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Re: E-M:/ What to Tell?
Enviro-Mich message from joonmck <firstname.lastname@example.org>
"Is the sky falling? or "Are we often in the Dark?
With her vigorous endorsement of the "Precautionary Principle,"
Steingraber highlights a central controversy in environmental health
communication: between risk assessment and the precautionary principle.
Do communities have a right to know all the facts, conjectures and
opinions about a given issue? Or must we continually turn to the
culture's ordained toxic specialists to filter the "chaos of cacaphonic
clamoring" about a given issue?
Most EMers are thoroughly familiar with this topic but others might
benefit from a review of the key issues. The following article, (on the
health effects of dioxin), published in Peter Montahue's renowned
Rachel's Environment & Health Weekly (August 1999), covers the topic
Montague, as is his inclination, cuts to the chase and makes some blunt
contrasts between the two approaches.
I encourage you all to read the entire piece below, and then I invite
Yours Brian McKenna, Ph.D.
#653 - Dioxin and Precaution, June 03, 1999
Dioxin and Precaution
Two years ago, in 1997, the International Agency for Research on Cancer
(IARC) formally concluded that dioxin causes cancer in humans. IARC
is a division of the World Health Organization (WHO) and its
recommendations carry considerable weight in the world of public health
Dioxin is the name of a family of 219 toxic chemicals, many of them
created as unwanted byproducts of numerous industrial processes:
incineration of municipal solid waste, hazardous waste and medical
waste; the smelting of metals; the manufacture of chlorine-bleached
paper; and the production of many pesticides and other toxic chemicals.
Basically, any time you have high temperatures and the presence of
chlorine-containing chemicals, you have conditions that can spawn
Over the years, many studies of laboratory animals have shown that
dioxins can cause many different kinds of cancer. However, in reaching
its 1997 conclusion, IARC relied on studies of humans, specifically,
four studies of workers exposed to high levels of dioxin on the job. The
four studies revealed a remarkably consistent effect from dioxin
exposure: a 40% increased chance of dying from cancer. In all four
studies, the effect was highly statistically significant.
In three of the four studies, data for estimating dioxin exposures was
available in 1997. Using the available exposure data, the authors of the
three studies were able to observe a clear "dose response relationship"
-- as the level of dioxin exposure increased, so did the chances of
dying of cancer. Seeing a "dose response relationship" gives researchers
more confidence that the relationship they have observed (in this case,
between dioxin exposure and cancer) is real.
Now information about dioxin exposures among the fourth group of workers
has become available, and a dose-response relationship can be seen in
those workers as well. The more dioxin they were exposed to on the
job, the greater their chances of dying of cancer.
This fourth group was the largest of them all -- 5132 workers at 12 U.S.
industrial plants where they were exposed to dioxin over many years.
Researchers at the U.S. National Institute for Occupational Safety and
Health (NIOSH) were able to find job histories for 69% of the 5132
workers and thus could categorize them into seven groups according to
their dioxin exposures.
The new information appears in the May 5 issue of the JOURNAL OF THE
NATIONAL CANCER INSTITUTE. In their report, the NIOSH researchers
explain that they saw a 13% increased chance of dying of cancer among
the 5132 workers, compared to an unexposed group. Among the highest two
exposure groups, they observed a 60% increased chance of dying of
In sum, we now have four separate studies of groups of humans who have
been exposed to dioxin and who are dying disproportionately from
cancers. These studies provide support for many previous studies of
laboratory animals showing that dioxin causes various cancers.
Does this close the book on dioxin and cancer? Unfortunately, it does
not. Every group of humans who have been exposed to high levels of
dioxins has now been studied. There aren't any other groups to study.
Therefore, the data that are available now are probably the only human
data we will ever have. (Of course as time passes these same groups will
be studied further, but the results are not likely to change
With today's data, it is still possible to reach conclusions that are
180 degrees out of synch with each other. In an editorial in the JOURNAL
OF THE NATIONAL CANCER INSTITUTE May 5, Dr. Robert N. Hoover of the U.S.
National Cancer Institute wrote, "My belief, based on the current weight
of the evidence, is that TCDD [the most potent dioxin] should be
considered a human carcinogen." This is precisely what the World
Health Organization concluded two years ago.
