Gunner Nelson uses the Gray Star Genesis II Unit to irradiate oysters at Gateway America in Gulfport. (Sean Gardner/For The Washington Post)

The nuclear energy that Frank Benso uses to kill bacteria in fruit and oysters has won widespread support from public health officials and scientists, who say it could turn the tide against the plague of foodborne illness.

The Food and Drug Administration has approved the use of radiation to wipe out pathogens in dozens of food products, and for decades it has been used in other developed countries without reports of human harm.

But it has barely caught on in the United States. The technology — called irradiation — zaps bacteria out of food and is highly effective, but for many consumers it conjures up frightening images of mutant life forms and phosphorescent food.

Benso, who opened Gateway America 18 months ago, also knows his new venture pits him against the nation’s growing buy-local, back-to-nature movement that shuns industrial food processing.

“Those naysayers better throw out their microwaves, because that is irradiation,” Benso said, standing in his 50,000-square-foot irradiation facility.

Irradiating food to keep it safe

Dozens of scientific studies have shown that irradiated food is safe for human consumption, and that no radioactive material has leaked outside any U.S. plant, according to the U.S. Nuclear Regulatory Commission. The three forms of energy that can be used — gamma rays, electron beams and X-rays — can virtually eliminate bacteria in minutes. All this has prompted the World Health Organization, the American Medical Association, the U.S. Centers for Disease Control and Prevention, and dozens of other groups to endorse its use.

Michael T. Osterholm, director of the Center for Infectious Disease Research and Policy at the University of Minnesota, blames an “anti-science movement” for the public resistance. He is frustrated with the federal government for endorsing irradiation but then not educating the public as it has with childhood immunizations and water fluoridation.

“Not using irradiation is the single greatest public health failure of the last part of the 20th century in America,” said Osterholm, citing CDC estimates that 1 in 6 people will get food poisoning this year and 3,000 will die. “We could have saved so many lives.”

The United States has dozens of irradiation facilities, but most of them are used to sterilize medical equipment and supplies. Consumer goods such as tampons and bandages are also routinely irradiated. A half-dozen facilities use radiation exclusively for food.

A steadfast team of consumer advocates has successfully campaigned against its use, first at the nonprofit group Public Citizen and then after founding the nonprofit organization Food and Water Watch.

The Washington-based group claims credit for keeping irradiated food out of the National School Lunch Program and blocking efforts to get rid of the federal requirement that all irradiated food in retail establishments carry a Radura label — a green plant in a circle — indicating it has been irradiated.

Food and Water Watch officials point out that the same energy that kills bacteria can also alter the chemical structure of food. The group’s concern is that carcinogens are created — something that Executive Director Wenonah Hauter warned about in her 2008 book “Zapped: Irradiation and the Death of Food.”

In recent years, the advocates have increasingly focused on a separate concern: that manufacturers using irradiation will slack off on other vital safety measures designed to keep pathogens out of food in the first place.

“We are concerned about the impact that the technology will have on the entire food-production process — that it will become less about prevention and more about treatment,” Assistant Director Patty Lovera said.

Where and how

Gateway America is in what Benso thinks is a sweet spot: At the Gulfport-Biloxi International Airport, near the Gulf of Mexico and major highways, where vast amounts of fresh fish, fruits and meat can be shipped, trucked or flown in and treated.

A few miles down the road from his high-tech facility is an old-fashioned oyster-shucking house filled with men and women wearing rubber boots and hairnets who work 10-hour shifts, knocking off mussels and clumps of dirt to provide a steady supply of oysters to Benso’s plant.

Benso not only had to gamble his life savings and recruit investors to launch his company, he had to pass a series of inspections — including one by the NRC — and is regulated by no fewer than 16 agencies. And for each food item that he and other irradiators treat, the FDA had to grant permission to do so.

It’s a slog to make it through the FDA’s approval process. Earlier this month, the agency approved irradiation for use on crustaceans — shrimp, lobsters, crabs — but it took 13 years. The last approval before that was for spinach and iceberg lettuce, in 2008, which took nearly a decade.

