Public health scientists have had an interest in food irradiation for more than 100 years. The first investigations occurred within a few years of the discovery of X-ray/short wavelength by the German physicist Roentgen in 1895. German and French scientists carried on studies to pasteurize food by radiation up to the war years, 1914. The problem at that time was that irradiated foods had an unacceptable taste. In 1915, the X-ray was reported to be effective in killing trichina cysts in pork meat. Later, the U.S. Department of Agriculture demonstrated that X-rays/short wavelengths of energy, could kill disease-causing organisms and halt food spoilage.

As food irradiation pioneer Dr. Edward Josephson pointed out in a recent review, food irradiation was the first entirely new method of preserving food since the thermal canning and pasteurization of wine, beer, and milk in the 19th century.¹ These methods of food preservation were all considered to be processes, but in 1958, under pressure from protesters, the Food, Drug, and Cosmetic Act designated food irradiation as an “additive.” Scientific research has never found evidence to call radiation an “additive” that remained in food; this unfair designation has been used to keep the technology from being used.

In the United States, scientists at the Massachusetts Institute of Technology instituted the first studies of food irradiation in 1899. During the first half of the 20th century, many more studies were undertaken to learn how ionizing radiation could be used to provide more and safer foods to humanity on a worldwide basis. However, the paucity of suitable radiation sources and their high cost prevented the full benefits of irradiation from being realized for use in food and biomedical research.

Since 1950, many beneficial effects of ionizing radiation have been observed, and documented. In addition to its potential to reduce the incidence of foodborne diseases, food irradiation can inhibit post-harvest sprouting in potatoes and onions; disinfest fruits, vegetables, and grains of insects; delay ripening in fruits; eliminate pathogens, using substerilization doses in meat, seafood, fruits, poultry, fruit juices, and vegetables; and, with sterilization doses, produce an array of prepackaged meats, poultry, and seafood, which can keep for years without refrigeration. In addition, irradiation can be used to eliminate pests such as the screw worm fly, which preys on cattle, the Mediterranean fruit fly, and the tsetse fly, by the release of sterile insects.²

Worries about nuclear weapons, combined with an anti-progress ideology, began to stymie food irradiation research after the war. Although there was now an adequate supply of gamma rays—the high-energy, short-wavelength rays given off by radionuclides—lawmakers became convinced by the anti-technology faction to control the development of nuclear technology for treating foods.

In 1958, when the Food, Drug, and Cosmetic Act was passed by the U.S. Congress, there were many unanswered questions: Would food be made radioactive? What would be the effect of this additional radioactivity above that of background upon humans? Would there be new toxic products formed in the irradiated foods? Would carcinogens be formed? Would there be excessive loss of nutrients? Would molecular fragments from packaging materials migrate onto the foods in amounts derogatory to the health of consumers? In the killing of pathogens, would new microbiological problems evolve? What radiation doses would be safe to use? What effect would radiation have on taste, odor, color, texture of the food?

Also, what adverse effect, if any, would result to the environment should there be accidents? What sources of radiation (gamma and machine) and what doses would be suitable for irradiation?

The U.S. Congress—with successful lobbying by well-known public figures in the movie and entertainment circles—convinced Congress to keep food irradiation under tight control. To do this, a legal fiction was created that ionizing radiation used to treat food is a “food additive.” This part of the 1958 law, known as the Delaney Clause, assured that no irradiated food could be approved for consumption without a lengthy drawn-out procedure, thereby singling out and stigmatizing foods so treated, by requiring a long period for research and petition writing to the Food and Drug Administration (FDA) and the U.S. Department of Agriculture, and then many months or years for evaluation.³

Finding the Answers
After 1961-1962, when Ed Josephson was placed in charge of the Department of Defense's food radiation research and development program, the top priority was to try to sort out the diverse claims—pro and con—about irradiated foods. During his tenure as head of the program, the U.S. Army Medical Services completed studies for testing in rats, mice, and beagle dogs, using 21 foods representing all major food classes in the diets of Americans. In a June 1965 hearing by the Joint Committee on Atomic Energy, the Army Surgeon General submitted a statement that all foods irradiated at sterilizing doses up to 5.6 Mrad (56 kGy) using cobalt-60, or electrons at energies below 10 MeV, were wholesome—that is, safe to eat and nutritionally adequate.⁴

Nutritional assessments showed that the irradiation process was no more destructive to nutrients than other processes then being used commercially. It was also demonstrated that there were no toxic products formed in quantities that would be hazardous to the health and well-being of consumers.

The microbiological standard for irradiation-sterilized foods was to use a radiation dose sufficient to reduce a theoretical population of spores of Clostridium botulinum by 12 logs. This standard, recommended by the National Academy of Sciences/National Research Council Advisory Committee to the Army’s program on food irradiation, was adopted. In the ensuing years, there was no record of any problem with possible C. botulinum survivors; although this has continued to be one of the anti-nuclear arguments against food irradiation. (See accompanying article, p. 28.)

