Mr. Padilla stayed at a Qaeda safe house in Lahore, Pakistan, for a time and conducted research on radiological devices on the Internet, officials said.

Health technology assessment (HTA): Taking responsibility for the physics component of health technology assessments related to medical radiological devices and /or the medical uses of radioactive substances/sources.

It is still unclear whether the plots involve conventional weapons or weapons of mass destruction, such as chemical, biological or radiological devices.

It was planned to test the ability of Chicago area hospitals to deal with simultaneous attacks featuring both biological agents and a crude radiological device, or a dirty bomb, the test raised serious concerns.

The range now has Biohazard Safety Level 4 lab facilities to deal with radiological devices, Bioweapon bombs and gas chemical weapons.

Some definitions of nuclear terrorism include the sabotage of a nuclear facility and/or the detonation of a radiological device, colloquially termed a dirty bomb, but consensus is lacking.

The unit has taken on roles never envisioned, with the threat of biological, chemical, and radiological improvised devices in our future.

To protect against threats from the dispersal of nuclear and radiological devices, INL researchers also examine radiological materials to understand their origin and potential uses.

Justice Department officials have backed away from their initial suggestion that they had compelling evidence linking him to a plot to build an explosive radiological device known as a dirty bomb.

Suggars had suffered for 41 years from "x-ray dermatitis", a slow and painful deterioration from his exposure to x-rays while developing radiological devices.