Hazards of electromagnetic radiation

Over-exposure to certain types of electromagnetic radiation can be harmful.

The higher the frequency of the radiation, the more energy it carries and the more damage it is likely to cause to the body:

  • radio waves in large doses are believed to cause cancer, leukaemia and other disorders, and some people claim the very low frequency radio waves from overhead power cables near their homes has affected their health, although this has not been reliably proven;
  • microwaves can cause internal heating of body tissues;
  • infrared radiation is felt as heat and causes skin to burn;
  • visible light from a laser which is very intense can damage the retina at the back of the eye;
  • ultraviolet can damage skin cells and lead to skin cancer and damage to eyes;
  • X-rays damage cells inside the body. They cause dangerous ionisation and when this happens with molecules in living cells, the genetic material of a cell, the DNA is damaged. This can lead to cancer. This is why doctors and dentists stand behind protective screens when taking lots of X-rays;
  • gamma rays also damage cells inside the body causing dangerous ionisation in living cells which damages DNA. This can lead to cell death and cancer.

Ultraviolet radiation and suntan

Ultraviolet radiation - UV - is found naturally in sunlight.

We cannot see or feel ultraviolet radiation, but our skin responds to UV exposure by turning darker over time.

This is called a sun tan.

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 prolonged exposure to ultraviolet radiation can cause skin cancer and damage to eyes.

It is sensible to wear high protection, UV blocking sunscreen on sunny days to avoid skin cancer.

Overexposure of our eyes to ultraviolet radiation can cause blindness, so we should also wear hats and sunglasses on sunny days.