- The U.S. Food and Drug Administration (FDA) has ignored
growing evidence that a new class of chemicals formed when food is irradiated
could be harmful, according to a report released today by Public Citizen
and the Center for Food Safety.
- The groups are urging the FDA to refrain from legalizing
irradiation for any additional types of food until the new chemicals are
tested for safety. The chemicals, called cyclobutanones, do not occur naturally
anywhere on Earth. They recently were found to cause genetic damage in
rats, and genetic and cellular damage in human and rat cells.
- The groups' report, Hidden Harm, details how the FDA
has ignored this unique class of chemicals, which are created in many irradiated
foods that the agency has legalized for sale in this country -- including
beef, pork, chicken, lamb, eggs, mangoes and papayas. It is expected that
cyclobutanones also would be formed in many other foods the FDA is currently
considering to legalize for irradiation.
- The organizations today also released a sworn affidavit
of toxicologist William Au, who was retained by the groups to independently
review the risks posed by cyclobutanones and other chemicals formed by
irradiation that could cause genetic damage.
- Along with a letter outlining numerous health concerns
caused by food irradiation, the groups filed Hidden Harm and Au's affidavit
with the FDA to oppose pending petitions to legalize irradiation for processed
foods, which comprise 37 percent of the typical American's diet; molluscan
shellfish, such as clams and oysters; crustacean shellfish, such as lobsters
and shrimp; and meat products.
- A fifth petition seeks to double the maximum dose of
radiation to which poultry can legally be exposed.
- "The risk that the FDA is taking with the health
of the American people cannot be overstated," said Wenonah Hauter,
director of Public Citizen's Critical Mass Energy and Environment Program.
"If government officials knowingly allow people to eat food that contains
these chemicals, they are courting a major public health disaster."
- Though federal regulations require the FDA to determine
whether food additives proposed for human consumption are likely to cause
cancer, birth defects or other health problems, the agency has not done
so for cyclobutanones, nor have agency officials explained why they have
failed to do so. Under federal law, irradiation is considered a food additive.
- Americans likely are unwittingly eating irradiated foods
containing cyclobutanones. Though most irradiated food sold in stores must
be labeled, there is no such requirement for restaurants, schools, hospitals,
nursing homes and other institutional settings. And there is no labeling
requirement for foods with irradiated ingredients, except those containing
irradiated meat. Moreover, due to a lack of reporting requirements for
food companies, it is unknown how much irradiated food is sold in the US,
- "Children are likely to be especially vulnerable
to the risks of these untested chemicals in their food," said Peter
T. Jenkins, policy analyst at the Center for Food Safety. "It is beyond
me why the FDA would take a chance by exposing American children in this
way. The science is against it."
- Au, an environmental toxicology professor at the University
of Texas Medical Branch in Galveston, is internationally recognized for
his work on the toxicological mechanisms that induce human disease. For
more than 20 years he has taught, published peer-reviewed research and
served on expert committees. He has received numerous awards, and has published
or co-published more than 100 articles.
- "An emphasis should be placed on the products that
are unique to the irradiation process and that are potentially mutagenic,
e.g. 2-DCB [2-dodecylcyclobutanone]," Dr. Au wrote in the affidavit.
"Without conclusive evidence regarding the safety of these products,
the safety of irradiated food cannot be assured." Au urged the FDA
to "seriously and explicitly" consider "repeated observations"
of genetic damage and reproductive toxicity in feeding experiments.
- Though cyclobutanones were first identified in irradiated
food in 1971, it was not until 1998 that German government scientists discovered
that one type of cyclobutanone, 2-DCB, caused genetic damage in rats, and
genetic and cellular damage in human and rat cells.
- Subsequently, the scientists found that two other types
of cyclobutanones -- 2-TCB and 2-TDCB -- caused genetic and cellular damage
in human cells. Rat feeding studies of these two chemicals are expected
to be completed soon.
- Despite these findings, the FDA not only has failed to
publicly acknowledge the potential risks posed by cyclobutanones, but the
agency proceeded to legalize irradiation for three classes of food even
after the first two German studies were made public.
- Last year, the FDA legalized the irradiation of eggs,
juice and sprouting seeds despite the fact that several high-ranking agency
officials four months earlier had attended an international conference
in Beijing at which the 2-DCB toxicity findings were presented and discussed.
- Ironically, cyclobutanones are so easily detectable and
have been known to remain in food for such lengthy periods - more than
a decade - that they are commonly used as "markers" to determine
whether food has been exposed to ionizing radiation.
- The groups are calling on the FDA to take several steps:
refrain from legalizing irradiation for any additional foods until comprehensive,
published, peer-reviewed research is conducted on cyclobutanones; conduct
a comprehensive analysis of the cyclobutanone levels in foods covered by
irradiation petitions already approved by or pending before the FDA; convene
public hearings to thoroughly explore the potential health effects of cyclobutanones.
