A typical cobalt-60 capsule, comprising:
(A) An international standard source holder (usually lead), (B) a retaining ring, and (C) a teletherapy "source" composed of (D) two nested stainless steel canisters welded to two (E) stainless steel lids surrounding an (F) internal shield (usually uranium metal or a tungsten alloy) that protects a (G) cylinder of radioactive source material.

Between March and July 1962, a radiation incident in Mexico City occurred when a ten-year-old boy took home an industrial radiography source that was not contained in its proper shielding. Five individuals received significant overdoses of radiation from the 200-gigabecquerel cobalt-60 capsule,[1] four of whom died.[2]

Reports differ as to the source's provenance: it was either found in a dump,[3] found in a field,[4] or was already in the house's yard when the affected family moved in and "was left to the family to keep and watch without any of the members of the family knowing exactly what the container was".[5] A 2008 report by UNSCEAR says it was left, unprotected, in the yard by an engineer.[1]

The boy is believed to have obtained the source some time after moving into the house on March 21. He kept it in his trouser pocket for several days. On April 1, his mother placed it in the kitchen cabinet of their home, where it remained until July 22. The boy died on April 29. Subsequently, his mother – six months pregnant at the time – died on July 19; his two-year-old sister died on August 18; and his paternal grandmother, who had been living with the family since April 17, died on October 15 that year.[5] The boy's father also received a significant radiation dose; although he was left permanently sterile,[1] he survived, presumably because he worked outside the home and his exposure was lower.[6][7][8]

See also

References

  1. 1 2 3 "Sources and Effects of Ionizing Radiation: 2008 UNSCEAR Report" (PDF). United Nations Scientific Committee on the Effects of Atomic Radiation. 18 May 2016. p. 9.
  2. ↑ Planning the Medical Response to Radiological Accidents p. 16.
  3. ↑ International Journal of Radiation Biology, 1998, vol. 73, no. 4, p.437 Online: http://www.reocities.com/CapeCanaveral/Hangar/8929/Seminars/2009_05_RadiationAccidents.pdf Archived 2014-10-06 at the Wayback Machine
  4. ↑ Andrews, Gould A. (1964). "Mexican Co60 Radiation Accident" (PDF). Isotopes and Radiation Technology. 1 (2): 200–201.
  5. 1 2 Comas, Frank V. (transl.). "Report entitled 'Observations on the Accidental Exposure of a Family to a Source of Cobalt-60', published in 1964" (PDF). U.S. Department of Energy OpenNet System. Retrieved 30 January 2023.
  6. ↑ Johnston, Wm. Robert. "Mexico City orphaned source, 1962". Database of radiological incidents and related events – Johnston's Archive. Retrieved 25 December 2016.
  7. ↑ Ortiz, P.; Oresegun, M.; Wheatley, J. (2002). "Lessons from major radiation accidents" (PDF). Safety. 21–1.
  8. ↑ Smith, H. (1983). "Dose-effect relationships for early response to total body irradiation". Journal of the Society for Radiological Protection. 3:5–10 (3): 5–10. Bibcode:1983JSRP....3....5S. doi:10.1088/0260-2814/3/3/001.



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