Burros' Burden of Proof

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An October 15 New York Times piece by Marian Burros contained misleading information about the safety of irradiated foods. Ms. Burros must have been convinced about the toxic effects of irradiated foods, since she quoted and echoed the views of Public Citizen and the Center for Food Safety, well known for their stances against food irradiation technology.

The facts, contrary to Burros' article, are:

(i) It is the European Commission (EC), not the European Parliament, which has jurisdiction over issuing directives (regulations) on irradiated foods. Neither the European Parliament nor the EC put the "moratorium on almost all irradiated foods," but the latter issued a directive in 1999 that approved irradiated aromatic herbs, spices, and seasonings, intending to complete the list of other irradiated foods in the future.

(ii) The FDA approved the use of irradiation for fruits, vegetables, meat, poultry, and eggs before a study on potential toxicity of 2-alkylcyclobutanones (2-ACBs are created by irradiation of fat-containing foods) was first published in 1999. The FDA, however, took into consideration the potential toxicity of not only 2-ACBs but all other substances that might be created by irradiation of various foods prior to such approval. They employed a large number of studies on long-term, multi-generation animal feeding tests of irradiated foods, including some 120 metric tons of chicken irradiated with doses as high as 60 kGy. None of the animal feeding tests carried out under proper scientific protocols demonstrated any toxic effects attributable to irradiation treatment. All animal feeding studies and other aspects of the wholesomeness of irradiated foods were evaluated by independent groups of experts appointed by the Food and Agriculture Organization of the United Nations, International Atomic Energy Agency, and World Health Organization over the past four decades. While there were some studies not carried out according to scientific protocols that showed some toxic effects of certain irradiated foods, overwhelming scientific evidence exists to demonstrate the safety and nutritional adequacy of any foods irradiated according to Good Manufacturing Practices. Based on these evaluations, the Codex Alimentarius Commission, the global standard-setting body whose mandate is to protect consumer health and ensure fair practice in food trade, in July adopted a revised Codex General Standard for Irradiated Foods, allowing food irradiation at any dose if necessary and for legitimate purposes. The safety of irradiated foods, at any dose, is clearly established.

The 2-ACBs in irradiated foods are similar to substances created in foods by other processes such as benzene, acrylamide, benzopyrine, etc., caused by heating. These substances in high concentration and purified form can be toxic for consumption. This does not mean that we should stop eating foods containing such substances (e.g., boiled eggs containing trace amounts of benzene, potato chips and French fries containing acrylamide, barbecued meat containing benzopyrene, etc.), nor should we stop using heat to process our foods. Foods contain many components that tend to react with potentially toxic compounds that exist in such foods, rendering them harmless for consumption. No one is likely to consume pure benzene, acrylamide, or even 2-ACBs. Thus, it is misleading to discuss potential toxicity of these compounds in isolation.

Ms. Burros referred to the opinion of Dr. William Au, who has no experience in toxicological studies of irradiated foods. Dr. Henry Delincee, from University of Karlsruhe, Germany, who was one of the senior authors of the studies on 2-ACBs, made it known to Public Citizen and others that in none of the studies carried out by him and his colleagues were 2-ACBs shown to be mutagenic. According to Dr. Delincee, "Dr. Au is exaggerating the potential risk by overstating that 2-ACBs are mutagenic. Obviously, he is not telling the truth."

Ms. Burros' article jumped to the wrong conclusion when it referred to the study conducted by Dr. Francis Raul and his colleagues in Europe, since:

(i) The study used extremely high concentrations of highly purified 2-ACBs to determine whether 2-ACBs as such would be dangerous for consumption. It should be noted that the daily amount of 2-ACBs (equivalent to 3.2 mg/kg body weight) administered to rats is some 500 times that ingested by humans eating irradiated food products (5-10 micrograms/kg body weight). Thus, the authors were correct in their conclusion that "the relevance of the results of this study for the risk assessment of human consumption of irradiated foods remains to be elucidated."

(ii) Irradiated foods contain many components that could react with 2-ACBs and render them harmless. This was demonstrated through several multi-generation animal feeding studies of irradiated foods, with some foods subject to doses as high as 60 kGy. None of these studies showed toxic effects of irradiated foods attributable to the irradiation treatment.

Even Europe's Scientific Committee for Food had dismissed results of studies on the potential toxicity of 2-ACBs and come to the conclusion in July 2002 that these studies are not relevant for assessing the safety of irradiated food. On the contrary, the Committee pointed to the numerous long-term feeding studies in animals, which provided reassurance as to the safety of fat-containing irradiated foods.

Irradiation of food is approved by the FDA and many other national health authorities in some fifty countries and endorsed by credible health and scientific organizations including the American Medical Association, Centers for Disease Control and Prevention, World Health Organization, Food and Agricultural Organization of the United Nations, and others. Food irradiation will enhance microbiological safety for entire populations, including school children with their still-developing immune systems. They have the right to choose safe foods and irradiation provides them that choice.

Let us hope that Ms. Burros and the Times will write future articles about food irradiation based more on facts and sound science.

Paisan Loaharanu is an international consultant and former head of the Food and Environmental Protection Section of the Joint FAO/IAEA Division of Nuclear Techniques in Food and Agriculture. He assisted in the creation of ACSH's guide to Irradiated Foods.