Radiation detection: There’s an app for that

The nuclear accident at Fukushima, which led to the release of radioactive fallout over densely populated areas, highlights a broader problem: What is the best way for the public to detect and monitor radiation levels in urban areas before, during, and after a major radiological event? The authors describe a system that would incorporate inexpensive radiation detectors in mobile phones equipped with the capability of continuously transmitting data to a central server. This server would correlate data from a large number of detectors carried by people moving randomly in an urban environment, locating fallout hot spots and illicit radiological sources carried by terrorists. The authors discuss both technical aspects of the system and some practical issues involved in implementing it, including cost.