In contrast, when the British medical journal LANCET ran a news story
reporting the latest dioxin findings from the JOURNAL OF THE NATIONAL
CANCER INSTITUTE, they quoted Michael Kamrin, a toxicologist from
Michigan State University (East Lansing, Mich. USA) who said the dioxin
data is "unconvincing and epidemiologically weak... These data don't
suggest to me that there's any health risk from dioxin [TCDD]. I didn't
think so before, and I don't think so now," Kamrin told the LANCET.
So the question is, how should ordinary people react to dioxin? When we
learn that we and our children are breathing dioxins created by a
medical waste incinerator, or a garbage incinerator, or a cement kiln
burning hazardous waste, what should we think? Should we accept the
opinion of Robert Hoover from the National Cancer Institute that
dioxin is probably a cause of human cancers? Or should we accept the
words of Michael Kamrin at Michigan State who says there isn't any
health risk from dioxin? Experts can always disagree, but citizens
must make choices in the best interests of themselves and their
It seems clear that science cannot solve this kind of dilemma. There has
never been a chemical studied more
thoroughly than dioxin. For the past decade the U.S. government has been
conducting a detailed analysis of
many hundreds of previous studies of the health effects of dioxins (in
animals and humans). Furthermore, the government has spent millions of
dollars conducting new studies of dioxin's effects on humans (for
example, the NIOSH study, discussed above) and animals. In addition, the
Chemical Manufacturers Association and the Chlorine Chemistry Council
have spent substantial sums of money hiring their own brand of scientist
to try to tilt the balance in the direction of "dioxin is no problem."
(As you might imagine, there are huge sums of money riding on the
outcome of the dioxin debate.)
For most chemicals, we can probably never expect to get data as good as
the data we have now for dioxin. Given
limited funds for study, and given that there are 70,000 chemicals now
in use and 1000 new ones added each year, we cannot realistically
expect anything like "thorough" data on the health effects of any
Therefore, how should we, the public, react to dioxin or any other toxic
chemical? There are two basic ways of
approaching such a question -- risk assessment or precaution.
Risk assessment asks the question, How much damage are we willing to
tolerate from dioxin exposure? Risk assessors usually answer this
question by saying that it is "acceptable" to kill one in every million
people exposed to dioxin. (Sometimes they give a different answer,
saying it is OK to kill as many as one in every 10,000 people exposed to
chemical A or chemical B, but usually their answer is that
one-in-a-million is the acceptable kill ratio.)
Now let us remove our rose-colored glasses for just a moment and be
blunt. You rarely find a risk assessor who
will say so, but the one-in-a-million formula is, at base, a
prescription for legalized murder. The dead person is selected at random
and is killed anonymously. But it is still a premeditated, planned
death. If "risk assessment science" improved to the point where the
victim's identity were known, then everyone would agree that a murder
had been committed.
Once the community of risk assessors has accepted that it is OK to kill
one-in-a-million citizens by exposing them to dioxin (or some other
toxicant du jour), then the mathematicians and toxicologists go to work
and develop a formula that says "exactly this much dioxin can be emitted
into the community, and no more, if we are to abide by the
one-in-a-million limit of 'acceptable risk.'" Then it is up to the
engineers to design a machine that will emit just the "acceptable"
amount of dioxin or other toxicant and no more. And then the government
regulators ratify and enforce the engineer's limit. That is the sum and
substance of the "risk assessment" approach to controlling toxic
exposures, from dioxin or from any other deadly agent.
A different way to view the problem is to ask, How can we avoid dioxin
exposures and so avoid the possibility of killing people with dioxin?
This is the approach embodied in the "principle of precautionary
precautionary principle says,
"When an activity raises threats of harm to human health or the
environment, precautionary measures should be
taken even if some cause and effect relationships are not fully
established scientifically. In this context the proponent of an
activity, rather than the public, should bear the burden of proof. [See
"The process of applying the Precautionary Principle must be open,
informed and democratic and must include
potentially affected parties. It must also involve an examination of a
full range of alternatives, including no action."
A precautionary approach to dioxin would look at the available
(sometimes conflicting) evidence about dioxin
and ask, "If we think it is better to be safe than sorry, shouldn't we
avoid dioxin exposures when we can?" And then the search would begin for
alternative ways to avoid dioxin exposures. Shutting down incinerators
-- or, better yet, not ever building incinerators -- would be one
feasible approach. There are numerous alternatives to incineration, and
a "better safe than sorry" strategy would examine all of them.
