Occupational Physical Hazards "Temperature changes+ Noise + Vibration + Radiation + Atmospheric Pressure changes"

1. Dr. Dalia El-Shafei
Ass.Prof of Occupational Medicine

5. ‫المخاطر‬((HAZARD:
‫مثال‬ ‫أذي‬ ‫يسبب‬ ‫قد‬ ‫العمل‬ ‫مكان‬ ‫في‬ ‫شئ‬ ‫أي‬( :‫الكهرباء‬–‫الكيماويات‬–
‫الساللم‬ ‫علي‬ ‫العمل‬-‫ا‬‫التنظ‬ ‫في‬ ‫أكلة‬ ‫حارقة‬ ‫تنظيف‬ ‫مواد‬ ‫ستعمال‬‫يف‬)
‫المخاطرة‬(‫الخطر‬ ‫احتمال‬)(RISK):
‫سو‬ ‫ما‬ ‫شخص‬ ‫بأن‬ ‫صغيرا‬ ‫أو‬ ‫كبيرا‬ ‫كان‬ ‫سواء‬ ‫االحتمال‬ ‫أو‬ ‫الفرصة‬ ‫هي‬‫ف‬
‫الشخص‬ ‫على‬ ‫الضرر‬ ‫هذا‬ ‫شدة‬ ‫ومدى‬ ‫المخاطر‬ ‫هذه‬ ‫من‬ ‫لألذي‬ ‫يتعرض‬.

7. This is a HAZARD

8. This is a RISK

9. Hazard
Source of Danger
E.g. Chemical, Flammable
Liquid
Risk
Exposure to danger
E.g. Uncontrolled fire, personal
injury, air & water pollution
CAUSE EFFECT

12. Occupational
hazards
Physical
Chemical
MechanicalBiological
Socio
phycological

14. 1- High or low Temperature.
2- Noise.
3- Radiation (ionizing & non-ionizing).
4- Vibration.
5- Atmospheric Pressure changes.
6- Electricity.

15. 1- Toxic Metals.
2- Dusts & Fumes.
3- Noxious Gases.
4- Toxic Organic compounds.

16. 1- Parasites.
2- Bacteria.
3- Viruses.
4- Rickettsia.

17. Work stress
Post Traumatic Stress Disorder “PTSD”
Night work shifts
Long working hours .
Violence at work

18. Accidents
Ergonomics
“Wrong lifting, Wrong movements, Wrong
postures, and Slippery floor or stairs

21. Dry heat as working
in front of ovens
e.g iron & steel
industry
Working in hot humid
place as working in
front of boilers.
Direct exposure to sun
as working in desert
construction workers
Working in badly
ventilated closed places
with low air movement
Heat
Disorders
Increase heat gain
Occupational exposure to Heat

22. Heat Disorders
Systemic
Heat cramps
Heat syncope
Heat exhaustion
Heat stroke
Skin
Heat rash
Cancer “Basal cell
carcinoma” UVRs
Heat burn
Psychoneurotic
Chronic heat
fatigue
Eye Cataract “UVRs”

23. Heat cramps
Increase sweating
Loss of water & salts
Dilution of Nacl in blood “Hyponatremia”
Muscle cramps
Painful spasm of voluntary muscles
following hard works in hot areas
Compensation of water only
*Definition:
*Mechanism:

24. *Manifestations :
-Hot moist skin
-Normal pulse
-Normal body temperature
-Painful muscle spasm
*Treatment:
-Provide water & salts -Stretch or relax the cramped muscle

26. Heat Syncope “Fainting”
*Mechanism:
Increase body temperature
Vasodilatation
Decreases blood pressure
Decrease blood flow to brain
Syncope
*Treatment:
-Remove the patient
from hot environment.
-Heat must be lowered.
-Raise the patient`s feet to
maintain blood flow to
the brain.
-Supply fluids when patient
regain his consciousness.

27. Excessive sweating, salt & water depletion
without replacement causing heamo-concentration &
hypovolemia & circulatory failure.
Clinical picture:
- Headache, weakness and fatigue.
- Anorexia, vomiting and excessive sweating.
- Signs of peripheral circulating failure (pallor - cold
moist skin - hypertension - weak rapid pulse).
Treatment of heat exhaustion:
- Removal of the patient to cool place.
- Water & salt replacement.
- Treatment of shock.

