This is a chronological list of orphan source incidents and accidents.

Metric prefixes are used where appropriate: kilo (k), mega (M), giga (G), tera (T).

Note: As incident reporting has used inconsistent units of measurement, the table below shows conversion factors.

Property non-SI unit SI unit equivalent Radioactivity 1 Curie (Ci) 37 gigabecquerels (GBq) Equivalent radiation dose 1 rem 0.01 Sievert (Sv) Absorbed radiation dose 1 rad 0.01 Gray (Gy)

20th century

1960s

1962 – Mexico City – 1962 Mexico City radiation accident in which a boy brought home an unshielded cobalt-60 capsule, radiation from which killed all of the family members but one. January 11, 1963 – Sanlian, Hefei, Anhui, China – A cobalt-60 source from an industrial seed irradiator was removed from a buried waste repository and taken to a residence by a child. Over the next 5–9 days, six total family members were exposed. Two died and four were injured. May 3, 1968 – La Plata, Argentina – A construction worker at a chemical plant discovered a caesium-137 source and carried it in his pants pocket for 17 hours (right pocket for 7 hours, left pocket for 10 hours). The worker suffered a localized dose of , leading to permanent sterility and the eventual amputation of both legs. 17 workers were exposed to an estimated dose of . September 18, 1968 – F.R. Germany – An iridium-192 source was mishandled by workers, with one person placing the source in their jacket pocket. Six workers were exposed, with one receiving a whole body dose and localized dose to their pelvic and thigh regions.

1970s

1971 – Chiba, Japan – a iridium-192 source used for industrial radiography was lost. Six construction workers received doses of . January 8, 1977 – Sasolburg, Free State, South Africa – a iridium-192 source fell out of its container at a construction site. The radiographer did not notice the loss of the source and left the site. A construction supervisor later picked up the source and placed it in his shirt pocket. He travelled home and placed the source in a cupboard. The source was recognized as lost two days later after workers were shown a replica and it was recovered the same day. The supervisor received a whole body dose of and required the amputation of two fingers. His wife and child received doses of and respectively. May 5, 1978 – Sétif, Algeria – A iridium-192 source fell off a truck during transport. Two children found it and kept it for several days before giving it to their grandmother, who kept it in the kitchen of her home. After 38 days radiation exposure was identified by medical personnel. The grandmother died of radiation injuries, and six members of her family received varying radiation injuries. November 14, 1978 – Kambalda East, Western Australia, Australia – A density gauge containing caesium-137 at the Kambalda Nickel Operations was discovered to be missing. Subsequently, caesium-137 radiation contamination was found at a furnace in Singapore which had accepted scrap metal from the Kambalda operation. After years of negotiation, 119 drums of slightly contaminated waste, holding bricks and sludge from the Singapore furnace, were eventually transported to Western Australia in December 1981 and stored in a bunker at Kambalda. June 5, 1979 – Los Angeles, California, United States – A iridium-192 source was lost on a job site. A worker picked it up and carried it in his pocket for 45 minutes before giving it to a manager. The worker received a whole body dose and a surface dose ( at 1-cm; ⅜ inch depth) to his buttocks.

1980s

October 5, 1982 – Baku, Azerbaijan SSR – An individual carried a caesium-137 source in their pocket, exposing several individuals. Five people died and 13 others were exposed, including one person who suffered ARS. 1982 – Vikhroli, Mumbai, India – An iridium-192 source was lost during transport. A railway worker who found the source suffered significant exposure. December 6, 1983 – Ciudad Juárez, Mexico. Ciudad Juárez cobalt-60 contamination incident. A local resident salvaged materials from a discarded radiation therapy machine containing 6,010 pellets of cobalt-60. The transport of the material led to severe contamination of his truck. Remaining pellets in the scrapyard contaminated another 5,000 metric tonnes of steel to an estimated of activity. This steel was used to manufacture kitchen and restaurant table legs and rebar, some of which was shipped to the U.S. and Canada. The incident was discovered months later when a truck delivering contaminated building materials to the Los Alamos National Laboratory drove through a radiation monitoring station. Contamination was later measured on roads used to transport the original damaged radiation source. Some pellets were actually found embedded in the roadway. In the state of Sinaloa, 109 houses were condemned due to use of contaminated building material. This incident prompted the U.S. Nuclear Regulatory Commission and Customs Service to install radiation detection equipment at all major border crossings. March 19, 1984 – Casablanca, Morocco – A iridium-192 source was lost and taken home by a laborer, who placed the source on a table in the family bedroom. The source remained in the house for several weeks. Eight people died and three were injured. September 13, 1987 – In the Goiânia accident, scavengers broke open a radiation-therapy machine in an abandoned clinic in Goiânia, Brazil. They sold the caesium-137 source as a glowing curiosity. Two hundred and fifty people were contaminated; four died. 1980-1989 - The Kramatorsk radiological accident occurred in Kramatorsk in the Ukrainian SSR. In the late 1970s, a radioactive capsule from a radiation gauge was lost in a quarry; quarried gravel and the capsule were later used to construct the walls of an apartment building. A family consisting of a mother, daughter, and son were all diagnosed with leukemia and died within two years whilst living in the contaminated unit. A father and his two sons moved in shortly afterward. The two sons were also diagnosed and died of leukemia within 2 years. The father pushed for an investigation which led to the discovery of the cesium-137 in the wall.

