Pediatric emergency medicine trisk 1973 1973

FIGURE 90.10 Types of radiation.

Alpha particles have a 2+ electrical charge and a large mass (two protons and
two neutrons). Beta particles have a single negative charge and a small mass (one
electron). Charged particles do not penetrate the body very well. Because of their
larger mass and charge, alpha rays cannot penetrate even the dead layers of skin.
239Pu (plutonium), an alpha emitter, is a biologic hazard only when it is inhaled,
ingested, or otherwise introduced into the body. Beta particles (“beta rays”) are
more penetrating and in high doses can severely damage the skin. Beta rays
cannot damage the deep radiation-sensitive organs in the body unless the
radioactive source is incorporated into the body. At the Chernobyl nuclear plant
accident in Ukraine, some of the firefighters had severe skin damage due to
intense beta particle exposure, which contributed to their deaths.
The words “radiation” and “radioactive” are often confused. An atom that is
unstable spontaneously gives off energy as radiation and is therefore radioactive.
In contrast, an x-ray machine cannot spontaneously give off radiation: an external
power source is needed. Therefore, an x-ray machine is not radioactive. A patient