Reducing our use of chlorine-containing chemicals would be a second
approach. There are few, if any, uses of
chlorinated chemicals that are essential and irreplaceable. Alternatives
In sum, a precautionary approach would not ask "How many dioxin deaths
can we tolerate in our society?" --
instead, it would ask, "How can our society avoid making dioxin?"
The risk assessment approach, which has been the "official" approach in
the U.S. for the past 25 years, excludes citizens for the most part
because they don't have the knowledge to calculate the one-in-a-million
kill ratio. Only the "risk experts" are able to do that. In that sense,
the risk assessment approach is undemocratic and even anti-democratic.
\tab But when it comes time to deciding whether an incinerator is the
best way to handle the community's garbage, people can get involved.
They can ask citizens in other communities how they are handling THEIR
garbage. They can sponsor public discussions in which various groups
(including waste companies) send representatives to tell how they would
handle the community's wastes. People can ask about the sources of waste
in their community and they can demand a "clean production" approach to
those sources. (See REHW #650, #651.) Then people can discuss the pros
and cons of what they have heard and can make up their own minds about
what's best. Unlike risk assessment, the precautionary approach fosters
citizen participation and promotes democracy.
--Peter Montague (National Writers Union, UAW Local
 Douglas B. McGregor and others, "An IARC
Evaluation of Polychlorinated Dibenzo-P-dioxins and
Polychlorinated Dibenzofurans as Risk Factors in Human
Carcinogenesis," ENVIRONMENTAL HEALTH
PERSPECTIVES Vol. 106, Supplement 2 (April 1998),
 Robert N. Hoover, "Dioxin Dilemmas," JOURNAL
OF THE NATIONAL CANCER INSTITUTE Vol. 91,
No. 9 (May 5, 1999), pgs. 745-746.
 Kyle Steenland and others, "Cancer, Heart Disease,
and Diabetes in Workers Exposed to
2,3,7,8-Tetrachlorodibenzo-p-dioxin," JOURNAL OF
THE NATIONAL CANCER INSTITUTE Vol. 91, No.
9 (May 5, 1999), pgs. 779-786.
 Marilynn Larkin, "Public-health message about
remains unclear," LANCET Vol. 353 (May 15, 1999),
Descriptor terms: iarc; who; dioxin; carcinogens; risk
assessment; precautionary principle; clean production;
back to the top
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> Enviro-Mich message from joonmck <email@example.com>
> Rachel Carson, the author of Silent Spring, perhaps the most influential
> environmental treatise of the last century, had breast cancer during the
> writing of the book in the early 1960s. But she remained silent about
> it. She didn't want her enemies to take that information and accuse her
> of being "biased" in her expose. Though her illness had nothing to do
> with the facts in the book (except perhaps, as a motivator).
> Interestingly, Carson wrote about three types of silences in American
> culture. First there was the silence about heated scientific
> disagreements in the literature (in addressing the public, the
> "scientific community" usually spoke with one voice, even though
> insiders knew better....somewhat akin to Jeffrey Wigand, the
> cigarette whistle blower of Brown and Williamson fame....seen in the Al
> Pacino movie). Second there were the silences of the song birds in
> Spring, sacrificed to the ravages of environmental destruction. Finally,
> there were the silences of the "experts" who knew truths about things,
> but were afraid to speak out.
> Funny, if you read the NEW Silent Spring, Sandra Steingraber's
> brilliant, "Living Downstream" (1997), it turns out that those three
> silences persist today...BIG TIME!
> Readers familiar with "Living Downstream," know that Sandra (a U of M
> biologist) has uterine cancer. Unlike Carsen, Steingraber reflexively
> revealed her illness in the book. In fact, she made it a centerpiece of
> the narrative, probing the possible linkages (known and personally felt)
> between toxins and her disease. And wouldn't you know it? Some
> Steingraber reviewers have publicly accused her of bias in her work. She
> was accused of being biased (and the implication is that her words are
> less legitimate) because of her (self professed) cancer. It seems that
> one's enemies will use anything they can against you. More on this
> Brian McKenna, Ph.D.
> ENVIRO-MICH: Internet List and Forum for Michigan Environmental
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