The ‘Mexican Chernobyl’: How a Forgotten Machine Unleashed a Radiological Nightmare
For decades, the story of the Cobalt-60 accident in Ciudad Juárez, infamously dubbed the ‘Mexican Chernobyl,’ remained a chilling whisper, a testament to negligence and a stark warning of invisible dangers. Now, through declassified documents, anonymous testimonies, and painstaking reconstruction, we expose the full extent of this radiological disaster, a chain of contamination that originated in a forgotten hospital and left a toxic legacy across Mexico and beyond.
The Genesis of a Catastrophe: A Hospital, a Machine, and a Fatal Oversight
The tale begins on December 6, 1983, in Ciudad Juárez, when a private hospital became the unwitting epicenter of one of Mexico’s most severe radiological incidents. A Picker C-3000 radiotherapy machine, containing a potent Cobalt-60 source, lay abandoned in a warehouse. Acquired in 1977 by Dr. Abelardo Lemus without proper permits or oversight from the National Institute of Nuclear Energy (INEN), the machine was never used, its deadly core silently awaiting its fateful release.
According to investigations, Dr. Lemus bypassed import regulations to save costs, bringing the machine into Mexico in his own car. For six years, it remained a forgotten relic until that December night when Vicente Sotelo, a hospital technician, and his friend Ricardo Hernández, removed the equipment. Sotelo claimed he acted under Lemus’s instruction, a claim the doctor vehemently denied, accusing Sotelo of theft. These conflicting accounts are recorded in preliminary investigation 79/85 of the then Attorney General’s Office (PGR), as reported by journalist Laura Sánchez Ley for Gatopardo.
The Invisible Spread: From a Pickup Truck to Thousands of Homes
On that fateful night, Sotelo and Hernández extracted the radioactive source from its shielding and perforated its encapsulation, releasing Cobalt-60 granules into the environment. The contamination began its insidious spread. The pickup truck used to transport the source became a mobile hazard, its bed impregnated with radiation. For 40 days, the truck sat on Aldama Street in the Bellavista neighborhood, a silent killer as children played around it, unknowingly inhaling the invisible poison.
Their intention was to sell the machine for scrap. It was taken to Yonke Fénix, a local junkyard, where workers, unaware of the danger, handled the radioactive source without protection. Antonio Fabela, a 23-year-old worker, died seven months later from radiation exposure, suffering hair loss and skin lesions before succumbing to cancer. But the contamination didn’t stop there. The radioactive scrap was sold to Aceros de Chihuahua, S.A. (Achisa) and Falcón de Juárez, where it was melted down and incorporated into rebar and industrial bases. The Cobalt-60 source, with an initial activity of 1003 curies in 1977, still retained approximately 450 curies by late 1983 – a highly dangerous amount.
The Accidental Discovery: Los Alamos and an International Crisis
The true scale of the disaster came to light by sheer chance. On January 16, 1984, a truck carrying contaminated rebar from Acereros de Chihuahua, lost its way and passed near the Los Alamos National Laboratory in New Mexico, USA. Radiation detectors immediately activated, triggering an alarm that would soon reverberate across two nations.
Three days later, the Texas Department of Health notified Mexico’s National Commission of Nuclear Safety and Safeguards (CNSNS). The news quickly made international headlines. Proceso magazine reported “A Thousand Tons of Radioactive Rebar, Lost in the Country,” while The New York Times warned that the Juárez accident could become one of the worst nuclear disasters in America.
On January 20, 1984, CNSNS personnel began investigations at the Achisa foundry and Yonke Fénix, confirming widespread contamination. Two days later, Cobalt-60 granules were found scattered on the streets of Ciudad Juárez. By then, much of the contaminated rebar had been exported to the United States and distributed across at least 16 Mexican states, including Chihuahua, Sonora, Baja California, and Sinaloa. The investigation estimated that approximately 6,000 tons of contaminated rebar were produced, exposing around 4,000 people to radiation.
‘La Piedrera’: Chihuahua’s Radioactive Graveyard
Decontamination efforts began the same month. Collected material was encased in massive concrete sarcophagi at La Piedrera, Chihuahua, which became a permanent radioactive waste disposal site. Earlier, in February 1984, a site in the Samalayuca desert, 12 km south of the Km 28 checkpoint, had been chosen for the definitive storage of radioactive waste. This site, with a capacity of 12,000 m³ for 10,000 tons of contaminated material, was deemed suitable after extensive studies. However, strong opposition from the Employers’ Confederation of the Mexican Republic in Ciudad Juárez led to the cancellation of the Samalayuca site in September.
Finally, in early November, ‘La Piedrera,’ located 15 kilometers southwest of Samalayuca, in the El Vergel ejido, was selected with the consent of local landowners.
The Cobalt-60 File: Scars That Remain
Investigations revealed that approximately 4,000 people were exposed to radiation, with five receiving extremely high doses ranging from 300 to 700 rems. The CNSNS report acknowledged irreversible damage to some individuals and the demolition of hundreds of homes. Contaminated rebar had been used in the construction of 814 homes, and over 2,300 tons of rebar were recovered before being used. In total, approximately 36,000 tons of contaminated waste were buried.
Symptoms among junkyard and foundry workers were almost immediate: headaches, diarrhea, fever, hair loss, and skin lesions. Some received extremely high doses, and others, like brothers Agustín and Pedro de la Cruz, suffered irreversible sterility. The official file remained a state secret for decades. Although the CNSNS and IMSS attempted medical follow-ups, these efforts were eventually abandoned. The population was left in uncertainty, unaware if their homes, streets, or workplaces were contaminated.
While dubbed the ‘Mexican Chernobyl,’ specialists clarify that the scale of the Cobalt-60 accident was not comparable to the 1986 Soviet disaster. More than four decades later, the whereabouts of Vicente Sotelo Alardín remain a mystery. Official records place him last in the mid-1980s, after being accused of theft, though no crime was ever proven. Blood tests in 1984 showed no radiation damage, but he disappeared shortly after. For some, he was merely a worker following orders; for others, the direct cause of the disaster.
Source: Investigative journalism, declassified files, anonymous testimonies, CNSNS reports, and media archives.
