Irrational Irradiation Fears
There is a lot of misunderstanding of the sciences involving food, including genetic engineering, pesticide risks, and the idea that some foods are “natural.” But by far, the most misunderstood science is that involving irradiating food. The science of irradiating food has been around for 120 years but both consumers and regulatory agencies have been slow to catch up.
Irradiating food is done with “ionizing radiation,” which is a form of energy that removes electrons from atoms and molecules (non-ionizing radiation does not remove electrons). Sources of ionizing radiation include X-rays, CAT scans and cosmic rays. Non-ionizing radiation sources include microwaves and ultraviolet rays from heat lamps and the sun. In fact, we are exposed to radiation from everywhere including the ground, building materials, foods (carrots and red meat), water, air, and even from elements in our own bodies. Most exposure to humans comes from natural background radiation (82%) as opposed to manmade sources (e.g., X-rays and computer screens).
Around 1900, a U.S.-British project announced a patent for the use of ionizing radiation to destroy harmful microorganisms in food. This became particularly important in the 1940s with experiments to preserve fruits, vegetables, meats and fish by the U.S. military. This research continued in the 1950s and 60s by the Army and, in 1958, FDA said gamma rays, x-rays and electronic beams could be used for food. Today, food is irradiated in 55 countries, primarily by gamma rays, to control molds, parasites, pathogens, insects, and to extend shelf life and sterilize packages. Irradiation is also an excellent way to reduce an estimated 40% loss of global crops due to insect infestation.
Is it safe? Studies conducted by FDA, CDC, the World Health Organization and the International Food and Agriculture Organization have all concluded it is safe. Although FDA has concerns about radiation from medical sources of food, they say, “Irradiation does not make foods radioactive, compromise nutritional quality, or noticeably change the taste, texture, or appearance of food. In fact, any changes made by irradiation are so minimal that it is not easy to tell if a food has been irradiated.”
What about radiation more broadly? Clearly exposure to high doses of radiation can lead to cancer or death. That’s the key – high doses can cause acute radiation sickness. Although hundreds of thousands of deaths were predicted from the Chernobyl explosion in 1986, there were actually only 31 total deaths. Except for an increase in thyroid cancers found a year later, a United Nations Scientific Committee found no increase in solid tumors, leukemia or genetic diseases. In fact, a 15 to 30 percent decrease of solid cancer mortality was found among Russian emergency workers and there was a 5 percent reduction of solid cancer incidence among the populations of the contaminated areas.
There are two levels of exposure to radiation that are important: thresholds and hormetic levels. A threshold is a low level below which there is no harm. Because all living things evolved millions of years ago on an earth with high levels of radiation and toxic chemicals compared to today, we evolved a repair mechanism to handle lower doses.
Below the threshold dose, for radiation and over half of the chemicals that have been studied, there is a hormetic level. Without necessarily knowing it by name, all of us are familiar with hormetic relationships. Low levels of medicines, exercise, vitamins, foods and many chemicals have beneficial effects, but higher doses are toxic. For example, the benefits of exercise are extensive but over exercise can harm your immune system. Even something as necessary as water can be harmful if too much (about 6 quarts) is consumed at once. Finally, excessive love can lead to stalking and other disorders. So, like Goldilocks, not too hot (high) or not too cold (low), is the key.
A Google Scholar search of hormesis and radiation reveals 19,000 papers. Nevertheless, the Department of Energy does not acknowledge the hormetic effects of radiation nor even that there is a low dose threshold for cancer effects. EPA also assumes that there is no safe levelof exposure to ionizing radiation.
As for consumers, one of the goofiest statements comes from an anti-irradiation advocate, Michael Colby, the director of Food and Water Watch. “When I shop, I seek mold as a confirmation that the food I am buying is not irradiated. I think it’s (irradiation) a travesty.” Molds can produce mycotoxins and aflatoxins, which are dangerous.
Irradiating more foods than we currently do would go a long way to preventing 48 million cases of foodborne disease and 3,000 deaths per year. Getting over our fear of radiation can lead to safer foods, efficient power generation (small nuclear power reactors), and even medicinal uses. Hopefully, it won’t take another 120 years.