By Donella Meadows
–February 27, 1992—-
The first shipment of 2300 pints of irradiated strawberries left a new $7 million plant in Tampa last January — the first commercial food irradiation plant in the United States. When the berries arrived at a North Miami Beach supermarket, they were greeted by protesters.
In the Ivory Coast in Africa a similar plant is under construction. Its primary product will be irradiated yams. Some 36 countries around the world have approved the sale of irradiated foods ranging from fish to potatoes to eggs. But nowhere are consumers entirely comfortable with the idea of eating food that has been treated with radiation.
Their qualms come from ignorance, say the UN Food and Agriculture Organization, the International Atomic Energy Agency, and the World Health Organization, all of which have pronounced irradiated food safe. The idea of preserving food with radiation has been studied for 40 years. Eleven years ago the Codex Alimentarius Commission, the 130-country body that sets international food standards ruled that irradiation “presents no toxicological hazard.”
The confusion in the minds of many protesters is the idea that irradiated food is radioactive. It isn’t, not any more than you are when you get an X-ray.
Here’s how irradiation works. The food is carried on a conveyer belt into a lead-lined, thick-walled protective chamber, like the one around a nuclear power plant. When the food is inside and the chamber is sealed, glowing blue rods of cobalt-60 are mechanically lifted out of a pool of water. The cobalt-60 is unstable; its atoms break down, and as they do so, they release gamma rays, streaks of energy, much like X-rays.
If you had a fleck of cobalt-60 inside you it could do a lot of damage, because it would continually be sending out gamma rays, which would break down your cells and tissues. If you stood near a fleck of cobalt-60, however, the gamma rays would bombard you from a greater distance, and if you walked away, or if the cobalt source was removed, the damage would stop. You wouldn’t continue to carry its source around with you.
The strawberries in the irradiation plant are exposed to cobalt-60 from a distance. Gamma rays zap into them, carrying just the right frequencies of energy to break some of the bonds that hold together the organic molecules that make up insects, molds, and bacteria that spoil food. The radiation may also tear apart enzymes within the berries that cause them to overripen, or cells within onions and potatoes that cause them to sprout.
Different foods are exposed to the radiation for somewhere between 15 minutes and an hour. Then the cobalt-60 is lowered back into the pool, and the conveyor belt carries the food to a sanitized chamber, where it is wrapped so that no further spoiling agents can touch it.
This treatment can extend the life of fresh strawberries by three weeks. Irradiation can kill weevils in grain, salmonella in chicken, and trichinosis in pork. Especially in the tropics, it could reduce the shocking 40 percent post-harvest loss of food in countries that badly need more food. Irradiated foods should easily pass international quarantines, because they could be guaranteed not to be carrying Medflies or anthrax or potato blight or any other infection or pest.
Those are the benefits and potentials, and they are many. Then there are the costs and problems. Irradiation is not a cheap or simple technique. It involves the transport, use, and disposal of dangerous radioactive materials. And then there is the interesting question of what the gamma rays, which are so deadly to the enemies of the food, do to the food itself.
The radiation hits whatever chemical bond it hits. It could take apart a DNA molecule so a mold cell can’t reproduce, or it could take apart a molecule that gives the strawberry its wonderful aroma and flavor. It may alter an amino acid so it is no longer a human nutrient; it may knock apart a vitamin or a sugar molecule.
Foods that have been irradiated have somewhat altered taste and nutrient content, but the damage is random and partial. As far as anyone knows — though in truth no one knows for sure — none of the molecular fragments that are created are harmful. Mostly an irradiated strawberry is still a strawberry.
Is it worth eating? It’s probably safe, but unless I were starving, I wouldn’t eat it. In poor countries radiation may be a justifiable method of food preservation (although the cost of a plant might better be spent on decent storage bins or refrigerators). But in rich countries, let’s face it, irradiation is mainly a way for stores to keep strawberries on the shelves for three weeks.
Like additives, like packaging, like most kinds of prepared foods, irradiation increases the convenience and profit of food purveyors, not the health or welfare of consumers. It further distances us in space and time from the sources of our food. It further trains our sense to be satisfied with vague hints of the tastes and smells of fresh produce. Even if irradiated foods are not provably harmful, they are a long way from whole or healthy.
Radiation rips apart not only the bonds within the food molecules, but also the bonds between the farmer and the buyer, between the consumer and the land — bonds that in our world are already too much broken.
Copyright Sustainability Institute 1992