A scientist who made himself wealthy by conducting risk assessments for
industrial clients has now published a paperback book on the _theory_
of risk assessment. CALCULATED RISKS, by Joseph V. Rodricks of Environ
Corporation, is the best book we have yet seen on the _theory_ of risk
assessment -- lucidly written, and evenhanded so far as it goes. If
you want to understand the _theory_ of risk assessment from the
viewpoint of a successful risk assessor, this is the book for you.
Unfortunately, since the _theory_ of risk assessment is quite different
from the _practice_ of risk assessment, Rodricks's book is little more
than an enthusiastic description of the emperor's scientific new
In loving detail, Rodricks's book describes all the theoretical steps
in a risk assessment. What the book does not discuss are:
(1) the insurmountable limits of science in determining chemical
(2) the environmental justice problems that government officials create
when they use risk assessment to prioritize environmental problems; and
(3) the widespread destruction of the environment that is occurring
because of our single-minded reliance on risk assessment;
(4) other, better approaches to establishing "safety" and to deciding
environmental priorities, besides risk assessment.
This week and next, we will discuss these 4 points.
The limits of science: Risk assessors are usually working with
information that ranges from slim to none, and this will always be the
case because the chemical industry invents new chemicals much faster
than the government can test all their various negative effects.
Rodricks acknowledges that our ignorance is vast: "Toxicologists know a
great deal about a few chemicals, a little about many, and next to
nothing about most," he says [pg. 146].
As Rodricks's book illustrates, the government often doesn't even know
what toxic effects to test for. For example, Rodricks's book is as
thorough and up-to-date as he could make it in 1992 (when the hardback
edition first appeared), and yet it does not even mention chemicals
that damage the endocrine system. The endocrine system, in wildlife and
humans, is a complex set of bodily organs and tissues whose activities
are coordinated by chemical messengers called hormones, which control
growth, development and behavior. Bears hibernate because of chemical
signals from the endocrine system, and women menstruate under control
of their endocrine systems. In the past decade, evidence has
accumulated that several dozen pesticides and other industrial
chemicals mimic, or interfere with, hormones and thus disrupt the
endocrine system. In both wildlife and humans, it is the reproductive
system of unborn offspring that is most prone to disruption by hormone-
For 20 years, risk assessors like Rodricks -- well-meaning people
inside and outside of government -- have given the green light to
exposing people and wildlife to thousands of chemical compounds without
understanding that some chemicals mimic, or interfere with, hormones.
The very best risk assessments gave the answer "No problem" when in
fact there were significant problems.
This is an insurmountable shortcoming of all risk assessments. If there
are effects from chemicals that scientists have not suspected and
studied, those effects will be ignored in a risk assessment.
Furthermore, because it costs roughly $400,000 to $1,000,000 to study a
chemical even crudely, major harm must be demonstrated before study
commences. Therefore, the risk- assessment method of setting "safe"
standards always requires that harm must be done to wildlife and humans
before study begins.
Rodricks -- like every other person who makes a living conducting risk
assessments -- is not deterred by the absence of information about
chemical effects. When good data are not available, risk assessments
are put together from "science policy choices" (a fancy name for
informed guesses), assumptions, and speculation.
This is a key point. Rodricks [pg. 187] says, for example, that in most
cases the relationship between dose and response at low levels of
exposure is not known. (In other words, nobody knows how sick your
child will get from eating small amounts of several poisons every day.)
There are usually several "scientifically plausible models" that could
describe the dose-response relationship, Rodricks says, and "scientists
cannot be sure which is correct." Moreover, the different models "yield
sometimes substantially different pictures of the risk for the same
exposure," he says. And, "If a risk assessment is to be completed, a
science policy choice (the phrase used by the NRC [National Research
Council]) must be made about the model to be used.... SEVERAL SIMILAR
CHOICES HAVING TO DO WITH OTHER UNCERTAINTIES ARE NEEDED TO COMPLETE
MOST RISK ASSESSMENTS," Rodricks says [emphasis added]. In other words,
guesswork is central to every risk assessment.
Interestingly, Rodricks does not elaborate on the "several similar
choices" that go into every risk assessment--perhaps because to do so
would reveal that risk assessment is not the scientific enterprise it
appears to be, but is in fact largely a political exercise. Rodricks
does say that, "To base risk assessment and risk management decisions
upon such uncertain scientific knowledge is bad public policy" [pg.
227]. Unfortunately, his answer is not to reduce our reliance upon risk
assessment but to do more studies, as if more studies will eliminate
all the important uncertainties in our scientific knowledge of the
effects of chemicals on humans and ecosystems. Dream on. (See RHWN
From the viewpoint of someone eager to dump exotic new chemicals into
the ecosystem, this is the real beauty of risk assessment: no matter
how flimsy the base of information, every risk assessment still gives
the same satisfyingly numerical answer. Furthermore, the answer you get
is completely dependent upon the "science policy choices" that you
made, yet the final result appears to be entirely objective and
impartial. A political choice swaddled in scientific trappings. This
emperor is really a snappy dresser!
