Food Irradiation: 
Toxic to Bacteria, Safe for Humans 
by Dale Blumenthal 

  A measure FDA announced in the Federal Register this year may go unused 
because of consumer apprehension. On May 2, 1990, FDA issued a rule defining
the use of irradiation as a safe and effective means to control a major 
source of food-borne illness--Salmonella and other food-borne bacteria in 
raw chicken, turkey, and other poultry. However, FDA has received written 
objections that it must evaluate before the rule can go into effect.
  Experts believe that up to 60 percent of poultry sold in the United States
is contaminated with Salmonella, according to Joseph Madden, Ph.D., acting
director of FDA's division of microbiology. Madden adds that studies suggest
that all chicken may be contaminated with the Campylobacter organism. 
  People often become ill after eating contaminated poultry. Symptoms may 
range from a simple stomachache to incapacitating stomach and intestinal
disorders, occasionally resulting in death. 
  As equipment used to irradiate food is regulated as a food additive, the
FDA rule is the first step in permitting irradiation of poultry. However, 
although the U.S. Department of Agriculture will soon propose a companion 
rule finalizing guidelines for commercial irradiation of poultry, industry
groups cite consumer apprehension as a drawback to implementing the 
procedure. And reaction to FDA's new rule has elicited more questions than
answers.

A Scary Word
  Irradiating food to prevent illness from food-borne bacteria is not a new 
concept. Research on the technology began in earnest shortly after World War
II, when the U.S. Army began a series of experiments irradiating fresh foods
for troops in the field. Since 1963, FDA has passed rules permitting
irradiation to curb insects in foods and microorganisms in spices, control
parasite contamination in pork, and retard spoilage in fruits and vegetables. 
  But, to many people, the word irradiation means danger. It is associated
with atomic bomb explosions and nuclear reactor accidents such as those at
Chernobyl and Three Mile Island. The idea of irradiating food signals a kind
of "gamma alarm," according to one British broadcaster. (Gamma rays are 
forms of energy emitted from some radioactive materials.) 
  But when it comes to food irradiation, the only danger is to the bacteria 
that contaminate the food. The process damages their genetic material, so 
the organisms can no longer survive or multiply.
  Irradiation does not make food radioactive and, therefore, does not 
increase human exposure to radiation. The specified exposure times and
energy levels of radiation sources approved for foods are inadequate to 
induce radioactivity in the products, according to FDA's Laura Tarantino, 
Ph.D., an expert on food irradiation. The process involves exposing food to 
a source of radiation, such as to the gamma rays from radioactive cobalt or 
cesium or to x-rays. However, no radioactive material is ever added to the
product. Manufacturers use the same technique to sterilize many disposable
medical devices.
  Tarantino notes that in testing the safety of the process, scientists used
much higher levels of radiation than those approved for use in poultry. But 
even at these elevated levels, researchers found no toxic or cancer-causing 
effects in animals consuming irradiated poultry.

Beyond the Gamma Alarm
  Market tests show that once consumers learn about irradiation, they will
buy irradiated food. For example, Christine Bruhn, Ph.D., of the University 
of California's Center for Consumer Research in Davis, Calif., reports that 
irradiated papayas outsold the nonirradiated product by more than 10 to 1 
when in-store information was available. And, Danny Terry, Ph.D., a consumer
researcher at Central Missouri State University in Warrensburg, Mo., says 
that a recent market test he conducted with irradiated strawberries showed
that consumers who received written information about irradiation along with
the fruit were slightly more interested in buying irradiated products in the
future. 
  Nevertheless, concern about the process remains strong. Since 1989, three 
states (Maine, New York, and New Jersey) have either banned or issued a 
moratorium on the sale of irradiated foods. According to a U.S. General 
Accounting Office report prepared in May 1990 at the request of Rep. Douglas
Bosco (D-Calif.), "officials of these states told us that their states took 
the actions in response to public concern by citizen groups rather than as a
result of scientific evidence questioning the safety of food irradiation."
  "Something quite aside from food safety appears to lie at the root of the 
entire controversy, which may explain why it continues to flourish in the 
face of all safety assurances," says Carolyn Lochhead in the August 1989
issue of Food Technology magazine. "Many opponents charge that the Food and 
Drug Administration, the World Health Organization, and the nuclear power 
industry are conspiring to promote the technique as a way to dispose of 
nuclear waste." 
  Lochhead discusses concerns that one source of radioactive material for 
food irradiation, cesium 137, is recovered from spent fuel rods in nuclear
power plants. The conspiracy charge promotes unwarranted fear among 
consumers, says Lochhead. 
  "For economic, as well as other, reasons," says Department of Energy
official Barbara Thomas, "the U.S. commercial nuclear power industry does 
not attempt to recover material, such as cesium 137, from spent fuel."
  According to DOE, commercial irradiators in the United States choose their
irradiation source (whether the gamma-emitting radioactive materials cesium 
137 or cobalt 60, or accelerators that can produce electrons, x-rays or 
both) based on practical requirements, such as cost. The product to be
irradiated also influences the choice. Many foods require low energy levels 
to kill harmful organisms, while medical supplies may need higher doses for 
sterilization.
  However, the fallout from a falsely characterized cesium recovery plan has
charged the legislative atmosphere. George Giddings, Ph.D., a consultant
food scientist and expert in food irradiation matters, sees it as the 
"single most inciting issue in the food irradiation area." Giddings suggests
that legislators are wary of supporting food irradiation measures some
critics say are linked to increased nuclear activity, including the 
production of nuclear weapons.
  A 1982 congressional amendment bars using spent commercial fuel for 
military purposes. The Department of Energy has no interest in changing this
law.
  Michael Colby, director of Food and Water, Inc., one of the more vocal
groups lobbying against food irradiation, says the new poultry regulation 
will lead to nuclear hazards, including "the continued generation of
radioactive wastes for which a secure isolation technology has yet to be
developed." Colby submitted the comment during a 30-day objection period
following publication of the final rule. In the case of food additives, FDA 
evaluates objections in order to determine whether any changes in the final 
rule are appropriate. Based on FDA's findings, those raising the objection
may be entitled to a hearing before the commissioner. 
  FDA inspections of all irradiation plants conducted from 1986 to 1989 
showed no violations of the food irradiation regulations. 
  Giddings contends that groups such as Food and Water play on the public's 
fear of nuclear energy and misrepresent the safety questions surrounding
food irradiation. They frame it as a "populist" issue to legislators and
pressure them to introduce legislation banning food irradiation.

