Is food irradiation safe?

Dear Cecil: A few years ago I heard of a process where perishable foods such as milk and lettuce were bombarded with radiation to dramatically increase their shelf life. This process would also kill off any bacteria and vermin. Foreign countries seemed to employ this with positive results. There was talk of using this process in the U.S., with the only proviso being that the food in question be labeled with a special system. However, try as I might, I cannot find any radiation-treated food in my local grocery store — not that I’m terribly eager to try it. How is food treated with radiation? Is it safe? What has happened to the process in the U.S. since the news stories first came out Thomas Cotrel, Burbank, California

Cecil replies:

Depending on whom you talk to, food irradiation is yet another plot to poison the food supply for profit or the victim of antinuclear hysteria. The worst fears are certainly exaggerated. Despite what many people think, the process does not make food radioactive. Pallets of strawberries, chickens, or other foods are exposed to a radioactive source, usually cobalt, for a specified number of minutes inside a shielded room. The radiation kills, or at least is supposed to kill, deadly microorganisms such as salmonella while leaving the food itself more or less intact.

It’s the “more or less” part that’s the kicker. Ionizing radiation, which is what we’re talking about here, causes some of the chemical compounds in food to transmute into other ones. Most of the new chemicals, called “radiolytic products,” are the same as naturally-occurring compounds and are probably harmless. But a few may not be, and who knows, may even be carcinogenic. What’s more, irradiation destroys some vitamins and other nutrients. Estimates of the amount of loss vary widely, from 4 to 40 percent, and it should be pointed out that merely cooking most foods will destroy a percentage of the vitamins. Just the same, the questions surrounding food irradiation have led a number of respected scientists to oppose the practice.

They’re in the minority, though. What’s keeping irradiated food out of the marketplace isn’t scientific uncertainty but consumer resistance — or rather, fear of consumer resistance. The U.S. Food and Drug Administration has approved irradiation for a number of food items but the industry has been nervous about putting the stuff on store shelves lest consumers go nuts.

More’s the pity, say irradiation advocates. A huge percentage of world food production, as high as 50 percent in developing countries in warm climates, spoils before it can be eaten. Despite numerous improvements in public health practices food poisoning is still fairly common in the U.S. and other countries. Irradiation would reduce both these problems. Maybe 20 years from now it’ll be as commonplace as fluoridation. Then again, 20 years ago they thought nuclear power would make electricity cheap.

Cecil Adams

Send questions to Cecil via cecil@straightdope.com.