In the environmentalists war against technology, nowhere are the stakes higher than the assault on pesticides. The current battleground is the Delaney Clause of the Food Additives Amendment of 1958, which bans anything that causes cancer in humans or rodents from being added to processed food.
One problem with the environmentalists argument is their claim that the tiny amount of pesticide residue left on food puts us all at risk of cancer. (About 1 percent of fruits and vegetables have residues above the legal limit; most have none at all.)
This stems from assumptions that a human will react the same way to a chemical as a rodent in a laboratory will. But 30 percent of the chemicals that cause cancer in rats at high doses do not harm mice, and vice-versa. With such a discrepancy between closely related species, what does that say about extrapolating from either of them to man?
Another questionable assumption is that chemicals that cause tumors in rodents when administered in huge doses will cause tumors in humans at a fraction of those doses. It ignores the scientific axiom "only the dose makes the poison." The iron in a tablet that many adults take regularly has killed babies. Eating a lot of salt-cured meat can increase the risk of stomach cancer, but people must have some salt to survive.
Half of all synthetic chemicals tested in animals have caused tumors. But only the most dogmatic chemophobe believes that half of all man-made chemicals are carcinogens at the levels to which humans are exposed. And those who believe it must accept the sobering fact that half of the chemicals that occur naturally in foods have also been found in tests to cause cancer.
Four years ago, a CBS 60 Minutes report panicked the nation with the claim that a chemical used in apple-growing, Alar, was the "most potent cancer-causing agent in our food supply." The evidence against Alar was that a chemical into which it decays may have caused tumors when fed in huge doses to mice (rats suffered no ill effect).
But two cancer researchers at the University of California at Berkeley, Lois Gold and Bruce Ames, pointed out that organic apple juice often contains up to 137 naturally occuring volatile chemicals, of which five have been tested. Two of these five have been found to be carcinogenic in laboratory animals. Another, alcohol, is a human carcinogen. Yet the Delaney Clause has not been applied to organic juice.
"Waiter! Theres a carcinogen in my coffee!"
There is no scientific rationale for banning synthetic pesticides while leaving the natural ones alone. Notwithstanding this, the National Resources Defense Council last year won a Federal court decision upholding the strictest enforcement of the Delaney Clause. This decision will likely remove from the market 35 different chemicals that appear in more than 10 percent of the basic pesticides farmers use.
The clause needs to be updated. Just as the Founding Fathers put no provision in the Constitution allowing for an air force, it could not have occurred to Congress 35 years ago when it passed the Delaney Clause that in testing rodents with massive doses we would find that half of all chemicals cause cancer. Nor could anyone have known that the clause would be used to exclude the tiniest amounts of manmade carcinogens while allowing huge amounts of natural ones
Nobody is stopping environmentalist extremists from shopping at organic-food stores where they can pay far more for food. But as the evidence continues to grow that eating fruits and vegetables helps prevent cancer, we cannot allow special-interest groups to declare their superstitions as science.