Business was almost as brisk as the publicity, though protesters sometimes outnumbered the customers when David Laurenzo started selling irradiated strawberries at his produce market in North Miami Beach two weeks ago.
The fruit was the first retail irradiated food to come from the first American commercial food irradiation facility, Vindicator of Florida, Inc. in Mulberry, Fla. But proponents believe it is just the beginning of a vast new industry to provide, among other things, salmonella-free chicken and pesticide- and preservative-reduced produce that will keep its flavor, color and texture long after it has been ripened on the vine or tree.
The Vindicator plant ran 3,400 pints of strawberries through 1 kiloGray of radiation on Jan. 23, and they went on sale at Laurenzo`s Jan. 25. The berries-still looking crisp with no signs of mold-were mostly sold out by last Saturday, 10 days later, about a week longer than they normally last, says Laurenzo.
Irradiation-the process of subjecting certain edible products to controlled doses of gamma rays to kill harmful microrganisms-is a technology developed over the past 50 years, one which has been accepted in other countries and that enjoys almost universal support from the medical and scientific communities.
Irradiating food, even to the degree that it takes to kill off salmonella, campylobacter and other pathogens, presents much less of a health risk than grilling a steak, some scientist say. Those who fear it, do so because it is new and because it inlvolves the same kind of energy associated with nuclear reactors, they say.
The main critics, though few, say that despite years of study and reams of research, too little testing has been done to assure the irradiation process is absolutely safe.
”It will be no fun 10 years down the road if somebody does find a potent carcinogen in irradiated chicken, then says, like with breast implants, that
`there really hasn`t been that much research,` ” cautions Richard Piccioni, a biophysicist and senior scientist for Food and Water, Inc., an advocacy group organized to lobby against irradiating food.
If you`re like most consumers, you are confused: When it comes time for you to decide whether to buy a product bearing the required radura symbol (see illustration)-and eventually you will have to make that decision-which should you choose?
Food not radioactive
First, although the food is subjected to as much as 3 kiloGrays of gamma ray radiation (equivalent to about 30 million chest X-rays), most of the radiation passes through it, and the food does not become radioactive. The radiation, depending on the dose, does kill micro-organisms that cause rot and in some cases disease.
Second, irradiated food is virtually the same as untreated food in color, taste, smell and texture. Indeed, scientists still are trying to find a workable way to determine if a food has been irradiated or not.
There are more than 40 irradiation facilities in the country sterilizing medical equipment and other products, but Vindicator is the first American plant devoted to irradiating food for retail sale. While the United States has been developing the technology for irradiating food products since 1947, other countries were first to put commerical food irradiation into use. It has been approved for use on food in 19 other countries.
The FDA has allowed some foods to be irradiated since the mid-1960s when it approved the process for wheat, flour, potatoes and canned bacon, though it hasn`t been used. In 1983 the FDA approved irradiation of spices, herbs and seasonings, and some of those products now go through the process, especially imported spices. Treating pork was approved in 1985 and fruits and vegetables in 1986, but none of these products were irradiated commerically. In 1990 the FDA approved the irradiation of poultry at 3 kiloGrays to ”pasteurize” it against salmonella and other microbiotic contaminants, but poultry producers so far have resisted using it, at least partially because they perceive negative public reaction.
The irradiation process has been endorsed not only by the FDA but by the American Medical Association, the American Dental Association, The Council for Agricultural Science and Technology, the International Atomic Energy Agency, the World Health Organization and the Food and Agriculture Organization of the United Nations.
”Let`s get something straight,” says F. Jack Francis, professor of food science ermeritus at the University of Massachusetts, Amherst, and a specialist in food safety. ”On a world-wide scale there is a virtual scientific consensus that irradiating foods presents no health problems. Scientists are not divided on this, as some media reports would have us believe.”
Harmful URPs?
However, there are a couple scientists who do disagree about whether food subjected to irradiation is safe. They bring up two main points: the possible destruction of nutrients in the food and the creation of microscopic amounts of possibly cancer-causing chemicals called unique radiolytic products or URPs.
”When you irradiate organic matter with high energy, particularly in an aqueous (water-based) solution, you powerfully disrupt chemistry and break molecular bonds, producing radiolytic products (or RPs),” says Samuel Epstein, professor of occupational and environmental medicine at the University of Illinois at Chicago. ”The concentration depends on the intensity of radiation and whether it is wet or dry. A lot of these radiolytic products have not been characterized (i.e. URPs).” Some of the radiolytic products can be toxic such as benzene and formaldehyde, some are chemical compounds whose effects are not known (URPs), he says. ”You are, in fact, playing toxicological roulette.”
At the 1 kiloGray dose of radiation the FDA has approved for produce, a very small amount of radiolytic products is produced, explains George Pauli, the food irradiation coordinator for the FDA, which regulates food
irradiation. ”Most of them are the same as compounds found naturally in other foods as a result of environmental radiation.” Products like benzene and formaldehyde do exist naturally in some foods, but at such small levels they are insignificant. There are a few URPs that so far have not been found in other foods, but that often are very similar in their chemical structure to those which have, he says. They exist in such insignificant amounts that they do not constitute a safety problem, and the FDA has determined further testing would be a waste, he says. Most other scientists agree, he says.
