Assignment 2
This assignment consists of four parts: A, B, C and D for a total of 13% of the course mark. Please refer to the D2L link Course Materials – Course Outline – Quizzes, Assignments and Exam Details and Course Schedule about completion, due date and submission of this assignment. Also refer to the ‘Assignment Instructions’ posted on the ‘Assignments’ link.
Answer the following questions, note that some answers may be given in point-form or in a table format.
Part A (Module 3 – Occupational Health Methods)
- There are five main reasons that would trigger an occupational hygiene assessment in a workplace. Using a hospital’s histology laboratory as an example, explain how these reasons would apply to this occupational setting. (Note: a histology lab would use chemicals such as formaldehyde, toluene, and xylene)
| Five Main Reasons | Explanation |
| 1. To carry out qualitative and quantitative assessment of workplace health hazards
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Reason being any exposure of the chemicals used in the histology lab such as formaldehyde, toluene, and xylene |
| 2. To determine whether exposure to a particular hazard is in compliance with exposure limits
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| 3. To relate health effects with exposure to specific hazards
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| 4. To evaluate the effectiveness of exposure controls
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| 5. To obtain exposure information for health research or epidemiological studies.
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- Name and briefly describe two commercially available DRI products that are used for workplace carbon monoxide sampling; your answer is required to include the following: product/brand name, product model, a brief description of the type of DRI sensor used, detection range, and the product specification websites. (Note: research on the internet is needed to obtain information of instrument via manufacturers/suppliers internet websites)
Part B (Module – 4)
- List the seven different kinds of defense mechanisms that are used to protect the respiratory system. For each of these, use three to five sentences to describe the function of each.
| Defense mechanisms | Functions |
| The coughing mechanism | Helps expel any build-up of harmful substances. When a person experiences an upper respiratory tract bacterial or viral infection such as the common cold, the coughing mechanism starts. In case of mucous build up the body’s natural reflex response will try to cough it up. |
| Humidification | This mechanism allows for compounds to be dissolved in the fluid or humid environment of the respiratory system. Causes harmful substances to be trapped and caught and prevent from moving into other areas. Also causes dust or air particles that are small enough to travel in the air to other areas. |
| Secretion of mucous | If an irritation is to occur the secretion of mucous will start in the respiratory tract. Will also initiate coughing reflex which will then expel or swallow harmful agents. This defense mechanism can also be harmful is large amounts of mucous is secreted which can block the small conducting airways. |
| Cilia | This is used in the conjunction with the mucous secretion. This helps and expels the mucous build-up. The action of the cilia is to move the substance that is trapped in the mucous up and outward the throat area. |
| Antibodies | Destroys harmful substances and micro-organisms. There are also anti-viral substances such as interferon. Which are produced when cells are infected by a virus and have the ability to inhibit viral growth? |
| Macrophages | |
| Filtration mechanism |
- Name the four stages of the respiratory process. Use three to five sentences to describe the functions of each stage.
- Explain the following terms; provide at least two to three points for each:
- Spirometer
- Forced Vital Capacity
- FEV
- Describe the characteristics of the following chemical gases and vapours with respect to the absorption through the respiratory system and/or the respiratory toxic effects:
- HCN
- Nitrogen dioxide and sulphur dioxide
- Anaesthetic gases
- Paraquat
- Sulphuric acid
- Simple asphyxiants
- Define the following terms:
- Aerodynamic Diameter
- Terminal Velocity
- Impaction
- Sedimentation
- Brownian Motion and Diffusion
- Explain the different clearance mechanisms associated with the different regions of the respiratory system.
- List the four categories of effects of toxic agents on the respiratory system. Give examples of at least one toxic agent that fall under each category.
| Toxic Agents | Examples |
| Acute cell injury | Sulphur dioxide |
| Increase in airway resistance | Toluene diisocyanate (TDI) |
| Disturbances of the mucociliary transport | Tobacco smoke |
| Chronic lung disease | Arsenic |
Part C (Module 5 – Particulates and Solvents)
23 Name and give the definitions of the four types of particulate matters. In each case describe two industrial processes that generate these particulates
- Name the five different factors that influence the movements of particulate matters. In each case, describe a control method best used to minimize the dust exposure caused by such actions.
- Name and describe the disease process caused by the exposure of both crystalline free silica and asbestos?
- Explain the term “organic dusts”. Give three examples of such type of dusts and in each case briefly describe the source and health effects of exposure.
- Describe the general occupational health and safety hazards related to the use of organic solvents. Name three organic solvents and for each named solvent, the common usage in industries.
- Given these two organic solvents: methyl ethyl ketone (MEK) and benzene. Find out the six solvent properties described in Lesson 5.4 for each and list them in a table format. Give your reasons as to why one is preferred over the other from an occupational health and safety standpoint. You’re required to provide the references that give you the information. (Hint: the Internet has numerous resources to obtain the data for these solvents; however, you’ve to ensure that the sources are credible and that the information is current)
- Name the two most common health effects caused by organic solvent exposure. Provide the name of five organic solvents and indicate their respective health effects related to occupational exposure.
- Name and describe the characteristics of the two classes of respiratory protective equipment. Explain the basic difference in respiratory equipment designs regarding protection against particulate matters and solvent vapours.
Part D (Module 6 – The Skin and Eye)
- Briefly explain why the skin and eye are two vulnerable organs of the human body with respect to occupational health.
- Briefly describe the meaning of these terms:
- Stratum corneum
- Sloughing process
- Melanin
- Describe the five components of the dermis layer of skin. Briefly describes the important function of each from the health and safety standpoint.
- Explain the factors that affect the skin as a route of absorption and excretion of chemical exposure.
- What are the four main classifications of occupational skin diseases? For each class, give two examples of such disease and the workplace exposures causing such diseases.
- Explain the difference between irritant contact dermatitis and allergic contact dermatitis. Give examples of agents (at least three) that cause each of these two types of skin disorders.
- Briefly describe the four different types of eye hazards. For each type, give at least one example of such hazard in a workplace.
- Briefly describe, using three to four points, the meaning of each of the following terms and their significance in occupational health:
- Dermatitis
- Erythema
- Chloracne
- Miliaria
- Photosensitization
- Glaucoma
- Conjunctivitis
- Welder’s flash
- Blinking reflex
- Lacrimal glands
Describe the control measures that are common to both occupational skin and eye hazard exposure. Your answer should highlight the unique control measures that apply to skin and eye hazards respectively.
