A radioactive contamination incident occurred in 1984 in Ciudad Juárez, Mexico, originating from a radiation therapy unit purchased by a private medical company and subsequently dismantled for lack of personnel to operate it.
[1] In November 1977, the Centro Médico de Especialidades, a private hospital in Ciudad Juárez, Chihuahua, purchased a Picker C-3000 radiotherapy unit containing approximately 6,000 cobalt-60 pellets of 2.6 GBq each,[2] which had been introduced to Mexico without complying with current regulations.
[4] Vicente Sotelo Alardín, then an employee of the medical center, dismantled the unit on December 6, 1983, to sell it as scrap metal at the Fénix junkyard at the request of the hospital's maintenance manager.
The truck, now contaminated by the cobalt-60, subsequently suffered a mechanical failure upon Sotelo's return from the junkyard and remained immobile near his home in Ciudad Juárez for 40 days.
The detector went on because a truck carrying rebar produced by Achisa had taken an accidental detour and passed through the entrance and exit gate of the laboratory's LAMPF technical area.
[6] Local authorities realized that the rebar triggered the alert and notified Mexico's National Commission on Nuclear Safety and Safeguards [es] (CNSNS) on January 18.
CNSNS confirmed a wide dispersion of radioactive material had occurred and ordered Achisa to suspend the distribution of manufactured rebar until it was verified that it was not contaminated.
[4] Upon further investigation the CNSNS concluded that in addition to the Fénix junkyard, Achisa, and Falcón, three other companies had received contaminated material: Fundival in Gómez Palacio, Alumetales in Monterrey, and Duracero in San Luis Potosí.
[10] In February 1984, the CNSNS identified a site in the Samalayuca desert for the construction of a "cemetery" facility known as La Piedrera to house the radioactive material, where the rebar collected in Chihuahua was eventually stored in September 1984.
[12] In 2004, an analysis by the National Autonomous University of Mexico revealed that radiation levels in Samalayuca were still alarmingly high and heavily criticized the fact that the waste had been stored without adequate containment measures.