On September 13, 1987, the largest radiological accident in Brazil began in Goiânia, capital of the state of Goiás. The source of the disaster was a radiotherapy device left in a disabled clinic.
The equipment was found by scavengers and taken to a junkyard. What the two men did not know is that it contained a radioactive material, cesium-137 .
The substance that is harmful to humans has caused hundreds of direct and indirect victims due to the radioactivity of cesium chloride powder (CsCl).
Accident history summary
The story of the accident began in downtown Goiânia, where the Goiano Institute of Radiotherapy worked. Two garbage collectors entered the abandoned clinic and came across a huge device left on the premises.
In order to sell the valuables, as they contain steel and lead, the men took the equipment to Devair Alves Ferreira’s junkyard at Rua 26-A, in the Aeroporto Sector.
When disassembling the equipment, Devair found a nuclear capsule containing a white powder that in the dark had a blue glow. Fascinated by the material and thinking it was something of value, he exhibited the discovery to family, friends and neighbors without knowing the danger that was in his hands.
Since cesium is a radioactive element, the nucleus of its atom undergoes disintegration. The unit used to measure the radioactivity of the material is Becquerel (Bq), which corresponds to one disintegration per second, or Curie (Ci), which is equivalent to 3.7 x 10 10 disintegrations per second.
When the equipment was manufactured in 1971 in the United States, there was approximately 28 g of cesium chloride and the radioactive activity was 2,000 Ci. When found, 16 years later, the capsule still contained 19.26 g of the substance and had a activity of 1,375 Ci or 50.9 TBq.
The amount of cesium-137 was sufficient to generate a great contamination, since the radioisotope spread quickly because it is a fine powder that easily adheres to places with humidity.
The consequences of exposure
Hours after the first contact with cesium-137, symptoms of intoxication began. People who experienced dizziness, diarrhea and vomiting went to hospitals. Unaware of the radioactive material in the region, doctors believed it to be a contagious disease.
Just two weeks after the exhibition, Devair’s wife went to the Health Surveillance, taking part of the equipment that was in the junkyard with her.
The radioactive accident was only confirmed on September 29, when the nuclear physicist Walter Ferreira was called to the site and with the use of detectors indicated the high levels of radiation. The National Nuclear Energy Commission (CNEN) was immediately called upon to implement an emergency plan.
The radiation effects were felt by residents who had direct contact with the material and those who worked to remedy the accident, such as doctors, nurses, firefighters and police.
The accident victims: how many and who were they?
According to official data, the accident resulted in four fatalities one month after contact with the substance. The main causes were hemorrhage and generalized infection.
The first death was that of Leide das Neves Ferreira, a 6-year-old girl who became a symbol of the tragedy. Maria Gabriela Ferreira, who helped unravel the mystery, was the second fatal victim, as were Israel Santos and Admilson Souza, scrap metal workers.
However, it is estimated that more people died from complications and many still carry the consequences of radioactive inheritance.
The measures taken after the accident
For the decontamination of the site, seven main foci were identified and isolated. About 112,800 people were monitored and grouped according to exposure and symptoms presented.
3500 m 3 of nuclear waste were collected and stored in concrete containers and buried 23 km from Goiânia, in the city of Abadia de Goiás. The Regional Center for Nuclear Sciences in the Midwest monitors the activity of radioactive waste.
In 1988, the Leide das Neves Ferreira Foundation was created, by the State of Goiás, to monitor radiation victims according to exposure levels. Today, services are provided by the State Radio Assistance Center – CARA.
In 1996, those responsible for the Instituto Goiano de Radioterapia were tried. The sentence for manslaughter (when there is no intention to kill) was three years and two months in prison, but the sentence was replaced by provision of services.
Law No. 9425, created on December 24, 1996, granted a special pension to the victims of the biggest nuclear accident in Brazil and in the world, which occurred outside nuclear power plants.
Cesium-137: what is it? and effects on the body
Cesium is a chemical element in the periodic table, atomic number 55 and symbol Cs. Its name comes from the Latin Caesium and means “blue sky”. This alkali metal has 34 known isotopes, which are unstable or radioactive.
The cesium-137 isotope is unstable and its nucleus is easily disintegrated, promoting radioactive emissions. When the nucleus of an atom disintegrates, nuclear fission occurs, which produces a new chemical element and emits radiation (alpha, beta or gamma).
What is cesium-137 used for?
Radioactive emissions are capable of destroying cancer cells, which are more sensitive to radiation. Therefore, calculated doses of cesium radioisotope are used in the treatment of cancer.
The dangers of cesium-137: the reason the accident was so serious
The danger occurs when ionizing radiation, which has a high penetrating power, emits high concentrations of radioactive particles. The main biological effect is the change in blood cells, such as the loss of white blood cells.
The cesium-137 isotope, for example, acts on the body causing:
- hemorrhages,
- infections,
- acute diseases,
- hair loss
- death (depending on the amount and time of exposure).