Figures 5, 6, and 7 show the data for questions 1, 2, and 3 grouped according to whether or not
the subjects had reported past training and experience. The hypothesis tested was that miners with
more experience would report fewer physical and emotional symptoms and would be less surprised at
their reactions during the smoke drill. Experience was measured in three ways: smoke training, smoke
experience and experience with apparatus. In all cases, miners with more experience reported fewer
physical symptoms, less emotional stress, and were less surprised by their reactions. The statistical

significance of the findings is reported based on one-tailed f tests.

Figure 5: Effect of Past Experience on Physical Symptoms

physical symptoms (in %)

by previous smoke training

(NO)1 2 3 4 8 (YES)
physical symptoms (in %)

| Not trained, N=54, mean=2.43,
Hl Trained, N=20, mean=1.65, sd=.75 by smoke experience

oa

(NO) 1 2 3 4 5 (YES)

t=1.98, di

sig.

7] No experience, N=42, mean =2.43, si
HM Been in smoke, N=32, mean=1.94, s

physical symptoms (in %)
by worn apparatus in smoke

(NO) 1 2 3 4 5{(YES)

—_] No experience, N=47, mean=2.51, sd=1.06
Used appartus, N=27, mean=1,7, sd=.91


Discussion

In an emergency situation such as escape under apparatus in smoke from an underground
mine, the stress response is a normal reaction. Placing miners in a realistic simulation as was done by
design in this study, created a stressful situation for these subjects. Their responses to this situation
presented an opportunity to compare individuals having previous experience or training in smoke with
those who had no previous experience or training. The study also allowed for a comparison of reactions

to stress based upon previous experience or training.

The general finding that miners who had more experience or training also tended to report less
stress during the exercise suggests the value of realistic instruction. Thus, the following

recommendations are offered:

. Develop emergency escape simulation training as part of Annual Refresher Training in the
U.S.
. In the training, include information about the human stress response for all mine workers and,

especially, for mine rescue teams.
Additionally, foster an environment in which this type of training can occur. It is suggested that, in
planning procedures for dealing with mine emergencies. mining companies develop relationships and

arrange for collaboration among mine management, community health (including mental health), and

local emergency personnel.

References

Kowalski K [1995]. A human component to consider in your emergency management plans: the
critical incident stress factor. Safety Science 20:115-123.

Selye H [1993]. History of the stress concept. In: L. Goldberger and S. Breznitz (Eds.) Handbook of
Stress Theoretical and Clinical Aspects. The Free Press, MacMillan, pp. 7-20.

Vaught C, Cole H, Wiehagen W. Bmich, M [1990]. Overview of research on mine emergency skills.
Proceedings of the Seventh U.S./Korea Joint Workshop on Coal Utilization Technology. Department
of Energy, pp. 30-51.


had physical symptoms

Figure 1: Question 1. I experienced physical symptoms

of stress such as sweaty palms, increased or rapid

Se heart beat.

(NO}1 2 3 4 s¢vesy

had emotional symptoms

Figure 2: Question 2. I experienced emotional

symptoms of stress such as distress, fear, panic.

surprised by reactions

Figure 3: Question 3. My physical and/or emotional

reactions surprised me.

training about stress

| . 10>
stress should be part of emergency evacuation training. i IP

Figure 4: Question 4. The topic of human response to

(Hoyt 2 3 <5 (veS}


Figure 6: Effect of Past Experience on Emotional Symptoms

emotional symptoms (in %)

by previous smoke training

t=3.71, df=60.86
sig. = .000

=] Nottrained, N=54, mean=2.07, sd=1
FA Tained, N=20, mean=1.35, sd=.59

emotional symptoms (in %)

by smoke experience

t=1.44, df=72
sig. =.078 (No) 2 3 4 5 (YES)

F] No experience, N=42, mean=2.02, sd=1.12

H@  Been in smoke, N=32, mean=1.69, sd=.82

emotional symptoms (in %)

by worn apparatus in smoke

t=2.96, df=72
a” sig. = 002

(NO}1 2 3 4 5 (YES)

~] No experience, N=47, mean=2.13, sd=1.03
Hl Used appartus. N=27, mean=1.44, sd=.80


WORKER RESPONSES TO REALISTIC EVACUATION TRAINING
by C. Vaught,' L. Mallett,' K. Kowalski,’ and M. Bmich?

This paper discusses the data collected during an emergency evacuation training exercise at an
underground mine in the United States. The focus of this paper is on the human reaction to smoke and

the use of personal protective equipment. Specific issues related to the human stress response during an

emergency will be discussed.

Background

From the early days of coal mining in the United States, workers have been taught to barricade
themselves in the event of an explosion or fire underground. Barricades often were constructed crudely
from whatever materials were close at hand, and frequently failed to protect trapped individuals from
the contaminated mine atmosphere. Until the last decade, however, when caught in contaminated air,
miners had few alternatives.

In the early 1980's, though still taught as part of annual refresher training under 30 CFR 48,
barricading became devalued as a survival strategy. The reason for this shift was the universal
deployment of oxygen generating breathing apparatus. These apparatuses, called “self-contained self-
rescuers” (SCSRs) were designed to provide a one hour supply of oxygen which, theoretically, would
allow an escaping miner to reach fresh air. A major effort in taining therefore came to be focused on
proficiency in using an SCSR and knowledge of the mine’s escapeways.

Although escape skills have received much attention in the past 15 years, research has shown
that miners receive little actual practice in survival techniques under realistic conditions (Vaught et al.,
1990). Training tends to be didactic, delivered in the classroom, instead of heuristic hands-on
instruction. As a consequence, miners who must escape a buming coal mine may have to move through
smoke for the first time in their lives, use a breathing apparatus with which they are largely unfamiliar,
and try to find their way out in escape routes that they have traveled infrequently, if at all. All those
factors may add stress to an already stressful situation.

