The Radiation Protection Authority of Zimbabwe would like to set the record straight on
microwave oven claims being circulated on social media.
To dispel these particular misconceptions, it is important to note that microwaves do not
make any materials including food “radioactive” nor does any microwave energy remain in
the oven or the food after the microwave oven is switched off.
Microwaves are high frequency radio waves and are part of the electromagnetic spectrum.
Microwaves are used primarily for TV broadcasting, radar for air and sea navigational aids,
and telecommunications including mobile phones. They are also used in kitchens for cooking
food. Materials containing water, for example foods, fluids or tissues, readily absorb
microwave energy, which is then converted into heat.
Food is heated by absorbing the energy from the microwaves produced in the microwave
oven. Simply, we are saying that water molecules within the food are vibrated back and forth
by the microwaves and the resulting friction causes the food to be heated up.
According to the World Health Organization fact sheet on ELECTROMAGNETIC FIELDS
AND PUBLIC HEALTH:
It is advised for food heated in a microwave oven to rest for several minutes after cooking is
completed to allow heat to distribute throughout the food because of the fact that Microwave
energy does not penetrate well in thicker pieces of food, and may produce uneven cooking.
Food cooked in a microwave oven is as safe, and has the same nutrient value, as food cooked in a
conventional oven. The main difference between these two methods of cooking is that microwave
energy penetrates deeper into the food and reduces the time for heat to be conducted throughout
the food, thus reducing the overall cooking time.
There is no established evidence that microwave ovens cause any health effects when used
according to the manufacturer’s instructions and maintained in good working order.