A patient with internal contamination will have in some way introduced the radioactive material into his/her body, for example, through inhalation, ingestion, or entry through an opening in the body. This chapter suggests that controls regarding exposure to nuclear radiation and contamination with radioactive materials. Radiation exposure is being bombarded with radiation. The magnitude or severity of the dose received from exposure to ionizing radiation depends mainly on the type and energy of radiation, the exposure rate of the radiation, and the duration of the exposure. The faster the exposure is delivered the higher the exposure rate. Again using the beachbody example, the exposure rate from the noon sun is higher than the exposure rate from the early morning or late afternoon sun. External exposure is simply being exposed to radiation from a source outside the body. The chances of a transportation incident producing gamma exposure rates that even approach an acute exposure hazard level are small.