Pesticides

ABC News' John Stossel's book "Myths, Lies and Downright Stupidity: Get Out the Shovel -- Why Everything You Know Is Wrong" was the subject of a blog post (below) and a GMLc print column. In it, Stossel explodes some commonly held misconceptions and badly reported or overblown stories in the media.

A reader called to question Stossel's credentials as an expert on pesticides when he wrote that  the thinking that pesiticide residues in food cause cancer and other diseases is not true. The truth? The residues are largely harmless.

The reader said au contraire, that pesticide residue on food is known to be harmful to humans, and that Stossel is not a good source.

GMLc just wanted to point out that Stossel is not the source on pesticides.He's just the reporter. His source was  Dr. Bruce Ames, a biochemist and molecular biologist at the University of California, Berkeley. Some excerpts from Stossel's book in which he interviews Ames:

"Ames laughs at the claims of chemically induced cancers, and he should know -- he's the one who invented the test that first frightened people about a lot of those chemicals. It's called the Ames Test, and its first use in the 1970s raised alarms by revealing there were carcinogens in hair dye, and in the flame retardants in children's pajamas. Ames helped get the chemicals banned. Before the Ames Test, the traditional way to test a substance was to feed big doses of it to animals and wait to see if they got cancer or had babies with birth defects. But those tests took two to three years and cost $100,000. So Dr. Ames said, "Instead of testing animals, why not test bacteria? You can study a billion of them on just one Petri dish and you don't have to wait long for the next generation. Bacteria reproduce every twenty minutes." The test proved successful. It was hailed as a major scientific breakthrough, and today, the Ames Test is one of the standards used to discover if a substance is carcinogenic. But after getting the hair dye and the flame retardants banned, Dr. Ames and other scientists continued testing chemicals. "People started using our test," he told me, "and finding mutagens everywhere-in cups of coffee, on the outside of bread, and when you fry your hamburger!" This made him wonder if his tests were too sensitive, and led him to question the very bans he'd advocated. A few years later, when I went to a supermarket with him, he certainly didn't send out any danger signals.

DR. AMES: Practically everything in the supermarket, if you really looked at it at the parts per billion level, would have carcinogens. Vegetables are good for you, yet vegetables make toxic chemicals to keep off insects, so every vegetable is 5 percent of its weight in toxic chemicals. These are Nature's pesticides. Celery, alfalfa sprouts, and mushrooms are just chock-full of carcinogens.

STOSSEL: Over there it says "Organic Produce." Is that better?

DR. AMES: No, absolutely not, because the amount of pesticide residues-man-made pesticide residues-people are eating are actually trivial and very, very tiny amounts! We get more carcinogens in a cup of coffee than we do in all the pesticide residues you eat in a day. In a cup of coffee? To put the risks in perspective, Ames and his staff analyzed the results of every cancer test done on rats and mice. By comparing the dose that gave the rodents cancer to the typical exposure people get, they came up with a ranking of the danger. Pesticides such as DDT and EDB came out much lower than herb tea, peanut butter, alcohol, and mushrooms. We moved over to the mushrooms as the cameras continued to roll, and Dr. Ames put his mouth where his convictions were. DR. AMES One raw mushroom gives you much more carcinogens than any polluted water you're going to drink in a day.

STOSSEL: So you're saying we shouldn't eat fresh produce?

DR. AMES: No. Fresh produce is good for you! Here, I'll eat a raw mushroom even though it's full of carcinogens.

Dr. Ames is widely respected in the scientific community, but he is not on many journalists' electronic Rolodexes. He's the real deal, and no help at all if you're looking for screaming headlines."