Australian officials Wednesday called for an investigation into potentially radioactive material discovered during the renovation of a highway. The possibly toxic waste, unearthed by construction workers in early April, left five people with nausea, sore throats, dry mouths and vomiting, The Daily Telegraph (Australia) reported. \"Independent chemical specialists could not find any radioactive material in samples taken... but investigations are ongoing into other possible substances,\" said Roads Minister Duncan Gay. The materials came from a truck carrying nuclear isotopes, cesium 137 and americium 241, the pesticide DDT and food to Brisbane on Dec. 4, 1980, that collided with a panel van, killing the other driver. An Australian Nuclear Science and Technology Organization spokesman said containers holding the nuclear material were not damaged and were transported, along with the food, to Brisbane. The rest of the material on the truck was buried at the scene.