Which types of electromagnetic radiation harm living tissue and why?
In GCSE physics curriculum, when living cells absorb radiation, damage can occur in different ways:
- The heating effect can cause damage
- Ionising radiation, such as ultraviolet radiation, can damage cells, causing ageing of the skin
- Ionising radiation can cause mutations in the nucleus of a cell, which can lead to cancer
- Different amounts of exposure can cause different effects, e.g. high-intensity ionising radiation can kill cells leading to radiation poisoning
In GCSE physics, MICROWAVES are strongly absorbed by water molecules, which means microwaves, can be used to heat objects containing water – there is water in all food substances.
Microwave ovens have a metal case and a wire screen door – this reflects the microwaves and protects users by preventing too much radiation from escaping. The door screen also absorbs microwaves, protecting users from the radiation as mentioned in GCSE physics.
There may be a health risk from the low-intensity microwaves of mobile phone handsets and masts, though evidence for this is disputed because the intensity of the microwaves is too low to damage tissues and microwaves are not ionising.
End of this part! Remember to read part II.
Drafted by Gina (Physics)