Thousands of irradiated components of meals have been served to volunteers. In every respect, the irradiated foods have come through with flying colors. Irradiated foods have been eaten by astronauts on the Moon flight, and on many other space missions, by immune-compromised patients, and by military personnel in several parts of the world.

World Health Groups for Irradiation
Every conceivable possibility for harm has been carefully considered. None was found. Nor have any chemicals formed that are unique to food irradiation. In the meantime, irradiated foods have been approved by the health authorities in 40 countries.

Between 1964 and 1997, the World Health Organization (WHO), in concert with the Food and Agricultural Organization (FAO), and the International Atomic Energy Agency (IAEA), held a series of meetings of experts from many countries to assess the quality and safety of foods.⁵ The latest meeting, in September 1997, recommended approval of irradiated foods without restrictions at all doses, up to the highest dose compatible with organoleptic properties. At each meeting, the internationally recognized health authorities have concluded that all irradiated foods are safe to eat without the need for further toxicological testing, at doses as high as taste would be acceptable.

In view of the foregoing, food scientists believe that the FDA and the USDA should follow the WHO/FAO/IAEA recommendation that food irradiation is a process.

Scientists have thought for three decades that the legal fiction designating ionizing radiation as a food additive, instead of a food process, unjustly penalized food irradiation, and helped delay its implementation for almost 30 years. On the other hand, during these years, the additive designation has stimulated those working in the field to perform at the highest level of good science, thus convincing the scientific community worldwide that food irradiation has an important role to play to combat hunger and disease.

When we look at the big picture, we find that we have essentially reached our objective in documenting that food irradiation is a safe and beneficial process. Now we need to “educate” government officials, as well as health workers, food processors, marketers, and the public, on the safety and advantages of food
irradiation.

The Pasteurization Example
With approximately 9,000 people dying annually in the United States from food poisoning, and an estimated 30,000,000 cases of food infection each year, the time has come to use food irradiation more widely for the benefit of mankind.

Today in the application of ionizing radiation to protect the public health against foodborne pathogenic bacteria, public health officers face the same arguments that were voiced against pasteurization at the beginning of the century, and later against canned and frozen foods. In the history of pasteurization, many voiced disbeliefs of pasteurization’s benefits for sanitation, nutrition, physical and bacteriological quality, public health and safety, and economics. Loss of hair, skin tone, and general well-being, as well as potency, were also alluded to. All of these mistaken beliefs are cited today against the irradiation of food.

Food irradiation is now recognized as another method of preserving food and ensuring its wholesomeness by sterilization or cold pasteurization, and has wide application worldwide. If it had been in place in the United States, recent foodborne disease outbreaks caused by E. coli0157:H7, which are found in food-producing animals, would not have occurred. If one attempts to tabulate tens of thousands of Salmonella, Campylobacter, Yersinia, Listeria, and Escherichia coli foodborne disease outbreaks related to poultry and meat, the totals exceed millions of human illnesses, over the course of the more than 40 years since the Delaney Clause established the travesty that gamma rays are a food additive. (Fortunately, the Congress did not redefine the entire electromagnetic spectrum, which encompasses all kinds of rays and waves.)

The Death Toll
How many thousands of deaths and illnesses could have been prevented if public health authorities had implemented food irradiation and educated the public as to its benefits, we will never know.

The morbidity and medical expense of meat- and poultry-borne diseases can be prevented, just as milk-borne disease can be prevented by pasteurization. All of the bacteria cited above can be present in unpasteurized milk, even though the U.S. Public Health Service Grade A standards require that milk be free of disease-causing organisms. Imagine the public outcry if the governments allowed the marketing of unpasteurized milk in which Salmonella were found, or E. coli virulent strains, or Listeria in soft cheese or Mexican-style cheese.

In 1984, the Secretary of Health, Margaret Heckler, endorsed food irradiation, after lengthy studies had proven its safety. If public health officers had spoken out then for the irradiation of foods that are known to carry pathogenic bacteria, events like the E. coli0157:H7 outbreaks from undercooked hamburger (3 deaths and more than 400 cases of illness) that occurred in the northwest United States in January 1993, could have been prevented.

Even today, no national or state local health authority is speaking out to require pasteurization by irradiation of hamburger meat patties, of which some tens of millions are consumed daily. The same attitude and apathy exists in Europe, where Listeria-contaminated pork meat and other food caused the death of 63 persons in France, as reported in 1993. Since then, Listeria has become a serious public health problem in America.

One hesitates to ask who is in charge of the protection of the public health in these United States, or our neighbors in the Americas or Europe. The “anti” activist can always be relied on to oppose new technologies, and among them are powerful interests. Environmentalists, health food advocates, food processors, wholesalers, retailers, and producers—all for their own reasons are saying that the consumer is not ready, or does not want it, or is against it.

