Irradiated foods are foods that have been exposed
to a radiant energy source to kill harmful bacteria,
insects, or parasites, or to delay spoilage, sprouting,
or ripening.
There are many reasons that foods are irradiated.
The most common reason is for increased food safety.
The United States Centers for Disease Control (CDC)
estimates that there are about 76 million cases of foodborne
illness each year in the United States, resulting
in about 5,000 deaths annually. Irradiating foods can
reduce the risk of many foodborne illnesses by killing
the bacteria or pathogens responsible, or harming
them to such an extent that they are not able to reproduce
or cause disease.
The National Aeronautics and
Space Administration (NASA) exposes the food that
astronauts eat while in space to a level of irradiation
far higher than that approved for commercial use in
order to reduce the risk that astronauts will develop
illness while in space. Patients who have diseases that
severely impair the functioning of the immune system
are often fed irradiated foods to decrease the risk that
they will develop a serious disease.
Irradiation can also be used to destroy insects and
other pests that may be present on produce. When
produce is shipped from Hawaii to the mainland
United States, it must be fumigated to kill any insects
or insect eggs that might be present so that they do not
spread to the mainland. Irradiating this produce is
sometimes used as an alternative to fumigation, and
does not leave residue of chemicals on the produce in
the way that fumigation can.
Some fruits and vegetables can be kept fresh longer
by the use of low to moderate levels of irradiation.
When exposed to low levels of radiation, potatoes,
onions, and other vegetables do not sprout as quickly.
Strawberries and other berries can benefit from irradiation
as well, as irradiation can significantly delay
the growth of mold. Strawberries stay fresh from 3–5
days when they are not irradiated or treated in any
way, but can stay fresh and unspoiled for up to three
weeks after being irradiated.
