Radiations are of several types and are grouped under the
categories of ionizing and non- ionizing radiations.
Ionizing radiations could be harmful as the energy can get
into the cells and change the chemical composition and working of the cells.
Too much exposure to ionizing radiation can cause burns, radiation sickness,
and cancer. Ionizing radiation can damage any cell in the body. But it all
how much radiation the cell gets.
Non-ionizing radiation does not carry enough energy to
change cells chemically. The radiation from the microwave oven is non-ionizing.
Other examples of such radiation are UV rays from the sun, electromagnetic fields, radiowaves, and radiation waves
from household electrical appliances etc.
non-ionizing radiations and are a part of the electromagnetic radiation
spectrum. They are very high frequency radio waves. Infrared radiation,
ultraviolet light and X-rays are also
radiations, but have shorter wavelengths than microwaves.
materials reflect microwaves whereas most non-metallic materials such as glass
and plastics are partially transparent to microwaves. Food and even people, absorb
microwave energy. An electronic device called a magnetron is used to produce
microwaves. These microwaves then pass into the oven cavity where they are
reflected around the oven walls and absorbed by the food placed in the oven.
Microwaves penetrate the food or liquid and agitate the water molecules in the
food to cause molecular
thereby producing heat. This results in a rapid rise in temperature.
Extensive researches have provided no
substantiated evidence that microwave exposure, at any level, could either
cause or promote cancer. Microwaves generated in microwave ovens do not
exist once the electrical power to the magnetron is turned off. They do not
remain in the food once the power is turned off. Going by this logic they
cannot make the food or the oven, radioactive. Therefore the food cooked in a
microwave oven cannot be straight away labeled as a radiation hazard.
ovens have at least two safety interlock switches which stop the generation of
microwaves immediately when the door is opened. The design of microwave ovens
is such that the microwaves should be contained within the oven, but it is
still possible for some leakage to occur
around the doors
of certain microwave ovens.
There are tests
which assess the level of microwave leakage and according to the Australian/New Zealand Standard for
Household appliances, 'the microwave leakage at any point 50 millimetres
or more from the external surface of the appliance shall not exceed 50 watts
per square metre'. The experts view the recommended limit as conservative and
feel that leakage levels moderately above the
limit will have
no adverse effects on health.
organizations providing testing services say that the microwave oven leakage in
excess of the recommendations is
rare and an oven in good condition and used appropriately is safe.
looking at the possible link between microwave ovens and cancer. Some studies
suggest that there may be a link but other studies haven't been able to prove
this at all. Microwaves produce a magnetic field while they are in use. But
this doesn't tend to last long as we tend to cook for very short
emission stops once the door is opened.
Most experts say that microwave
ovens don't give off enough energy to change or damage the
genetic material (DNA) in cells. So they
definitely cannot cause cancer.
Although microwaves are safe to use, cooking in them can
affect the nutritional value of some foods, viz., loss of vitamins from fruit
and vegetables. But nutrients are lost when heating foods irrespective of the
cooking method employed - boiling, grilling, frying or even steaming. It is the extent of cooking and water loss
from the food that are the major determinants of the nutrient content of a
Vitamins are extremely heat sensitive and water soluble.
Cooking food on very high temperature for a long time such as in baking, frying
or draining away the water used during cooking are reasons for
major nutrient losses.
The best way to keep as many nutrients as possible in the
food is to use as little water as you can and not overcook them. Therefore as
long as we do not overcook the food, microwave cooking can actually
be quite healthy since it uses only a little water and
cooks or warms the food in just a few minutes.
Radiation Protection and Nuclear Safety Agency, 2011 updates on radiation