What is Radiation?

Radiation is energy. It travels through space in the form of particles or waves. Radiation is energy such as heat, light, sound, microwaves, radio waves, X-rays and radar. Radiation is everywhere. It is in the air we breathe, the water we drink, and the food we eat. This makes up the "background radiation" that we are all exposed to everyday.

Alpha particles are very heavy and lose their energy quickly. They are positively charged, and are also quite large, and therefore cannot travel very far, or pass through matter such as a piece of paper or human skin. However, care should be taken not to swallow or inhale anything likely to emit alpha particles, as they can cause damage to body organs.

Beta particles are small (and negatively charged). They are fast moving and can travel further than alpha particles. They can penetrate up to 1 - 2 centimetres of matter such as human skin.

Gamma rays are high-energy waves, similar to light, but have much higher energy, and can travel very long distances. However, matter such as concrete, lead or metal, or even water can stop them in their tracks.