Chapter 1

Question 1

What is toxicology?

The study of of _ or on living organisms?

Answer 1

The study of adverse effect of chemical or physical agents on living organisms

Question 2

What are the 2 goals of toxicology?

Answer 2

Toxicity of the substance/
safe/acceptable level

Question 3

Why everything can be toxic?

Answer 3

The dose differentiates remedy and poison.

Question 4

What is the difference between pharmacology and toxicology?

Answer 4

Pharmacology: therapeutocal
Toxicology: toxicosis or disease effect

Both goes hand in hand

Question 5

What antiquity contains info on toxic plants and animals?

Answer 5

Ebers payrus

Question 6

Dioscorides wrote what?

Answer 6

Materia de medica

for treatment/killing/disease

Question 6

Dioscorides wrote what?

Answer 6

Materia de medica

for treatment/killing/disease

Question 7

How did Qin Shi Huang die?

Answer 7

Mercury poisoning

Question 8

What is the role of Cleopatra the Egypt Queen?

Answer 8

Ancient toxicologist

Question 9

Who is Catherine de Medici?

Answer 9

First experimental toxicologist

Question 10

Who is Catherine Deshayes?

Answer 10

Resposible for >2000 infants death

Question 11

What’s wrong with the chimney carcinogen?

Answer 11

Beonzoate -> ethyl ring
Burn tar -> continuous exposure -> skin cancer

Question 12

What happened in Minamata Bay?

Answer 12

It was a fishery bay. Hg polluants were thrown to the bay, accumulated in seafoods.

Question 13

What happened in Seveso (Italy)?

Answer 13

An explosive release of TCDD (Dioxin)

Question 14

What happened in Seveso (Italy)?

Answer 14

An explosive release of TCDD (Dioxin)

Question 15

What happened in Bhopal, India?

Answer 15

A chemical leak -> 3000 deaths

Question 16

What’s wrong with Spanish oil syndrome?

Answer 16

Pretend olive oil -> fake oil -> continuous exposure will degenerate neuron.

Question 17

What toxic substance was found in paper in 1980s?

Answer 17

Dioxin

Question 18

For the fake milk powder, what was found toxic?

Answer 18

melamine

Question 19

For the fake milk powder, what was found toxic?

Answer 19

melamine

Question 20

Can the adverse effects be affecting the next generation?

Answer 20

yes

Question 21

What’s the issue for fake alcohol for tuourists?

Answer 21

The ethanol was mixed with methanol, where methanol is inedible. Some people lack the enzymes to break down.

Question 22

What are the 3 classifications of toxicology?

Answer 22

1. Descriptive toxicology : What do we expose to? What type of toxin?
2. Mechanistic toxicology: Why will it induce adverse effect?
3. Analytical toxicology: How much is the dose?

Question 23

What are the 4 types of applied toxicology?

Answer 23

1. Occupational toxicology
2. Clinical toxicology
3. Forensic toxicology
4. Regulatory toxicology
5. Developmental toxicology

Question 24

State the definition of toxicity

Answer 24

The degree to which a susbstance can harm animals or humans

Question 25

What are the 3 types of toxicity?

Answer 25

1. Acute 2. Subchronic 3. Chronic

Question 26

Memorize the definition of acute toxicity

Answer 26

Acute toxicity describes the **adverse effects** of a substance that results from either **a single/multiple exposures** in a **short space of time (< 24hrs).** The adverse effects should occur **within 14 dats of administration of the substance**. 1. Exposure is within 24 hrs 2. Adverse effect within 14 days 3. single/multiple exposure 4. A single substance

Question 27

Memorize the definition of subchronic toxicity

Answer 27

The ability of toxic substance to **cause effects for more than 1 year** but **less than the lifetime of the exposed organism**. Usually following exposure to a **repeated/continuous** dose over **a period up to about 90 days**. 1. Exposed to repeated/ continuous exposure 2. Up to 90 days 3. One single compound 4. Adverse effect > 1 year < life span

Question 28

Memorize the definition of chronic toxicity

Answer 28

The ability of **a substance or mixture of substances** to cause harmful effects over an extended period. Usually upon repeated or continuous exposeure, some can last for the **entire life of the exposed organism**. 1. Mixture of substances/ single substance 2. Exposure can be the whole life time of the organism 3. Adverse effect can be entire life

Question 29

What are the 8 classifications of toxicants?

Answer 29

1. Target use 2. Intended use 3. Source 4. Special effect 5. Physical state 6. Toxicity 7. Chemical composition 8. Mechanism of action

Question 30

Describe immediate toxicity

Answer 30

* Equivalent to acute toxicity * Cyanide, arsenic * Easy to detect and can link a particular exposure to a particular chemical.

Question 31

Describe delayed toxicity

Answer 31

* Long latency period * Can be 20-30 yrs after exposure before tumours are observed * The long delayed latent period makes if diffcult to demonstrate/prove the cause&effect * Asbestos 石棉 (1 exposure can cause adverse effect)

Question 32

Toxic effects can be reversible or irreversible, T/F?

Answer 32

T

Question 33

Toxic effects can be reversible or irreversible, T/F?

Answer 33

T

Question 34

What is the most important factor in determining the reversibility of damage?

Answer 34

Regeneration capcity of tissues | High regeneration capacity makes it better to revover from toxic insult

Question 35

Is liver damage reversible? Why?

Answer 35

Yes, cuz high regenerative capacity of the liver.

Question 36

Is brain cell damage reversible? Why?

Answer 36

No, CNS has a limited regenerative capacity

Question 37

What is special about oedema of the respiratory mucosa?

Answer 37

* It is a reversible toxic effect * But it can have irreversible consequences * Asthmatic person exposed to SO2 (irritant), oedema can lead to restriction of airways -> death * Although oedema itself can be reversed

Question 38

What are the 2 **natures** of toxicity

Answer 38

Local (bee) or systematic (snake)

Question 39

Give some features of systemic effects of toxicants

Answer 39

* Absorbtion and distribution from entry point to a distant site, where adverse effects are produced. * the target organ is not the site of the highest concentration * CNS, circulatory, skin, blood and haematopoietic system, visceral organs.... * Muscle and bone are less frequent

Question 40

Recall the toxicity rating of oral human dose

Answer 40

Read lecture notes, 5 as a unit

Question 41

What is the meaning of LD50?

Answer 41

The dose that kills 50% of the animals

Question 42

What are the differences between public perception and scientific evaluation/reality?

Answer 42

* Perception thinks synthetic toxins pose greater carcinogenic hazards than natural toxins * Proportion of natural chemicals that is carcinogenic when tested in both rats and mice is the same as for synthetic chemicals * All chemicals arer toxic at some dose