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OHS611S - OCCUPATIONAL HEALTH AND SAFETY 2A - 1ST OPP - JUNE 2022 |
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nAm I BIA un IVE RS ITV
OFSCIEnCEAno TECHn OLOGY
FACULTYOF HEALTH,APPLIEDSCIENCESAND NATURALRESOURCES
DEPARTMENTOF HEALTHSCIENCES
QUALIFICATION: BACHELOR IN ENVIRONMENTAL HEALTH SCIENCES
QUALIFICATIONCODE: 08BOHS
LEVEL: 6
COURSE:OCCUPATIONAL HEALTH & SAFETY 2A COURSECODE: OHS 611S
DATE:JUNE 2022
SESSION:SEMESTERONE, 2022
DURATION: 3 HOURS
MARKS: 100
EXAMINER(S)
FIRSTOPPORTUNITYEXAMINATION PAPER
MR. JOSHUA HIDINWA
MODERATOR:
MR. IMMANUELZERIAPI
THIS QUESTION PAPERCONSISTSOF 6 PAGES(Including this front page)
INSTRUCTIONS
1. Answer ALL the questions.
2. Write clearly and neatly.
3. Number the answers clearly.
PERMISSIBLEMATERIALS
None
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SECTION A (30 MARKS}
QUESTION 1
(10 MARKS)
1.0 Select most appropriate answer from the options provided.
1.1 Lighting surveys in the work environment are usually done to determine:
(1)
A. Luminous intensity
B. Luminous flux
C. Illumination
D. Brightness
1.2 Which of these terms describe radiation effects which are determined
by the level of radiation dose the person is exposed to?
(1)
A. Stochastic effects
B. Collective dose effect
C. Deterministic effect
D. Radioactivity
1.3 Presbycusis is a form of hearing loss due to:
A. Exposure to occupational noise
B. Exposure to chemicals (especially solvents)
C. Ear diseases or infections
D. Sensory hairs damaged with age
1.4 Which of these terms describe hearing lost due to loud noise?
(1)
(1)
A. Stochastic effects
B. Collective dose effect
C. Deterministic effect
D. Sociocusis
1.5 The purpose of Hearing Protection Devices is to :
(1)
A. Relieve employer from having to do noise control
B. Protect the worker from acquiring hearing loss due to noise exposure
C. Keep foreign bodies out of the ear
D. Allow the employer to increase production noise for better production
throughout.
1.6 The purpose of audiometric test is to:
(1)
A. Identify employees who need hearing protection
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B. Minimize employer liability for hearing loss
C. Identify employees with a temporary shift in hearing due to noise
exposure
D. Collect evidence of workers hearing loss
1.7 In a steel making factory with furnaces and red-hot metal rods, the
main thermal hazard will be through:
(1)
A. Radiation
B. Conduction
C. Convection
D. Air conduction
1.8 Heat disorder which results from thermoregulatory failure in
persons is known as:
(1)
A. Heat oedema
B. Heat syncope
C. Heat stroke
D. Heat exhaustion/ cramp
1.9 The condition where there is physical damage to body tissues caused by a
difference in pressure between air spaces inside the human body
tissues and the surrounding fluids is known as:
(1)
A. Hypoxia
B. Dysbarism
C. Decompression sickness
D. Barotrauma
1.10 The total pressure exerted by a gaseous mixture is equal to the sum of the
partial pressures of each individual component in a gas mixture.
This is a definition of:
(1)
A. Charles' gas law
B. Boyle's gas law
C. Henry's gas law
D. Dalton's gas law
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QUESTION 2
{10 MARKS)
2. 0 Indicate which of the following statements is True or False.
2.1 The breathing rate of people exposed to low pressure environments
increases to compensate for low oxygen diffusion.
(1)
2.2 Isotopes are nuclides with the same atomic number but different mass
numbers.
(1)
2.3 A hyperbaric environment refers to a low altitude environment
with increased barometric pressure.
(1)
2.4 In terms of the Namibian Health and Safety legislation, it is not a
requirement for organizations to have an Occupational Health and
Safety policy.
(1)
2.5 Employees should purchase and maintain their own Personal
Protective Clothing and Equipment.
(1)
2.6 The Labour Act requires that an employer pays Health and Safety
representatives an allowance for conducting their duties at
the work place.
(1)
2.7 The biological half-life of a radio-active material in radiation refers
to the time required for the number of radio-active atoms in a
sample to decrease by one-half.
(1)
2.8 The eye's ability to focus on near and distant objects is known as
visual acuity.
(1)
2.9 Occupational health and safety is premised (based) on disease
and injury prevention rather than curative or treatment of workers.
(1)
2.10 Heat acclimatized workers generally sweat less than
their unacclimatized counterparts.
(1)
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QUESTION3
(10 MARKS)
3. O Match the statement in Column A to the corresponding concept(s) in Column B.
WriteonyouranswersheetthecorrectcolumnA numbewr itha correcct olumnB letter.
COLUMNA
3.1 Shielding
3.2 Ototoxicity
3.3 Boyle's Law
3.4 Hand arm
vibration
3.5 Whole body
vibration
3.6 Heat syncope
3. 7
3.8
3.9
3. 10
Dalton's law
Infra-red
radiation
Tinnitus
WBGT
COLUMNB
A Ringing sound in the ear following exposure to high
noise level
B Total pressure exerted by a gaseous mixture is equal
to the sum of the partial pressures of each individual
constituent gases
C Electromagnetic radiation of longer wavelength than
visible light
D Lower back pain
E Hearing loss due to exposure to chemicals or drugs
F A protective barrier, usually of dense material that
reduces the passage of radiation
G Heat Stress Index
H Heat disorder resulting in affected persons fainting
I Vibration white finger
J Volume of gas of fixed mass and temperature is
inversely proportional to its pressure
Marks
(1)
(1)
(1)
(1)
(1)
(1)
{l)
(1)
(1)
{l)
SECTION B (40 MARKS)
QUESTION 4
4.1 Why is the A weighting often used when measuring sound levels?
(15 MARKS)
(2)
4.2 Explain concisely how sound is transmitted from its source and through
the components of the ear.
(5)
4.3 An employee is working in an environment where he is exposed to
98dB(A) noise level. The Safety Officer supplies him with earmuffs with a Noise
Reduction Rating (NRR)of 30dB.
A. Calculate the actual noise reduction this would offer.
(3)
B. Would the noise reduction offered be adequate to protect the
employee from hearing loss?
(2)
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4.4 The noise level for a new pump is known to be 78d(B)A. The background
noise level in the area where the pump is installed is 82dB(A). What is the
overall noise when the pump is operating?
(3)
QUESTION 5
5.0 Differentiate the following Occupational Health and Safety terms:
5.1 Hazard and Half-life.
(25 MARKS)
(5)
5.2 Dose and Effective dose.
(5)
5.3 Ionizing and non-ionizing radiation.
(5)
5.4 Hypobaric and hyperbaric pressure environments.
(5)
5.5 Alpha radiation and Beta radiation.
(5)
SECTION C (30 MARKS}
QUESTION 6
6.1 Discussthe following terms used in Illumination.
(30 MARKS)
a. Adaptation.
(5)
b. Accommodation.
(5)
c. Visual acuity.
(5)
d. Glare.
(5)
6.2 Elaborate on the process you would use to carry out thermal stress assessment. (10)
Good luck!!
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