Software Vault: The Gold Collection/Software Vault - The Gold Collection (American Databankers) (1993).ISO/cdr12/sierames.zip/SIERAMES.TXT

Text File | 1993-05-23 | 12KB | 239 lines

The Topic of Cancer
Sierra Magazine vs. Bruce Ames

Bruce N. Ames, professor of biochemistry and molecular biology at
the University of California, Berkeley, is a world-famous authority
on cancer and carcinogens. In the fail of 1991, he was asked by
Sierra, a publication of the Sierra Club, to contribute to a
special, centennial issue devoted to the theme "If I Ruled the
World." Ames wrote the piece, but Sierra chose not to run it. Here
we reprint Ames's contribution, along with the letters of invita-
tion and rejection from Sierra's editor-in-chief, Jonathan F. King.
These documents first appeared in the autumn/winter 1992 issue of
the Paris-based quarterly "Projections", which noted, "In our
opinion, the point of view of such an authority as Bruce N. Ames
deserves to be known even if it is nonconformist and attacks
preconceived ideas."

Letter of Invitation
November 14, 1991

Bruce Ames
Berkeley, CA 94709

Dear Professor Ames,

    Next year marks the Sierra Club's 100th anniversary. In May
1992, Sierra, the Club's national magazine, will publish a special
Centennial issue that celebrates the past, surveys the present, and
takes bets on the future. I am writing to ask if you would like to
be pan of that effort.

    We plan to present the thoughts of a wide range of individuals
whose knowledge, experience, and creativity qualify them to answer
the following question: Given that our planet faces a future that
appears bleak if not terrifying, what steps would you take to
ensure our survival for the next 100 years?

    Consider this an opportunity to play "If I Ruled the World," an
imaginative exercise whose goal is to achieve environmental
serenity and security. You may assume that you have the ability to
direct the course of governments and institutions, and that you
have the wealth, brains, and political support of' the world's
citizens at your disposal.

    As well as offering your general scenario for the future,
please be as specific as possible: name those whom you would
empower, and those whom you would have pay penance. Regulate
industries, or set them free; draw geographical boundaries, or
erase them; impose democracy on dictatorships, or vice versa;
develop and distribute resources, or conserve them; plan our menus,
our reading lists, and our births. Should you hold that our
survival depends on successfully addressing just one or two key
issues, feel free to offer your solutions in that light.

    If this exercise is something that appeals to you, and you'd
like to take it on, we'll need your thoughts by January 1, 1992.
Responses can be as long as 1,000 words--though we recognize that
some very sensible prescriptions could be offered in as few as 100.
Please include the biographical information you'd like to accompany
your contribution.

    On behalf of our 600,000 readers across the United States and
Canada, I hope we'll be able to include your vision in our
Centennial issue. We look forward to heating from you.

Sincerely,

Jonathan F. King Editor-in-Chief

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The Article:
"Science and the Environment"

     It is popular these days to espouse an apocalyptic vision of
the future of our planet. Pollution is being blamed for global
warming and ozone depletion, pesticides for cancer. Yet these and
many other environmental causes are based on weak or bad science.
The reality is that the future of the planet has never been
brighter. With the bankruptcy of Communism, the world is hopefully
on the path to democracy, free markets, and greater prosperity.
Science and technology develop in a free society, and free markets
bring wealth, which is associated with both better health and lower
birth rates. Scientific advances and free markets can also lead to
technologies that minimize pollution for the lowest cost. A market
for pollution rights is desirable-polluting shouldn't be free--and
is much more effective than a bureaucratic monopoly. In my scenario
for the future, I would like to see environmentalism based on
scientific fact, directed at solving real problems rather than
phantoms.

    An example of this problem is the public misconception that
pollution is a significant contributor to cancer and that cancer
rates are soaring. As life expectancy continues to increase in
industrialized countries, cancer rates (unadjusted for age) also
increase; however, the age-adjusted cancer death rate in the United
States for all cancers combined (excluding lung cancer from
smoking) has been staying steady or decreasing since 1950.
Decreasing since 1950 are primarily stomach, cervical, uterine, and
rectal cancers. Increasing are primarily lung cancer (which is due
to smoking, as are 30 percent of all U.S. cancer deaths), melanoma
(possibly due to sunburns), and non-Hodgkin's lymphoma. Cancer is
fundamentally a degenerative disease of old age, although external
factors can increase cancer rates (cigarette smoking in humans) or
decrease them (eating more fruits and vegetables).

    A second misconception is that high dose animal cancer tests
tell us the significant cancer risks for humans. Approximately half
of all chemicals-whether natural or synthetic--that have been
tested in standard animal cancer tests have turned out to be
carcinogenic. These standard tests of chemicals are conducted
chronically, at near-toxic doses--the maximum tolerated dose-and
evidence is accumulating that it may be the high dose itself,
rather than the chemical per se, that is the risk factor for
cancer. (This is because high doses can cause chronic wounding of
tissues or other effects that lead to chronic cell division, which
is a major risk factor for cancer.) At the very low levels of
chemicals to which humans are exposed through water pollution or
synthetic pesticide residues, such increased cell division does not
occur. Thus, they are likely to pose no or minimal cancer risks.

