Response to radiation incidents and radionuclear threats

Editor—I agree with Turai et al that radiation injury could occur by accident in countries where disintegrating political entities such as the former Soviet Union leave the debris of their nuclear programmes lying around for an unsuspecting public to pick up.¹,² However, I am less sure of the real, as against hysterical, threat in Western Europe and North America.

Outside closely guarded nuclear power stations, weapons establishments, and waste stores the most available stores of radioactive materials are in hospitals or industry. Solid sources used in industry and radio-therapy are well shielded and sealed. If these seals were broken by a terrorist the most likely person injured would be him or her.

The radiation would have to be dispersed, presumably by an explosive device. However, this would not ensure ingestion—the best way to get a lot of radiation into someone—and would be easily detected. Also, once the radiation was dispersed the activity per person would drop. Such sources could be used to target an individual, but a cheap radiation detector as used in airports or banks would pick up such a source, which may be quite bulky.

Unsealed sources are found mainly in hospitals, most of which do not have enough on site even to kill one person. The most likely radioisotope is iodine-131, and 32 GBq would need to be administered to give a 2 Gy dose.³ Such an activity, much greater than used to treat patients, is unlikely to be left where it can be easily accessed.

Although radiological bombs grab the headlines, they are probably much less dangerous than explosive, chemical, or microbiological attacks, and it is on these threats that countermeasures should be concentrated.