Quantifying the risks of radiation exposure.

The considerations leading to the recommendation of dose-equivalent limits by the International Commission for Radiological Protection are outlined. The dose-equivalent limits are based on radiation risk factors estimated from effects of radiation observed over many decades. These limits are designed to ensure that radiation exposure does not entail a greater risk than that experienced in other safe occupations or accepted by the general public in everyday life. The risk factors should, however, not be used to assess the risk to patients from diagnostic procedures.