done quite a few field studies with it. It is a fluorescent whitening agent that,
in some cases in the past, has been added to plastics to make them bright or to laundry detergent. It is a
powder. It is partially soluble in water. We mix it into the aqueous system. The fluorescent material and
the active ingredient of the pesticide are being sprayed onto a surface, and we can only confirm that the
pesticide penetrates through these garments by doing chemical analysis with samples underneath the
garment. We have done such and found the pesticide. It is not necessarily true that this is an exact sur-
Togate foi any particular pesticide. We have approached it more from a generic point of view. But we have
confirmed repeatedly that when we see this material going through a garment we, indeed, can find the active
ingredient under that garment as well,

(inaudible): You are taking a sample of the material (inaudible) material (inaudible) pesticide (inaudible)
look at how it penetrates as a mixture. Is here any synergism there to actually enhance permeation or is
here any difference (inaudible) breakthrough (inaudible)?

Dr. Richard Fenske: That is certainly worth investigating. It has had a rather low priority because the con-

centrations we are using are very low. I think from a chemical point, having spoken with chemists about it,
there was no feeling that there would be that kind of a effect.

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