occupational medicine

1. Occupational
disease induced
by physical
factors

2. Temperature
working in a hot environment- humans maintain
normal body temperature by perspiring and by
increasing the blood flow to the surface of the body.
large amounts of water and salt lost in perspiration
and need to be replaced. In the past, miners who
perspired profusely and drank water to relieve their
thirst experienced intense muscular pain—a
condition known as miner’s cramps—as a result of
restoring their water but not their salt balance. When
salt was added to their drinks, workers no longer
developed miner’s cramps.

3. Heat exhaustion
Characterized by thirst, fatigue, muscle
cramps and fainting. Heatstroke, sometimes
lethal condition, results when prolonged
exposure to heat and high humidity
prevents efficient perspiration (by
preventing evaporation of sweat), causing
the body temperature to rise above 41° C
and the skin to feel hot and dry. If victims
are not quickly cooled down, coma,
convulsions, and death can follow.

4. Cold environments
Work in cold environments may also have serious
adverse effects. Chilblains, frostbite, or the freezing of
tissue, can lead to gangrene and the loss of fingers. If
exposure is prolonged and conditions (such as wet or
tight clothing) encourage heat loss, hypothermia may
result. physiological processes are slowed,
consciousness is impaired, cardiorespiratory failure,
and death may occur. Workers exposed to extreme
cold require carefully designed protective clothing to
minimize heat loss.

5. Atmospheric pressure Decompression sickness (caisson
disease) can result from exposure to
high or low atmospheric pressure.
Under increased atmospheric
pressure, such as that experienced by
deep-sea divers or tunnel workers,
fat-soluble nitrogen gas dissolves in
the body fluids and tissues. During
decompression, the gas comes out of
solution and, if decompression is
rapid, forms bubbles in the tissues.
These bubbles cause pains in the
limbs, breathlessness, angina,
headache, dizziness, collapse, coma,
and in some cases death.

7. Treatment
Emergency treatment of
decompression sickness consists of
rapid recompression in a compression
chamber with gradual subsequent
decompression. The condition can be
prevented by allowing sufficient
decompression time for the excess
nitrogen gas to be expelled naturally.

8. Noise
Occupational noise is the amount of acoustic energy received by an
employee's auditory system when they are working in the industry.
Occupational noise is considered an occupational hazard and can be
present in any workplace. Temporary or permanent hearing loss may
also occur, depending on the loudness, intensity, pitch, frequency,
length, pattern of exposure and the vulnerability of the individual.
Prolonged exposure to sound energy of intensity above 80 to 90
decibels is likely to result in noise-induced hearing loss.

10. Prevention
The condition can be
prevented by enclosing noisy
machinery and by providing
effective ear protection.
Routine audiometry gives an
indication of the effectiveness
of preventive measures.

11. Audiometry

12. Vibration
Raynaud’s syndrome or vibration white finger (VWF), can
result from the extensive use of vibratory hand tools,
especially in cold weather. The condition is seen most
frequently among workers who handle grinders, drills
and hammers. Initial signs are tingling and numbness of
the fingers, followed by intermittent blanching; redness
and pain occur in the recovery stage. In a minority of
cases the tissues, bones, and joints affected by the
vibration may develop gangrene. VWF can be prevented
by using properly designed tools, avoiding prolonged use
of vibrating tools, and keeping the hands warm in cold
weather.

13. Carpal tunnel syndrome
Thumb abduction, in more severe
cases of CTS, where there is
involvement of both motor and
sensory median nerve fibers.