2. At the end of this lesson student will be able to-
➢Definition of terms
➢Elements of safe working environment
➢Occupational health hazards
➢Occupational health hazards prevention and control measure
3. Introduction
Occupational Health/Hygiene is an area of health & safety
management involved in the anticipation, understanding,
evaluation & control of the adverse health effects of workplace
hazards on workers and general environment (Boyd, 2020)
Scope Of Occupational Health isThree-fold
Recognition and anticipation of workers health problems
➢causes may be chemical, physical, biological, psychological,
and ergonomical
Evaluation of the recognized problem
➢encompasses mainly data collection, analysis,
interpretation, and recommendations
Development of Corrective actions
➢to eliminate or limit the problem
4. ☺it requires the knowledge of physics, biology, chemistry,
ergonomics, medicine, engineering, and related sciences
☺it also requires public health management skills for proper
communication and decision making
☺A public health worker has been always on the side of
public health protection
☺A public health worker
He/she is an activist and a professional in the control of
communicable diseases and environmental hazards
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6. Workplace and Health
➢Millions of workers die or are injured or fall ill every year as a
result of workplace hazards
➢the economic costs of the failure to ensure occupational health
and safety are so great
➢loss to GNP caused by workplace accidents and work-related ill
health in EU Member States is in the range of 2.6-3.8 per cent
➢Improving occupational health and safety is in the best interests
of all governments, employers and workers
➢more than 250 million work-related accidents every year and
over 160 million workers to fall ill annually
➢than 1.2 million workers die as a result of occupational
accidents and diseases
7. Elements of Occupational Setting
4 basic elements in an occupational setting
these are:-
=> The worker
=> The tool
=> The process
=> The work environment
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8. The Worker
Work force has several distinct characteristics:-
1. people who are employed work in the informal sectors
2. high rates of unemployment
3. workers are at greater risk of hazards due to
because of low education and literacy rates
unfamiliarity with work processes and exposures
predisposition not to complain about working conditions
high prevalence of endemic diseases and malnutrition
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9. The Tool
tools can range from very primitive tools hammer,
chisel, and needle, to automated equipment
The Process
in the process, materials used can be toxic
process itself can affect the potential harmfulness
E.g., the physical state (solid, liquid/gas) of potentially
harmful substances can determine effects of substances
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10. The Work Environment
the sum of external conditions and influences which
prevail at the place of work
industrial worker today is placed in a highly complicated
environment
work environment is getting more complicated as man is
becoming more innovative/inventive
there are 3 types of interaction in a working environment:-
=> Man and Physical, chemical and biological agents
=> Man and machine
=> Man and his psychosocial environment
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11. Small-Scale Enterprises and informal sectors where the
Inspection, Education and Evaluation
Tannery
Pottery
Bakery
Weaver
Oil-seed crushers
Blocket, pipe, tile makers
Stone crushers
Brick-makers
Carpentry
Welders
Garage
Glass cutters
Butchers
Charcoal producers
Carpet makers
Dairy farm
Chicken farm
Soap makers
Bee farm (honey)
Animal fattening farm
Mining
Grinding
Boiling
Painting and paint making
Quarrying
Cutting
Burning
Cleaning 11
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12. Classification of occupational health hazards
➢the various hazards arise from the work
➢occupational diseases or adversely affect health
➢may be classified as:-
Physical Hazards
Mechanical Hazards
Chemical Hazards
Biological Hazards
Ergonomic Hazards
Psychosocial Hazards
13. A. Physical Hazards
are hazards that arise at work due to the influence of
various forms of energy
has possible cumulative or immediate effects on the
health of employees
employers and inspectors should be alert to protect the
workers from adverse physical hazards
Physical hazard include:
a. extremes of temperature
b. radiation
c. vibration
d. excessive noise
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14. Extremes of Temperature
work environment is either comfortable or extremely cold or
hot and uncomfortable
common physical hazard in most industries is heat
Heat Stress
situation when human body feels thermal discomforts (e.g.,
heat load) in dissipating excess heat and sweating
fluctuation in core temperature about 20c/30c
Sources of heat stress: => Natural Conditions
=> Hot work processes related to furnaces, kilns, boilers and
smelting
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18. Vibration
Physical factor which affects man by transmission of mechanical
energy from oscillating sources
Types => Segmental & Whole body vibration
=> Segmental vibration
Health Effects:
Hand Arm Vibration Syndrome (HAVS)
tingling, numbness, blanching of fingers
pain
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19. B. Mechanical Hazards