Consumers Want Irradiation!
But this is not true: The U.S. Department of Agriculture survey of consumer attitudes, and actual market tests by Susan Conley, say that 70 percent of the American public wants safe food and will accept food irradiation to ensure that this is so. The University of California survey by Dr. Christine Bruhn found Californians of the same mind. A University of Georgia survey went further, and found the consumer willing to pay more for irradiated food that would offer the same protection as pasteurized food. The consumer said the same in surveys by the Food Science departments at Purdue, Iowa State, and Kansas State universities. More recently, several national consumer surveys find the public seeking an opportunity to test irradiated foods.

Why have public health scientists not given the consumer the benefits of food irradiation?

Where were the national public health leaders who spoke for irradiation? The American Medical Association was among the few early supporters, as was the American Veterinary Medical Association. But the American Public Health Association was outspoken against food irradiation, and it opposed any discussion of resolutions supporting radiation.

The only academic support came from universities and colleges with food science and home economics departments. Strangely, some public health schools and medical colleges were afraid to support food irradiation, or spoke against it, calling it “dangerous” and “destructive.” So-called health letters warned their readers against food processors, who would supposedly use irradiation to cover up failed hygiene.

The first top public health officials to speak out on the importance and value of food irradiation was James Mason, M.D., the Assistant Secretary of Health, HHS, in an editorial in Public Health Reports, Sept./Oct. 1999.⁶ He concluded: “The bottom line on food irradiation is that the nation deserves to have—and should claim—the health benefit this technology will surely provide. We don’t know how great that benefit will be—but we do know it will be significant.”

Two years later, Philip R. Lee, M.D., the Assistant Secretary of Health, Director of the U.S. Public Health Service stated:⁷

“It is the U.S. Public Health Service’s responsibility to use what we know to protect and improve the health of the public. Each modern food-processing advance—pasteurization, canning, freezing—produced criticism. Food irradiation is not different. It is up to leaders in the health professions to dispel the myths.

“The technology of food irradiation has languished too long already. Perhaps our nation has become dangerously complacent about the importance of public health measures. The current health care debate offers us both a mandate and an opportunity to increase the understanding of the importance of public health for ensuring personal health. If this message is lost, our efforts to advance and protect the nation’s health will not succeed.”

James H. Steele, a pioneer in food irradiation, is a former public health veterinarian with the U.S. Public Health Service, and has more than 45 years of global public health experience. Steele has held the position of Assistant Surgeon General of the USPHS, and is currently Professor Emeritus of the School of Public Health, University of Texas at Houston. This article was adapted from a paper Steele presented at a June 1999 conference on irradiated foods, sponsored by the Minnesota Health Department.

Notes

1. E.S. Josephson and H.A. Dymsza, (1999). “Food Irradiation,” Technology, Vol. 6, pp. 235-238.

2. S.D. Baily et al., 1957. Radiation Preservation of Food by the U.S. Army Quartermaster Corps (Washington, D.C.: U.S. Government Printing Office).

3. Anonymous, 1958. “Federal Food, Drug and Cosmetic Act, as amended. 21 U.S. code 321,21 Code of Federal Regulations, part 121—Food Additives.

4. Statement on the wholesomeness of irradiated foods by the Surgeon General, Department of the Army, in “Radiation Processing of Foods.” Published Hearings before the Subcommittee on Research and Development and Radiation of the Joint Committee on Atomic Energy of the United States, June 9 and 10, 1965.

5. The report of the 1964 meeting in Rome was published in WHO Technical Report Series, No. 316 (Geneva: World Health Organization, 1966). The report of the 1969 meeting in Geneva was published in WHO Technical Report Series, No. 451 (Geneva: World Health Organization, 1970). The report of the 1976 meeting in Geneva was published in WHO Technical Report Series, No. 604 (Geneva: World Health Organization, 1977). The report of the 1980 meeting in Geneva was published in WHO Technical Report Series, No. 659 (Geneva: World Health Organization, 1981). The report of the 1997 meeting in Geneva was published in WHO Technical Report Series, No. 890 (Geneva: World Health Organization, 1998).

6. J.O. Mason, 1993. “Food Irradiation—Promising Technology for Public Health,” Public Health Reports, Vol. 108, No. 3, p. 402.

7. P.R. Lee, 1994. “Irradiation to Prevent Foodborne Illness, JAMA, Vol. 272, No. 4, p. 281 (July 27).

World Health Groups for Irradiation

The Pasteurization Example

The Death Toll

Consumers Want Irradiation!

Notes

“The advancement of food preservation hygiene since the time of early civilizations has been marked by the increased longevity of man. In the 20th century, human mortality has had a constant decrease. The extension of human life and well-being is attributable to good public health practices, immunization of all children and adults, chlorination of potable water, sewage disposal of human and industrial waste, and food hygiene, including pasteurization. All have contributed to improved life and longer survival of human beings. The irradiation of food will further improve human health by the prevention of foodborne disease.

—J.H. Steele and R. Engel, “Radiation Processing of Food,” JAVMA, Vol. 201, No. 10, p. 1522 (1992)