”Absolute safety or comparable safety is the reasoning here,” says Manuel Lagunas-Solar, senior radiochemist at the University of California, Davis. ”While you can detect levels of natural toxicants generated naturally by sun-drying, cosmic rays and other background radiation, by comparison the amount of these same chemicals found in irradiated food is considerably lower and virtually undetectable. They are not going to be health hazards simply because they are in insignificant concentrations.”
That`s not good enough for Food and Water`s Piccioni, who describes himself as a pain in the neck. ”The question is: Can we make a reasonable statement of assurance? I say no. What we don`t know can be very important. Irradiation is a technology that will have an enormous influence on the food supply, especially if it is used on poultry. Because the (salmonella) bacteria are virtually ubiquitous, we are talking about all the chicken-80 pounds per person per year. I`m concerned about substances that may be residual.
”We need to apply a high level of scrutiny to this technology. Even if we are talking about only a small or modest amount. If the risk is only 1 part in 1,000 for lifetime consumption, you have to realize that that risk is being experienced by 250 million people.”
Only poultry qualified
The FDA will permit irradiating food above the level of 1 kiloGray only on a product-to-product basis after appropriate testing. So far, only poultry has qualified, based mostly on animal testing done in the Netherlands, Pauli says.
Piccioni disagrees with the interpretation of the results of the Dutch tests, however, saying that they were not sensitive enough. Using his own statistical projection, he says the test results can be interpreted to show a potential cancer risk of as much as 1 in 100, much greater than the FDA`s rule-of-thumb standard of 1 in 1 million.
”It`s not that there`s clear evidence there is a problem,” Piccioni says, ”but the burden should be on the promoter.”
Regarding nutrient loss, ”There is impressive evidence that irradiated foods lose vitamin content, paticularly vitamins A, C, E and the B complex,” Donald R. Louria, chairman of the preventative medicine department at the New Jersey Medical School in Newark, says in an article for ”The Bulletin for Atomic Scientists.” In general there is a direct relationship between the amount of irradiation and the extent of nutrient loss, he says.
Most advocates of irradiation don`t dispute a detectable loss of selected nutrients, but explain that at low doses the loss is no greater than what might be found naturally in some unradiated fruits. However, at higher doses there is more loss depending on the particular food.
”At higher doses there is a loss of some nutrients,” says the FDA`s Pauli, ”so you must ask the question: Is the nutrient important to the diet from this source? If the food normally contributes little of the nutrient to the diet to begin with, then a 20-percent loss would be insignificant. If it`s a significant source of a vitamin, then we have to look closer.”
Nutrient loss is another factor the FDA will consider before approving foods for more than 1 kiloGray of irradiation, he says.
In the past four decades hundreds of studies in humans and animals have shown no harmful effects from irradiation, some using much higher doses than proposed in the U.S. and some involving several generations of test animals. In one Chinese study, one of the few using humans, 400 medical students were fed a 100-percent irradiated diet over several months with no detectable problems, says Christine M. Bruhn, PhD., a food marketing specialist at the University of California`s Center for Consumer Research at Davis.
Safety advantage
Irradition`s role in eliminating food poisoning is its greatest safety advantage, Bruhn says. ”More and more people are suffering from foodborne illness-from 3 million to 81 million cases each year, depending on whom you listen to. The discrepancy comes because so many don`t report it, but still 3 million is a lot. Of that there are 9,000 deaths, mostly the young, older people, and people recovering from illnesses or disease or who otherwise have a reduced immunity.
”The second significant advantage is spices. Some imported spices now are irradiated. But many spices now are fumigated with ethylene oxide, which leaves a residue. It has its hazards and is a known carcinogen so that it is now banned in California,” Bruhn says.
”Irradiation is not sterilization,” says Francis, ”It`s more like pasteurizing. It will reduce the salmonella, campylobacter and other pathogens to a level that`s almost insignificant. I feel very good about that because salmonella in poultry is a real problem. There`s no other good way to take care of it.”
”I`ve changed from a skeptic to one waiting and anxious to buy
(irradiated food),” says Bruhn. ”People should have a choice. Those who don`t want to buy irradiated food shouldn`t have to. But those who feel that irradiated foods are safer have a right to buy it.”
But according to Food and Water director Michael Colby, ”Using irradiation to stop salmonella is like using a chain saw to cut butter. It`s dangerous, excessive. Salmonella is a problem of industry. Why not clean up the poultry industry?”
To Vindicator president Sam Whitney, public acceptance is a foregone conclusion. Given a choice between a chicken fraught with toxic bacteria and one that`s almost totally free of those pathogens that costs a nickel more, who wouldn`t chose the latter? he asks.