1990s 1990 – Sasolburg, Free State, South Africa – A cobalt-60 source was left behind following radiography work. Six people handled the source for approximately 5–20 minutes. November 19, 1992 – A cobalt-60 source (which was used for an agricultural project) was taken home by a worker from a well within a construction site which used to be part of an environmental monitoring station in Xinzhou, Shanxi, China. This resulted in three deaths and affected 100+ people. A woman was exposed to radiation while nursing her sick husband. 41 days after the accident, her dose was estimated to be by means of a blood test. Her then unborn child (induced at 37 weeks, with a birth weight of 2 kilograms; 4 lb) received a dose of almost in utero; at the age of 16, the child had an IQ of 46. Eight years after the event, her second baby died because of an incident six months into pregnancy. 16 years after the accident, the woman suffered from premature aging. November 16-December 1, 1992 - Ohio, United States - 1992 Pennsylvania Brachytherapy Incident. An iridium-192 source used for remote afterloader brachytherapy was accidentally left inside the patient after its source wire broke. Radiation alarms went off, but were ignored by staff due to a history of false alarms.Institute of Medicine (US) Committee for Review and Evaluation of the Medical Use Program of the Nuclear Regulatory Commission; Gottfried KLD, Penn G, editors. Radiation In Medicine: A Need For Regulatory Reform. Washington (DC): National Academies Press (US); 1996. 1, Introduction. Available from: https://www.ncbi.nlm.nih.gov/books/NBK232721/ The patient, an 82-year-old woman named Sara Mildred Colgan, returned to her nursing home with the source still in her tumor. Four days later, on November 20, the source fell out, and was put into normal biomedical waste storage because it was not recognized as radioactive. Colgan died the next day, on November 21, as a result of the radiation overdose. The source was not found until it set off radiation alarms at a biomedical waste incineration site on December 1. During the 10 days between her death and the recovery of the source, almost 90 people were exposed to radiation, but no other deaths resulted. October 21, 1994 – Estonia – Theft of radioactive material in Tammiku. A caesium-137 source was stolen from a waste storage facility by three brothers. One received a 4,000 rad whole-body dose and died 12 days later. His family's dog also died, and his stepson developed radiation burns on his hands after touching the source. 1995 – France – A worker disassembled a density gauge at a textile treatment plant and handled a cesium-137 source for 30–45 minutes.

January 5, 1996 – Jilin, Xinzhou, China – A worker found a iridium-192 source on the ground. He held it in his hand for 15 minutes before putting the source in his pants pocket. The man received a whole body dose as well as large localized doses to the left hand, left wrist, and right thigh. June 1996 – October 9, 1997 – Lilo, Tbilisi, Georgia – 11 servicemen at the Lilo Training Center were hospitalized for symptoms found to be consistent with radiation exposure between April and September 1997. An additional hospitalization in June 1996 was later recognized as having been caused by radiation exposure. An investigation in October 1997 found a number of sources throughout and around the property, including 200 radium-226 coated gun sights. The primary and most active source, a metal cylinder containing cesium-137 with an estimated dose rate of /h at 1 meter's distance, was found in the pocket of a winter jacket stored in an underground shelter. It was estimated that the servicemen were exposed intermittently via the jacket over a period ranging from 60 to 300 days. It is believed that the radiation sources were training material left over from Soviet use of the installation, and a further 352 contaminated sites were identified within the country during subsequent investigations spurred by this incident. July 24, 1996 – Gilan, Iran – A radiographer was using a iridium-192 source to check boiler welds at a power plant. The source become detached from the device cable and fell into a trench where it was found by a worker who put it into his chest pocket. The worker carried around the source, at times removing it from his pocket and examining it. After approximately 90 minutes he began to experience nausea, dizziness and a burning sensation in his chest; he then returned the source to the trench and left it where he found it. The source was recovered by operators, unaware it had been handled in the intervening period. The worker received a whole body dose of . December 2, 1997 – Volgograd, Russia – An accidental exposure to an iridium-192 source caused 1 injury. 1997 – Georgia – A medical teletherapy cobalt-60 source was left unsecured near a station, causing a fatal radiation exposure to one individual. May 1998 - Algeciras, Spain - Acerinox accident. A cesium-137 source was inadvertently melted in the Acerinox stainless steel plant in Algeciras. Six people were mildly contaminated.