occupational health hazards

1. LECTURE 3
HEALTH HAZARDS
Instructor: Engr. Beenish Akbar Khan
Iqra National University (INU)
Occupational Health Safety and
Environment
Btech Civil/Elect.
Department
7th Semester
Fall 2015

2. The modern definition of Occupational
Health (ILO and WHO) is:
“The promotion and maintenance of the
highest degree of physical, mental and social
well-being of workers in all occupations –
total health of all at work”

3.  Awareness of health hazards
 1556 – hazards of metal mining
 1567 – diseases of mine
 1572 – lead
 1575 – carbon monoxide
 1630 – arsenic
19th century:
 Workers with exposure to lead, white phosphorus, explosives,
rubber – periodic exams
 Notification of industrial disease – lead, phosphorus, arsenic,
anthrax
 1898 – Medical Inspector of Factories

4.  Workers’ compensation
 Many enquiries
 Continual modifications, additional benefits & coverage
 Occupational disease:
 1913 – industrial disease
 1926 – silicosis, pneumoconiosis
 1932 – cancer
 1947 – generic definition of industrial disease
Mid 20th Century:
 Occupational Health and Safety legislation

5.  Diseases caused by agents
 Chemical, physical, biological
 e.g. Beryllium
 Diseases by target organ system
 Respiratory, skin, musculoskeletal
 e.g. Pneumoconioses
 Occupational cancer
 Cancer caused by the following agents
 e.g. Asbestos

6. OCCUPATIONAL DISEASES
Diseases due to Physical Agents
 Heat - Heat stroke, Burns
 Cold - Frost bite
 Light - Miners Nystagmus, Cataract
 Pressure - Caisson disease, Air embolism
 Noise - Hypertension, Irritability
 Vibration - Neuromuscular diseases, Peripheral vascular diseases
 Radiation - Leukemia, Aplastic anemia
 Mechanical - Injuries, Accidents
 Electricity - Electric shock, Burns

7. Diseases due to Chemical Agents
 Gases - CO, CO2, HCN, H2S,CS2
 Dusts - Pneumoconiosis
 Metals - Lead, Mercury, Chromium, Manganese
 Chemicals - Acids, Alkali's
 Solvents - Benzene, Trichloroethylene

8. 4 P’s:
Promote and maintain the highest degree of physical, mental &
social well-being of workers of all occupations
Prevent workers from departures due to health caused by their
working conditions
Protect workers in their working environment from hazards and
risks usually causing adverse health effects
Place & maintain a worker in an occupational environment
adapted to his/her physiological ability

9. OCCUPATIONAL HEALTH HAZARDS
Types:
1. Physical Hazards
2. Chemical Hazards
3. Biological Hazards
4. Mechanical Hazards
5. Psychosocial Hazards

10.  Temperature - Heat / Cold
 Illumination
 Noise
 Vibration
 Radiation
 Atmospheric pressure

11. Heat - Heat hyperpyrexia, Heat Exhaustion, Heat Syncope, Heat
Cramps, burns, Prickly heat
Cold - Frost bite
Light – Occupational Cataract
Atmospheric-pressure-Caisson disease, air embolism, explosion.
Noise - Occupational deafness,
Radiation - Cancer, Leukemia, aplastic anemia, Pancytopenia
Electricity - Burns, Shocks

12. Types of Noise-Induced Hearing Loss
 Temporary Threshold Shift (auditory fatigue)
 temporary loss of hearing acuity after exposure to loud noise
 recovery within 16-48 hrs
 Permanent Threshold Shift
 irreversible loss of hearing

13. Other Harmful Effects of Noise
• Hypertension
• Hyperacidity
• Palpitations
• Disturbs relaxation and sleep

14. Physical factor which affects man by
transmission of mechanical energy from
oscillating sources
Types
 Segmental vibration
 Whole body vibration

15. • Health Effects:
—Hand Arm Vibration Syndrome
(HAVS)
—tingling, numbness, blanching of
fingers
—pain

16. Health effects:
 Fatigue
 Irritability
 Headache
 Disorders of the spine

18. EXTREME TEMPERATURE
Sources of heat stress:
 Natural Conditions
 Hot work processes related to furnaces,
kilns, boilers and smelting

19. Health Effects of Heat Stress
Disorders Clinical features
Prickly Heat (Miliaria rubra) Pruritic rash
Heat cramps Cramps in the body,
usually legs
Heat exhaustion Dizziness, fainting attack,
blurring of vision, cold,
clammy and sweaty skin
Heat stroke Cyanosis, muscle
twitchings, disorientation,
delirium, convulsions

20.  Sources of Cold Environment:
 Ice plants and freezers in the food industry

21.  Frost bite: reddening of skin, localized
burning pain and numbness. Fingers, toes,
cheeks, nose, ears are most susceptible.
 Caused by freezing conditions which cut off
circulation, usually in extremities (hands,
feet, ears, nose), which may be permanently
affected. Frost-bitten areas are cold, pale or
marbled-looking, solid to the touch, and
painless (until circulation is restored).
 trench foot or immersion foot: numbness,
pain, cramps, ulceration and gangrene.
Health Effects of Cold Temperature

23. Area of Operation Min Lighting
Level (lux)
Cutting Cloth
Fine machining
 2000
Transcribing handwriting
Drafting
1000
Welding
First Aid station
500
Lunch Room
Rest Room
300
Recommended Illumination Levels

24. Health Effects
 Visual Fatigue
 Double Vision
 Headaches
 Painful irritation
 Lacrimation
 Conjunctivitis

26. 0
10
2
10
4
10
6
10
8
10
10
10
12
10
14
10
16
10
18
10
20
X-rays, about
1 billion
billion Hz
can penetrate
the body and damage
internal organs and tissues
by damaging important
molecules like DNA.
This is called “ionization.”
Microwaves, several billion Hz,
can have “thermal” or hearing
effects on body tissues
Power frequency EMFs 50 or
60 Hz carry very little energy,
have no ionizing effects
and usually no thermal
effects. They can, however,
cause very weak electric
currents to flow in the body.
Gamma rays
X-rays
Ultraviolet radiation
Visible light
Infrared radiation
Microwaves
Radio waves
10
22
Very low frequency (VLF)
3,000 - 30,000 Hz
Extremely low frequency
(ELF) 3 - 3,000 Hz
Direct current
60 Hz
15 - 30 Hz &
50 - 90 Hz
800 - 900 MHz
Source Frequency in hertz (Hz)
Electromagnetic Spectrum

27. Types Sources Health Effects
Ionizing X-rays
Gamma rays
Cancer, congenital
defects, death
Non-ionizing Ultraviolet
Infrared
Laser
skin redness, premature
skin ageing, and skin
cancer
corneal and conjunctival
burns, retinal injury,
cataract
Skin and eye problem