conducted by psychologists reveal that individuals have a difficult time
determining the relative risks in many activities. We also often have
a hard time ranking the frequency of many causes of death, because some
“exposures, shcuh as floods and motor vehicle accidents are catastrophic
and highly publicized while other types of causes such as obesity and
diabetes are chronic, and are not as obvious causes of death. Further
experiments also show that we are often overconfident in our ability to
strategy to estimate risk is called "heuristics.” A "heuristic"
is a simple set of rules based on information available to an individual
(information that is often based upon experience, or "trial and error")
that he or she then uses to make decisions or estimations about a given
situation. Two of the main heuristics we use in estimating risk are the
availability heuristic and the anchoring and adjustment heuristic.
heuristic simply means that people determine the probability of an event
occurring by how easily they can recall or imagine examples of the occurrence
of a similar event. A good example of the availability heuristic in action
is how one overestimates the deathes by bee sting and cancer and underestimates
those from diabetes.
feelings about exposure to a risk are also strongly influenced by whether
they chose to expose themselves to that risk. For example, a smoker who
accepts the risk of her smoking habit might react strongly to the risk
of dioxins leaching from tampons and creating the risk of cervical cancer.
She may take precautions in this case, even though the risk is smaller
than that from smoking.
behind risk assessment is to get a "number" that could be used
objectively to determine impacts. However, we discussed all the problems
involved with the assessment particularly the DRA. In addition, the risk
you calculated is for a generic population. Although, Can you answer the
question of "will I get cancer if I live next to this risk?,"
Or, "am I safe?" No you can't answer those questions definitively.
In a democratic society, people have a say in their exposure to chemical
risks. Therefore, it is important to understand something about how people
assessment of risk may be markedly different from quantitative risk assessment
using collected data. Several reasons for this discrepancy include:
events alter perception. Media articles, lots of deaths occurring at
one time, sudden deaths occurring (airline crash, student shooting spree)
risk versus individual risk alters perception- uncertain as to who will
be the 1 in a million. People still play the lottery hoping to be that
1 in a million or even 1 in 10 million.
of talking about risk influences public perception of risk and that
perception may change over time (media, surveys)
beliefs change slowly despite evidence to the contrary
way information is presented affects public perception (risk of death
is 32% versus risk of survival is 68% say the same thing but can lead
to different perceptions)
versus involuntary risks cause different reactions from the public.
Often it is okay to choose a risk but it is not okay for government
or industry to put me at risk
versus artificial risk are often viewed differently even if the risk
is the same (spices versus pesticides)