it is not accounted for and not good methods to dispose of it properly. >> reporter: cobalt 60 is used to treat cancer and used in hospital- like settings. it was on the way from a hospital in mexico to a nuclear facility. >> thank you, casy in dallas. it locks like we averted a tragedy when the truck with radioactive material was found. what if the truck had fallen in the wrong hands. congressman, thank you for being with us. >> thanks for having me. >> it was a nerve wracking two days where we didn't know where the truck was. how much radioactive material is floating on our highways or mexico's highways. >> i can't give you a precise amount but there are hundreds of hospitals that have this material. after 9/11 with the federal