TOPICS > Science

FDA Weighs Approval of Irradiating Produce

February 8, 2007 at 2:17 PM EDT

TOM BEARDEN, NewsHour Correspondent: The spinach in this bowl was deliberately contaminated with enough E. coli bacteria to kill a human being. No amount of rinsing could make it safe to eat.

But businessmen Harlan Clemmons and Dave Corbin dumped on some salad dressing and ate it anyway, betting their lives on a process called irradiation.

HARLAN CLEMMONS, Sadex President: I am very confident in the process. What we do here has over 100 years of research behind it.

TOM BEARDEN: Clemmons runs an irradiation facility for the Sadex Corporation in Sioux City, Iowa. He says irradiation could prevent many of the 5,000 deaths and 76 million illnesses that occur each year from contaminated food.

The claim is getting new attention, in light of the recent E. coli outbreaks involving spinach and lettuce.

HARLAN CLEMMONS: I think the public needs to be aware of what capabilities in food safety is out there. There’s no reason for human illness due to pathogens; there’s no reason for people to get sick when we have the technology.

TOM BEARDEN: Although irradiation has already been approved by the Food and Drug Administration to treat some foods, like spices, wheat, red meats and poultry, it has not been widely embraced by the public, like people like San Francisco health food store owner Gilles DeSaulniers.

GILLES DESAULNIERS, Harvest Urban Market: I couldn’t imagine eating irradiated food. It’s just the idea horrifies me. I feel like I’m sitting next to a pellet of plutonium. I don’t understand why you have to irradiate food. It’s making our body lazy, I would think, you know, because you’re not exposing it to the elements that otherwise would be in the normal world.

The irradiation process

TOM BEARDEN: Past research focused mostly on meats. Only recently have scientists begun to study the effects on leafy greens.

Clemmons and other supporters want the Food and Drug Administration to finally act on the food industry's six-year-old petition seeking approval to irradiate produce and many processed foods.

HARLAN CLEMMONS: Up on top, there's a white cap. That is the EGUN where we're boiling electrons off.

TOM BEARDEN: Sadex's system revolves around two large electron guns, which blast products with high-energy radiation to kill pathogens.

HARLAN CLEMMONS: As it passes into the accelerator, this gray tube, the electrons are speeded up to 99.99 percent the speed of light.

TOM BEARDEN: The guns are so powerful they're encased in several feet of concrete. One gun is aimed at the top of the conveyor belt; the other fires from underneath. Packages of food pass through the sweeping electron beams, which break the molecular bonds in the DNA of E. coli and any other bacteria that might be present.

Other facilities, which irradiate medical supplies like Band-Aids, use a radioactive source called Cobalt-60, or high-energy x-rays, to sterilize products. But no irradiation method renders any product radioactive itself.

On this day, Sadex was processing bags of animal feed. The company also irradiates ground beef for several food distributors. But it's difficult to find irradiated meats in most supermarkets.

Less than 1 percent of ground beef and poultry consumed in America has been irradiated. And all food that is treated must bear an international symbol called the Radura.

ARCHIVE FOOTAGE ANNOUNCER: For centuries, man has worked on the problem of preserving his food supplies against the spoilage produced by microorganisms.

TOM BEARDEN: Scientists first began studying the effects of irradiation back in the early 1900s. The U.S. Army began experiments in the 1940s.

ARCHIVE FOOTAGE ANNOUNCER: Tests conducted in line with strict government standards have shown that irradiation destroys bacteria with little or no change in the color, flavor, odor, texture or nutrient value of the selected foods.

TOM BEARDEN: To date, nearly 40 countries have endorsed it, as have the American Medical Association, the Centers for Disease Control, and many other public health organizations.

Proponents of irradiation

TOM BEARDEN: Professor Suresh Pillai runs the electron beam research center at Texas A&M. Spurred on by the recent E. coli outbreaks, he's studying what happens to spinach and lettuce when they're treated by irradiation. Pillai and his graduate students want to determine the minimum dose to ensure the food is not changed.