Back to our recently-discovered ignorance about hormone disrupting
chemicals. In testimony before Congress last October, Richard Wiles of
the Environmental Working Group in Washington, D.C., showed that we now
put 220 million pounds of endocrine-disrupting pesticidal chemicals
directly onto and into our food supply each year. The pesticide
found most often on fruits and vegetables is endosulfan and it is an
endocrine-disrupter. Analysis of data from the Food and Drug
Administration's (FDA) routine food monitoring program revealed
endosulfan on 21 out of 22 samples (95%) of fruits and vegetables
heavily consumed by infants and children, Wiles testified.
At the same hearing, Dr. Earl Gray, a section chief in U.S. EPA's
Health Effects Research Laboratory, reported his latest findings on a
fungicide called Vinclozolin -- a pesticide currently in use with EPA's
approval. "Vinclozolin, when administered to a pregnant rat,
demasculinizes the male fetuses in a manner identical to the anti-
androgenic drug flutamide and in effect these effects are so obvious
that all of the males look like females at birth," Dr. Gray testified.
He went on to say, "In the rats in vivo [in other words, in studies of
living animals] this chemical blocks development of the fetal male rat
reproductive system so that they have undescended testes, they develop
a vaginal pouch like a female, the penis fails to develop normally, and
they retain nipples which male rats do not normally do."
Congressman Henry Waxman (D-Ca.) asked Gray, "Do you think that
Vinclozolin could have the same kinds of hormonal effects on humans?"
Gray answered, "I think that is quite possible, and likely."
Earlier in the hearing, Dr. Theo Colborn, an expert on endocrine-
disrupting chemicals, made the point that a single dose of some
chemicals can disturb a baby's normal sexual development. She said,
"Nor is it comforting for a woman to realize that it takes only one
very low dose, it is called a hit, of an endocrine-disrupting chemical
during one of the many critical stages of embryonic development during
her pregnancy to change the course of sexual development of her
So long as we use risk assessment as our chief guide for allowing
chemical exposures, we can expect an unending series of unpleasant
surprises as today's "safe" dose is discovered tomorrow to be unsafe.
Joe Rodricks makes a clear distinction in his book between risk
assessment and risk management. First you assess the risk, then
government acts to protect the public, he says. Oh, this emperor is
really looking natty! How does this work in the real world?
At the hearing last October, Congressman Waxman asked EPA's Dr. Lynn
Goldman how long it would take before Vinclozolin would be removed from
the American food supply. Note the rich fudge of risk assessor's
language in Dr. Goldman's response:
"Well, the decision could involve a number of considerations. What we
are going to be concerned about is the issue of not only the inherent
risk of the pesticide, but also the science that tells us about the
exposures that might be expected given the various uses that are
allowed under the label, and so that there could be a variety of
actions that are taken ranging from, as you suggested, perhaps not even
allowing the registration to only allowing the registration on certain
uses that are safe, to allowing all of the uses that are currently
allowed if we are very certain that we have no exposures that would
cause harm to those who might come in contact with it, so the decision-
-this piece of information is one piece of the scientific data that
needs to be examined to make a good decision about this compound, but
obviously a very important piece."
How could EPA ever determine "uses that are safe?" How could EPA ever
become "very certain" that "we have no exposures that could cause
harm?" Science simply can never provide such assurances. So EPA will
rely on--what else?--risk assessment.
How can we really be sure that no humans or wildlife will be harmed by
Vinclozolin? There's only one way: Don't use any Vinclozolin. Pollution
 Joseph V. Rodricks, CALCULATED RISKS (New York: Cambridge
University Press, 1992; paperback edition, 1994).
 Wiles testimony in HEALTH EFFECTS OF ESTROGENIC PESTICIDES; HEARING
BEFORE THE SUBCOMMITTEE ON ENERGY, COMMERCE AND ENVIRONMENT OF THE
[HOUSE] COMMITTEE ON ENERGY AND COMMERCE... OCTOBER 21, 1993 SERIAL NO.
103-87 (Washington, D.C.: U.S. Government Printing Office, 1994), pgs.
 Gray testimony in HEALTH EFFECTS..., cited in note 2 above, pgs.
 Colborn testimony in HEALTH EFFECTS..., cited in note 2 above, pg.
 Goldman testimony in HEALTH EFFECTS..., cited in note 2 above, pg.
Descriptor terms: risk assessment; joseph rodricks; science; endocrine
disrupters; wildlife; testing; costs; pesticides; endosulfan; richard
wiles; earl gray; epa; health effects research laboratory; henry
waxman; theo colborn; vinclozolin; lynn goldman;