Gamma rays are the most harmful external hazard. Beta particles can partially penetrate skin, causing “beta burns”. Alpha particles cannot penetrate intact skin. Gamma and x-rays can pass through a person damaging cells in their path.
Accordingly, can alpha particles penetrate the skin?
Alpha particles are the least dangerous in terms of external exposure. They don't penetrate very deeply into the skin, if at all -- in fact, clothing can stop alpha particles. Unfortunately, alpha particles can be inhaled or ingested, usually in the form of radon gas.
What is alpha radiation blocked by?
In general, beta particles are lighter than alpha particles, and they generally have a greater ability to penetrate other materials. As a result, these particles can travel a few feet in the air, and can penetrate skin. Nonetheless, a thin sheet of metal or plastic or a block of wood can stop beta particles.
What can alpha radiation pass through?
The penetrating power of alpha rays, beta rays, and gamma rays varies greatly. Alpha particles can be blocked by a few pieces of paper. Beta particles pass through paper but are stopped by aluminum foil. Gamma rays are the most difficult to stop and require concrete, lead, or other heavy shielding to block them.