The stress response is a normal human reaction in which the body prepares to fight or to run

when faced with a threatening situation. It is sometimes referred to as the “fight or flight response” and

"Research sociologist.
*Research psycholoyist.
Mining engineer.

Piusburgh Research Center, National Institute for Occupational Safety and Health, Pittsburgh, PA.


Figure 7: Effect of Previous Experience on Surprise to Reaction

reactions were a surprise (in %)
by previous smoke training

= oa

T 7

(NO) 1 2 3 4 5 (YES) t=3.62, df=72
sig. = .001

TJ Not trained, N=54, mean=2.57, sd=1.14

WM Trained, N=20, mean=1.55, sd=.89

reactions were a surprise (in %)

by smoke experience

(NO) 1 2 3 4 5 (ves)

reactions were a surprise (in %)

by worn apparatus in smoke

(NO) 1 2 3 4 S (YES)

No experience, N=47, mean=2.68, sd=1.11
BM Used appartus, N=27, mean=1.83, sd=.97


is regarded as a survival mechanism. Psychosocial (emotional) stressors may be described as
environmental events in which the individual's interpretation is key to triggering the stress response.
Regardless of the source of stress, there are definite physiological reactions such as dry mouth, sweaty
palms, cessation of digestion, the movement of blood to the skeletal muscles, an increase in heart rate,
temperature, respiration, an increase in visual acuity, and other bodily reactions (Kowalski, 1995). All
these reactions prepare the body to fight or to run. Some symptoms may evoke additional anxiety. A
pounding heart, sweaty palms and dry mouth may cause an individual to ask “What is the matter with

me? What is happening to me?” causing further anxiety and reaction.

Research Questions

It is important to note that psychosocial stressors do not directly cause the stress response. The
interpretation the individual affords the stressor determines whether the stress response is initiated.
The issue of individual interpretation is key when we look at controlling or mitigating the stress
response. Are individuals who have had experience with a particular stressful situation more likely to
interpret a potential stressor as more or less harmful? Can training impact the interpretation and thus

the initiation of the stress response?

Research Method

This study centered upon a mock evacuation from an underground mine. Realism was added to
the exercise with the use of nontoxic theatrical smoke and training models of SCSRs. Small groups of
miners were required to don their SCSRs, enter a smoke-filled area, and travel approximately 270
meters to a door through which they exited into fresh air. Individual subjects then provided self-reports
of their experiences on questionnaires administered immediately upon the completion of their walk
through smoke.

The evacuation exercise presented a number of potential sources of stress for the subjects.
First, trainees had to don and wear SCSRs through the exercise. Although all these miners had donned
this equipment in past training sessions, many never had worn the apparatus for more than a couple of
minutes. Second, each person had to walk through theatrical smoke which reduced visibility to less
than “2 meter. Most of the miners had little or no experience traveling through smoke. Another
potential source of stress came from going through this experience with co-workers. These subjects
would continue to see each other and work together after this study was completed. It is therefore likely
that they did not want to appear inept or foolish in front of co-workers. Combinations of these elements
produced stressful situations during this study.

The setup for this field experiment consisted of isolating an area of an underground mine so

that ventilation within the area would be stopped. This was accomplished by erecting two seals


approximately 270 meters apart in a passageway. Each seal had a door through which subjects could
pass. Three smoke generators were placed in the passageway between the seals. “Smoke” was
produced until visibility was lowered to no more than % meter.

The SCSRs were placed on the smoke-free side of the first seal. Several observers were
stationed on the smoke-free sides of the seals to monitor the SCSR donning portion of the experiment
and observe miners’ interactions. Another observer, serving as a safety check, walked through the
“smoke” with the subjects. This safety person stayed within hearing distance of the miners, but well
out of their sight. Small groups of six to nine miners went through the exercise together. During the
exercise, they were allowed to assist and interact with each other if they wished. All the subjects
completed the activity without observer intervention.

After they left the smoke area and removed their SCSRs trainees were asked to complete,
anonymously, a one page questionnaire. Miners’ responses on the confidential questionnaire provided
demographic information and also data regarding their perceptions of the smoke evacuation
experience. Seventy-four miners participated in the ten groups that made up the field experiment. The
subjects were coal miners with an average of 19 years of underground mining experience. The average
age of the group was 43. Twenty-seven percent of them had received some form of prior smoke
training and 43% had experienced real smoke (of varying intensity) in their work setting. Thirty-seven
percent of trainees had wom a breathing apparatus in smoke at some time in their mining career. When
asked if they thought that “the smoke drill training was realistic,” 97.3% responded that it was.

Four questions which directly addressed the issue of stress were included on the questionnaire.
The miners were asked if they had experienced 1) physical or 2) emotional symptoms of stress; 3) if
their reactions surprised them; and 4) if they thought that the topic of human response to stress should
be part of mine emergency evacuation training. They were asked to respond by circling a number on a
scale from 1 to 5 (1=Not at all, 3=Somewhat, and 5=Totally). Results of miners’ responses are shown
in figures | through 4. To simplify the figures, the scales are anchored with No, corresponding to the
response Not at all, and Yes, which corresponds to the response Torally.

A detailed analysis shows that the responses provided to questions 1, 2, and 3 varied, based
upon the miners’ backgrounds. Those who had received prior smoke training, had encountered smoke
underground, or had wom a breathing apparatus in smoke prior to the training, responded differently
from those miners without such experiences. Extent of experience, however, seems unrelated to the
answers to question 4, which asks whether human response to stress should be part of emergency

evacuation training.