The "good" thing about radiation is, it's easy to track:
> By Dec. 6, Mr. Sotelo had thrown the capsule off his truck into the salvage yard. The date is known because all paperwork from the junkyard dated Dec. 6 or later is radioactive.
…
> The capsule was made of nonferrous metal. Every time it was scooped up by the magnet, it eventually fell to the ground, spilling out cobalt pellets like salt from a shaker. The pellets were ferrous. The magnet picked them up and mixed them into the scrap leaving the junkyard. Some pellets were pulverized and thoroughly spread across the huge junkyard, and others are believed to have become imbedded in truck tires and spread along highways.
> In this manner, 300 curies of radioactive cobalt made its way to two foundries. One in Juarez manufactured metal table legs and sent them to the largest distributor of restaurant tables in the United States. Another in Chihuahua produced about 5,000 tons of rebar, or steel rods used to reinforce concrete in building projects.
> About 600 tons of the contaminated steel was shipped to the United States in December and January.
> Spill Discovered by Accident
> When a delivery truck took a wrong turn near the Los Alamos National Laboratory in New Mexico on Jan. 17, a radiation alarm was tripped. Thus, by accident, did the American and Mexican authorities learn of the contamination. It was quickly traced to the junkyard, which was closed Jan. 20. Mr. Sotelo's truck was impounded Jan. 26.
> By Dec. 6, Mr. Sotelo had thrown the capsule off his truck into the salvage yard. The date is known because all paperwork from the junkyard dated Dec. 6 or later is radioactive.
…
> The capsule was made of nonferrous metal. Every time it was scooped up by the magnet, it eventually fell to the ground, spilling out cobalt pellets like salt from a shaker. The pellets were ferrous. The magnet picked them up and mixed them into the scrap leaving the junkyard. Some pellets were pulverized and thoroughly spread across the huge junkyard, and others are believed to have become imbedded in truck tires and spread along highways.
> In this manner, 300 curies of radioactive cobalt made its way to two foundries. One in Juarez manufactured metal table legs and sent them to the largest distributor of restaurant tables in the United States. Another in Chihuahua produced about 5,000 tons of rebar, or steel rods used to reinforce concrete in building projects.
> About 600 tons of the contaminated steel was shipped to the United States in December and January.
> Spill Discovered by Accident
> When a delivery truck took a wrong turn near the Los Alamos National Laboratory in New Mexico on Jan. 17, a radiation alarm was tripped. Thus, by accident, did the American and Mexican authorities learn of the contamination. It was quickly traced to the junkyard, which was closed Jan. 20. Mr. Sotelo's truck was impounded Jan. 26.