- Expert Affidavit on Safety of Irradiated Food
- By William W. Au, Ph.D.
- William Au, being duly sworn, hereby deposes and says:
- A. My address is: Division of Environmental Toxicology,
Department of Preventive Medicine and Community Health, Ewing Hall, 700
Harborside Drive, University of Texas Medical Branch, Galveston, Texas
77555-1110, where I have been employed as a Professor since 1991. My Curriculum
Vitae is attached hereto indicating my professional qualifications as a
toxicologist. My primary research interest is in conducting molecular and
cellular studies to elucidate toxicological mechanisms for the induction
of human disease. Since obtaining my Ph.D. from the University of Cincinnati,
I have more than 20 years of experience teaching, conducting and publishing
peer-reviewed research, consulting and speaking internationally, editing
professional publications, and serving on numerous expert committees. I
am a member of the major scientific societies related to toxicology and
have received approximately one dozen awards recognizing my professional
contributions. I have delivered more than 35 invited lectures internationally
and published or co-published more than 100 articles in the toxicology
- B. I submit this Affidavit on the food irradiation petitions
pending before the United States Food and Drug Administration, most specifically
FAP 9M4697 (Docket No. 99F-5522), addressing "ready-to-eat foods,"
however, the conclusions herein also apply generally to other past and
pending irradiation petitions.
- C. I submit this Affidavit on behalf of two Washington,
DC, non-profit groups, the Center for Food Safety and Public Citizen, who
have retained me as a consulting expert. Prior to this consultation I had
no prior involvement with those or any other non-profit groups involved
in food irradiation issues.
- D. In formulating my opinion, I have reviewed relevant
documents and studies that were provided by my clients and conducted independent
research including several publications that I have selected from the literature.
- My opinion, based on a reasonable degree of scientific
certainty, is as follows: Ionizing radiation is a well-documented teratogen,
mutagen and carcinogen whereas some other procedures for food decontamination
/ sterilization such as heat and steam are not. Ionizing radiation interacts
with cellular macromolecules that are also present in food products to
generate toxic products. Therefore, the use of radiation to decontaminate/sterilize
foods that are destined for human consumption should be evaluated for health
concerns very carefully. Whenever other processing methods or combination
of methods that are equally effective in reducing the risk of food borne
disease are available, the use of the radiation procedure should be avoided.
- Therefore, it is surprising to learn from the Food and
Agriculture Organization/International Atomic Energy Agency/World Health
Organization report (1999) that those agencies gave a blanket statement
of approval in the conclusion section "the study group concluded that
no upper dose limit need be imposed." (p. 161). This decision can
lead to misuse of the procedure in processing food for human consumption.
Some reports in the peer-reviewed literature on mutagenic activities of
irradiated foods were not considered in the 1999 FAO/IAEA/WHO report (Bhaskaram
and Sadasivan, 1975; Vijayalaxmi, 1975, 1976, 1978; Vijayalaxmi and Sadasivan,
1975; Vijayalaxmi and Rao, 1976).
- Although the observations from these studies are not
confirmed by some publications in the literature, the positive findings
have support from other publications (Bugyaki et al, 1968; Moutschen-Dahmen,
et al., 1970; Anderson et al., 1980; Maier et al., 1993). Furthermore,
repeated observations of activities that have significant public health
implications such as polyploidy in somatic cells, genetic alterations in
germ cells and reproductive toxicity should not be ignored, but should
be considered seriously and explicitly by FDA with respect to the pending
food irradiation petitions.
- Radiolytic products are formed during the irradiation
of food (Schubert, 1969). Their potential health hazards have not been
adequately evaluated. An emphasis should be placed on the products that
are unique to the irradiation process and that are potentially mutagenic,
e.g. 2-dodecylcyclobutanone (Delincee and Pool-Zobel, 1998; Delincee et
al., 1998). The quality and quantity of these radiolytic products may be
different from one food type to another. Without conclusive evidence regarding
the safety of these products, the safety of irradiated food cannot be assured.
Conclusive evidence of safety of these products can be derived from in
vivo studies published in peer-reviewed journals.
- The formation of hazardous free radicals in irradiated
food that can cause DNA damage is of serious concern. For food with high
water content, the free radicals are rapidly degraded after irradiation.
Therefore, human exposure to the free radicals through the food chain is
minimal. For food with low water content, the Food and Drug Administration
stated that "irradiated dry spices and seasonings are examples of
foods in which free radicals are known to persist for long periods of time."
(FDA, 1986, p. 13379).
- However, the FDA concluded that this should not be of
concern based on the manner in which these foods are used. On the other
hand, the concerns for other dry foods that are consumed without further
cooking and that are consumed in large quantities, such as dried fruits
and nuts, are not considered. This possibility should be evaluated to determine
the potential for exposing consumers to free radicals. This concern should
be included in the FDA?s analysis of the "ready-to-eat food"
irradiation petition, FAP 9M4697.