Consumer Uncertainty
  Other consumer groups have taken more moderate positions. The Center for
Science in the Public Interest, for instance, says that "at a minimum,
irradiated foods should be labeled" so that consumers know what they're 
buying. 
  Since 1966, FDA has required that irradiated foods be labeled as such. In 
1986, a mandatory logo was added to this labeling requirement. The
international logo, first used in the Netherlands, consists of a solid
circle, representing an energy source, above two petals, which represent the
food. Five breaks in the outer circle depict rays from the energy source. 
  Consumer surveys show mixed reactions. According to an article in the 
October 1989 issue of Food Technology magazine, which reviewed surveys
conducted by various academic and consumer research groups, consumers are 
more concerned about chemical sprays and pesticide residues, preservatives, 
and food-borne illnesses than about food irradiation. A Louis Harris poll,
conducted from 1984 through 1986, however, found that 76 percent of 
Americans consider irradiated food a hazard.
  "Consumer acceptance of irradiation as a treatment for foods is showing 
only minimal positive change, at best," said Fred Shank, Ph.D., director of 
FDA's Center for Food Safety and Applied Nutrition, in a symposium on food
irradiation at the 1990 annual meeting of the Institute of Food Technology. 
Shank said that the greatest concern about the process is its perceived 
association with radioactivity and nuclear power. 
  Another concern, raised often in comments to FDA when it proposed the use 
of radiation to kill microorganisms in spices and insects in fresh foods, is
that irradiation may produce substances not known to be present in
nonirradiated foods.
  These substances, described by scientists as "radiolytic products" sound
more threatening than they actually are, says George Pauli, Ph.D., an FDA 
food irradiation expert and policy maker. For instance, Pauli says, when we 
heat food it often creates new substances that produce new tastes and 
smells. These substances could be called thermolytic products--an 
intimidating word for a harmless change.
  In 1979, FDA established the Bureau of Foods Irradiated Food Committee
(BFIFC) to review safety assessments of irradiated food. Experiments have 
shown that very few of these radiolytic products are unique to irradiated 
foods. In fact, the BFIFC estimated that approximately 90 percent of the
substances identified as radiolytic products are found in foods that have 
not been irradiated--including raw, heated and stored foods. Moreover, many 
of these substances are not well known because the foods usually have not 
been studied at the minute (parts per million) levels scrutinized by
chemists who analyzed the irradiated foods. 

