People who absorb lethal but not massive doses of plutonium would not sense any of its effects for weeks, or perhaps years. The presence of finely divided plutonium in an area could be detected only with sensitive radiation monitoring equipment. Such equipment is now only used to monitor the presence of plutonium or other dangerously radioactive materials in nuclear installations. Except in such installations, therefore, people would not know they were exposed until they were told, either by those responsible for the threat, or by someone in authority who happened to detect the plutonium with instruments.

We are not aware of any successful non-military attempts to use chemical, bacteriological, or radiological poisons to contaminate large areas. Whether any such means will be used in the future for criminal or terrorist purposes is, we believe, an even more speculative question than whether nuclear explosives will be so used. Many types of potentially lethal poisons are no more difficult to acquire than chemical high explosives. However, high explosives are being used with greater frequency and in increasing amounts by terrorists and extortionists, while we have found no evidence that they have ever used poisonous agents. The practically instantaneous, quite obvious destruction that is produced by an explosion apparently better suits the purposes of terrorists and extortionists than poisons that act more slowly and subtly, but that are at least as deadly. Unlike other poisons, however, plutonium can be used either as a poison or as explosive material. Accordingly, a threat using a plutonium dispersal device could conceivably be followed by a threat involving plutonium used in a nuclear explosive.