Part III Lecture 7

Question 1

Toxicokinetics?

Answer 1

Quantitation of the time course of toxicants in the body during the processes of absorption, distribution, biotransformation, and excretion or clearance of toxicants
End result: biologically effective dose

Question 2

Toxicodynamics?

Answer 2

Molecular, biochemical, and physiological effects of toxicants in biological systems

Question 3

Dose-response concept

Answer 3

Magnitude of the toxic effect depends on the concentration of altered molecular targets, which in turn is related to the concentration of the active form of the toxicant at the site where the molecular targets are located

Question 4

Risk

Answer 4

Probability of injury, disease, death from exposure to a hazard
- a function of exposure potential, receptor characteristics, and likelihood of occurrence of exposures and health effects

Question 5

Hazard

Answer 5

Agent or set of conditions with potential to cause harm (source of risk)

Question 6

What are the 3 components of risk assessment?

Answer 6

1. Hazard identification
2. Exposure assessment
3. Dose-response assessment

Question 7

What is hazard identification?

Answer 7

Describe the potential adverse health effects caused by a specific agent, and the mechanisms (dose, route, duration, timing)

Descriptive, not quantitative

Question 8

What is exposure assessment?

Answer 8

Define the exposure of interest and the route of exposure (intensity, frequency, duration of exposure)

Question 9

What is dose-response?

Answer 9

Allows us to quantify risk (quantitative relationship between dose and incidence)

Question 10

E.g. of dose-response shapes?

Answer 10

• Linear
• Convex
• Concave
• Threshold (not a 0,0)

Question 11

What is risk characterization?

Answer 11

• Integrates hazard identification, exposure assessment and dose-response
• Evaluates quality of assessment and confidence
• Describe risk in terms of extent, severity of probable harm
• Communicate to decision makers