Types of Radiation For purposes of radiation safety only radiation with the capability to cause ionization is of concern. Ionization occurs when electrons are dislodged from a neutral atom. When this happens an atom becomes positively charged and some energy is transferred. Ionization is the process by which radiation affects the human body and by which it can be detected as well. The main properties of each type of radiation are briefly discussed below.
Alpha particles consist of two protons and two neutrons and carry a positive charge.
They are emitted with high energy from the nucleus of heavy elements during radioactive decay, but lose energy rapidly in passing through material. A couple sheets of paper are sufficient to stop most alpha particles. Since they cannot penetrate even the outer dead layer of our skin, they are not an external hazard. Beta particles are electrons emitted from nucleus of atoms at nearly the speed of light. They have a very small mass compared to protons or neutrons and carry a negative charge.