Risk assessment Flashcards
What is the definition of Risk Assessment?
Process in which the hazard and risks of negative effects on humans
and/or the environment as a result of exposure to substances are
evaluated
What is a hazard?
something that has the potential to cause unwanted consequences
What is a risk?
the chance that undesirable consequences will occur
How is risk calculated?
Risk = hazard x exposure
What is researched with a hazard assessment?
Has the compound the potency to
cause an adverse effect?
What is researched with a Dosis-effect assessment?
What is the relationship between
the dose and manifestation of
the effect in humans?
What 3 assessment does risk assessment consist of?
Hazard assessment
Dosis-effect assesment
exposure assessment
What does risk characterisation determine?
The estimated
occurrence of a
negative effect in a
given population
What aspects determine experience of risks?
-risk of health damage
-consequences of health damage
-voluntary exposure
-attention in media
-trust in responsible authorities
What is LD50?
Dose at which 50% lethality occurs
(=acute toxicity value)
What are the 2 classification types of substances?
- non-genotoxic substances = threshold
-genotoxic carcinogens = non-threshold
What are steps to derive a standard for threshold?
- Toxicity tests
- Point of Departure (PoD)
- Establish critical effect
- From PoD to standard
What is the purpose of a chronic test?
estimate NOAEL
What is TDI?
Tolerable Daily Intake
- unavoidable compounds
What is ADI?
Acceptable Daily Intake
- avoidable compounds
Wat is de formule voor TDI?
NOAEL / UF x UF
(UF = uncertainty factors)
What are 4 uncertainty factors?
Semichronic => chronic
- LOAEL => NOAEL
- Limited dataset
- Type laboratory animal
What are disadvantages of NOAEL?
- NOAEL must be one of the doses tested
- Except NOAEL, the rest of the dose response curve is ignored
What is an alternative to NOAEL?
BMD = Benchmark Dose
What is BMD?
a dose or concentration that produces a predetermined change
in the response rate of an adverse effect
What is MOE?
Margin of Exposure
MOE of 100 or more is safe
What is the MOE formula?
TD10 / exposure dose
What is the mutage of acrylamide?
Glycidamine
What is MOS?
Margin of Safety = toxic value/dose
What are uncertainties/considerations for risk assessment with animals?
- Extrapolation animal -> humans
- Different diet groups
- other pathways
- bioavailibility is lower in humans
- humans metabolise less and excrete more = less exposure
What is ED?
Effective Dose
What is TD?
Toxic dose effect
What is TI?
Therapeutic Index = measure of relative drug safety
What is disadvantage of TI? What is a alternative?
Slope dose-respons curve ED and TD
MOS