Proving the Absence of a Ghost
  For 30 years, FDA has reviewed experiments attempting to show possible
harmful effects of consuming irradiated food. But, "just as we can't prove
the absence of a ghost, scientists cannot point to some 'thing' that proves 
the absence of risk," Pauli adds. "One can only search diligently." 
  The only relevant safety issue in food irradiation, BFIFC determined, 
would be the production of harmful substances. BFIFC examined all available 
data on such products obtained by the U.S. Army's high-protein food 
sterilization program. Only six substances (found in beef irradiated at 50
kiloGrays) of the 65 identified by Army researchers could not be verified in
the literature as present in nonirradiated foods. These six substances were 
similar to natural food constituents. 
  The committee determined that even a diet consisting mainly of food 
irradiated at the 1 kiloGray level (see accompanying article) would not be
likely to contain a significant amount of any of these products.
  BFIFC concluded in 1980 that food irradiated at a dose not exceeding 1
kiloGray is safe for human consumption, and that animal tests are 
recommended only for foods irradiated above 1 kiloGray. 
  A second team of scientists then reviewed all animal feeding and other
irradiated food toxicity studies--several hundred--from agency files and the
scientific literature and reaffirmed the BFIFC recommendation.
  Since then, FDA has set the use of food irradiation at levels higher than 
1 kiloGray. The 1990 rule, for instance, would allow irradiation of poultry 
at levels up to 3 kiloGrays after animal data again revealed no hazardous 
effects.
  In a separate review, the international community reached a similar 
conclusion. Representatives from the United Nations, the International
Atomic Energy Agency, and the World Health Organization, making up the joint
"Committee on the Wholesomeness of Irradiated Food," declared in 1980 that
the irradiation of any food up to an overall average dose of 10 kiloGrays 
causes no toxicological hazard and introduces no special nutritional or 
microbiological problems. The Codex Alimentarius Commission, a United 
Nations organization that recommends international food standards, adopted
the recommendation in 1983. 

The Future of Food Irradiation
  The World Health Organization believes irradiation can substantially
reduce food poisoning. According to a 35-year WHO study, there has been a 
constant increase in the incidence of food-borne diseases, as well as 
emergence of "new" disease-causing organisms, such as Campylobacter and 
Listeria. 
  Food irradiation would be another weapon in the arsenal against food-borne
illness. FDA and WHO, however, emphasize that irradiation is not a
substitute for careful handling, storage and cooking of food. Irradiated
poultry can become recontaminated, for instance, if placed next to
contaminated, nonirradiated poultry, or left unrefrigerated so that 
remaining organisms can grow. 
  To date, 35 countries have issued unconditional or provisional clearances 
allowing irradiation of commercial foods. Of the more than 140 industrial 
gamma irradiators in over 40 countries, 29 are used part-time to irradiate
food items and conduct food-related research. (They are used mostly for 
sterilizing disposable medical supplies.) A 1989 Library of Congress report 
prepared for Congress estimates that by the early 1990s, 55 facilities
worldwide will be used for food irradiation and related food irradiation
research. 
  However, as Tanya Roberts of USDA's Economic Research Service stresses, 
the future of irradiation depends upon consumer acceptance--based largely on
proof that the process can produce safer foods at lower cost. Roberts 
estimates that the cost of medical treatment and lost productivity for five 
food-borne diseases--trichinosis, toxoplasmosis, salmonellosis, 
campylobacteriosis, and beef tapeworm--totals more than $1 billion annually.
  The last chapter in the story of food irradiation still remains to be 
written. Will the fear of nuclear energy prevent this technology from being 
used to its fullest potential? Or will education win acceptance for a 
procedure that can lower the incidence of food-borne illness? Only consumers
can supply the answers. n 

Dale Blumenthal is a staff writer for FDA Consumer. 

Poultry Producers Respond 

  With one hand, poultry producers are giving a thumbs up sign to FDA's rule
permitting irradiation of poultry. With the other, they are putting its use 
on hold.
  Stuart Proctor, executive vice president of the National Turkey 
Federation--which represents 95 percent of turkey growers and 
producers--says "we are encouraged by FDA's decision. The industry should be
allowed to use any science available that makes food safe from food-borne 
illness and also is safe." He continues, "as soon as consumers are ready to 
accept the product, we'll use it."
  As George Watts, president of the National Broiler Council, says, "the
U.S. poultry industry has always been a consumer-driven business, 
demonstrated by the variety of new products developed over the years to meet
the American public's demand." He says that should consumers desire 
irradiated food products, "the industry will respond."
  Perdue Farms, Inc., a large, East Coast chicken producer, says it has no
plans to use the irradiation process. Steve McCauley, a company spokesman,
said that the firm sees no need for decontaminating its poultry with
irradiation because Perdue tests its products stringently. He claims this 
keeps them safe from contamination. 
  The need is for consumer education. Although poultry groups say they do 
not have the resources for the costly campaign needed, they believe that
once consumers understand more about food irradiation, they will demand it. 
  Proctor compares reaction to food irradiation to earlier apprehension 
about microwave ovens. Once consumers recognized microwave cooking as safe, 
desire for fast and convenient food led to a microwave revolution. He said
he could foresee the same demand for irradiated food, prompted by a desire
to cut down on food-borne illness, once consumers are no longer afraid of 
the process. n

--D.B.