    The third misconception is that human exposures to carcinogens
and other toxins are nearly all to synthetic chemicals. On the
contrary, the amount of synthetic pesticide residues in plant foods
are insignificant compared to the amount of natural pesticides
produced by plants themselves. Of all dietary pesticides, 99.99
percent are natural: they are toxins produced by plants to defend
themselves against fungi and animal predators. Because each plant
produces a different array of toxins, we estimate that on average
Americans ingest roughly 5,000 to 10,000 different natural
pesticides and their breakdown products. Americans eat an estimated
1,500 mg of natural pesticides per person per day, which is about
10,000 times more than they consume of synthetic pesticide
residues. By contrast, the FDA found that residues of 200 synthetic
chemicals, including the synthetic pesticides thought to be of
greatest importance, average only about 0.09 mg per person per day.

    The fourth misconception is that synthetic toxins pose greater
carcinogenic hazards than natural toxins. On the contrary, the
proportion of natural chemicals that is carcinogenic when tested in
both rats and mice is the same as for synthetic chemicals--roughly
half. All chemicals are toxic at some dose, and 99.99 percent of
the chemicals we ingest are natural.

    The fifth misconception is that the toxicology of manmade
chemicals is different from that of natural chemicals. Humans have
many general, natural defenses that make us well buffered against
normal exposures to toxins, both natural and synthetic. DDT is
often viewed as the typically dangerous synthetic pesticide.
However, it saved millions of lives in the tropics and made
obsolete the pesticide lead arsenate, which is even more persistent
and toxic, although all-natural. While DDT was unusual with respect
to bioconcentration, natural pesticides also bioconcentrate if they
are fat-soluble. Potatoes, for example, naturally contain
fat-soluble neurotoxins detectable in the bloodstream of all potato
eaters. High levels of these neurotoxins have been shown to cause
birth defects in rodents.

    The sixth misconception is that correlation implies causation.
The number of storks in Germany has been decreasing for decades. At
the same time, the German birth rate also has been decreasing.
Solid evidence that storks bring babies! Cancer clusters in small
areas are expected to occur by chance alone, and there is no
persuasive evidence from either epidemiology or toxicology that
pollution is a significant cause of cancer for the general
population.

     There are tradeoffs involved in eliminating pesticides. Plants
need chemical defenses--either natural or synthetic--in order to
survive pest attack. One consequence of disproportionate concern
about synthetic pesticide residues is that some plant breeders are
currently developing plants to be more insect-resistant and
inadvertently are selecting plants higher in natural toxins. A
major grower recently introduced a new variety of highly
insect-resistant celery into commerce. The pest-resistant celery
contains 6,200 parts per billion (ppb) of carcinogenic (and
mutagenic) psoralens instead of the 800 ppb normally present in
celery. The celery is still on the market.

    Synthetic pesticides have markedly lowered the cost of plant
foods, thus making them more available to consumers. Eating more
fruits and vegetables is thought to be the best way to lower risks
of cancer and heart disease other than giving up smoking; our
vitamins, antioxidants, and fiber come from plants and are
important anticarcinogens. Thus, eliminating essential pesticides
is likely to increase cancer rates. Huge expenditure of money and
effort on tiny hypothetical risks does not improve public health.
Rather, it diverts our resources from real human health hazards,
and it hurts the economy.

--Bruce N. Ames

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Letter of Rejection
March 27, 1992

Dr. Bruce N. Ames
University of California
Berkeley, CA 94720

Dear Dr. Ames,           -

    I fear that you have yet to receive a response from us to your
inquiry about the status of the essay you sent us in response to
our invitation to contribute to our May/June feature, "If I Ruled
the World." If that is so, I apologize; we have just sent that
issue to press, and are now catching up with much postponed
correspondence and other work.

    Your essay was not among those we chose to include, though we
passed no judgment on its contents in making that decision. By that
I mean, our concurrence with an author's ideas was not a prerequi-
site to publication; there was no "litmus test" of ideological
purity to be passed. Our problem with your piece was more stylis-
tic: We found the focus on pollution and pesticides far narrower
than the sweeping prescriptions other contributors were making,
such that it seemed at times as though the question ("How would you
solve the environmental crisis ff you ruled the world.'?") was in
danger of being forgotten by the reader. In some cases we solved
problems of focus by editing a contribution down, but in your case
that clearly could not be done without doing damage to the
arguments themselves. Space being at a premium--we received more
contributions than we could possibly run, even when some were
edited down--there was no question of running the piece uncut, at
least in this format.

    Since we have long found your thinking provocative--it
challenges some basic presuppositions of the environmental
movement--we hope to be able to share your ideas with our readers
in the future. But it simply wasn't feasible within the context we
set for this special issue, and I wanted to be sure you understood
the rationale behind our decision not to publish "Science and the
Environment" at this time.

Sincerely,

Jonathan F. King Editor-in-Chief