Sunday, September 18, 2011

⅏Did You Know.. Goiânia Accident of 1987 - Caesium-137 Poisining in Brazil

Did You Know...

On September 18th, 1987 -
Cesium-137 was removed from an abandoned cancer-therapy machine in Brazil. Hundreds of people were eventually poisoned by radiation from the substance, highlighting the danger that even relatively small amounts of radiation can pose.

In 1985, the Goiania Institute of Radiotherapy moved to a new location and left behind an obsolete Cesium-137 teletherapy unit in their abandoned headquarters. The institute failed to inform the authorities of the existence of the outdated device and the machine sat in the building in downtown Goiania, 600 miles from Sao Paulo, for over a year before two criminally enterprising men removed the machine.

A wheel type radiotherapy device which has a long collimator to focus the radiation into a narrow beam. The caesium chloride radioactive source is the blue square and gamma rays are represented by the beam emerging from the fuchsia iridium window
The source of the Goiânia accident was a small thimble containing about 93 grams of highly radioactive caesium chloride (a caesium salt made with a radioisotope, caesium-137) encased in a shielding canister made of lead and steel with an iridium window. 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 position

The Theft and Contamination
On 13 September 1987, the security guard in charge of daytime security, Voudireinão da Silva, did not show up to work, using a sick day to attend a cinema screening of Herbie Goes Bananas with his family.  That same day, scavengers Roberto dos Santos Alves and Wagner Mota Pereira entered the partially demolished facility, found the teletherapy unit, which they thought might have some scrap value, placed it in a wheelbarrow and took it to Alves' home, about 0.6 km north of the clinic. There, they partly dismantled the equipment, taking the billiard ball-sized caesium capsule out of the protective rotating head.

The gamma radiation emitted by the capsule's iridium window nauseated the men and within a day or so, the two men became ill, experiencing vomiting, diarrhea and dizziness. The clinic's diagnosis was that the men were suffering an allergic reaction caused by eating bad food.  The two continued their efforts to dismantle the unit, eventually rupturing the source capsule and exposing the radioactive material. The exposure eventually caused localized burns to their bodies and one later had to have an arm amputated.
A few days later one man broke open the iridium window which allowed him to see the caesium chloride emitting a deep blue light.

The exact mechanism by which the light was generated was not known at the time the IAEA report was written. The light is thought to be either fluorescence or Cherenkov radiation associated with the absorption of moisture by the source; similar blue light was observed in 1988 at Oak Ridge National Laboratory during the disencapsulation of a 137Cs source. The man scooped out some of the radioactive caesium and tried to light it, thinking it was gunpowder, and eventually gave up
Greenpeace Activists in Brazil chained
themselves to the gates of the
National Nuclear Energy Commission (CNEN),
placing a memorial plaque in tribute to the
victims of the tragedy of Cesium-137 in Goiânia,
the worst radiation accident in an
area urban history. - August 24, 2008
On September 18 Roberto dos Santos Alves and Wagner Mota Pereira sold the items to a nearby scrapyard. That night the owner, Devair Alves Ferreira, went in the garage and saw the blue glow from the caesium capsule. Over the next three days he invited friends and family to view the strange glowing substance. Ferreira intended to make a ring for his wife, Gabriela Maria Ferreira, out of the material.

Several people who visited the home came into contact with the dust and spread it around the local neighborhood and to other towns nearby. Ferreira's ownership led to many people becoming contaminated. A brother of the scrapyard owner used the dust to paint a blue cross on his abdomen. He also contaminated the animals at his farm, several of which died. At this scrapyard, a friend of Ferreira's (given as EF1 in the IAEA report) hammered open the lead casing. On 25 September 1987, Devair Alves Ferreira sold the scrap metal to another scrapyard. He survived the incident.

Ivo, Devair's brother, scraped dust out of the source, taking it to his house a short distance away. There he spread some of it on the floor. His 6-year-old daughter, Leide das Neves Ferreira, later ate while sitting on the floor, absorbing some of the radioactive material (1.0 GBq, total dose 6.0 Gy). She was also fascinated by the blue glow of the powder, applied it to her body and showed it off to her mother.

Gabriela Maria Ferreira was the first to notice that many people around her had become severely sick all at the same time, and her actions from that point on probably saved lives. She first suspected the culprit was a beverage they had shared, but an analysis of the juice showed nothing untoward. On 28 September 1987 (15 days after the item was found) Gabriela went with one of her scrapyard employees to the scrapyard then in possession of the materials. She reclaimed them and transported them by bus in a plastic bag to a hospital. There, physician Paulo Roberto Monteiro rightly suspected that it was dangerous. He placed it in his garden on a chair to increase the distance between himself and the object. Because the remains of the source were kept in a plastic bag, the level of contamination at the hospital was low.

About 130,000 people overwhelmed hospitals.  Of those, 250 people, some with radioactive residue still on their skin, were found, through the use of Geiger counters, to be contaminated.  Eventually, 20 people showed signs of radiation sickness and required treatment.
  • Leide das Neves Ferreira, aged 6, was the daughter of Ivo Ferreira. Initially, when an international team arrived to treat her, she was confined to an isolated room in the hospital because the hospital staff were afraid to go near her. She gradually developed 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, as a result of the contamination. She was buried in a common cemetery in Goiania, in a special fiberglass coffin lined with lead to prevent the spread of radiation. There was a riot in the cemetery, where over 2,000 people armed with stones and bricks tried to prevent her burial.
  • Gabriela Maria Ferreira, aged 38, wife of junkyard owner Devair Ferreira, became sick about three days after coming into contact with the substance. Her condition worsened and she developed internal bleeding, especially in the limbs, eyes, and digestive tract, and suffered from hair loss. She died 23 October 1987, about a month after exposure.
  • Israel Baptista dos Santos, aged 22, was 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 hospital, and died 6 days later on 27 October 1987.
  • Admilson Alves de Souza, aged 18 (5.3 Gy, 500 REM), was also an employee of Devair Ferreira who worked on the radioactive source. He developed lung damage, internal bleeding, and heart damage, and died 18 October 1987.
Other individuals
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 ameliorate the effects of radiation poisoning.
More than 40 homes in the city were found to have high levels of contamination and had to be demolished. The after-effects were also serious. Many of the citizens suffered psychologically from their fear of contamination. In fact, fear was so widespread that other cities shunned the people and products of Goiania following the incident.
Following this disaster, Brazil completely overhauled their laws regarding the storage of radiation sources.

  • Caesium-137 is a radioactive isotope of caesium which is formed as a fission product by nuclear fission, and has a half-life of about 30.17 years?
  • All caesium-137 existing today is unique in that it is totally anthropogenic (man-made). Unlike most other radioisotopes, caesium-137 is not produced from its non-radioactive isotope but from uranium, meaning that until now, it has not occurred on Earth for billions of years. By observing the characteristic gamma rays emitted by this isotope, it is possible to determine whether the contents of a given sealed container were made before or after the advent of atomic bomb explosions. This procedure has been used by researchers to check the authenticity of certain rare wines, most notably the purported "Jefferson bottles".
  • As of 2005, caesium-137 is the principal source of radiation in the zone of alienation around the Chernobyl nuclear power plant. 
  • As of April 2011, it was also being found in the plumes emanating from the continuing leakage at the Fukushima reactors in Japan. In July 2011, meat from 11 cows shipped to Tokyo from Fukushima prefecture was found to have 3 to 6 times the legal limit of 500 becquerels per kilogram of radioactive caesium.
  • Accidental ingestion of caesium-137 can be treated with Prussian blue, which binds to it chemically and then speeds its expulsion from the body.


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