ROLE OF PRECAUTION IN RISK ASSESSMENT
AND MANAGEMENT: AN AMERICAN'S VIEW
D. Graham, Ph.D., Administrator
Office of Information and Regulatory Affairs
Office of Management and Budget
Executive Office of the President of the United States
Prepared for "The US, Europe, Precaution and Risk Management: A Comparative
Case Study Analysis of the Management of Risk in
a Complex World"
Organizers: The European Commission (Group of Policy Advisers), the US
Mission to the EU, the German Marshall Fund with the European Policy Centre
and the Center for Environmental Solutions, Duke University
that each new year brings new concerns about risks to human welfare, quality
of life, and environmental protection. Most public concern in the USA
relates now to the war against terrorism and the economic recession. There
are also continuing concerns about the health and safety risks that people
face from the consumer products, production methods, and wastes that support
the high standard of living we now enjoy. And there are some broader concerns
about what economic development is doing to the global environment and
the welfare of future generations. Given the explosion of information
about possible risks in life, it is difficult for the public to know which
of the many possible risks justify attention by policy makers.
Administration believes that science should have a strong role in setting
risk-management priorities. Even in the relatively simple case of health
risks, sound science is critical. First, there is the basic hazard question:
What is the degree of certainty that any hazard exists? For example, how
confident are we that the magnetic fields emitted from electric powerlines
cause an elevation in cancer rates among people living near powerlines?
Second, if the hazard exists, a probability assessment is required to
distinguish a significant risk from a negligible one. For example, if
magnetic fields do cause cancer, how much is the probability of cancer
increased by a lifetime of exposure to a nearby powerline? Third, the
number of people exposed to a hazard needs to be considered because population
exposures contribute to the public health significance of the hazard.
Fourth, the severity of the health effect is relevant. Even in the case
of a dreaded disease such as leukemia, we need to be sensitive to the
distinctions between those forms of leukemia that are untreatable and
rapidly fatal versus those forms that can be treated effectively by the
tools of modern medicine. The number and quality of life years lost from
disease need to be considered. Although these basic scientific questions
have been framed for health risks, it is feasible to frame a related set
of questions for other types of risks, such as threats to natural resources
and global ecology.
of how much scientific knowledge there is, public officials need to consider
the degree of public concern about possible risks and how that compares
with expert assessments. Although some of my academic colleagues might
argue that this is a perspective that I have only recently begun to appreciate,
it is surely a good thing that there is an emerging science of risk perception
and communication. How much does the public understand and care about
a hazard? How volatile is public opinion likely to be in the face of new
evidence or dramatic portrayals of danger? Does the hazard have characteristics
that elevate public concern, such as an unfair distribution of risks and
benefits? These social science questions remind us that the challenge
of risk management will not be resolved by hard science alone. We need
to consider the type and degree of public participation that is appropriate
for decisions about risks and I have always been impressed by the depth
of thinking by European social scientists on these questions.
sweeping questions about risk, what can we possibly hope to accomplish
in two short days? I would frame our task as follows: There is a subset
of possible risks in daily life that are subject to substantial scientific
uncertainty - often on all four of the scientific questions that I mentioned
- but that, for one reason or another, trigger significant public concern.
Under these circumstances, what is the appropriate role for precaution
in the responses of risk managers? I have in mind risk managers in both
the public and private sectors.
I mean by precaution? I can assure you that I do not intend to define
any universal precautionary principle. As you know, the US government
supports precautionary approaches to risk management but we do not recognize
any universal precautionary principle. We consider it to be a mythical
concept, perhaps like a unicorn.
I do believe
that a dictionary definition of "precaution" is a useful starting point
for the conference. WEBSTER'S Second College Edition of the NEW WORLD
DICTIONARY defines precaution as "care taken beforehand", or more precisely,
as "a measure taken beforehand against possible danger." I presume that
the word "beforehand" means before science has resolved all the key technical
questions about the hazard of interest. Precaution is a well-respected
concept: people practice it regularly in the stock market and in hospitals
to cope with the uncertain risks of life.
Americans have experienced the pain and suffering that can result from
insufficient precaution in risk management. The health risks of smoking,
the neurotoxic effects of low doses of lead, once used as an additive
to gasoline, and the respiratory diseases from exposure to asbestos in
the workplace: each became major public health problems in the USA. Public
health historians teach us that these problems could have been reduced
or even prevented altogether if early signals of danger had stimulated
precautionary measures by risk managers. I would be interested to learn
how promptly and effectively European policy makers addressed these concerns.
not belittle the scientific challenges in each of these examples. Consider
tobacco. Although the causal link between smoking and lung cancer now
seems obvious, in the middle of the previous century it did not seem obvious
to many well-trained and thoughtful physicians. They argued that they
had treated many smokers for a lifetime who never developed a significant
lung ailment. Likewise, they had treated patients with lung cancer who
were not smokers. The science of toxicology did not resolve this dilemma
because it proved difficult to produce tumors in laboratory animals with
tobacco exposures. The field of science that proved to be most decisive
is the one that some people now trust the least: epidemiology. There was
in fact a large statistical study of the health of British physicians
that played an important role in building the medical consensus against
smoking. Interestingly, epidemiology also played a pivotal role in uncovering
the neurotoxic effects of lead at low doses and the diseases associated
with exposure to asbestos on the job.
If we knew
that scientific progress would always verify early signals of danger or
show that hazards are worse than predicted, then the challenge of precaution
would be much easier. Yet the dynamics of science are not so easily predicted.
