December 6, 1983 – Ciudad Juárez, Mexico, A local resident salvaged materials from a discarded radiation therapy machine carrying 6,000 pellets of 60Co. The dismantling and transport of the material led to severe contamination of his truck; when the truck was scrapped, it in turn contaminated another 5,000 metric tonnes of steel with an estimated 300 Ci (11 TBq) of activity. This material was sold for kitchen or restaurant table legs and building materials, some of which was sent to the U.S. and Canada; the incident was discovered when a truck delivering contaminated building materials months later to the Los Alamos National Laboratory accidentally drove through a radiation monitoring station. Contamination was later measured on the roads that were used to transport the original damaged radiation source. In some cases pellets were actually found embedded in the roadway. In the state of Sinaloa, 109 houses were condemned due to contaminated building material. This incident prompted the Nuclear Regulatory Commission and Customs Service to install radiation detection equipment at all major border crossings.[21]