In its reviews, the FDA looks at whether the treatment could increase the toxicity of the food, degrade nutrients or create new opportunities for pathogens to flourish instead of die. With crustaceans and leafy greens, concerns from Food and Water Watch and other groups arose about furans, potentially carcinogenic substances that are produced by “ionizing radiation.”

The treatments use either gamma rays, X-rays or electron beams to eliminate bacteria by destroying their genetic material, but this also can alter the chemical makeup of the food.

Food scientists say it sounds scary, but they emphasize that the same thing happens when peaches are heated during canning or when eggs are scrambled over a flame. The question that the FDA had to answer is whether irradiation produced levels of furans comparable to canning and cooking or triggered an explosion of them.

Dennis Keefe, director of the FDA’s food-additive safety office, said the research shows that the amount of furans produced was “much lower than what would be produced during the normal cooking process.”

Still, Keefe said the FDA continues to be conservative about the level of irradiation it allows. The agency still expects food processors to eliminate as many bacteria as possible before irradiation, which comes at the end and is treated as an “add-on” measure.

“It’s not intended to be a substitute for good manufacturing practices,” Keefe said.

Overusing irradiation can make food unappealing. In ground beef, a high dose can produce a “wet dog” odor. Too much radiation can make spinach limp and walnuts taste fishy.

The only documented health problems linked to irradiation involved cats in Australia that ate pet food treated with a high dose. In this episode, dozens of cats suffered paralysis and had to be euthanized. In response, Australia has banned cat-food irradiation. Irradiation experts point out that the dosage levels used in Australia were 100 times the level allowed for pet food in the United States — and about five times what is approved for human food.

It’s in there

Americans already may eat more irradiated food than they realize.

Irradiated ingredients end up in processed foods that fill refrigerated and frozen-food cases in grocery stores throughout the United States. None of those products have to carry a special label.

So irradiated shrimp would have to bear the Radura logo if packaged on its own, but not as an ingredient in tortellini or gumbo, for example.

Restaurant owners don’t have to disclose whether menu items include irradiated food.

“The big food companies, if they are making a TV dinner or a meal, they use spices that have been irradiated for the most part. They don’t want to introduce possible pathogens that could spoil the food. Food companies reduce risk any way they can,” said Jeff Barach, former vice president of science policy at the Grocery Manufacturers Association.

The federal government does not keep track of the amount of food that is irradiated. One source for that information is a food industry consultant, Ronald T. Eustice, who also publishes the monthly newsletter Food Irradiation Update.

By Eustice’s estimates, which are backed by other industry tallies, spices represent the largest proportion of irradiated food products in the United States — more than 175 million pounds — which is about one-third of all commercial spices. (Spices are often treated because they can have high levels of salmonella and other contaminants, sometimes introduced in foreign countries where they are harvested and dried outdoors.)

Irradiated hamburger totals about 18 million pounds and is sold at Wegmans supermarkets and by mail from Schwan’s Home Service and Omaha Steaks.

The only large expansion of irradiated food in recent years — and a big driver behind Benso’s and two other irradiators’ decision to start operating — is with imported fruits and vegetables.

In 2007, 10 million pounds of fruits and vegetables that are imported or from Hawaii were being irradiated, typically to kill invasive insects that could harm domestic crops. Now, according to U.S. Department of Agriculture and industry estimates, it’s closer to 40 million pounds.

The treatment, called phytosanitation, is beginning to replace fumigation and other chemical methods that can be used without consumer notification.

Food irradiation must carry a label because federal law treats it as a food additive, which requires that it be treated like other ingredients. Other processes such as chemical washes for chickens and fumigation for strawberries do not have to be disclosed on packaging.

Which is part of why irradiation advocates have fought to remove the label. Professor Christine Bruhn of the University of California at Davis and others are pushing for ways to get consumers to view irradiation in a positive light.

“I would like to change the label to say ‘Irradiated to Protect your Family’ or ‘Irradiated for Maximum Safety,’ ” said Bruhn, who has been studying consumer attitudes toward irradiation for 30 years. “But a lot of people — they just want to get rid of the i-word.”

Alice Crites contributed to this report.