plutonium are incorporated in the body, they pose a serious cancer threat.

Beta--Another form of radioactive decay is the emission of a beta particle,
or electron. The beta particle has only about one seven-thousandth the
mass of the alpha particle, but its velocity is very much greater, as much
as eight-tenths the velocity of light. As a result, beta particles can
penetrate far more deeply into bodily tissue and external doses of beta
radiation represent a significantly greater threat than the slower, heavier
alpha particles. Beta-emitting isotopes are as harmful as alpha emitters
if taken up by the body.

Gamma--In some decay processes, the emission is a photon having no mass at
all and traveling at the speed of light. Radio waves, visible light,
radiant heat, and X-rays are all photons, differing only in the energy
level each carries. The gamma ray is similar to the X-ray photon, but far
more penetrating (it can traverse several inches of concrete). It is
capable of doing great damage in the body.

Common to all three types of nuclear decay radiation is their ability to
ionize (i.e., unbalance electrically) the neutral atoms through which they
pass, that is, give them a net electrical charge. The alpha particle,
carrying a positive electrical charge, pulls electrons from the atoms
through which it passes, while negatively charged beta particles can push
electrons out of neutral atoms. If energetic betas pass sufficiently close
to atomic nuclei, they can produce X-rays which themselves can ionize
additional neutral atoms. Massless but energetic gamma rays can knock
electrons out of neutral atoms in the same fashion as X-rays, leaving them
ionized. A single particle of radiation can ionize hundreds of neutral
atoms in the tissue in multiple collisions before all its energy is
absorbed. This disrupts the chemical bonds for critically important cell