Definition - What does Alpha Radiation mean?
Alpha radiation is a type of ionizing radiation that consists of emitted alpha particles—positively charged particles that consist of two protons and two neutrons. Alpha particles are the largest and most highly charged form of radiation energy.
Alpha radiation has little penetration ability, and is a low-risk to workers as a source of external exposure; however, it is a significant health hazard if ingested, inhaled, or absorbed through broken skin.
Safeopedia explains Alpha Radiation
Alpha radiation has a lower kinetic energy than any other form of common radiation. The large size of alpha particles restricts them to traveling only a few centimeters through air and their positive charge allows them to be easily shielded against. If alpha radiation makes contact with a human it will not penetrate further than the outer layers of human skin, and is normally stopped by dead skin cells. When alpha radiation is emitted inside the body, however, the large size and positive charge of alpha particles make alpha radiation the most damaging type.
The most significant source of hazardous alpha radiation is radon gas, which decays into alpha radiation-emitting “radon daughters”. Radon daughters can attach to atmospheric dust and water droplets which can be breathed into the lungs and airways. This is a major risk factor for lung cancer. OSHA recommends that personal protective equipment should be used where high levels of alpha radiation are found in order to prevent external contamination with material containing inhalable alpha radiation emitters.