3

Question 1

types of exposure routes / pathways?

Answer 1

ingestion
injection
inhalation
dermal
through mucous membranes

Question 2

factors affecting toxicity of a substance in an individual:

Answer 2

dose amount (how much)
dose frequency (how often)
dose duration (how long)

Question 3

define dose =

Answer 3

conc or amount of toxin that enters the living organism at a given time

Question 4

define exposure dose =

Answer 4

dose present in environment

Question 5

define absorbed dose =

Answer 5

proportion of exposure dose that enters living organism

Question 6

define toxic dose =

Answer 6

dose that causes adverse or harmful effects
TD0, TD10, TD50, TD90

Question 7

define threshold dose =

Answer 7

dose at which toxic effect is first observed

Question 8

define lethal dose =

Answer 8

statistically derived dose
LD50

Question 9

define effective dose =

Answer 9

indicates effectiveness

Question 10

what do monotonicity and nomonotinicity refer to?

Answer 10

changes in the slope of the curve describing dose and response

Question 11

monotonic curves…

Answer 11

may be linear or non-linear
but slope never reverses from pos to neg or vice versa

Question 12

nomonotonicity curves…

Answer 12

slope changes sign
from pos to neg or vice versa
‘u-shaped’ or ‘inverted u-shaped’

Question 13

define administered dose =

Answer 13

experimental animals

Question 14

define internal dose =

Answer 14

amount of toxicant absorbed
reflects only that amount that is absorbed is available to cause harm

Question 15

define target organ dose =

Answer 15

amount that reaches the site at which adverse effects occur
AKA biologically effective dose

Question 16

why don’t we absorb all the exposed dose?

humans have…

Answer 16

natural barriers like placental, blood brain
keratin in skin reduces absorption
lungs inability to absorb large particles
high acid conc in intestine inhibits absorption

Question 17

what are the co-founding factors in individuality?

Answer 17

sensitivity
susceptibility
variability

Question 18

examples of biological factors:

Answer 18

age
sex
health
ethnicity

Question 19

examples of sociocultural factors:

Answer 19

diet
smoking / alcohol / drugs
occupation
religion
housing location

Question 20

how does gender have an effect on the dose-response relationship?

Answer 20

hormonal differences influences the response an individual has to possible endocrine-disrupting chemicals

Question 21

what is an endocrine disrupting chemical (EDCs)?

Answer 21

an exogenous substance that causes adverse health effects in an intact organisms or changes to endocrine system

Question 22

how do EDCs interact with the endocrine system?

Answer 22

bind to a specific site/gene in nucleus just like natural hormone

Question 23

what effects do EDCs have on endocrine system?

Answer 23

mimic / provoke…
block / inhibit…
elicit weaker / stronger…
make new…
…hormone response

Question 24

how are females more susceptible to toxins?

Answer 24

elevated levels of oestrogen and progesterone
coz enzymes involved in biotransformation are responsive to hormones

Question 25

why do females get drunk quicker?

Answer 25

lower levels of enzyme alcohol dehydrogenase reduces ability to detoxify alcohol

Question 26

biomarkers of exposure and uptake:

Answer 26

chemical, product of interaction measure of internal dose

Question 27

biomarkers of effect:

Answer 27

measurable biochemical / physiological / behavioural change associated with exposure of toxin

Question 28

biomarkers of susceptibility:

Answer 28

indicator of an inherent or acquired ability of an organism to respond to challenges of exposure

Question 29

biomarkers of clinical disease:

Answer 29

indicate a disease state but difficult to determine the contribution of environmental toxin to disease state

Question 30

define hazard =

Answer 30

potential for adverse or harmful effect psychological or physiological