Goiânia accident

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Coordinates: 16°40′29″S 49°15′51″W / 16.6746°S 49.2641°W / -16.6746; -49.2641 (Instituto Goiano de Radioterapia)

The Goiânia accident was an incident of radioactive contamination in central Brazil that killed 4, injured 28, and produced over 200 cases of detectable radiation poisoning. On 13 September 1987, an old radiation source was scavenged from an abandoned hospital in Goiânia, the capital of the central Brazilian state of Goiás. It was subsequently handled by many people, resulting in four deaths and serious radioactive contamination of 249 other people.[1] Time magazine has identified the accident as one of the world's "worst nuclear disasters".[2]

Contents

[edit] Nature of the source

The object was a small, highly radioactive thimble of caesium chloride (a caesium salt made with a radioisotope of caesium) 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 positions.

A wheel type radiotherapy device which has a long collimator to focus the radiation into a narrow beam. The caesium chloride radioactive source is highlighted in red and the gamma rays are represented by blue
Comparison of radioactivities
  TBq

Goiânia
source

 1971 74
when stolen (1987) 50.9
recovered 44
unrecovered (c. 1987) 7
unrecovered (c. 2008) 4.3
smoke detector 0.000000037

The source contained 74 terabecquerels (TBq) in 1971. The International Atomic Energy Agency (IAEA) describes the container—51 millimeters (2 inches) in diameter and 48 mm (1.8 inches) long—as an “international standard capsule.” The specific activity of the active solid was about 814 TBq·kg-1 of caesium 137 (half life of 30 years). The dose rate at one meter from the source was 4.56 gray per hour (456 rad·hr−1). While the serial number of the device was unknown, thus hindering definitive identification, the device was thought to be made in the United States at Oak Ridge National Laboratory and was used as a radiation source for radiation therapy at the Goiânia hospital.[3]

The IAEA document indicates that:

  • The dose rate due to external irradiation from uniform contamination of the ground by 137Cs is 1.6 × 10−12 Sv·h−1·Bq−1·m³.
  • The internal dose for ingestion is 1.2 × 10−8 Sv·Bq−1
  • The internal dose for inhalation is 8.7 × 10−9 Sv·Bq−1

The IAEA states that the source contained 50.9 TBq (1375 Ci) when it was stolen, and that about 44 TBq (1200 Ci, 87%) of radioactivity has been recovered during the clean up operation. This means that 7 TBq remained in the environment; it will have decayed to about 4.3 TBq by 2008.

For comparison, the average modern smoke detector contains about 37 kBq (1 μCi) of 241Am.[4]

[edit] Events

[edit] Scavenging of the source

Goiânia’s Instituto Goiano de Radioterapia (IGR)[3], located 1 km northwest of Praça Cívica, was abandoned in 1985. A caesium-137 based teletherapy unit was left behind. Over the following years, many homeless, squatters and scavengers entered the building. Eventually, on 13 September 1987, two men — Roberto dos Santos Alves and Wagner Mota Pereira — came across the radioactive teletherapy head and took it with them in a wheelbarrow to dos Santos's house about 0.6 km north of the clinic. There they partly dismantled the equipment, taking the billiard ball-sized cesium capsule out of the protective rotating head. The gamma radiation emitted by the capsule's iridium window made the men nauseous after a couple of days, but they assumed it was due to something they ate[1]. The exposure eventually caused localized burns to their bodies and one later had to have an arm amputated.

[edit] The source is partially broken

The two men attempted to open the cesium capsule, but failed. A few days later, however, one man did break open the iridium window which allowed him to see the cesium chloride emitting a deep blue light[1]. 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 Čerenkov radiation associated with the absorption of moisture by the source. Similar blue light was observed at Oak Ridge during the disencapsulation of a 137Cs source in 1988. The man scooped out some of the radioactive cesium and tried to light it, thinking it was gunpowder, and eventually gave up.

[edit] The source is sold and dismantled

On September 18 Roberto 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 cesium 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 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. Another brother of the scrapyard owner used the dust to paint a blue cross on his skin. 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.

[edit] Ivo and his daughter

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.

[edit] Maria Ferreira notifies authorities

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) Maria 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. The IAEA report suggests that 90% of the radioactivity originally in the source had escaped from it by this point. She died on 23 October 1987.

