RaDiAtIoN,MiCrOwAvEs AnD CaNcEr

What is radiation? Could the radiation used in a microwave oven cause cancer?

Microwave ovens don’t make foods radioactive. They just heat them. If you use a microwave oven in the correct way there is no known harmful effect on humans. But people still tend to worry. Understanding the different types of radiation may help to reassure you that cooking in a microwave is not dangerous and won’t cause cancer.



Radiation is the release of energy from any source. There are many different sources of energy around us. For example, our bodies give off heat, which is a form of energy. There is also energy released from everyday things such as

• Household electrical appliances
• Heaters
• The sun and
• X-ray machines

Not all radiation is harmful. It depends on the type of radiation and how much exposure to it you have. There are several types of radiation. All of which can be grouped under either

• Ionising Radiation or Non-Ionising Radiation
  

Ionising radiation

This is what most people mean when they talk about ‘radiation’. This type of radiation is made of high-energy waves. It is quite a complicated process. But the end result is the energy can get into cells and chemically change the way the cell works. This is called ionisation. As we know from medical tests, very small amounts of ionising radiation don’t do us too much harm. But too much can cause burns, radiation sickness and cancer.



The genetic material of a cell (known as DNA) is very sensitive to ionising radiation. DNA is a code of all the genes that carry the instructions for how our body works and its characteristics. For example, there is a gene to tell the body to have brown hair or blue eyes.



Ionising radiation can change a cell’s DNA. If this happens, then that cell’s inbuilt instructions about how to live and grow are jumbled about. It is then possible for the cell to do something very different from what it's been programmed to do. For example, it may become cancerous and keep reproducing in an uncontrolled way. This could take years to happen but it still means that a cancer may eventually develop.





Ionising radiation can damage any cell in the body. But it all depends on how much radiation the cell gets. There are 3 main types of ionising radiation that you may be exposed to. Too much of any of them can harm the body. They are

• Natural Background Radiation
  
• Medical Radiation and Non- Medical Radiation
  

Natural background radiation

We are constantly being exposed to ionising radiation from natural sources. It comes from

• Radioactive substances in the soil
• Radioactive gases given off from the earth such as radon
• Very small amounts of radioactivity in the body
• Cosmic rays from the solar system (the sun, stars and outer space)

Medical radiation

The use of radiation in medicine includes

• Diagnostic radiology which includes using X-ray machines to get pictures of the inside of the body
• Nuclear medicine which involves drinking a radioactive substance or injecting it into the body to help with diagnosing or treating diseases and
• Radiotherapy which uses high energy rays to kill cancer cells

Non-medical radiation

This includes nuclear radiation that comes from previous nuclear weapon explosions or accidents throughout the world, such as that at Chernobyl.

Non-ionising radiation

Non-ionising radiation has enough energy to move things around inside a cell but not enough to change cells chemically. The radiation from a microwave oven is non-ionising. Other examples include

• Ultraviolet rays from the sun or sunbeds
• Electromagnetic fields
• Radio waves
• Radiation waves given off from household electrical appliances, heaters, mobile phones with or without headsets and computers and their screens

The only type of non-ionising radiation that we know can cause cancer is over exposure to ultraviolet rays, which causes skin cancer.



There is research going on into other types of ionising radiation and any possible link to cancer. There is information on CancerHelp UK into the investigation of cancer risk and electromagnetic fields, mobile phones and computer screens.



As far as microwave ovens go, we do understand how they heat food.
The radiation they produce is absorbed by water molecules in the food. This causes the water molecules to vibrate and produces heat, which cooks the food. Any modern day microwave oven in good condition is perfectly safe as long as you follow the instructions for use.



Studies have looked at the possible link between microwave ovens and cancer. Some results suggest there may be a link but other studies haven’t been able to prove this at all. Most experts say that microwave ovens don’t give off enough energy to damage the genetic material (DNA) in cells so they can’t cause cancer.



Although microwaves are safe to use it is important to point out that cooking in them can affect the nutritional value of some foods, for example, fruit and vegetables. But nutrients are lost when heating foods in any way - boiling, grilling, frying or even steaming. The Food Standards Agency (an independent food safety watchdog set up by the Government) say that the amount of nutrients lost when cooking with a microwave is the same as with other cooking methods. The best way to cook fruit and vegetables is to use as little water as possible (steaming) and not to over cook them. This will preserve as many nutrients as possible.