Post on 26-Jan-2016
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PHYSICAL PHYSICAL HAZARDSHAZARDS
H.R.Sarreshtahdar, MDH.R.Sarreshtahdar, MD
Physical hazards
Heat
Cold
Vibration
Radiation
Atmospheric pressure changes
HEAT
How does body get rid of heat?
Conduction
Convection
Radiation
Evaporation
Factors affect body temperatureo Air temperature
o Radiation
o Air motion
o Humidity
o Type of clothing
o Time exposed
o Workload
o Age/sex/raceo Mass/weighto Health status
DiseasesDrugs
o Acclimatization status
WBGT index The most important index of workplace
heat exposure
Calculation:
• Air temp.
• Air motion
• Radiant heat
• humidity
Heat Balance
Body response to heat
Peripheral vasodilatation
Sweating
Change in metabolic rate
Increased plasma & fluid volume
Occupational exposure to heat
Outdoor
o Farmers
o Postage workers
o Ranchers
o Military personnel
o Fishers
o Construction workers
Indoor
o Foundry
workers
o Steel workers
o Oven/Furnace
workers
o Glassblowers
Heat-related syndrome
Heat stroke
Heat exhaustion
Heat cramps
Heat syncope
Heat stroke Signs and symptoms:
Cerebral dysfunction and altered mental status Hyperpyrexia (core temperature → 41.1°C) hot, dry skin (classic), or moist skin (exertional) Seizure, coma, tachycardia, hypotension
Laboratory: ↑leukocytes, ↓ serum K, Ca, P, ↑ BUN, CPK, ALT,
AST Concentrated urine with myoglobinuria, pr.uria,
tubular casts Hyperuricemia, DIC, thrombocytopenia
Heat stroke Treatment: Rapid reduction of body temperature: In the workplace:
Shady cool place removing clothes use evaporative cooling (The best method):
spraying entire body with cool water, blowing cool air to the body Or Use ice packs, or water immersion
PreventionPrevention Avoid reexposure to heat at least for 4 weeks
Work-rest regimens according to heat TLV
acclimatization
Engineering controls
Special suits
Shaded rest areas
Cool drinking water or electrolyte/carbohydrate
solutions
Heat exhaustion Strenuous work in hot climates
Volume/electrolyte depletion
Core temperature > 38°C
Symptoms and signs:
Intense thirst, weakness, nausea, headache,
confusion, tachycardia, profuse sweating, moist skin
Important: may progress to heat stroke
Treatment: placing the patient in a cool and shaded
area, provide hydration and salt (oral or IV)
Heat cramp Salt deficiency (replacement of sweat loss with
water) Symptoms and signs:Painful muscle contractions, weakness, nausea,
vomitingMoist and cool skinEuthermiaElevated CPKMove the patient to a cool environment + balanced
salt solutions (4tsp salt per gallon of water)1-3 days rest + salt supplementation
Heat syncope
Sudden unconsciousness after strenuous
work
Cutaneous vasodilation
Cool, moist skin
Hypotension
Treatment:
cooling and liquids
Prevention
Worker selection
Acclimatization
Work-rest cycles
Availability of cool places
Availability of cool drinks
COLD STRESS IN THE WORKPLACE
Body reaction to cold environment
Increase heat generation
Shivering
Decrease heat loss
Vasoconstriction
Risk factors
Alcohol
Opium
CNS depresants
Alpha agonists & antagonists
Direct vasodilatator
Beta antagonists
Cold-induced diseases
Systemic
Local
Freezing
Frost bite
Non-freezing
Immersion foot
Systemic hypothermiaBody core T <35°C
Mild
Moderate
Severe
Treatment
Remove wet garments
Protect against heat loss
Maintain horizontal position
Avoid excess movements
Monitor core temperature
Monitor cardiac rhythm
Treatment Pulse present:
Adequate ventilation and O2 administration Electrolyte and acid-base correction Blood pressure correction Rewarming:
Passive rewarming Active external rewarming (warm blankets, warm baths) Active internal rewarming (blood, peritoneal dialysis,
heated air)
Pulse absent: CPR until core T> 35 rewarming
PreventionPrevention Wind chill index
Temperature Wind velocity
Prevent core T from falling below 36°C Work-rest cycles according to WC index
and work intensity Suitable clothes Wind-protected, warm shelters Available hot food and drinks
FrostnipFrostnipFrostnip is the freezing of upper layers of the
skin.
