overboard and become lost at sea. Drug abuse or
permanent and temporary; headaches; fatigue; and
dependence is not only hazardous to the abuser, but also
to other personnel, to equipment, and to the operational
readiness of the command.
Polydrugs have created still another dimension of
drug abuse. The term refers to the mixing of two or more
drugs. Mixing alcohol with another drug is the most
common form of polydrug abuse. This combination
produces effects that can be fatal.
Fatigue begins when a person starts a task; the
fatigue increases as the task continues. It decreases
awareness and reflex actions while increasing the
chance of error. Symptoms include lower quality of
performance, irritability, impatience, forgetfulness,
confusion, and increased errors. Hard work long hours,
and lack of sleep produce fatigue. In addition, such
stresses as vibration, heat, high or constant noise,
inadequate illumination, anxiety, boredom, monotony,
and change in routine can produce fatigue.
Since motion sickness produces severe nausea, it
can weaken, distract, or disorient people. The most
commonly experienced forms stem from the motions
associated with aircraft, cars, trains, and ships. This
illness is particularly dangerous because it causes a loss
in normal alertness and decision-making abilities. Such
a loss can cause a person to make serious mistakes. Once
the body becomes adjusted to these movements, through
training and adaptation, nausea disappears and normal
Extreme temperatures impair a persons overall
performance, which increases the chances of
inefficiency and mishaps. Heat stress and temperature
extremes cause problems such as fatigue, increased
reaction time, decreased mental awareness, and loss of
dexterity and coordination.
nausea. Each of these effects can impair performance.
We often overlook vibration as a potential source of
decreased work performance, and yet it routinely
accompanies many activities. Very low-frequency,
high-amplitude vibrations can cause motion sickness.
Prolonged exposure to vibration commonly produces
annoyance and fatigue, which can reduce performance
and effectiveness. Exposure to levels of vibration that
produce discomfort can induce permanent physical
damage to the internal organs.
Mishap-free performance requires good visual
acuity. Different problems can affect your vision during
the day and at night. The most common problem during
daylight is glare. Intense light reflected in random
directions causes glare. Glare is hazardous because it
can momentarily blind you. The blindness can continue
for hours until your eyes have had time to adjust to low
levels of light.
Even if your eyes adjust easily, your visual acuity
at night is not as good as it is during the day. Night vision
is extremely sensitive to stray light sources. When your
eyes have adapted to darkness, a sudden flash of light
can blind you, as glare does during the day. These
conditions increase the chances of mishaps.
Mental factors have been cited as causes involved
in numerous mishaps. Mental factors range from just
being in a bad mood to having a serious personality
disorder. Although medical professionals usually
investigate mental factors, all mishap investigators
should look at these factors. In serious mishaps, a
medical officer is assigned to determine physical and
mental causes of human error. Medical records, prior
injuries, responses to stress, and documented
personality disorders are reviewed and investigated.
Unnecessary or unpleasant noise causes stress by
Behavioral factors include actions such as
overloading a persons nervous system. Stress can bring
skylarking, risk-taking, showing off, inattention,
about emotional outbursts. Since emotional outbursts
disregarding instructions or orders, and flaunting
are impulsive and unrestrained, they can result in
authority. Such behavior results when personnel ignore
mishaps. Intense noise can cause hearing loss, both
safe work procedures because of undesirable motives.