5.4 Laboratory Safety Guidelines

Time.   Radiation dose is directly proportional to the length of time exposed to a radiation source.  Therefore, the less time spent near such a source, the smaller the total dose received.

Distance.   Distance is one of the simplest and most effective means of reducing radiation exposure.  The relationship between distance and dose rate follows the inverse square law for point sources of penetrating radiation (x- or gamma).  That is, doubling the distance, from such sources, will reduce the exposure by approximately a factor of four.  Distance can be used to significantly reduce exposure from a radiation source.  Additionally, the use of tongs or other handling devices can significantly reduce finger extremity exposure.

Shielding.   Properly shielding sources of radiation can dramatically reduce the dose to personnel.  It is important to choose shielding appropriate for the type of radiation involved.  For instance, Plexiglas is an effective shielding for beta emitters, whereas lead is a better material for gamma radiation.  Shielding is available in a variety of forms, e.g., bricks, sheets, etc. Contact EHS at 353-5389 for guidance on shielding types and supplies.