29. Heat Stroke
*Definition:
Disturbance of
heat regulating center (HRC)
at brain
Heat retention in body
Essential triad of
Hyperpyrexia (>40 °c)
Loss of consciousness Red hot dry skin
Life-threatening Condition

33. Due to blocking of sweat gland ducts: sweat retention &
inflammatory reactions.
Clinical picture:
- Raised red vesicles on the affected skin.
- Prickling an itchy sensation on exposure to heat.
Treatment of heat rash:
- Removal to cooler environment.
- Skin cleanliness to prevent infections.
- Cool showers.
- Application of mild drying & soothing lotions.

35. Prevention of Heat-related Disorders
A) General measures:
*Substitution.
*Pre-employment medical
examination:
-to advice the worker as regards
the suitability of work place to
his health status.
*Segregation:
of heat production process
away from the work place.
*Isolation:
isolation of heat production
process inside the work place.
*Periodic medical examination:
for early detection of health
effects of heat to be treated
early.

36. *Ventilation:
air movement helps evaporation of
sweat.
*Monitoring:
measuring the environmental
temperature to assure that it does
not exceed allowable levels “Heat
Stress Index”.
*PPE:
e.g gloves, clothes containing
Heat insulators e.g. glass fibers.
*Health education :
about health hazards of heat, how
to protect their bodies from these
effects & importance of using
PPE & Urine chart.

39. Cooling vest

41. B) Specific measures:
1) Acclimatization.
2) Food & water intake.
3) Limit exposure to heat.
4) Frequent use of sunscreen or sun block.
5) Bath regularly.
6) Wear light loose cotton clothes.
7) Alternate work & rest cycles.
8) Perform heaviest work loads in cooler times.

42.  Adaptive process through repeated gradual
exposure to heat.
 Requires 4 to 6 days.

44. Food & Water intake
Avoid heavy meals as it decreases body ability to get rid
of heat because they redirect blood flow to GIT instead of
skin surface.
Water & salt replenish “1 tsp. of NaCl/ liter of water

45. Never take alcohol as it leads to dehydration & increase heat gain.
Avoid intake of excess protein to avoid increase of metabolism.
Increase intake of vitamins “vitamin A, B, C”.

46. Discuss the health effects resulting
from exposure to high temperature in a
glass factory?

48.  Construction workers
 Airport ground personnel/ support
 Outdoor recreation
 Fishing, diving
 Transport
 Agriculture & dairy
 Food processing, packing, storage
 Cold storage, warehousing
 Ice making
• Window cleaning
• Police, fire, & emergency
response
• Postal, delivery services
• Sanitation/trash
collecting

49. Cold conditions force your body to work harder to
maintain its temperature. The challenges you face from
a cold environment include:
• Air temperature
• Wetness: rain, snow, ice, humidity; sweat; wet clothes; water
• Air movement: wind speed (5 miles per hour and higher);
blown air from fan in cold rooms, etc.

50. Example: If the temperature is -15°F and wind
speed is 10 mph, it will feel like it’s -35°F, and
frostbite will develop in 30 minutes. If the wind
speed doubles to 20 mph, the time for frostbite
to occur drops to only 10 minutes.
Wind Chill Chart

51. Injury/Illness Cause
Hypothermia
- Core body temperature decreases to below 34°C
- Decreased physical & mental capacity.
- Shivering
- Severe Hypothermia is LIFE THREATENING!
Frostbite
- Ice crystal formation in skin & other tissues of body
- Permanent damage & destruction to blood vessels &
other structures, can result in amputation
Frostnip
- Ice crystal formation only in very outer layer of skin
- No permanent damage
Immersion
injury (Trench
foot)
- Exposure of wet feet (or hands, other body areas) to
cold temperatures over hours to days
- Damages nerves & muscles
- Permanent damage.

53. Gangrenous necrosis 6 wks after
frostbite injury

59. Sound waves spread out spherically… as can be
seen from this amazing aerial photograph of
shock waves created by a battleship!!

60. Inverse square law

70. Noise: Any unwanted or undesirable sound.
Auditory field:
- Between 20-20000 hertz (Hz) or cycles/ sec.
- If noise is below the lower level of normal
hearing (> 20 Hz) it is called infra sound but
if it is above the upper limit of normal
hearing (< 20 kHz) it is called ultrasound.
OUR HEARING IS 10X MORE
SENSETIVE THAN EYE SIGHT.

71. Classification of noise
According to Frequency
High frequency Saw sound
Law frequency Grinders
sound
White noise Boiler sound
According to Duration
Continuous noise Spinning &
waving industry
Interrupted noise Traffic noise
Impulse & impact
noise
explosions

72. 1- Duration of exposure.
2- Intensity of the sound.
3- Frequency of sound waves.
4- Type of noise (continuous noise or
impact noise “more dangerous”).
5- Personal susceptibility.

