Towards A More Precautionary And More Scientific Approach To Risk Assessment: A Consumer Perspective

Even at its simplest, as a dispute over new
technology introductions at the national level, this social dialogue
is very complex, involving both scientific debates and conflicts
between competing societal goals. At the international level,
complexity increases, as different countries, with different cultures
and at different stages of technological and economic development,
tend to have very different perspectives on how to strike the right
balance between “progress” and “precaution.”

The last half of the 20th century has been an
era of unprecedented economic progress, driven largely by
technological innovation. The pace of change is not slowing; indeed,
it may be accelerating, in response to burgeoning global market
forces and exponential growth in scientific information. One of the
strongest areas of science and investment as we open the 21st century
is the so-called “biotechnology revolution.”

The scientific and technological innovations of
the past 50 years, many of which involved advances in chemistry, have
improved life immeasurably for most people, at least in the developed
countries. We live much longer, and the quality of our lives is
better in countless ways. Most people would agree that the benefits
to humanity of this half-century of technological progress probably
vastly outweigh whatever harm has been done to human health and the
environment by the same innovations.

Nevertheless, many thoughtful observers note
that some new chemicals, and the ways we produce and use them, have
contributed to human diseases and have adversely affected ecosystems,
sometimes in unarguably harmful ways, and perhaps more often, in
subtler ways about whose ultimate consequences we are not yet fully
certain. Often, these adverse effects were not foreseen when the
technology was introduced. As the scientific evidence developed
documenting risks, intense controversies ensued, as those concerned
mostly about risks were challenged by those with an economic interest
in the risk-generating technologies and activities.

Experience with the unanticipated adverse
effects of new chemicals over the past half-century has led to
growing support for application of the so-called “Precautionary
Principle.” The precautionary approach calls for developing better
mechanisms for anticipating adverse side-effects of new technologies,
and for reviewing technologies more thoroughly, exploring alternative
ways for reaping benefits while minimizing adverse collateral
effects, before any major innovation is widely adopted.

Historically, at least in Western societies,
such decisions have been left to market forces. Innovators develop
and offer for sale products they believe are better in some important
way, and if capital investors and buyers agree, the technology
spreads. Governments oversee the process and may regulate the
introduction of technologies to some extent, but in free-market
societies, most legal and regulatory institutions are heavily biased
in the direction of permitting new products to enter the market,
assessing risks retrospectively, and demanding persuasive scientific
evidence of harm before restricting the use of a product.

This system has fostered innovation, but it has
also rewarded ignorance. According to a study done several years ago
by the U.S. National Research Council, about 80,000 high-volume
chemicals are produced in the U.S., and adequate toxicological data
exist for less than 5 percent of them. Today, a definition of
“adequate” data would undoubtedly include an assessment of effects on
the developing nervous, endocrine and immune systems, and very few
chemicals have been tested for these effects. Data on effects of
single substances cannot predict the interactive effects of the
multiple chemicals to which people are routinely exposed. Efforts to
assess the potential effects of chemicals on critical human
developmental processes are thus constrained severely by limitations
of science. Assessment methods for other hazards associated with
foods, such as microbiological contaminants and genetically modified
crops, are less robustly developed than those for chemicals. It is
therefore sometimes impossible, using available risk assessment
tools, to be reasonably certain that foods are “safe.”

When dealing with food safety, legislation and
regulatory philosophies in most Western, developed countries have
traditionally had a large, inherently precautionary component. Most
national governments, for example, require toxicity testing of food
additives to ensure that they are safe, before they are permitted to
be used in foods. Food plays a central role in our health and in our
cultures, and most societies agree that more caution should be
applied to food safety than is required for most other materials.

The current approach to food safety also relies
heavily on the use of risk assessment and on decisions based on
“science.” A consensus has grown that this approach has sometimes
failed to adequately prevent serious food safety problems. The
bovine spongiform encephalopathy (BSE) outbreak in the United
Kingdom, and contamination of foods with dioxins, a problem in many
countries, are recent examples of failures of the
risk-assessment-based food safety paradigm. Such problems, coupled
with growing awareness in all sectors of some inherent limitations of
risk assessment, have stimulated interest in applying the
“Precautionary Principle” more explicitly in food safety risk
analysis.

Seen properly, precaution is not an alternative
to scientific risk assessment, but rather an extension and expansion
of science in risk assessment. I have coined a term, precautionary
risk assessment, to emphasize the strong link between precaution and
science. The essence of precautionary risk assess-ment is to
treat scientific questions scientifically. Often, in food
safety risk analysis, science is used politically. Risk assessments
are narrowly focused on questions where ample scientific data exist,
and seem designed to show that risks are “acceptable.” A
precautionary risk assessment takes a broader approach,
defining a full array of risk-related questions needing answers. The
assessment then looks rigorously at such issues as how much data
exist about a given risk, which questions cannot be adequately
answered with the available data, the possible consequences of being
unable to answer certain questions (i.e., the risks of ignorance),
the knowledge gaps that need to be filled to get better answers, and
whether available scientific methods can answer all the important
risk questions.