There are in fact many cases of postulated or claimed hazards that have
not been confirmed.
that drinking coffee might cause bladder cancer were not confirmed. In
the 1970's, the US Food and Drug Administration declared a virtual war
against the artificial sweetener saccharin, after animal tests revealed
bladder cancers following administration of huge doses to rodents. The
American people resisted the FDA's conclusion and possibly for good reason.
After thirty years of biological experiments and large-scale statistical
studies of the consumers of saccharin, it now appears that the prediction
of a human cancer risk may have been incorrect. Indeed, the US government
recently took preliminary steps to remove saccharin from its official
list of carcinogens. More recently, scientific findings were publicized
claiming that low doses of chemicals now in widespread use may be doing
harm to the endocrine systems of the human body. Yet further science has
revealed that some of these early findings about so-called "endocrine
disruptors" cannot be replicated by qualified scientists.
of risk are also fallible. When I was a college student in the 1970's,
there were scholarly predictions of a Malthusian global catastrophe, in
part stimulated by reports of the Club of Rome. There were also economists
predicting that the world price of oil would rise so high, due to limited
petroleum reserves, that the price of gasoline at the pump in the USA
would increase dramatically. Looking back, some of these predictions may
have been erroneous. As an academic I contributed to the erroneous predictions
when I forecasted that front-seat airbags would save 9,000 lives per year
in the USA. It now appears that the correct number will be somewhere around
3,000 lives saved per year.
As we contemplate
the role of precaution in risk management, we must remember that sometimes
possible risks prove far worse than expected; other times predictions
of doom simply do not materialize.
It is therefore
useful to draw a distinction between the role of precaution in the scientific
assessment of risk and the role of precaution in risk management. When
analysts assess risks, they may introduce conservative assumptions or
safety factors into the analysis to account for unknowns. These protective
practices may be intended to establish an upper bound on the true yet
unknown risk. In the US, the technical community is now trying to bring
more valid data into the risk assessment process. When considering the
role of precaution in risk management, it is appropriate for policy makers
and the public to inquire about the degree of precaution embedded in the
is taken to an extreme, it can be very harmful to technological innovation.
Consider the following thought experiment: Imagine it is 1850 and a decision
is made that any technological innovation cannot be adopted unless and
until it is proven to be completely safe by the proponents of the innovation.
Under this scenario, what would have happened to electricity, the internal
combustion engine, plastics, pharmaceuticals, the computer, the Internet,
the cellular phone and so forth?
In the USA
we have also learned the hard way that the urge for precaution can lead
to unfortunate outcomes. In energy policy, for example, some of us regret
our historical decisions regarding nuclear energy. The possible risks
of nuclear power generation, coupled with the desire for precaution and
rising costs of construction, caused a virtual halt in the construction
of new nuclear plants in the US. Thirty years later, we now find ourselves
even more deeply dependent on fossil fuels, which are a major source of
environmental concerns and calls for precaution. Part of the answer lies
in cleaner coal technologies, renewables and energy conservation but it
may be very unwise to foreclose the advanced nuclear option.
people can disagree about what is precautionary and what is dangerous.
Consider whether the diesel engine should be used in passenger cars and
light trucks. Regulators in the State of California have set the tailpipe
emission standards for particles and nitrogen dioxide so stringently that
it may not be feasible to offer diesel-power cars for sale in the future.
California's regulators see this rule as a measure to protect public health
from the known or possible health risks of smog and soot in the air. Meanwhile,
European regulators and finance authorities have facilitated the growth
of the diesel-engine market in Europe to the point that a substantial
share of new cars in Europe are equipped with diesel engines. From a global
climate perspective, the pro-diesel policy in Europe looks precautionary
since the diesel offers significant fuel efficiency advantages over gasoline-powered
vehicles. Yet we should also not forget that the price of gasoline at
the pump is three to four times larger in Europe than it is in the USA,
reflecting European tax policies.
example reminds us that a zero-risk policy is rarely feasible. More often
policy makers are engaged in an exercise of risk selection and we should
not permit any rhetoric about complete safety to obscure this truth.
for this conference, I re-read the European Commission's February 2000
Communication on precaution and related comments from committees in the
European Parliament. I was encouraged by these documents, even though
we have many differences of opinion about specific risk-management issues
and even though the documents do not provide a definition of the precautionary
"principle" while asserting its existence. Based on these documents, I
detected the following points of possible conceptual agreement.
is a necessary and useful concept but it is also subjective and susceptible
to abuse by policy makers for trade purposes and other reasons. Second,
scientific and procedural safeguards need to be built into risk management
decisions that are based in part on precaution. Third, adoption of precautionary
measures should be preceded by a scientific evaluation of the hazard and,
where feasible, a formal analysis of the benefits, risks, and costs of
alternative precautionary measures. Fourth, concerns for fairness, equity
and public participation need to be reflected in risk management. Finally,
the set of possible precautionary measures is large, ranging from bans
or product restrictions to education or warnings to market-based reforms.
Even the initiation of a targeted research program to better understand
a possible risk is a precautionary measure. As we consider the case studies
in this conference, we might consider what mix of measures are appropriate
in various circumstances.
on notes of both optimism and caution. Before we launch into some heated
discussions of specific issues ranging from bioengineered foods to global
climate change, we should not forget that Americans and Europeans do share
some common ideas about what enlightened precaution means for decisions
by citizens and policy makers. At the same time, it may be wise to apply
a precautionary approach to any attempt to recommend a universal precautionary
very much for the opportunity to deliver these opening remarks. I look
forward to learning from the conference discussion.