Glow-in-the-dark food?

Fears that irradiated food is harmful to your health persist despite evidence to the contrary. How safe is irradiation? Here are some facts.

Have you heard that irradiation of food poses a serious threat to your health?

Maybe you've heard that microwaved food glows in the dark.

Has anyone told you that bombs can be made from the cobalt 60 with which food is irradiated?

People have heard these claims, and some believe them.

Types of irradiation. If you fall into that latter category, let me put your mind at ease. Actually there are three or more types of food irradiation. The first is infrared (IR) radiation. Infrared lamps are often used in restaurants to heat food or keep it warm.

Probably most of us are not concerned about the IR heating of food, similar to the sun warming us on a cool day. After all, IR radiation is not the part of sunlight implicated in sunburn or in causing skin cancer.

Another kind of radiation is microwave radiation, one we're familiar with because of the common use of microwave ovens.

Many have become uncertain about the safety of microwaving, even if they own and use a microwave oven. Others avoid microwaving entirely because some have suggested that it "devitalizes," or kills, the living food, and that eating microwaved food causes such complications as obesity and cancer. Or they believe it destroys the vitamins in food.

The truth is that microwaved food has one of the highest vitamin retentions of all prepared food. And contrary to the suggestions that "microwaved foods glow in the dark with residual radiation," radiation stops the instant the oven is turned off. There is absolutely no residual radiation in the food or microwave chamber, and thus no conceivable connection between the irradiated food and disease conditions some attribute to it.

As for the danger posed by the oven itself, a microwave oven leaks less radiation than does a color TV. We get less radiation from the microwave than from an ordinary telephone or electric razor.

Gamma irradiation. I was first introduced to gamma irradiation, often used to kill insects or insect eggs and to pasteurize or sterilize foods and spices, in 1964. At that time the military was irradiating food in an attempt to preserve certain foods without refrigeration. The technique they used has not changed greatly.

Food is brought into a large, lead-shielded room through a corridor having several 90-degree corners. Because irradiation goes in a straight line, the 90-degree turns virtually stop the radiation.

In the center of the room is a deep swimming pool filled with purified water. On the bottom of the pool rests the irradiation source, cobalt 60. The water keeps the gamma rays from the cobalt 60 source from reaching the surface.

When the food to be irradiated is in place beside the pool, the cobalt 60 source is hoisted by remote control out of the shielding water, and the food is irradiated in a matter of a few minutes. Then the gamma source is again lowered into the water so that workers can come into the chamber. Repeated sensitive tests show no residual radiation in the food. It does not glow in the dark and does not pose a hazard.

Why all the fuss? The first fear some express is that a terrorist group will fashion an atomic bomb from the cobalt 60 fuel--that our experiments in food preservation may just lead us all to an untimely end.

It's helpful to understand that cobalt 60 will not cause an atomic explosion. Since it does not produce neutrons, neither a nuclear chain reaction nor a "meltdown" is possible. Bombs simply cannot be made from cobalt 60.

A second fear is that an accident during transit of the cobalt 60 might occur, subjecting transit workers to irradiation.

Gamma irradiation technology, as a spinoff from medical cancer treatment, is more than 40 years old, with more than a million transfers of cobalt 60 and not one accident. There are more than 170 industrial-scale irradiators worldwide.

Within the past 10 years there has emerged a trend of irradiation through the use of electron beams that has several advantages, such as the ability to irradiate larger volumes of food more quickly.

A third fear is that industry might slip irradiated food into our food supply and we not know it.

That's where the little green "radura" symbol and the words "treated by radiation" or "treated by irradiation" come in. In the United States there is a requirement that both the radura symbol plus one of the written warnings be placed on irradiated foods. However, if a processed food contains ingredients such as spices that have been sterilized by irradiation, the warning need not be displayed.

Another fear arises because we tend to suspect new technologies, especially those associated with food. We're naturally apprehensive about food irradiation or anything unfamiliar placed in our food. The question is Do we fear as much the microorganisms that irradiation controls?

Together salmonella and campylobacter, two of the most common food-borne pathogens, caused at least 4 million people to become ill in 1992. Of these, 1,000 to 2,000 died.

That same year about 1,500 people were infected by listeria monocytogenes, with about 400 deaths resulting. Approximately 85 percent of these became infected through eating contaminated food.

The United States Department of Agriculture estimates that parasitic plus bacterial food-borne illnesses transmitted by meat and poultry cost an estimated $4 billion annually. Aside from eliminating the consumption of meat, fish, and poultry, one of the best ways we know to prevent these highcost outbreaks is to pasteurize these foods by gamma irradiation.

A Vermont-based consumer group has been vocal in condemning the use of gamma irradiation processing of food. They allege that "unique radiolytic products" (URPs), which could cause serious health problems, are produced. None have been found. This is not surprising, considering that URPs are entirely hypothetical.

It's true that irradiation may increase the production of "free radicals," very active molecules that may cause texture, color, or flavor changes in food. However, when we irradiate food at reduced temperatures and in inert atmospheres, these free radicals are kept at very low levels.

Fear can be a positive force as it motivates us to investigate and take precautions. Unfounded and unreasonable fear not only impedes our progress but diverts our attention from real dangers.

It is safe to investigate the sources of our information. It is wise to hear both sides of an issue. And it is common sense to fear most those things that again and again have proved deadly.