This precautionary approach to risk assessment
provides a better basis for decisions as to whether we should proceed
to adopt a technology that has risks of unknown magnitude, or whether
we should take more time and try to find alternative ways to benefit
from the technology while avoiding the risks, before a new technology
has been widely adopted.

Two current food safety concerns illustrate the
need for more precautionary approaches to risk assessment:

Environmental contaminants. While
chemicals that are deliberately added to foods generally are
rigorously assessed for safety, many other economically important
chemicals are dispersed in the environment, and contaminate our
foods, often at very low levels. A British journalist named Lucy
Johnston received wide publicity earlier this year, when she had a
sample of her body fat analyzed for chemicals, and wrote about what
the tests found. Hundreds of different pollutants, most of them
pesticides, were detected in her tissue. Analysts who have tested
larger populations this way report that more than 500 industrial
chemicals are commonly found in the average person’s body fat. And
those represent only those chemicals that are readily detected by
available analytical screening methods; they are but the tip of the
iceberg.

Our diet is a source of many environmental
contaminants. The cumulative health risks posed by the chemicals in
our foods are largely unknown, and perhaps unknowable. Most dietary
residues have not been tested adequately for toxic effects,
especially for effects on developmental processes that many
toxicologists now think are most sensitive low-dose damage. If our
health is being adversely affected by chemical contaminants, it will
be very difficult to measure the effects with existing scientific
methods. Animal test data on single substances can’t replicate
uneven exposure to mixtures of chemicals that people encounter.
Studies of human disease patterns can’t sort out all the confounding
variables, and there are no suitable unexposed populations to serve
as “controls” for such studies. In short, in trying to learn whether
pollutants in our foods are harming us, we are limited by the
boundaries of current scientific knowledge.

When faced with unanswerable questions of such
magnitude, many people respond with what psychologists call “denial,”
or refusal to acknowledge the problem. One classic form of denial is
to assert that no harm is occurring, since none has been
scientifically demonstrated. Another popular response is to claim
that exposures to chemicals known to be harmful at high doses are
invariably safe at low doses. Both of these commonplace assertions
rest on heuristics-that is, familiar, everyday strategies for
understanding daily experience-not on scientific reasoning.

I believe that the risk perceptions of
scientists as well as non-scientists are often colored by a
deep-seated belief that something that our senses cannot detect could
not be harmful. Many people, including many scientists, seem
convinced that “low-level” exposure to chemicals must be safe, and
define “low level” approximately by the concentrations that are
quantifiable with current analytical methods. Over the years, I have
been assured by many sincere people that one part per million of this
or one part per billion of that cannot possibly be harmful, it’s just
too small an exposure to be significant.

That attitude is in fact thoroughly
non-scientific; it is based on intuition and perhaps faith, but not
on rigorous examination of scientific data. A scientific perspective
on this question might consider the fact that the appropriate unit of
chemical exposure, in terms of biological activity, is a molecule,
rather than a part per billion. (Toxic effects occur, after all, at
the molecular level.)

To apply this scientific perspective, let us
look at an example. Baby bottles made of polycarbonate plastic can
release traces of bisphenol-A, a chemical with estrogen-like effects,
into liquids they contain. If the bottle holds infant formula, a
baby might be continuously exposed to a hormonally active agent at
concentrations around 1 part per billion.

Some (including the manufacturers of
polycarbonate bottles) have asserted that 1 ppb of bisphenol-A is too
low an exposure to have biological effects. But what is the science
behind this statement? There are no data on effects of bisphenol-A
on human babies. Some animal tests have reported adverse effects of
fetal exposure on the developing reproductive system, but the data
are not definitive yet, and have been hotly disputed by the
industry.

Simple chemistry offers another perspective on
the question. Using basic, undisputed facts-the molecular weight of
bisphenol-A, Avogadro’s number, and the volume of a baby bottle-one
can easily calculate that a 200 ml bottle of fluid contaminated with
1 ppb of bisphenol-A contains roughly 500 trillion (that is,
500,000,000,000,000, or 5 x 1014), molecules of bisphenol-A.

There could hardly be more contrast in these
two perspectives. One, based on firm conviction but no data, asserts
that there is no effect of bisphenol-A in baby bottles, because none
has been observed scientifically and because one part per billion of
BPA is “too low” an exposure level to have biological effects. The
other, based on simple, undisputed scientific facts, notes that
polycarbonate bottles can expose babies to unimaginably large numbers
of molecules of an estrogen-like chemical, several times a day. We
must ask, on what basis can we presume that such exposure has no
biological effects? What if “low-level” exposure is not
intrinsically “safe;” what if, instead, our inability to measure
effects has created an illusion of safety?

In short, a precautionary risk assessment in
this case would emphasize not the lack of concrete data showing harm
in babies exposed to 1 ppb of BPA in their formula, but rather would
recognize that 1 ppb is not necessarily a “low” exposure. It would
assess the difficulties of knowing whether or not the quadrillions of
molecules a baby ingests daily have any harmful effects on the tiny
consumer’s developing systems.

