Principle of risk assessment Flashcards
What is a risk assessment?
provides evalutaion of likelihood of unacceptable impact to humn health and the environment
Name five reasons for why you should do a risk assessment for a contaminated site
- identify exsisting hazardous situations
- anticipate potential problems
- provide a basis for regulatory control and remediation actions
- prioritize among objects
- setting environmental guidelines
What is a risk?
- the combined effect of the potential of the probability of a harmful event to occur and the magnitude of the consequence
ex. kärnkraft: låg risk för olyckor, stora konsekvenser –> totalt ganska säkert
What are the two fundamental phases of a risk analysis?
- risk assessment
- risk management
What is risk assessment and what is the aim?
- a process for understanding
- aim: to find out how much damage of injury that can be expected as a result of a specific event
What is risk management and what is the aim?
- a process for action
- aim: to determine the acceptability of hazards and what action (is any) should be taken to reduce (or eliminate) unacceptable risks.
- consider social, exonomic and political factors
When is something at risk?
- a HAZARD exsists
- a PATHWAY occures via which the effects of the hazard can be transmitted
- a TARGE OR RECEPTOR is exposed to doses of the contaminant hazard
OBS! if one factor is absent (chain is broken) there is no likelihood of risk
some risks are tolerable, if we know how to handle them
What are some of the pathways of a contaminant if a human is the receptor?
VAPOR
- inhalation of vapor
SOIL
- inhalation of dust
- intake of soil
- dermal contact
PLANTS
- intake of plants
GROUNDWATER
- intake of drinking water
What sould you consider when looking at the risk source?
- is there a hazard
- what is the hazard
- what are the physical and chemical properties
- the characteristics of the source
What sould you consider when locing at transport or spreading?
- how big problem might it be
- retardation or release processes
- degradation or chemical concersion
- methods to assess spreading
- transport or spreading modeling
Name the three different effects
- addiative efects: effect from both
- cumulative effects: increasing eachother
- antagonistic effect: cancel eachother out (ax. carbons and acid)
What sould you consider when locing at exposure assessment?
- the magnitude of actual and/or potential receptor exposure
- frequency and duration of exposure
- characteristict of population at risk (ex. kids)
- pathways be which exposure may occur
Why is tiered or sequential risk analysis prefered before “normal” risk analysis?
- you can make preliminary decisions between each step –> takes less time and resources (saves time and money)
What is considerd when deciding a guideline value?
the risk to:
- human health
- soil environment
- spreading
The guideline value is set to the lowest of the three values
the value is adjusted so:
- it is taken into acount that a person may be exposed to other sources as well
- occasional ingestionof soil sould not cause acute health effects
- the valuse sould not be lower then background values
What are some quantification of critical effects for an ecosystem?
- serious risk to the environmet = serious risk to ecosystem functions
- protected species of organisms in ecosystem protected –> ecosystem function protected
- risk to the environment –> probability that more than a certain frction of the species are harmed by contaminants
- protection of species at population level
