The Cobalt-60 Disaster in Ciudad Juárez: A Public Health Crisis

In Mexico, one of the largest nuclear disasters occurred years before the Chernobyl incident, involving a cobalt-60 radioactive bomb that threatened the safety of many Mexicans. The number of victims remains incalculable to this day.

In 1977, the Centro Médico de Especialidades S.A. in Ciudad Juárez clandestinely purchased a radiotherapy unit containing cobalt-60. This synthetic radioactive isotope emits gamma rays, which are toxic in high doses. The center aimed to attract cancer patients from the U.S. but opted to smuggle the unit from the U.S. to avoid importation paperwork.

The disaster began on December 6, 1983, when Vicente Sotelo, a maintenance employee, was authorized to sell the radiotherapy machine as scrap. Unbeknownst to him, he and a colleague started dismantling the dangerous device, which contained a cobalt-60 radioactive bomb.

While dismantling the machine, they accidentally opened a 100-kilogram head, releasing radiation. They noticed a blue light emanating from the cylinder and experienced a metallic taste in their mouths, along with an unusually warm environment, yet they ignored these alarming signs.

The two workers loaded the dismantled parts into a white Datsun truck and headed to the Phoenix junkyard, where they received 1,500 pesos for the scrap metal. During the journey, the open cylinder leaked cobalt-60 granules throughout Ciudad Juárez, with the truck emitting radiation levels up to 1,000 prats, equivalent to 20,000 X-rays.

Vicente left the truck parked at his home for three months, further exposing the surrounding area to the dangerous radiation from the open cylinder.

Radiation continued to emanate from the site, leading to the contamination of scrap metal at the Phoenix junkyard with cobalt-60. This contaminated scrap was subsequently sold and used to manufacture 30,000 table bases and 6,600 tons of rebar, which were distributed across nearly half of Mexico and some locations in the United States.

A truck transporting the contaminated rebar triggered nuclear material theft alarms at the Los Alamos National Laboratory in the U.S. This incident prompted an investigation, and the National Commission of Nuclear Safety and Safeguards in Mexico was notified to halt the distribution of the contaminated products immediately.

The investigation revealed that the truck carrying the contaminated material was emitting radiation levels higher than those experienced by workers at the Chernobyl nuclear plant. Approximately 450 local residents suffered from burns on the soles of their feet and long-term health issues. Nearly 90% of the contaminated material exported to the U.S. was returned to Ciudad Juárez, where 180 workers were assigned to collect the radioactive pellets dropped by the truck, but they lacked special protective equipment and were also affected by radiation.

After nine months, over 20,000 tons of contaminated material were collected in Chihuahua. To dispose of this hazardous waste, a radioactive cemetery was constructed in the Samalayuca dunes, which posed a further risk as water from this area was extracted for Ciudad Juárez, leading to water contamination. The exact number of individuals affected by this catastrophic incident remains unknown.

Vicente Sotelo, the local mayor, reported experiencing health issues that eventually subsided. Unbeknownst to him, he had initiated one of the largest nuclear disasters on the continent.