SURESH PILLAI, National Center for Electron Beam Food Research: So we are trying to find out, to research, how low can you really go to kill off viruses and bacterial pathogens? This is the only process currently that's available to the produce industry to get a pathogen-free product out there.

TOM BEARDEN: After contaminating the produce in a laboratory, Pillai and grad student Martha Cepeda took it across campus to the university's $5 million irradiation facility. Pillai says his research indicates leafy greens can be safely irradiated at levels lower than meat.

CHRISTINE BRUHN, Center for Consumer Research: There is no residual radiation in that food. That food can be lifted up and eaten immediately after treatment, if people so want.

TOM BEARDEN: Christine Bruhn is a strong advocate for the technology. She's the director of consumer research at the University of California at Davis and teaches courses about the benefits. At home, she buys only irradiated ground beef that is shipped frozen from Omaha Steaks, one of the few companies in the country that sells it.

CHRISTINE BRUHN: When you buy irradiated ground beef in the market, if you can find it in your market, it might be a few cents more, but that safety is worth so much, that piece of mind.

TOM BEARDEN: And irradiated produce?

CHRISTINE BRUHN: The data is clear: There are benefits. There's no indication of increased risk. So we're waiting for FDA to make a decision.

Research on the process's safety

TOM BEARDEN: But Dr. William Au isn't so sure the data is clear. He's a toxicologist at the University of Texas medical branch in Galveston. Au says a chemical called 2-ACB is formed in irradiated meats. He believes further study is needed to determine if long-term exposure to 2-ACB will cause health problems.

DR. WILLIAM AU, University of Texas Medical Branch: In the field of toxicology, we always have a good understanding that, if we're exposed to certain chemical, we may be exposed to a low dose of the chemical that are potentially toxic and will not cause any problem to us. But if we're exposed to those chemicals repeatedly and for a long time, they become more likely that those potentially toxic chemicals can cause health problems.

TOM BEARDEN: Au also says several studies show the nutrient content of some irradiated food is reduced. Several consumer and food safety groups vehemently oppose irradiation.

JOSEPH MENDELSON, The Center for Food Safety: I don't think that this technology has proven to be generally recognized as safe.

TOM BEARDEN: Joseph Mendelson is the legal director for the Center for Food Safety, a public health advocacy group.

JOSEPH MENDELSON: We have looked at studies that have gone on for several decades. And by our count and by our research, there's up to a third of them that have shown some problems with the end result of food irradiation and in the products or effects on humans.

TOM BEARDEN: The center was part of protests organized in 2002 against the FDA's approval of irradiated ground beef in the nation's school lunch program, protests that were successful in pressuring states not to order the meat. Mendelson says there are better, healthier ways to make the food supply safer, like better sanitation and government supervision.

JOSEPH MENDELSON: We should look at reforms on the farm and in processing that start well before you would ever get to irradiation. And I think we could save a lot more lives and prevent a lot more sickness and illness if we paid close attention to those and not go down the irradiation line.

TOM BEARDEN: He believes that food producers will pay less attention to sanitation and produce dirtier food if they know that irradiation will kill germs at the end of the process.

But Texas A&M's Pillai says that same argument was also made against the pasteurization of milk half a century ago. He says it's not an either/or situation.

SURESH PILLAI: Food irradiation should never be used as a substitute for good agricultural practices, good manufacturing practices, et cetera. I think that it's unacceptable in my mind that we would allow ourselves to be held hostage to consumer groups rather than making the food safe.

TOM BEARDEN: As for the FDA, which has been weighing a decision, the agency declined a request for an on-camera interview, but sent us this e-mail: "We certainly will be looking to see if sufficient data are available to answer key questions, such as, does it work? And at what irradiation doses? And what happens to the produce at those doses?"

The FDA has not indicated when action on the petition might be forthcoming.