refer to moving machinery that can cause injury or
death
mechanical hazards in industries are contributed from
machinery protruding and moving parts
➢are those that can potentially cause accidents like
Injuries, Falls, cuts, abrasions, etc
➢includes: unshielded machinery, unsafe structures at
the workplace and dangerous unprotected tools
accounts about 10% of accidents in industry
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20. Mechanical hazards
workers who use hand tools such as picks, hammers and
shovels
person who habitually kneel at their work may suffer from
"beat" condition of the hand, knee or elbow
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21. C. Chemical Hazards
chemical hazards form the most important group
(comprise the largest group by far)
comprise over 12,000 toxic materials
such materials may endanger life, affect health adversely
asbestos, coal dust, multitude of acids and alkalis, gases
such as CO2, SO2, CO, NOx, heavy metals poisoning, (Pb, Hg)
and long list of toxic substances such as pesticides, solvent
and preservatives
chemical substances to cause harm, must first enter the
body
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22. Routes of entry into the body
Inhalation
Ingestion
Skin Contact
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23. Classification of Toxic Effects
➢Local toxicity- occurs at the site of chemical contact
➢Systemic toxicity- occurs distant from point of contact, may
involve many organ systems
➢Acute toxicity- occurs almost immediately (hours/days)
after an exposure
➢Chronic toxicity-represents cumulative damage to specific
organ systems; occurs many months or years to have
recognizable clinical disease
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26. Asphyxia-substances which produce lack of oxygen in the blood
and tissue
Pneumoconiosis-accumulation of dust in the lung and the tissue
reaction to its presence
➢pneumoconiosis has different types
Siderosis--iron dust
Byssinosis--cotton dust
Asbestosis--asbestos dust
Anthracosis--coal Dust
Carcinogen =>chemicals that can cause cancer
e.g. Asbestos (lung cancer) and vinyl chloride (liver cancer)
Teratogens => Substances which act on unborn offspring (fetus) to
produce congenital malformation e.g. Thalidomide
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27. D. Biological Hazards
➢knowing the biohazards & their classification is very important
➢biological hazards include virus, bacteria, parasites etc.
➢Biological hazards can be transmitted to a person through:
a. Inhalation b. Injection
c. Ingestion d. Contact with the skin
➢employees are subjected to hazards as a result that the work
requires handling and manipulation of biological agents
(surgery, blood and laboratory specimens)
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28. Selected Infectious Diseases and Occupations
Agent / Disease Occupation
Tuberculosis Medical personnel
Anthrax Animal handlers and handlers of
carcasses, skins, hides, or hair of
infected animals, including wool carpet
processors and handlers.
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29. E. Ergonomic Hazards
The term is derived from the Greek roots
=> ERGON ==== work and strength
=> NOMOS=====law or rule
Ergonomics is the application of human biological science in
conjunction with the engineering science in order to achieve
optimum mutual adjustment of man and his work
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30. Ergonomics/Bioengineering/Functional design is the discipline
examining the capabilities and limitations of people
human characteristics and their connection with
workplace tools, materials, or facilities is compiled
the goal of "ERGONOMICS"
=> making work safe to humans
=> increasing human efficiency and well-being
to ensure a continuous high level performance work
system must be tailored to human capacities and
limitations measured by anthropometry & biomechanics
Improper lifting, repeated motions in an awkward position
can result in accidents
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31. Ergonomic Disorders- Musculoskeletal disorders (MSDs)
➢consist of minor physical disabilities. It describes a variety
of conditions that affect the muscles, bones and joints
➢are injuries and illnesses that affect muscles, nerves,
tendons, ligaments, joints or spinal discs
Common Symptoms of MSDs
➢painful joints
➢numbness in hands, forearms, knees & feet
➢stubbing pains and fingers or toes turning white
➢back or neck pain and Stiffness
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32. Risk Factor:-
➢ Static posture
➢ Forceful exertion
➢ Repetitive movement
➢ Extreme range of motion
➢ Awkward posture
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33. F. Psychosocial Hazards
"stress" means the strain imposed on the worker by
psychosocial influences associated with work design and
urbanization
poor supervisor support or high job demands
within the work environment itself, emotional stress may
arise from a variety of psychosocial factors
=> worker finds unsatisfactory
=> frustrating
=> demoralizing
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34. For example:
a peasant who migrates from the rural areas to a city will
face entirely different environment
workers may be working in shifts that will expose them to
unusual hours (upset their family’s life)
workers may be working with a person who is paid more
but who is incapable of working
financial incentives are too low etc.
