Learning Objectives:

• Understand the definition of ergonomics in engineering and recognize its significance in optimizing human-system interactions.
• Define human factors engineering and its role within the broader field of ergonomics.
• Identify ergonomic considerations for chairs, desks, and monitor placement.

Ergonomics is the study of designing and arranging things people use, so that the people and things interact most efficiently and safely. In chemical engineering, this includes the design of workspaces, equipment, and systems to optimize human well-being and system performance.

• Human Factors Engineering: Human factors engineering is a subset of ergonomics focused on the interaction between humans and the systems they operate.
• Workstation Design: Proper workstation design is crucial for preventing musculoskeletal disorders and ensuring optimal performance.
• Material Handling: Involves the design of equipment and processes for safely handling materials, minimizing physical strain on workers.
• Safety and Health: Ergonomics is integral to the overall safety and health programs in chemical engineering. Proper ergonomics can reduce the risk of accidents, injuries, and long-term health issues among workers.
• User Interface Design: Ergonomic design of control panels and interfaces is critical for efficient and error-free operation. Placement of controls, clarity of displays, and user-friendly interfaces to enhance operator performance.
• Environmental Factors: Ergonomics includes considerations for the physical environment, such as maintaining comfortable temperatures and proper lighting to reduce eye strain.

Solved Example: 9478-01

In workstation design, why is adjustability important for ergonomic chairs and desks?

A. To accommodate diverse workforce preferences

B. To minimize equipment costs

C. To enhance workplace aesthetics

D. To maximize production output

Correct Answer: A

Solved Example: 9478-02

What is the role of ergonomics in the layout of factories and plants?

A. Enhancing workplace aesthetics

B. Optimizing human-system interactions

C. Minimizing production output

D. Reducing material handling costs

Correct Answer: B

Learning Objectives:

• Differentiate between different types of PPE, including head protection, eye and face protection, respiratory protection, hand and foot protection, hearing protection, and fall protection.
• Identify specific PPE items within each category and their corresponding hazards.

1. Eye and face protection

   • Safety Glasses

   • Chemical Splash Goggles

   • Face Shields

2. Hand protection

   • Light latex, vinyl or nitrile gloves

   • Insulated gloves

   • Wire mesh gloves

3. Body protection

   • Traditional

   • Flame resistant

   • Barrier

4. Respiratory protection

   • Surgical masks

   • N-95 respirators

   • Full-face respirators

5. Hearing protection

   • Earplugs

   • Hearing band

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Learning Objectives:

• Define carcinogen and explain its significance in environmental engineering, occupational health, and public health.
• Identify and classify different types of carcinogens, including chemical, physical, and biological agents.
• Describe the characteristics and sources of common carcinogens, such as asbestos, tobacco smoke, and certain chemicals.

Solved Example: 9888-01

Match List I with List II
List I
(Emitted Pollutants)
A. $CO_2$
B. $CO$
C. $NO_x$
D. $C_6H_6$

List II
(Environmental Impact)
I. Formation of acid rain
II. Toxic and are carcinogenic
III. Toxic and can cause respiratory diseases
IV. Contribution to global warming as a Greenhouse gas
Choose the Correct Answer from the option given below:

A. A - IV, B - III, C - I, D - II

B. A - IV, B - II, C - I, D - III

C. A - IV, B - II, C - III, D - I

D. A - I, B - III, C - II, D - IV

Correct Answer: A

Solved Example: 9888-02

Which of the following statement is correct related to the carcinogens?

A. A few well-known carcinogens are asbestos, nickel, cadmium, radon, vinyl chloride, benzidene, and benzene.

B. Substances known to cause tuberculosis are called carcinogens.

C. Certain chemicals, including benzene, beryllium, asbestos, vinyl chloride, and arsenic are known possible human carcinogens.

D. Chloroform, DDT, formaldehyde, and polychlorinated biphenyls (PCBs) are examples of human carcinogens.

Correct Answer: A

Learning Objectives:

• Define toxicology and its primary objectives, which involve studying the adverse effects of chemical, physical, or biological agents on living organisms.
• Explain the concept of dose-response relationships, including how the magnitude of exposure relates to the severity of toxic effects, and how this relationship is often depicted on dose-response curves.

Dose-Response Curve:

These curves are also studies in pharmaceutical studies to find the effect of a drug of sample experimental group of people

Scientists consider these curves important because these mathematical relationships signify that a medicine is working according to a specific interaction between different molecules in the body.

Characteristics of a Typical Dose-Response Curve:

• Potency: location of curve along the dose axis
• Maximal efficacy or ceiling effect: Greatest attainable response
• Slope: change in response per unit dose.
• Biologic variation: Variation in magnitude of response among test subjects in the same population given the same dose of drug) also occurs.

LD stands for Lethal Dose. LD$_{50}$ is the amount of a material, given all at once, which causes the death of 50% (one half) of a group of test animals. The LD$_{50}$ is one way to measure the short-term poisoning potential (acute toxicity) of a material.

LC stands for Lethal Concentration. LC values usually refer to the concentration of a chemical in air but in environmental studies it can also mean the concentration of a chemical in water. The concentrations of the chemical in air that kills 50% of the test animals during the observation period is the LC$_{50}$ value. Other durations of exposure (versus the traditional 4 hours) may apply depending on specific laws.

Solved Example: 9186-01

Toxicology is the study of:

A. Human Behavior

B. Poison

C. Soil Erosion

D. Rocks

Correct Answer: B

Solved Example: 9186-02

Given below are two statements:

Statement I: Chronic toxic effects result from a single dose of a very high toxic substance or continuous exposure to a sub-lethal dose.

