Lecture 9 - DA Flashcards
Where did risk assessment originate from?
Insurance industry
Why are error bars necessary in biological statistics?
There is always inherent variability.
Why does ecological risk assessment consider non-human species?
More sensitive to environmental contamination, as non-human species have higher contact with pollutants, while humans have low contact.
Define ecological risk assessment.
Process that evaluates the likelihood that adverse ecological effects may occur or are occurring as a consequence of exposure to one or more stressors.
What is the consequence in an ecological risk assessment?
The hazard, which is the toxicant.
Name 2 ways to define risk (formula).
Risk = exposure x effect Risk = likelihood x consequence
Is risk always consistent? Give an example with zinc.
No it isnt.
Zinc has the same effect at a given concentration, but bioavailability will differ in freshwater systems compared to marine due to pH.
Why are LC50 tests done on the most sensitive species?
It would be useless to do it on tolerant species.
Define hazard.
Potential to cause harm.
Define risk.
Probability that harm will be caused.
What 2 factors are ecological risks based on?
Toxicity of a compound (ie LD50).
Anticipated exposure of an organism to that compound.
How are risk assessment endpoints developed?
In collaboration with stakeholders.
Define and explain the two categories risk assessment, and describe where the management focus is, and the degradation status.
Predictive - for proposed future actions
No degradation yet, focus is on prevention.
Retrospective - investigation of past activities that may have ongoing consequences.
Degradation has occurred and focus will be on remediation.
Define complications of inference.
Whether observations in the field are due to contaminants or another anthropogenic cause, or natural variability.
Whats more complex, human risk assessment, or non-human risk assessment?
Non-human risk assessment.
