week 2 risk assessment/managment Flashcards
What is a hazard?
threat to human health or the environment; could be chemical, physical, biological, or cultural
What is risk?
probability of harm (there is no such thing as zero risk)
What is safety?
freedom from danger, risk, or injury (there is no such thing as 100% safe)
What is risk assessment?
determination of probability that an adverse effect will result from a define exposure (this is a scientific process)
What are the four steps of risk assessment?
Hazard identification, dose-response assessment, exposure assessment, risk characterization
What is risk management?
Process of weighing policy alternatives and selecting the most appropriate regulatory actions based on the results of risk assessment and social, economic, and political concern; science and value judgement; “what do we do about it?”
What are the components of risk? How is risk calculated?
- Existence and severity of a hazard
- likelihood or probablity of exposure
RISK= (SEVERITY OF HAZARD) X (PROBABILITY OF EXPOSURE)
What factores influence risk perception?
- trust
- control
- dread
- risk vs. benefit
- human-made vs. natural
- “could it happen to me?
- new or familiar
- children
- uncertainty
- age
How does controllabity and observability affect risk?
- observable & controllable= low risk
- not observable & controllable/ observavble & not controllable= medium risk
- not observable or controllable= high risk
What level of risk is acceptable?
Arbitrary number, depends on situation; see slides for examples
What is the purpose of risk assesment?
- weigh the harms and benefits (risk/rewards)
- set target exposure/dose levels
What is hazard identification?
Looking at if a hazard is having an impact on health; might use observational or experimental data
How do we weigh evidence in hazard identification?
- Human data prefered (relevant species, capture genetic variation, real-world exposures)
- Animal data (more controlled, similar physiological patterns, some correlation with human effects, accepted by scientific community, require by regulatory community)
What is the dose-resposnse assesment?
- characterization or quantification of the relationship between exposure/dose and effect
- describes how likelihood/severity of adverse health effects are related to amount/condition of exposure to agent
What are the two steps in dose-response assessment?
- Model the shape of the dose-response curve in observable range
- Extrapolate the dose-response curve to estimate dose that starts to cause increased risk in population of interest
When and why is linear extrapolation used?
Used for carcinogens, suggests there is NOT a safe level
When and is nonlinear extrapolation used?
curved line is used for carcinogens, suggests there is no safe level
What is NOAEL?
- No Observable Adverse Effect Level
- Highest expoure level at which no statistically or biologically increases are seen
What is LOAEL?
- Lowest Observable Adverse Effect Level
- lowest expoure level at which no statistically or biologically increases in frequency or severity of adverse effects
What is BMD?
- Benchmark Mark Dose
- dose or concentration that produces a predetermined change in response rate of an adverse effect compared to background
What is BMDL?
- Benchmark Dose Lower Level
- a statistical lower confidence limit on the dose or concentration at the BMD
What do you use to graph non-carcinogens?
NOAEL, LOAEL, or threshold (BMD/BMDL)
What do you use to graph carcinogens?
slope (q*) and point of departure (POD)
What is the end-product of dose-response step for carcinogens and non-carcinogens?
Carcinogens: slope factor
Noncarcinogens: NOAEL, LOAEL, BMDL