Characterized by:- white, waxy skin.- general numbness
Frostnip is generally reversible and does no major tissue damage.
Frostnip - treatmentFrostnip - treatmentGently warm area by blowing warm air on it
or by placing it near a warm body part.
DO NOT rub the area! Rubbing can rupture frozen cells, causing extensive damage.
• Frostnip is a warning sign of possible frostbite
FrostbiteFrostbiteFrostbite is a freezing of the surface and
deep layers of tissue.
Characterized by:- white, and feels “woody”- numbness, possible anesthesia- deep frostbite can affect bone and muscle- purple/black color is from ruptured blood vessels
Frostbite - treatmentImmerse affected area in 40-42 degrees C
water until thawing is complete.- part will be extremely painful
Wrap affected part in sterile gauzeAffected part should not be used for
anything- keep part from refreezing
Immersion Foot – trench footImmersion foot is caused by prolonged exposure of
the feet to wet, cool conditions.
Characterized by:- yellowish, smelly feet- possibly numb- sloughing of skin tissue/itching
*Immersion foot may cause permanent damage to foot tissues, leaving person susceptible to cold injuries in future.
Immersion Foot - treatment- Careful washing and drying of feet.
- Keep feet dry as much as possible.
- Keep off feet as much as possible until healed.
VIBRATION
Types
Whole- body vibration
Segmental vibration
WBV A kind of cummulative trauma
Jobs: drivers, miners, heavy equipment
operators
Frequency: 1 – 80 Hz (esp. below 20 Hz)
Two types: vertical (4-8Hz)
horizontal (1-2Hz)
Disorders Musculoskeletal (LBP, Disk degeneration,
disk calcification, …) Neurological (decreased visual acuity,
Labyrinth disorders, insomnia,…) Circulatory Digestive Reproductive (abortion, congenital
malformation, …)
Prevention
↓ exposure duration
↓ unnecessary exposures
Isolation
Careful maintenance of machines
Resting after exposure
Segmental Vibration
Frequency: 5-5000 Hz (esp. 125-300 Hz)
Jobs: work with chain saw, grinder, sander,
pneumatic drill, jackhammer
Disorders: HAVS (Vibration-induced white
finger)
HAVS A kind of secondary Raynaulds
phenomenon Signs and symptoms:
numbness and tingling → blanching →cyanosis → atrophy → ulceration → gangrene
Advanced disease: bone and cartilage degeneration, joint stiffness, clumsiness
Treatment
Removing from more exposure
Massage, Shaking, Warm water
Nifedipine
PGE
Prevention Better tool design
Anti-vibration gloves
HAV standards
Work practices
Medical surveillance
Work/rest cycles
Work practices A/V gloves
Adequate clothing
Keep the hands warm
Avoidance from wetting the hands
Avoidance from smoking
Let the tool do the work
Maintain tools carefully
Types of radiationTypes of radiation Ionizing
Electromagnetic energy X-ray Gamma ray
Subatomic particles Electron Proton Α particle
Non-ionizing
Definition: energy in the form of particles or waves
Types of radiation Ionizing: removes electrons from atoms
Particulate (alphas and betas) Waves (gamma and X-rays)
Non-ionizing (electromagnetic): can't remove electrons from atoms
infrared, visible, microwaves, radar, radio waves, lasers
Radiation wavelength in angstrom units
108 106 104 102 1 10-2 10-4 10-6
X-RaysRadio Infrared Visible
Ultra-VioletLight
Gamma Rays
Cosmic Rays
10-10 10-8 10-6 10-4 10-2 1 102
Photon energy in million electron volts (MeV)
22 4 10