A thought-provoking editorial crossed my desk this morning and I
thought the list might be interested in a few excerpts as they relate
to ecofeminist concerns. The piece was written by Bruce Ames,
professor of biochemistry and molecular biology at UC-Berkeley. Ames
is an expert on cancer and carinogenicity--his Ames assay, developed
in the '70's, is a biochemical test for mutagenicity now in
widespread use. The assay has resulted in MASSIVE reductions in
animal use for carcinogenicity studies (although Ames' critique of
high-dose animal studies is scientific, not ethical, to the best of
my knowledge).
Note: I am not endorsing Ames'views, only presenting them for
discussion by the list, if the list is interested. My own questions
upon reading the article are 1) What if he is right ? 2) If he is
right, what impact should this research have on ecofeminist critiques
of science and technology ? and 3) How can ecofeminists work with
Ames and other scientists to develop a more rigorous and
scientifically sound critique of current practices ?
Excerpts from Viewpoint: Science and the Environment by Bruce N. Ames
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 bad or weak science...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...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...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. They, they are likely to pose no or minimal
cancer risk.
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, 99.9 percent are
natural: they are toxins produced by plants to defend themselves
against fungi and animal predators...
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 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 man-made chemicals
is different than 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.
...
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
developing plants to be more insect resistant and inadvertently are
selecting plants higher in natural toxins...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.
End Ames
The thing that interests me most about this article is the
counter-intuitive proposition that "synthetic" is not necessarily
more harmful than "natural."
