Goiânia accident
The Goiânia accident was a radioactive contamination accident that occurred on September 13, 1987, in Goiânia, Goiás of Brazil, after an unsecured radiotherapy source was stolen from an abandoned hospital site in the city. It was subsequently handled by many people, resulting in four deaths. About 112,000 people were examined for radioactive contamination and 249 of them were found to have been contaminated.
In the consequent cleanup operation, topsoil had to be removed from several sites, and several houses were demolished. All the objects from within those houses, including personal possessions, were seized and incinerated. Time magazine has identified the accident as one of the world's "worst nuclear disasters" and the International Atomic Energy Agency called it "one of the world's worst radiological incidents".
The source
The radiation source in the Goiânia accident was a small capsule containing about of highly radioactive caesium chloride made with the radioactive isotope caesium-137, and encased in a shielding canister made of lead and steel. The source was positioned in a container of the wheel type, where the wheel turns inside the casing to move the source between the storage and irradiation positions.The activity of the source was 74 terabecquerels in 1971. The International Atomic Energy Agency describes the container as an "international standard capsule". It was 51 millimeters in diameter and 48 mm long. The specific activity of the active solid was about 814 TBq·kg−1 of caesium-137, an isotope whose half life is 30 years. The dose rate at one meter from the source was 4.56 grays per hour – more than the median lethal dose of 4 grays. While the serial number of the device was unknown, hindering the ability to verify its identity, the device was thought to have been made in the U.S. at Oak Ridge National Laboratory as a radiation source for radiation therapy at the Goiânia hospital.
The IAEA states that the source contained when it was taken and that about of contamination had been recovered during the cleanup operation. This means that remained in the environment; it would have decayed to about by 2016.
Events
The Instituto Goiano de Radioterapia, a private radiotherapy institute in Goiânia, was northwest of Praça Cívica, the administrative center of the city. When IGR moved to its new premises in 1985, it left behind a caesium-137-based radiotherapy unit purchased in 1977. The fate of the abandoned site was disputed in court between IGR and the Society of Saint Vincent de Paul, then owner of the premises. On September 11, 1986, the Court of Goiás stated it had knowledge of the abandoned radioactive material in the building.Four months before the theft, on May 4, 1987, Saura Taniguti, then director of Ipasgo, the institute of insurance for civil servants, used police force to prevent one of the owners of IGR, Carlos Figueiredo Bezerril, from removing the radioactive material that had been left behind. Figueiredo then warned the president of Ipasgo, Lício Teixeira Borges, that he should take responsibility "for what would happen with the caesium bomb". The Court of Goiás posted a security guard to protect the site. Meanwhile, the owners of IGR wrote several letters to the National Nuclear Energy Commission, warning them about the danger of keeping a teletherapy unit at an abandoned site, but they could not remove the equipment on their own once a court order prevented them from doing so.
Theft of the source
On September 13, 1987, the guard tasked with protecting the site did not show up for work. Roberto dos Santos Alves and Wagner Mota Pereira illegally entered the partially demolished IGR site. They partially disassembled the teletherapy unit and placed the source assembly in a wheelbarrow to later take to Roberto's home. They thought they might get some scrap value for the unit. They began dismantling the equipment. That same evening, they both began to vomit due to radiation sickness. The following day, Pereira began to experience diarrhea and dizziness, and his left hand began to swell. He later developed a burn on his hand in the same size and shape as the aperture, and he underwent partial amputation of several fingers.On September 15, Pereira visited a local clinic, where he was diagnosed with a foodborne illness; he was told to return home and rest. Roberto, however, continued with his efforts to dismantle the equipment and eventually freed the caesium capsule from its protective rotating head. His prolonged exposure to the radioactive material led to his right forearm becoming ulcerated, requiring amputation on October 14.
On September 16, Roberto punctured the capsule's aperture window with a screwdriver, allowing him to see a deep blue light coming from the tiny opening he had created. He inserted the screwdriver and successfully scooped out some of the glowing substance. Thinking it was perhaps a type of gunpowder, he tried to light it, but the powder would not ignite.
The exact mechanism by which the blue light was generated was not known at the time the IAEA report of the incident was written, though it was thought to be either ionized air glow, fluorescence, or Cherenkov radiation associated with the absorption of moisture by the source; a similar blue light was observed in 1988 at Oak Ridge National Laboratory in the United States during the disencapsulation of a caesium-137 source.
On September 18, Roberto sold the items to a nearby scrapyard. That night, Devair Alves Ferreira, the owner of the scrapyard, noticed the blue glow from the punctured capsule. Thinking the capsule's contents were valuable or supernatural, he immediately brought it into his house. Over the next three days, he invited friends and family to view the strange glowing powder.