A model of the bus cabin was subsequently recreated, and it is estimated that a hypothetical passenger who remained in the worst possible location for the entire bus trip (15 minutes) would have suffered a dose of less than 0.3 Sv to the legs. This dose would not cause any injury or acute radiation syndrome. If this hypothetical passenger had been separated by 2.7 meters from the source, then the leg dose would decline to 0.04 Sv. While these prospective leg doses are larger than the normal organ limits for the general public, they are unlikely to cause serious harm in either the short or long term.

[edit] The source's radioactivity is detected

In the morning of 29 September 1987 a visiting medical physicist (named WF in the IAEA report) used a scintillation counter borrowed from NUCLEBRAS (a national government agency which is involved in the nuclear fuel cycle, including searching for uranium ore) to confirm the presence of radioactivity. The accident response started that evening.

[edit] Health outcomes

Ages in years are given, with dosages listed in Gy, or Gray.

[edit] Fatalities

  • Leide das Neves Ferreira, 6, (6.0 Gy, 600 REM), 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 a month later (23 October 1987) and was buried in a lead coffin, sealed with concrete.
  • Gabriela Maria Ferreira, 38, (5.7 Gy, 550 REM), wife of junkyard owner Devair Ferreira, got 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, 22, (4.5 Gy) 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, 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.

[edit] Survivors

  • Devair Ferreira, 36, (7.0 Gy, 700 REM), survived. He received more radiation than most individuals, but it is believed that his dose was fractionated over time.
  • Wagner Mota Pereira, 19, went to the hospital about 11 days after exposure and was hospitalized for about four days. The doctors treated it as a tropical disease.
  • Maria Gabriela Abreu, 57, (4.3 Gy) was the mother of Maria Ferreira. She was exposed to the material and either intentionally or unintentionally returned home with the material. She received an intake of 10 MBq (270 µCi), and after becoming critically ill, survived the incident.
  • Geraldo Guillerme da Silva, 21, (GS) (3.0 Gy) was the employee who went with Maria to reclaim the radioactive parts and transport them to the clinic.
  • Ernesto Fabiano (4.5 Gy) was a friend of Devair who hammered open the casing. He had taken some of the fragments home. He was hospitalized with radiation poisoning.
  • Edson Fabiano, 42, (5.3 Gy) was the brother of Ernesto. He was hospitalized with radiation poisoning.
  • Roberto Santos Alves (600 REM), 22, had his right forearm amputated about a month after exposure.
  • Ivo Alves Ferreira, 40, was the father of Leide das Neves.
  • Kardec Sebastio dos Santos, 30, transported some of the parts to Devair's junkyard.

[edit] Other individuals

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 ameliorate the effects of radiation poisoning.

This is a barchart showing the outcome for the 46 most contaminated people for whom a dose estimate has been made. The people are divided into seven groups according to dose.

[edit] Other affected persons

Afterwards, about 112,000 people were examined for radioactive contamination; 244 were found to have significant levels of radioactive material in or on their body. Of this group 129 persons had internal contamination. The majority of the internally contaminated persons only suffered small doses (< 50 mSv, less than a 1 in 400 risk of getting cancer as a result).

A thousand persons 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 (between a 1 in 2000 and a 1 in 100 risk of developing cancer as a result).

[edit] Legal matters

In light of the deaths caused, the three doctors who had owned and run IGR were charged with criminal negligence. The main cause of this incident was the severe negligence of the facility's former operators who had left behind such a dangerous item. The accident demonstrated the importance of keeping an inventory and monitoring of all strong radiation sources by public authorities, which now is legally required in many countries. In 2000, CNEN, the National Nuclear Energy Commission, was ordered by the 8th Federal Court of Goiás to pay compensation of BRL 1.3 million and to guarantee medical and psychological treatment for the direct and indirect victims of the accident and their descendants down to the third generation[5]. As the accidents occurred before the promulgation of the Federal Constitution of 1988 and because the substance was acquired by the clinic and not by the individual owners, the court could not declare the owners of IGR liable. One of the medical doctors owning IGR and the clinic’s physicist were ordered to pay BRL 100,000 for the derelict condition of the building. The two scrap metal dealers were not included as defendants in the public civil suit.

