Man-made carcinogens are no more harmful to the American
public than a peanut-butter sandwich, says this renowned scientist.
Cancer & Are We Going Too Far?
Condensed from CALIFORNIA
Marla Cone
Last year, California governor George Deukmejian called
together many of the state's best scientific minds to begin implementing
Proposition 65, the state's Safe Drinking Water and Toxic Enforcement Act.
This new law bans industries from discharging chemicals suspected of causing
cancer (carcinogens) or birth defects into water supplies. Some claim it
will also require warning labels on everything that might cause cancer.
A day of esoteric science and incomprehensible jargon was
predicted. But Bruce Ames, chairman of the department of biochemistry at
the University of California at Berkeley, had plans to liven the proceedings.
walking into the room, Ames looked like the quintessential
scientist: wire-rimmed bifocals, rumpled suit, tousled hair and a sallow
complexion that shoed he spent more time in his laboratory than in the
California sunshine. As someone intoned about the mechanisms of
carcinogenesis, Ames began to interject his own views.
"The whole world is chock-full of carcinogens,"
Ames declared. "A beer, with its 700 parts per billion of
formaldehyde and five parts per 100 of alcohol is a thousand times more
hazardous than anything in the water. If you have beer on your breath,
does that mean you have to warn everyone who comes within ten feet of you?"
In an era when headlines shout about the latest cancer
scare, Ames has a different message: the levels of most man-made carcinogens are
generally so low that any danger is trivial compared with the levels of natural
carcinogens.
Ames is not a quack. At age 59, he is one of the
nation's most respected authorities on carcinogenesis. His resume is
packed with honors, including the Charles S. Mott Prize from the General Motors
Cancer Research Foundation, on of the most prestigious awards in cancer
research, and membership in the National Academy of Sciences. Even his
critics say the Ames test--his simple, inexpensive laboratory procedure that
helps determine whether a substance might cause cancer--is a remarkable
achievement.
But Ames slaughters sacred cows. He's taking on the
environmental movement, which some have called the single most important social
movement of the 20th century. In April 1987, for instance, he and two
colleagues, Renae Magaw and Lois Swirsky Gold, published a report in Science
magazine that ranked various possible cancer risks. Based on animal tests
of nearly 1000 chemicals, the data show that daily consumption of the average
peanut-butter sandwich, which contains traces of aflatoxin (a naturally
occurring mold carcinogen in peanuts), is 100 times more dangerous than our
daily intake of DDT from food, and that a glass of the most polluted well water
in the Silicon Valley is 1000 times less of a cancer risk than a glass of wine
or beer is. He's not advising people to stop consuming peanut butter, beer
and wine. What he's saying is that most cancer risks created by man are
trivial compared with everyday natural risks, and it's not clear how many of
these are real risks. Both types distract attention from such enormous
risk factors as tobacco.
Ames's cancer research began about 25 hears ago over a bag
of potato chips. Ames, then conducting research for the national
Institutes of Health in Maryland, was reading the ingredients on the bag.
It struck him that no one knew what each chemical did to human genes, and there
was no easy way to find out.
At that time, scientists testing for carcinogenicity had
to set up time-consuming and costly lab experiments on rats and mice.
Armed with the knowledge that bacteria are sensitive to substances that cause
mutation, and the carcinogens were likely to be mutagens, Ames developed a
carcinogen test using bacteria. The Ames test was hailed as a major
scientific development and is now used worldwide.
One day in 1974 Ames, now teaching at Berkeley, suggested
that some students test various household products. To his surprise, many
common hair dyes tested positive, as did a flame retardant used in children's
pajamas. Almost overnight, Ames became a hero of environmentalists when
his findings led to new regulations and bans on certain chemicals.
For the next decade public concern over carcinogens
continued to rise. "Then," Ames says, "I started realizing
something wasn't right." Too many natural substances also tested
positive as carcinogens or mutagens: fruit juices, brown mustard, celery,
parsley. In fact, about half of all chemicals tested by Ames--both natural
and man-made--turned out to be potentially carcinogenic when given in enormous
doses to rats and mice.
Ames at first assumed he had erred with his test. He
hadn't. His error had been making the common, but naive, assumption that
only man-made chemicals could be dangerous. "Why assume nature is
benign?" he now says.
The campaign supporting California's Proposition 65
convinced Ames that he had a duty to explain this to the public.
"When people said certain birth defects were caused by a part per billion
of something in the water, I thought it irresponsible," he says.
"It's just playing with people's fears. You can always find a part
per billion of something in the water."
In testimony before a California senate committee, Ames
noted that tap water, for instance, contains the carcinogen chloroform at about
83 ppb due to chlorination. But coffee contains two natural carcinogens at
about 4000 ppb each, while human blood averages 3000 ppb of formaldehyde from
normal metabolism.
Some people assume Ames is a stooge for the chemical
industry, which he is not. He does no consulting for the chemical, drug or
food companies, or for law firms. And he accepts no grants from business.
Environmentalists reject Ames's arguments, saying that we
are obligated to keep the total exposure to carcinogens as low as possible.
"Somehow he thinks there has to be a choice," says Carl Pope of the
Sierra Club. "If we had to choose between TCE [a suspected
cancer-causing solvent] in drinking water and public education on cigarette
smoking, maybe he's right. But we don't have to make a choice."
Ames's reply: "You don't want every chemical company
dumping their garbage out the back door. But the price you pay for living
in a modern, industrial society is a few parts per billion of chemicals in the
water. You can get rid of it, but at enormous cost. If you spend all
your time chasing trivia, you lose sight of the important risks."
~Copyright 1987 by Marla Cone, CALIFORNIA (Aug87), Suite
1800, 11601 Wilshire Blvd., Los Angeles, CA 90025
This just in 4/24/02 . . . Exhibit One:
STOCKHOLM (Reuters) - Potato chips,
french fries, biscuits and bread, eaten daily by millions of people round the
world, contain alarmingly high amounts of a substance believed to cause cancer
, Swedish scientists said on Wednesday.
Research carried out at Stockholm
University in cooperation with the government food safety agency showed that
acrylamide, well known as a probable cancer-causing agent, is formed in very
high concentrations when carbohydrate-rich foods such as rice, potatoes and
cereals are fried or baked -- but is not present when they are boiled.
The results of the research were deemed
so important, and so surprising, that the scientists took the rare step of going
public with their findings before publishing them in an academic journal and
having them reviewed by other scientists.
"I have been in this field for 30
years and I have never seen anything like this before," said Leif Busk,
head of the National Food Administration's research department, of the results
of the study.
Food Administration officials told a
news conference they had found that an ordinary bag of potato chips may contain
up to 500 times more acrylamide than the maximum concentration the World Health
Organization (WHO) allows in drinking water.
French fries sold at Swedish franchises
of the U.S. fast-food chains Burger King Corp, a unit of Britain's Diageo plc,
and McDonald's contained about 100 times the equivalent of the WHO limit for
water, they said.