73. Noise Exposure
Occupational Non occupational
“Sociocusis”
* Traffic noise
* Recreational activities
as Hunting
Effects of Noise
Non auditory effectsAuditory effects (Noise induced
hearing loss “NIHL”)
- Conductive - Sensorineural - Mixed

74. Non auditory effects of noise
Insomnia
Work stress
Anxiety
HPN & CHD
Lack of
communication
Lack of
concentration
Absenteeism
Turnover
Accidents
Production
compensation

78. Sensorineural NIHL
#Destruction of the hair cells of the organ of corti in
the inner ear .
# Gradual & progressive loss of hearing .
# Begins at the frequency 4000-6000 hz & then
spreads to other lower & higher frequencies
#Difficulty of hearing high pitched sounds e.g sound of
women & children
# Difficulty of group communication due to difficulty of hearing
of words containing high frequency letters

79. Temporary Threshold Shift ‘TTS’
Short term exposure to noise
- Hearing returns when away from the noise
Permanent Threshold Shift ‘PTS’
Exposure to a moderate or high level of
noise over a long period of time
- Hearing loss is PERMANENT

82. Prevention of NIHL
Medical measuresEngineering measures
# Eliminate exposure to noise
#Substitution of noisy machines or
noisy operation by less noisy one
# Segregation of noisy machines in
remote places
# Isolation of noisy machines by using
sound absorbing materials to reduce noise
* Pre employment audiogram
* Periodic medical examination
* Personal protective devices
* Health education

88. Double-wall construction gives good
transmission losses (TL)

89. 89

91. OSHA requires hearing protection for workers
depending on dB level & exposure time

92. If you have to raise your voice to be heard by
someone less than three feet away, than you
need hearing protection
Workers under occupational noises >85 dB, set
their car stereos ~9 dB higher after work than
before work. (Evidence of Temporary Threshold
Shift ‘TTS’)

93. Sound Level Meters (SLM)
Continuous on-mobile sources
Determine loudness (dB) of noise at any given
moment
Personal Dosimeters
Mobile/variable noise sources
Worn by employees
Measures the average loudness in an 8 hour work
shift “8hr. TWA” (Time Weighted Average)

94. 94
In the field, we determined the loudness of 2
compressors right next to each other
 How loud is this area?
 Do we add?
 Do we add and take the average?
89 dB 87 dB

95. 82 dB + 83 dB = 86 dB
87 dB + 89 dB = 91 dB
Difference in dB Values Add to Higher Level
0-1 dB 3 dB
2-3 dB 2 dB
4-9 dB 1 dB
10 dB or more 0 dB

100. Microphone
is placed
midway
between neck
& shoulder in
an upright
position.
Dosimeter
should be
placed on the
shoulder that is
normally
between noise
source & ear.

101.  Tuning fork
 Audiograms
 Most common
 Tests the hearing threshold for different frequencies
 Base-line & Annual.

102. 102

104. 10/1/99 104

105. •Reference audiogram against
which future audiograms are
compared.
•Must be provided within 6
months of an employee’s 1st
exposure at or above 8-hour
TWA of 85 dBA “Action level”.
•Must be preceded by 14 hours
without exposure to noise “TTS”.

106. • After baseline audiogram has been
taken, each employee exposed to noise
levels at the 85 dBA or above shall have
annual examination.
• Must be conducted within 1 year of the
baseline.
• Compared with baseline audiograms.

107. • To determine whether an employee has
experienced any recordable hearing loss.
• The hearing loss is referred to in the
OSHA standard as: Standard Threshold
Shift (STS).
OSHA defines STS as “A change in
hearing threshold relative to the baseline
audiogram of an average of 10 dB or more
at 2000, 3000, and 4000 Hz in either ear.

110. 125 250 500 1000 2000 3000 4000 6000 8000
10
0
10
20
30
40
50
Baseline Audiogram
(The initial audiogram
taken by worker when
1st employed.)

111. 10
0
10
20
30
40
50
BASELINE
ANNUAL
16
9
8
16 + 9 + 8 = 33
33 / 3 = 11
125 250 500 1000 2000 3000 4000 6000 8000

112. 112
Left Ear
500 1000 2000 3000 4000 6000
Baseline 1983/06/01 5 10 25 20 35 25
Annual 1999/07/24 10 10 15 20 15 35
Right Ear
500 1000 2000 3000 4000 6000
Baseline 1983/06/01 10 10 10 25 25 10
Annual 1999/07/24 10 10 15 20 15 35
Mild high-frequency hearing loss at 6000 Hz bilaterally.