Genetically modified foods. The
“biotechnology revolution” will probably expand and accelerate over
coming decades, especially if the developers of GM crops can begin to
deliver the promised but to date largely unachieved benefits of
genetic engineering, in terms of more abundant and sustainable food
production, and healthier and more appealing foods.

And yet, at this early stage many observers,
including many in the consumer movement, are deeply concerned that
risks associated with biotechnology are not adequately understood,
and that the rush to commercialize GM crops almost guarantees that if
evidence should ultimately emerge of damage done by these crops, it
will then be too late to reverse it.

In particular, genetic modifications designed
to enhance crops’ resistance to pests seem likely to pose risks
similar in many ways to those of chemical pesticides. The benefits
of chemical pest control sped widespread adoption of the new
technology, while the negative side-human health hazards and
ecological effects that made pest control more difficult and harmed
non-pest wildlife-were documented only gradually, over decades. Many
who recall that experience would prefer not to see it repeated with
GM crops.

Scientific humility also suggests that we don’t
yet know enough about the nature of genetically modified organisms to
be sure how they will behave in natural ecosystems. Nor do we
understand how ecosystems work fully enough to be sure how
introduction of genetically modified organisms, and over time,
combinations of many modified organisms, will affect the health and
the stability of our natural life-support systems. Consumers, who up
to this point have derived few direct benefits from genetically
modified crops, are generally open-minded about the technology,
anticipating benefits, but also interested in ensuring that safety
questions are carefully answered.

From the standpoint of policy, societies have
an opportunity to learn from experience with chemicals, and to take
another approach with genetically modified crops. The alternative
approach would exercise more caution at the outset, take a more
precautionary approach to risk assessment, and give more weight to
the need to avoid future harm, without abandoning the many potential
benefits food biotechnology has to offer.

Some of the most important food safety issues
of the day cannot be resolved by relying on scientific data and
traditional risk assessment methods. As our understanding of risk
advances, we have learned that many questions about food-related
risks cannot be answered with current knowledge. Precaution,
sensibly applied, is one useful tool for making decisions of this
nature.

A precautionary approach does not reject
science and risk assessment. More accurately, it requires an even
more rigorous use of science. It pays greater attention to what
science does not know, and to the possible consequences of
knowledge gaps, when assessing risks.

The growing emphasis on precaution also implies
a shift in philosophy on some long-standing conflicts in societal
values. One involves the concept of “burden of proof.” For
decades, new technologies have been presumed safe until proven
harmful. Today, there is a growing tendency to place a greater
burden on proponents of a new technology, to demand that risk
questions be better identified and addressed, before innovations are
widely adopted. This reflects social learning from past mistakes,
and a greater sense of equity-an assertion that consumers, and future
generations, have the right not to have risks imposed upon them
without more discussion of who is benefiting, and of how much risk is
acceptable.

The precautionary approach also implies a
greater role for government, and less reliance on unbridled market
forces, to chart the course of technology. It requires a conscious
effort to look for alternative solutions to food-related technical
problems, and to choose options with the best risk/benefit ratios.
Attempts to “control” technology risk stifling innovation, and
governments will proceed cautiously, seeking the right balance. But
a better balance must be found than has prevailed for the past 50
years.

The international health community is now
moving towards expanding use of precaution. I believe that this is
the right direction, and that the trend will continue. I think most
consumers would like to avoid repeating the history of chemical
innovations, as the biotechnology revolution unfurls. We need to
learn from our experience with chemicals, by reflecting objectively
on what we still do not know about potential harm to our health and
our planet from the myriad contaminants in our foods and our bodies.
It is too late to “call back” dispersed chemicals, but not too late
to prevent the release of potentially harmful transgenic organisms.
Undoubtedly, we can do a better job of understanding what we need to
know, and of gathering data to inform our decisions, before we
release thousands of new organisms into the global environment.

Adopting a more precautionary approach to risk
assessment will not be easy. In the Codex debate, simply defining
the terms clearly enough to permit a trans-national, trans-cultural
dialogue on this topic has proven exceedingly difficult. Sorting out
science and value trade-offs is complicated enough, and in the
international arena, national interests in promoting trade, private
sector resistance to restrictions on markets, and other political
factors have all confounded efforts to improve food safety risk
analysis.

We also must recognize that the “right” balance
point will differ for different societies, and that a developing
country may choose to pursue the benefits of rapid economic growth,
and be less precautionary about risks than a wealthy nation with
mature technologies might prefer. An international consensus on the
“right” amount of precaution may be nearly impossible to find.

As difficult as it will be to achieve, a more
precautionary approach to risk assessment is essential to meet the
food safety challenges of the 21st century, and I have faith that all
involved will continue to pursue this critical goal.

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http://www.consumersunion.org/food/codexcpi200.htm

2. Raffensperger, C. and J. Tickner, Editors
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7. Somogyi, A. (1999), The Value of
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8. National Research Council (1993),
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