They are produced during radioactive decay of high atomic number materials in which the ratio of neutrons to protons in the nucleus is too low. They can be easily shielded by a sheet of paper or by the outer layer of skin. The exposure hazard, consequently, is not external but rather internal. If ingested or inhaled they will produce a great amount of damage in a small area. The only experience with alpha sources at Emory will be with sealed sources.
Beta particles are ordinary electrons and can be positively or negatively charged.
They are emitted from the nucleus of an atom in which the neutron to proton ratio is too high. The penetrating power of the beta particle depends on its energy. In fact, the low energy betas will not cause the film on the dosimeter to be exposed. However, these materials are capable of causing internal damage like alpha particles. Protective clothing should be worn when handling these materials, but no additional shielding is necessary.