By Scott Stewart The government of Kazakhstan announced Sept. 2 that it was searching for a container of radioactive cesium-137 that fell off a truck in the western part of the country. Such radioactive sources are commonly used for medical, commercial and industrial purposes, and from time to time are reported lost or stolen. The material was recovered, but the incident highlighted the risks of radioactive material falling into the wrong hands. Occasionally, the loss or theft of a radioactive source will result in an accidental dispersal of radioactive material. For example, in 1987, a small radiotherapy capsule of cesium chloride salt was accidentally broken open in Goiania, Brazil, after being salvaged from a radiation therapy machine at an abandoned health care facility.