Statement II: Acute toxic effects are long-lasting and irreversible mainly caused due to prolonged exposure to toxins and the survival rate is very low.

In the light of the above statements, choose the correct answer from the options given below:

A. Both Statement I and Statement II are true

B. Both Statement I and Statement II are false

C. Statement I is correct but Statement II is false

D. Statement I is incorrect but Statement II is true

Correct Answer: C

Solved Example: 9186-03

Given below are two statements:

Statement I: Dioxins and furans are highly toxic substances produced mainly during incineration of municipal solid waste, hazardous and medical wastes.

Statement II: Dioxins and furans play a crucial role in photochemical smog formation.

In the light of the above statements, choose the correct answer from the options given below:

A. Both Statement I and Statement II are true

B. Both Statement I and Statement II are false

C. Statement I is correct but Statement II is false

D. Statement I is incorrect but Statement II is true

Correct Answer: C

Learning Objectives:

• Define and differentiate between various occupational exposure limits (OELs), including Threshold Limit Values (TLVs), Permissible Exposure Limits (PELs), and Recommended Exposure Limits (RELs).

Solved Example: 9887-01

Given below are two statements: One is labelled as Assertion (A) and the other is labelled as Reason (R) :

Assertion (A): Carbon monoxide (CO) is a serious asphyxiant even a short exposure may have fatal health issues.
Reason (R): Hemoglobin present in the blood has a greater affinity towards carbon monoxide than oxygen.

In the light of the above statements choose the most appropriate answer from the options given below :

A. Both (A) and (R) are correct and (R) is the correct explanation of (A)

B. Both (A) and (R) are correct but (R) is NOT the correct explanation of (A)

C. (A) is correct but (R) is not correct

D. (A) is not correct but (R) is correct

Correct Answer: A

Solved Example: 9887-02

Given below are two statements:

Statement I: Chronic toxic effects result from a single dose of a very high toxic substance or continuous exposure to a sub-lethal dose.

Statement II: Acute toxic effects are long-lasting and irreversible mainly caused due to prolonged exposure to toxins and the survival rate is very low.

In the light of the above statements, choose the correct answer from the options given below:

A. Both Statement I and Statement II are true

B. Both Statement I and Statement II are false

C. Statement I is correct but Statement II is false

D. Statement I is incorrect but Statement II is true

Correct Answer: C

Learning Objectives:

• Understand the basic principles of ionizing and non-ionizing radiation and their sources in various engineering applications.
• Identify common sources of ionizing radiation (e.g., X-rays, gamma rays, alpha and beta particles) and non-ionizing radiation (e.g., ultraviolet, microwave, radiofrequency).
• Describe the biological effects of ionizing radiation on living organisms, including acute and chronic effects on health.
• Explain the concept of dose-response relationships in radiation exposure.

Types of Radiation:

• Ionizing/Non-Ionizing Radiation
• Particulate Radiation: Alpha and beta particles

Sources of Radiation:

• Natural: Terrestial radiation from Earth), Cosmic Radiation (from Sun), from radioactive elements (Uranium, etc)
• Man-made: Consumer products, air travel, nuclear fuel atmospheric fallout, medical radiation

Effects of Radiation on Human Body:

• Acute effects (erythema, hair loss)
• Effects on the embryo and fetus (mental retardation)
• Late effects: Cataracts (Cancer, Lukemia)
• Genetic effects: Hereditory disorders (Congential anamolies)

Solved Example: 9886-01

Gamma radiation can be shielded with:

A. Paper

B. Human Skin

C. Aluminum

D. Lead

Correct Answer: D

Solved Example: 9886-02

A person's dose resulting from his exposure to radiation is described in the following units:

A. Radium

B. Sievert

C. Gray

D. Becqurel

Correct Answer: B

Learning Objectives:

• Identify common sources and characteristics of biohazards, such as bacteria, viruses, fungi, and parasites.
• Describe the potential health effects of exposure to biohazards, including infections, allergies, and toxicity.
• Understand the modes of transmission of biohazards, such as airborne, droplet, contact, and vector-borne transmission.

Solved Example: 9300-01

What is an example of biological hazard?

A. Salmonella

B. Dirt

C. Cleaners

D. Antibiotics

Correct Answer: A

Learning Objectives:

• Define and explain the concept of half-life in the context of chemical kinetics and nuclear decay.
• Be able to calculate the remaining quantity of a radioactive substance after a given number of half-lives.
• Perform calculations involving half-life, including determining the remaining quantity of a substance and the time required for a given percentage of decay.

The half-life of a radioactive substance is the time interval during which half of the given number of radioactive nuclei decay.

Half lives can vary considerably as shown in the following examples

• Radon-222: 3.82 days
• I-131: 8.02 days
• Thorium-234: 24.10 days
• C-14: 5715 years
• U-238: 4.47 $\times$ 10$^9$ years

\[ N = N_0 e^{-\lambda t}\]

$ N = N_0 e^\left({\dfrac{-0.693 t}{\tau}}\right)$       Page 330

where, N$_0$ represents the number of undecayed radioactive nuclei at t= 0.

Half life is mathematically given by:

$t_{1/2} = \dfrac{\ln 2}{k} = \dfrac{0.693}{k}$       Page 330

KieranMaher at en.wikibooks, Public domain, via Wikimedia Commons

Solved Example: 9185-01

The material remaining after three half-lives of a radioactive material will be:

A. $\dfrac{1}{3}^{\mathrm{rd}}$ of original amount

B. $\dfrac{1}{6}^{\mathrm{th}}$ of original amount

C. $\dfrac{1}{8}^{\mathrm{th}}$ of original amount

D. $\dfrac{1}{9}^{\mathrm{th}}$ of original amount

Correct Answer: C