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Science

The electromagnetic spectrum

Hazards of electromagnetic radiation

Over-exposure to certain types of electromagnetic radiation can be harmful. The higher the frequency of the radiation, the more damage it is likely to cause to the body:

  • microwaves cause internal heating of body tissues
  • infrared radiation is felt as heat and causes skin burns
  • X-rays damage cells, causing mutations (which may lead to cancer) and cell death
  • gamma rays also damage cells, causing mutations (which may lead to cancer) and cell death.

Microwaves

Microwave radiation can be used to transmit signals such as those for mobile phone calls. Microwave transmitters and receivers on buildings and masts communicate with the mobile phones in their range.

Watch

There is concern that microwave radiation from mobile phones and masts may be harmful to health.

You may wish to view this BBC news item (2006) about this issue.

Ultraviolet light

Ultraviolet radiation - UV - is found naturally in sunlight. We cannot see or feel ultraviolet radiation, but our skin responds to it by turning darker. This happens as our bodies attempt to reduce the amount of ultraviolet radiation reaching deeper skin tissues. Darker skins absorb more ultraviolet light, so less ultraviolet radiation reaches the deeper tissues. This is important, because ultraviolet radiation can cause normal cells to become cancerous.

The three main types of ultraviolet radiation, and some of their effects

typefrequencyhazard
UV Chighcauses severe damage to cells
UV Bmediumcauses severe sunburn and damage to cells
UV Alowweaker effects than UV B

Back to The electromagnetic spectrum index

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