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Other Lessons:
Physical hazards are environmental hazards which are not chemicals or elements or organisms, but those that you could feel or hear, i.e. those that can be detected by our senses such as temperature.
Environmental temperature can cause serious health effects by increasing or decreasing the body temperature. The body temperature increases when we are in a hot environment such as hot tub and decreases when we are in a cold environment such as a mountain slope.
Following are the factors that increases or decreases body heat.:
Heat
Balance Equation
S
= M + W + R + C + K + E
S
is the change of temperature in the body (loss or gain).
M
is the heat gained due to the metabolic process in the body (as a byproduct of
metabolism).
W
is the heat gained from external work such as physical activity, which leads
to contraction of muscles, producing heat.
R
is the radiant heat exchange rate (if outdoors – taking in warmth from sun,
if indoors then no heat taken in).
C
is the loss of heat due to wind velocity.
K
is the conductive heat exchange rate ( If in a hot tub – conduct heat from
warm water, if fall into the sea – lose heat from the body due to cold
environment)
E is the rate of evaporative heat loss (amount of heat lost during jogging)
The Exposure Table
|
Environment |
Source |
Health Effects |
|
Hot Environment |
Hot tub, Summer, |
Heat
stroke, Heat exhaustion, Dehydration (loss of fluid in the body), Heat
syncope (sudden loss of consciousness related to dehydration), Heat
cramps, Heat rash (prickly heat) |
|
Cold Environment |
Hill station, diving in sea, winter |
Reduced
blood flow to skin, Shivering, Frostbite, Raynaud’s Phenomenon
(occurs in individuals sensitive to cold environment - skin turns
white and often painful. It is a reversible phenomenon, Hypothermia
(body temperature becomes low - this can occur at less than 500
F) |
Would you rather be in an extremely cold or hot environment?
Noise & Vibration
We are constantly exposed to noise of varying degree in our day to day life. Exposure to noise could lead to serious health effects such as hearing loss.
Vibration is the back-and-forth, side-to-side, and up-and-down motion of the body that starts from and returns to the same reference position. Exposure to vibration motion could occur at an occupational setting or during a pleasure trip in ship or car.
The Exposure Table
| Hazard | Source | Type | Properties | Health Effects |
| Noise | Loud noise- diesel engine room, chain saw, jet flyover,
live rock and roll band, farm tractor.
Moderately loud - passenger car, auto traffic near freeway, air conditioning unit, dishwasher, living room music, television, vacuum cleaner. Quiet noise - Rustling leaves, normal conversation |
Acute - a loud noise Chronic - long term exposure to hazardous noise level.
|
Frequency - How often.
Intensity - how loud. Duration - how long each time. |
Annoyance, distraction, interference with oral, communication, cardiovascular disease, hearing loss. |
| Vibration | WBV - traveling in car, truck, ship, or aero plane,
vibration of the building during construction, farming.
HAV - Using chain saw, brush cutter |
WBV (whole body vibration) - The vibration is transferred
to the entire body.
HAV (hands-arm vibration) - affects only a part of the body. |
Frequency -
Low - traveling in a ship. High - |
Performance degradation, tiring, reduced comfort, low
back pain, HAVs – causes blanching of fingers, numbness, and
tingling sensation on fingers |