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35. Preventive and protective measures
General considerations
➢accidents and work-related diseases and injuries in most
occupational sectors is still regrettably high
➢occupational accidents and diseases cause great pain, suffering
or death to victims
Occupational accidents and diseases also result in
➢ loss of skilled and unskilled but experienced labour
➢ material loss, i.e. damage to machinery and equipment
➢ high operational costs through medical care, payment of
compensation, repairing damaged equipment
36. Core occupational health and safety principles
➢identified basic principles , including the following:
1. All workers have rights
➢Workers, employers and governments, must ensure that
these rights are protected decent conditions of labour
➢International Labour Conference stated in 1984:-ILO
(a) work should take place in a healthy working environment
(b) work site should be consistent with workers’ well-being
(c) work should offer real possibilities for personal achievement,
self-fulfillment and service to society
37. Core occupational health and safety principles
2. Occupational health and safety policies must be established
➢such policies must be implemented at both the governmental
and enterprise levels
3. There is need for consultation with the social partners (that
is, employers and workers) and other stakeholders
4. Prevention and protection must be the aim of occupational
health and safety programmes and policies
5. Information is vital for the development and implementation
of effective programmes and policies
38. Core occupational health and safety principles
6. Health promotion is a central element of occupational health
practice
7. Compensation, rehabilitation and curative services must be made
available to workers who suffer occupational injuries, accidents and
work-related diseases
8. Education and training are vital components of safe, healthy
working environments
9. Workers, employers and competent authorities have certain
responsibilities, duties and obligations
10. Policies must be enforced
39. Preventive and protective measures
➢eliminating or reducing the sources of potential risks that trigger
hazards can be achieved in a number of ways:
1. engineering control
2. design of safe work systems to minimize risks
3. substituting safer materials for hazardous substances
4. administrative or organizational methods
5. use of personal protective equipment
40. Engineering control and housekeeping
➢engineering control involves controlling the hazard at the
source
➢ensure that exposure to hazardous substances is
prevented/controlled by prescribing engineering controls
➢engineering controls should be built in during the design
phase
➢more expensive to implement than methods which depend on
continual vigilance by the worker
➢is the mechanization process that involves the use of a
machine to do dangerous work
41. Substitution
➢the competent authority should require the replacement
of hazardous substances by substitute materials
➢For example, in the case of asbestos or products
containing asbestos
42. Work practices and organizational methods
➢elimination of risk and total enclosure of machinery are both
impracticable, employers should reduce exposure
➢administrative or organizational measures, so as to
1. reduce the source of the hazard, so that risks are confined to
some areas
2. adopt adequate work practices and working-time
arrangements
3. minimize the magnitude of exposure, the number of workers
exposed and the duration of exposure
e.g. carry out noisy operations at night or weekend
43. Personal protective equipment
➢when none of the above approaches is feasible, or when the
degree of safety achieved is considered inadequate
➢is the final line of defense and should be used only as a last
resort
➢the employer has a duty to ensure its proper use
➢workers have the obligation to make proper use of and take
good care of
44. ➢devices worn by the workers to protect against hazards
in the work place
➢popular with employees b/c it is appears a relatively
cheap solution
=>Eye protector e.g. Eye spectacle , goggle
=>Hearing protector e.g. Ear plugs-fit inside the ear
Ear muffs-fit over and a round the ear
=>Protective clothing
e.g. gown
Personal protective equipment (PPE)
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45. 1- Air purifying respirators
➢designed to draw in contaminated air from the work
place and purify it before it is breathed
2- Air supplied devices
➢supply of clean air from outside the working environment
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RPE (respiratory protective equipment)
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47. “I still need more healthy rest in order to work at my
best.
My health is the main capital I have and I want to
administer it intelligently.”
---Ernest Hemmingway
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