RISK newsletter:
On Merging Our Two Risk Cultures
Source: The Society for Risk
Analysis' RISK newsletter,
Second Quarter 1995
"Let this be our challenge: to insist on the practice of
risk assessment being a true example of genuine interdisciplinary
problem solving. We can do this only with a reasonably balanced
representation from all the sciences, including engineering, as
well as from the legal, economic, and management communities. By
making this the signature of SRA, we will serve all of society in
the best possible way." --- B. John Garrick
As the most recent recipient of SRA's Distinguished
Achievement Award, a dedicated member of the Society, and a
long-time practitioner of risk analysis for engineered systems,
former SRA president B. John Garrick was uniquely qualified to
both criticize and advise the Society during his address at the
1994 Annual Meeting.
Pointing out that the Society had thus far failed in its goal
to "get this multicultural risk community to work as a
team," he said that risk analysts had coalesced around two
basic groups -- engineers and non-engineers -- who had little
appreciation for each other and too often worked against each
other, thereby confusing real decision makers, namely, the
public.
Garrick believes the reason for this extends beyond the
inherent philosophical differences of the two groups on problem
solving and is primarily due to their different beginnings.
Although earlier work had been done, the engineers had their big
boost into the risk assessment field with the 1975 reactor safety
study directed by SRA's 1990 awardee, Norman C. Rasmussen. The
non-engineers (whom Garrick also broadly classified as
environmentalists) had their start in the field with the cancer
risk assessment guidelines issued by the U.S. Environmental
Protection Agency in the mid-1970s and later with the paradigm on
risk assessment issued by the National Academy of Sciences in
1983.
Although a reasonable merging of the two cultures occurred
for early risk assessments of nuclear plants, Garrick said the
same level of comprehensiveness has not been applied to other
systems, and that needs to be changed. "We engineers greatly
need to embrace the ideas of risk communication, [and] we need
the help of the health scientists to improve and update our
health effects models." At the same time, "the
environmentalists need to catch up in the areas of information
processing, the quantification of uncertainty, and a more liberal
consideration of different performance measures beyond
cancer."
Turning to specific issues, Garrick addressed the continuing
debate about thresholds for radiation and chemical carcinogens.
By assuming that no-damage thresholds do not exist, he said, risk
assessors are predicting statistical deaths that give decision
makers only the most conservative and costly choices_this in
spite of the fact that risk assessments were begun as a means of
offering decision makers realistic appraisals.
Risk analysts must quantify their uncertainties, which, if
nothing else, will provide guidance for research and corrective
actions, Garrick said. "It shouldn't be a question of
whether or not there is a no-damage threshold, but rather a
question of how likely there is and how likely there isn't, and
that should be the basis of our calculations." That is, the
challenge is for risk analysts to translate their knowledge into
the language of uncertainty, which is the language of
probability. While the two cultures have not worked well together
in this area, the only possible way to quantify uncertainties
with any kind of credibility is for the two groups to combine
their talents and commit to a common goal.
Garrick also believes that the performance measures
calculated shouldn't be limited to those required by law. Citing
the nuclear waste repository as an example, he said that risk
analysts shouldn't be in their current position of waiting to be
told what to calculate, but instead should be calculating all
performance measures: doses to humans, releases to the biosphere,
etc. "Not only would it be cheaper, but we would do a better
job of characterizing the risk."
Another of Garrick's concerns is the issue of
"acceptability and decision." Since risk is a
continuous and not a discontinuous function, he said,
decision-theoretic approaches to risk problems should be adopted.
Again citing the repository as an example, he said that the dose
delivered to the biosphere can be made as small as desired. But
what will the cost be? "The real questions and the real
decisions that have to be made are all concerned with the
allocation of societal resources."
Garrick also talked about how the Society can better serve
the risk management activities of the nation. One way, he said,
is to meet the challenge of the distortion of risk information by
the media, congressmen, and other institutional representatives
by being willing to bridge the gap between popular risk and
scholarly risk. "We owe it to our Society and the public to
get involved, and from the media's perspective, we just haven't
been doing so."
In another area, the Society can help ensure a workable
process for involving the public in risk assessment and
management. For example, the U.S. Department of Energy has
recently adopted the recommendations of a National Academy of
Sciences committee report written in response to a DOE inquiry on
"whether a risk-based approach to evaluating the
consequences of alternative actions (regarding their
environmental-remediation program) is feasible and
desirable." Having served on the NAS committee, Garrick says
that the DOE public-participation policy, which addresses many
more issues than risk, is to be handled on a site-specific basis.
Unless risk experts get involved in articulating clearly and
concisely the questions that need answers, he fears that the same
mistakes that created the almost impossible licensing process for
nuclear facilities will preclude a rational approach to
remediating nuclear facility and nuclear weapons sites.
"I think we can make a difference because the core
values of the DOE policy include such qualities as accuracy,
communication, consistency, honesty, innovation, openness, and
scientific credibility. All of these and more are the very
foundation of quantitative risk assessment, and to deal with the
honesty value we must be quantitative. By which I mean we must
quantify our uncertainties. By which I mean we must deal with
probabilities, which is the language of uncertainty. To those who
say that this is a risk communication problem, I say that unless
you have something with substance to communicate, you will not
succeed in the public arena."
Garrick said that even though risk assessment is more of a
thought process than a genuine science or engineering discipline,
it can greatly improve science and engineering by facilitating
better decisions on alternative solutions to societal problems.
"We always need to be thinking about solving problems, about
how to wrap up the science and get on with closure of projects.
[In so doing], we will provide a knowledge base that will give
greater assurance that the standards and regulations that follow
will indeed provide protection."
Returning to the issue of merging the two cultures, Garrick
said, "A competent risk assessment and risk management
program is not just multi-diciplinary but more importantly
interdisciplinary, as has been discussed by two former recipients
of this honor, Chauncey Starr in 1984 and Sheila Jasanoff in
1992."
Garrick concluded by issuing the challenge to the Society
printed at the beginning of this article.
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