How harmful radiation is depends on many factors, but the three main ones are:
1. What type of radiation you are exposed to
2. Where the radioactive source is located
3. How much radiation you are exposed to
As there are many different types of radiation, we can categorise them as either ionising or non-ionising.
Examples of ionising radiation include:
Ionising radiation is typically more harmful than non-ionising radiation. This is because they can penetrate, and then damage the atoms and molecules in our living cells. Ionising radiation can also mutate our DNA, which can lead to the development of cancer. A disease in which the body’s cells will grow uncontrollably and spread to different parts of the body.
Examples of non-ionising radiation include:
Non-ionising radiation is not as harmful. For example, too much ultraviolet radiation can still damage our DNA, which in turn may lead to cancer.
How harmful radiation is depends on the location of the radioactive source.
If the radioactive source is outside the body, then alpha radiation is not as harmful because it is not very penetrating, so it can’t penetrate the skin. In this case, beta and gamma radiation is the most harmful because they can both penetrate the skin to damage our cells.
If the radioactive source is inside the body, then alpha radiation is the most harmful because it is easily absorbed by cells. In the body, it is unlikely for beta and gamma radiation to be absorbed by cells, they will typically pass straight through it.
The dose of radiation refers to the amount of radiation you are exposed to and this depends on:
The higher the dose of radiation to a cell, the more likely it is that the cell will become cancerous.