On September 21, at the scrapyard, one of Ferreira's friends freed several rice-sized grains of the glowing material from the capsule using a screwdriver. Ferreira began to share some of them with various friends and family members. That same day, his wife, 37-year-old Maria Gabriela Ferreira, began to fall ill. On September 25, 1987, Devair Ferreira sold the scrap metal to a third scrapyard.
The day before the sale to the third scrapyard, on September 24, Ivo, Devair's brother, successfully scraped some additional dust out of the source and took it to his house a short distance away. There he spread some of it on the concrete floor. His six-year-old daughter, Leide das Neves Ferreira, later ate an egg while sitting on the floor. She was also fascinated by the blue glow of the powder, applying it to her body and showing it off to her mother. The egg was also exposed to dust from the powder; Leide absorbed 1.0 GBq and received a total dose of 6.0 Gy, a fatal dose for which medical intervention was ineffective. Leide's mother, Lurdes Ferreira, also got sick from the radiation.
Maria Gabriela Ferreira had been the first to notice that many people around her had become severely ill at the same time. On September 28, 1987 – fifteen days after the item was found – she reclaimed the materials from the rival scrapyard and transported them to a hospital.
In the morning of September 29, a visiting medical physicist used a scintillation counter to confirm the presence of radioactivity and persuaded the authorities to take immediate action. The city, state, and national governments were all aware of the incident by the end of the day.
Health outcomes
News of the radiation incident was broadcast on local, national, and international media. Within days, nearly 130,000 people in Goiânia flooded local hospitals, concerned that they might have been exposed. Of those, 249 were indeed found to be contaminated – some with radioactive residue still on their skin – through the use of Geiger counters. Eventually, twenty people showed signs of radiation sickness and required treatment.Fatalities
Ages in years are given, with dosages listed in grays. For reference, the LD1, LD50 and LD99 is 2.5, 5 and 8 Gy, respectively.- Admilson Alves de Souza, aged 18, was an employee of Devair Ferreira who worked on the radioactive source. He developed lung damage, internal bleeding, and heart damage, and died October 28, 1987.
- Leide das Neves Ferreira, aged 6, was the daughter of Ivo Ferreira. When an international team arrived to treat her, she was discovered confined to an isolated room in the hospital because the staff were afraid to go near her. She gradually experienced swelling in the upper body, hair loss, kidney and lung damage, and internal bleeding. She died on October 23, 1987, of "septicemia and generalized infection" at the Marcilio Dias Navy Hospital, in Rio de Janeiro. She was buried in a common cemetery in Goiânia, in a special fiberglass coffin lined with lead to prevent the spread of radiation. Despite these measures, news of her impending burial caused a riot of more than 2,000 people in the cemetery on the day of her burial, all fearing that her corpse would poison the surrounding land. Rioters tried to prevent her burial by using stones and bricks to block the cemetery roadway. She was buried despite this interference.
- Maria Gabriela Ferreira, a 37-year-old woman, was the wife of scrapyard owner Devair Ferreira and who turned the material over to the authorities. She became sick about three days after coming into contact with the substance. Her condition worsened, and she developed hair loss and internal bleeding, especially of the limbs, eyes, and digestive tract. She suffered mental confusion, diarrhea, and acute renal insufficiency before dying on October 23, 1987, the same day as her niece, of "septicemia and generalized infection", about a month after exposure.
- Israel Batista dos Santos, aged 22, was also an employee of Devair Ferreira who worked on the radioactive source primarily to extract the lead. He developed serious respiratory and lymphatic complications, was eventually admitted to the hospital, and died six days later on October 27, 1987.
The outcomes for the 46 most contaminated people are shown in the bar chart below. Several people survived high doses of radiation. This is thought in some cases to be because the dose was fractionated. Given time, the body's repair mechanisms will reverse cell damage caused by radiation. If the dose is spread over a long time period, these mechanisms can mitigate the effects of radiation poisoning.
Afterwards, about 112,000 people were examined for radioactive contamination; 249 were found to have significant levels of radioactive material in or on their body. Of this group, 129 people had internal contamination. The majority of the internally contaminated people only suffered small doses. A thousand people were identified as having suffered a dose which was greater than one year of background radiation; it is thought that 97% of these people had a dose of between 10 and 200 mSv.
In 2007, the Oswaldo Cruz Foundation determined that the rate of caesium-137 related diseases are the same in Goiânia accident survivors as they are in the population at large. Nevertheless, compensation is still distributed to survivors, who suffer radiation-related prejudices in everyday life.
The mortality from pancreatic cancer in the Central-Western region of Brasil, which includes Goiás with Goiânia, has seen higher mortality rates than other areas of the country.