EESA10H3 Chapter Notes - Chapter L#11: Long-Term Memory, U.S. Consumer Product Safety Commission, Trade Secret
5 Jul 2018
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LECTURE 11
MECHANICAL HAZARDS (pg 214-216)
- about 3.5 deaths p/100,000 for work related injuries
- constant vibration from mechanical machinery can damage nerves, constant repetitive
work can cause carpal tunnel syndrome
- greatest fatality rates are in fishermen and logging workers
Noise
- defiend as unwanted sound; from a health perspective, it is defined as sound that can
damage hearing or otherwise harm health
- when sound hit human ear, it follows certiain steps: strike ear drum first translated as
virbration into 3 small bones and then vibrations in the fluid inside an ear structure
called the cochlea cochlea has special cells called hair cells (that are topped with
things called hair bundles) when vibrations cause the cochlear fluid to move, the hair
bundle moves this becomes a physical signal to the hair cell send a nerve impulse to
brain brain interprets the sound
omost damage occurs through the damage of hair bundles (they are typically
upright)
othose that are damaged are flattened this damage is permanent
-decibel: sound intensity measurement unit
othe scale most often used in assessing human perception of env. Noise is known
as the A-weighted decibel scale (dBA) measures sound relative to the hearing
threshold of health young person
volume threshold: the decibel level at which sound can be perceived; it is
diff. at diff. frequencies
hearing loss appears as an upward shift in the threshold at which sound
a certain frequency can be perceived (called a threshold shift)
ohearing loss is caused by noise exposure excessive noise exposure can cause
tinnitus: a continuous ringing, roaring, and other sound in the ears (and is
permanent)
oindustrial noise and smoking have synergistic effects in inducing hearing loss
oindustries w/ high annual incidence of hearing loss at animal slaughtering and
iron foundries
military service as well
Light during the “biological night”
- hours after sunset are well lit and many people were evening or night shifts shift work
causes circadian disruption, which is a group 2A carcinogen (probably carcinogenic to
humans)
ocircadian: the cycles of roughly 24 hours that occur in various physiological
processes, reflecting organisms’ adaptations to the fundamental cycle of day and
night
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Document Summary
Mechanical hazards (pg 214-216) about 3. 5 deaths p/100,000 for work related injuries constant vibration from mechanical machinery can damage nerves, constant repetitive work can cause carpal tunnel syndrome greatest fatality rates are in fishermen and logging workers. Noise defiend as unwanted sound; from a health perspective, it is defined as sound that can damage hearing or otherwise harm health. Noise is known as the a-weighted decibel scale (dba) measures sound relative to the hearing threshold of health young person volume threshold: the decibel level at which sound can be perceived; it is diff. at diff. frequencies. 4. 6 b users globally emit electromagnetic radiation in the microwave range microwave radiation"s potential to cause cancer is active area of research has produced inconclusive results. Devices emit uv-a radiation and some uv-b all types of uv are carcinogenic (uv. Not all exposures to noise are work related worry about kids listening to music at high noise levels and potential hearing loss.