116. Earmuffs Earplugs Canal Caps
Hearing protectors must be available & be worn
by all employees exposed to an 8-hour TWA of
85 dBA or greaters.

118.  Hearing protection is designed to reduce
noise by the NRR, but that is unlikely to
happen due to :
 Leaks in the seal
 Vibration
 Improper insertion
(NRR - 7)

119.  The noise at a large compressor is 109 dB
 You are wearing the Express plugs with an NRR
of 25
 Do you have enough protection to place you
below 90 dB level?

122. • Employees training is very important. All
employees exposed to noise at a TWA of 85
dBA or greater shall participate in a
hearing conservation training program.
• An accurate records shall maintained of all
employee exposure measurements.

123. Your children can whisper to you now,
Don’t make them shout at you in the future

125. Contact with Vibrating Machine:
 Hand Arm Vibration “HAV”
 Whole Body Vibration “WBV”
Vibration transmitted through the seat or feet.

126. Industry Vibration
Type Common source
Agriculture WBV Loaders + Bulldozers + Tractors
Construction
WBV+
HAV
Heavy equipment vehicles +
Pneumatic tools
Forestry Tractors + Chainsaws
Mining Drills + Grinders + Vehicles
Textile HAV Sewing machines
Transportation WBV Bus + Train + Tram +Helicopters

133. Consultnet Limited © 133

140. Type:
A) Electromagnetic radiation: X- ray ,Gama ray
B) Particulate radiation:
* Alpha particles with low power of penetration and
great power of ionization.
* Beta particles with greater power of penetration.
* Neutrons * Protons * Electrons.

142. Radiation is the straight line transport of energy
through space or matter.
Classification of radiation:
1- Ionizing radiation: any electromagnetic or
particulate radiation capable of producing ions, directly
or indirectly when passing through matter.
2- Non ionizing radiation: electromagnetic radiation
with a wave length not sufficient for ionization.

143. 

or X-rayNeutron

144. OH
.
(hydroxyl radical)H
.
Radiation Damage
Water molecule “H2O”
-ray
2 OH
.
 H2O2
What happens when
water molecule is struck
by gamma ray?

145. Alpha Particles
Stopped by a sheet of paper
Beta Particles
Stopped by a layer of clothing
or less than an inch of a substance
(e.g. plastic)
Gamma Rays
Stopped by inches to feet of concrete
or less than an inch of lead
Radiation
Source
Neutrons
Stopped by a few feet of concrete::
1:100:10,000

147. 1- Uranium miners & Atomic millers.
2- Nuclear reactors & Atomic energy plant.
3- Radiologist.
4- Scientists using radioactive materials.

151. A) Acute effect:
1- Whole body irradiation “Doses > 1Gy”: Acute
radiation syndrome {Prodromal symptoms (nausea,
vomiting) + bone marrow depression (leukaemia,
anaemia, thrombocytopenia)}.
2- Local irradiation: Skin reactions from mild
erythema to tissue necrosis & ulceration.

154. B) Chronic effect:
1- Chronic radiation sickness.
2- Chronic radio-dermatitis: disturbed sensation,
focal hyperkeratosis, congestive hyperaemia, painful
cracks & ulceration with malignant changes.
3- Eye cataract: starts at posterior pole of lens capsule.
4- Carcinogenic & hereditary harm.

161. 1- Workers in compressed air that is too
rapidly decompressed (Caisson disease).
2- Divers who surface too rapidly from
depths greater than about 10 meters.
3- Crew or paratroopers in aircraft who
ascend too rapidly from sea level to
heights greater than 5487 meters.

165. Manifestations of DSI are due to
formation of nitrogen bubbles in body
fluids & tissues.
Symptoms: depend upon site in which
bubbles are formed.
Severity: depend upon size & rate of
growth of bubbles.

166. A) Acute symptoms that is divided into:
1- Type I: - Mild or severe limb pain.
- Skin mottling or skin irritation.
2- Type II: - Paralysis or weakness of the limbs
- Tingling or numbness of the limbs.
- Vertigo. - Headache.
- Dyspnea, chest pain. - Hypotension, coma.
B) Chronic symptoms:
- Aseptic necrosis of bones.
- Neurological or psychological symptoms.

168. 1- Gradual decompression
2- Use of pressurized airplanes.
3- Inhalation of helium/oxygen mixture
instead of air by divers to avoid nitrogen
narcosis.
4- Pre-employment medical exam.:
chronic sinusitis, otitis media, lung cysts
or emphysema must not be employed.
5- Periodic medical examination “X-
rays”.

169. 6- Treatment of decompression sickness:
recompressing the patient & reducing pressure
in accordance with a protocol laid down in set
of tables.