[edit] Cleanup

[edit] Objects and places

Topsoil had to be removed from several sites, and several houses were demolished. All the objects from within those houses were removed and examined. Those that were found to be free of radioactivity were wrapped in plastic bags, while those that were contaminated were either decontaminated or disposed of as waste. In industry, the choice between decontaminating or disposing objects is based only on the economic value of the object and the ease of decontamination. The IAEA recognized in this case, however, that to reduce the psychological impact of the event, greater effort should be taken to clean up items of personal value, such as jewelry and photographs. It is not clear from the IAEA report to what degree this was practiced.

[edit] Means and methods

After the houses were emptied, vacuum cleaners were used to remove dust before the surfaces and plumbing were examined for radioactivity. Painted surfaces could be scraped, while floors were treated with acid and Prussian blue mixtures. Roofs were vacuumed and hosed but two houses had to have their roofs removed. The waste from the clean up was moved out of the city to a remote place for storage.

Potassium alum dissolved in hydrochloric acid was used on clay, cement, soil and roofs. Caesium has a high affinity for many clays.

Organic solvents, followed by potassium alum dissolved in hydrochloric acid, were used to treat waxed/greased floors and tables. Sodium hydroxide solutions, also followed by dissolved potassium alum, were used to treat synthetic floors, machines and typewriters.

Prussian blue was used to internally decontaminate many humans. The urine was treated with ion exchange resin to compact the waste for ease of storage.

[edit] Recovery considerations

The cleanup operation was much harder for this event than it could have been because the source was opened, and the fact that the active material was water soluble. A sealed source need only be picked up, placed in a lead pot and transported to the radioactive waste storage. In the recovery of lost sources, the IAEA recommends careful planning and using a crane or other device to place shielding (such as pallet of bricks or a concrete block) near the source to protect recovery workers.

[edit] Contamination locations

The Goiânia accident spread significant radioactive contamination throughout the Aeroporto, Central, and Ferroviarios districts. Even after the cleanup, 7 TBq of radioactivity remained unaccounted for. Listed here are some of the key contamination sites.

[edit] Research

In 1991 Professors Barry W. Glickman, David Levin, and John D. Curry traveled to Goiania to collect blood samples from the high dosed survivors. Those samples were later analyzed by two Brazilian graduate students, Pexito da Cruz and Vera Saddi, at the University of Victoria, British Columbia. Several papers describing the results from these blood collections were published.[6][7][8][9]

[edit] See also

[edit] References

  1. ^ a b c d e f g h i The Radiological Accident in Goiania p. 2.
  2. ^ The Worst Nuclear Disasters
  3. ^ a b The Radiological Accident in Goiânia. IAEA. 1998-09-16. ISBN 92-0-129088-8. http://www-pub.iaea.org/MTCD/publications/PubDetAR.asp?pubId=3684. 
  4. ^ "Smoke Detectors & Radiation". United States Environmental Protection Agency. http://www.epa.gov/radiation/sources/smoke_alarm.html. Retrieved 2007-11-04. 
  5. ^ Case Law and Administrative Decisions, Judgement of the Federal Court in the Public Civil Action concerning the Goiânia Accident, http://www.nea.fr/html/law/nlb/Nlb-66/023-032.pdf
  6. ^ da Cruz AD, Curry J, Curado MP, Glickman BW. 1996. Monitoring hprt mutation frequency over time in people accidentally exposed to high doses of ionizing radiation. Environmental and Molecular Mutagenesis 27:165–175.
  7. ^ Saddi V, Curry J, Nohturfft A, Kusser W, Glickman BW. 1996. Increased hprt mutant frequencies in Brazilian children accidentally exposed to ionizing radiation. Environmental and Molecular Mutagenesis 28:267–275.
  8. ^ da Cruz AD, Volpe JP, Saddi V, Curry J, Curado MP, Glickman BW. 1997. Radiation risk estimation in human populations: Lessons from the radiological accident in Brazil. Mutation Research 373:207–214.
  9. ^ Skandalis A, da Cruz, AD Curry J, Curado M, Glickman BW. 1997. Molecular analysis of T-lymphocyte hprt- mutations from individuals exposed to ionizing radiation in Goiania, Brasil. Environmental and Molecular Mutagenesis 29:107–116.

[edit] External links

Retrieved from "http://en.wikipedia.org/wiki/Goi%C3%A2nia_accident"