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by Art Drysdale
February 14, 1999
Natural vs. Synthetic Chemical Pesticides
"The effort to eliminatesynthetic pesticides because of unsubstantiated fears about residues in food will makefruits and vegetables more expensive, decrease consumption, and thus increase cancerrates. The levels of synthetic pesticide residues are trivial in comparison to naturalchemicals, and thus their potential for cancer causation is extremely low."
Thatīs a quote from Bruce Ames.
In a paper to the American Chemical Society, "Pollution, Pesticides and Cancer: Misconceptions," researchers Bruce Ames and Lois Gold said pesticide regulatory policies that seek to eliminate minuscule levels of synthetic chemicals are unnecessarily expensive and driven by a series of scientific misconceptions.
As far back as the 1970s, Bruce Ames was the environmentalists hero. As inventor of the Ames test (which allows scientists to test chemicals to see whether they cause mutations in bacteria and perhaps cancer in humans), his work led to the banning of such synthetic chemicals as a flame-retardant called Tris that was used in childrens pajamas. I first became aware of him in the late 80s.
Today, Bruce Ames, professor of biochemistry and molecular biology at the University of California at Berkeley, stands on the other side of the chemical-ban debate. In 1990, he spoke out against Californiaīs Proposi-tion 128, which would have banned many pesticides. The best way to prevent cancer believes Ames, is to "eat your veggies."
Bruce Ames says that it isnt that we neednt worry about man-made chemicals causing cancer, but that natural carcinogens are far more common, and the consensus is that we shouldnt worry about them at all. Why the difference?
What people should have thought about, but didnt, is all the chemicals in the natural world. We seemed to get it in our heads (and it is still very much the case with many so-called environmentally conscious garde-ners!) that, if its man-made, somehow, its potentially dangerous, but if its natural, it isnt. And according to Bruce, that does not really fit in with what is generally known about toxicology. "When we understand how animals are resistant to chemicals, the mechanisms are all independent of whether its natural or synthetic. And in fact, when you look at natural chemicals, half of those tested come out positive."
"Almost all the world is natural chemicals, so it really makes you re-think everything. A cup of coffee is filled with chemicals. Theyve identified a thousand chemicals in a cup of coffee. But we only found 22 that have been tested in animal cancer tests out of this thousand. And of those, 17 are carcinogens. There are ten milligrams of known carcinogens in a cup of coffee and thats more carcinogens than youre likely to get from pesti-cide residues for a year!"
Published in 1996, the book Our Stolen Future is, to say the least, controversial. In his introduction, US vice president Al Gore compared it to Rachel Carsons Silent Spring. Bruce Ames saw it differently. Heres just one comment: "There is no risk-free world and resources are limited; therefore, society must distinguish between significant and insignificant risks in order to save the most lives. Putting resources into minimizing minuscule exposures to synthetic substances, such as pesticide residues, while ignoring the natural world, can also harm human health by having adverse side effects, which create more risk. For example, adequate consumption of fruits and vegetables plays a major role in lowering dise-ase rates; therefore if banning pesticides because of tiny hypothetical hazards of residues increases costs (organic food is very expensive), it harms public health. "
Since Bruce Ames findings and writings support the use of synthetic pesticides (the contrary position from what he took in the 70s), one might easily think that he is widely supported by the chemical companies for his research. That is not the case. He steadfastly refuses to accept any money from the chemical industry, or anything disguised as coming from the industry. If he accepts a speaking assignment from a chemical company, he insists the honorarium be sent to a charity. All of his rese-arch money comes from government, which field he describes as being fiercely competitive.
While environmental activists are suspicious of him, even critics gene-rally admit he has always done good science. And, now he is suspicious of a lot of the activists because he thinks they are not good problem sol-vers. "If you push in the wrong direction, then youre counterproductive."
by Art C. Drysdale, 6 Nesbitt Drive, Toronto, Ontario M4W 2G3
Art Drysdale is heard Saturdays from 9 to 11 am, with a live two-hour radio broadcast on Toronto's TALK640 (640 on the AM dial).