External dosimetry in the aftermath of a radiological terrorist event.

This paper reviews external dosimetry in emergency preparedness planning for a potential terrorist release of radioactive material in a densely populated area. The radiation dose received by response workers and members of the public is needed to understand health risks. The existing framework for dosimetry of routinely occupationally exposed workers is not directly applicable to all emergency workers who would respond to a radiological terrorist event. Emergency preparedness plans incorporate various old and new dosimetry technologies, including quartz fibre electrets, electronic dosemeters, personnel badges and wallet cards. Environmental monitoring and dose calculations are the usual methods for determining public dose. However, during the late-phase response, after removable contamination has been eliminated, it may be easier and more straightforward to provide individual dosimetry for members of the public who may be moving through a city with varying contamination areas. Doing so could allow resumption of normal activities earlier and promote confidence in reusing the site.