Don't pick up, take apart or sell metal parts of unknown origin, and stay away from anything with a trefoil warning sign

Cost

Free. If you see an unfamiliar metal cylinder, a lead canister, or a part removed from equipment, go around it; don't pick it up, take it apart or put it in your pocket.

What you get

As of 2025, China had about 178,000 (17.8万) radioactive sources in use and 355,000 (35.5万) radiation devices (units or sets). The annual rate of radiation accidents involving sources has stayed below 1 per 10,000 sources. The grading works like this. Loss, theft or loss of control of a Class I or Class II source makes a major radiation accident. Class III is a serious radiation accident. Loss or theft of a Class IV or Class V source, or exposure of people above the annual dose limit, is a general radiation accident. An official case: in June 2020, at the ironworks of Ningxia Steel Group, gamma-ray flaw detection was being done on a blast furnace pipeline renovation project. A Class II iridium-192 source exposed three workers. Chen had acute radiation skin injury of grade III on the left hand. Liu had grade IV on the left thumb and index finger and grade III on the middle, ring and little fingers. Fan had grade I-II on the left hand. All three received doses seriously above the dose limits in national standards, and the two responsible companies had their radiation safety licenses revoked and were fined 70,000 CNY (7万). An international case: in 1987 in Goiania, Brazil, a teletherapy machine from an abandoned clinic was dismantled, a cesium-137 source of 50.8 TBq was taken out, and the sealed capsule holding the source was broken. About 112,000 people were monitored. Of these, 249 were contaminated inside or outside the body. Of those 249, 129 were moderately to severely contaminated and 50 needed close medical monitoring. In the end 4 died (national / international).

Notes

If you do come across one: stay away, remember the location, don't move it, and call 110. The regulations require reporting to the ecological environment authority, the public security authority and the health authority. Distance and time are the only effective protection; a pocket or a plastic bag does nothing. Devices such as X-ray machines and CT scanners, which produce radiation using electricity, leave no radioactivity once the power is off. What is really dangerous is the sealed radioactive source inside equipment. Hospital radiotherapy machines, gamma flaw detectors on pipelines and boilers, well-logging tools and level gauges all contain sources. Opening the casing exposes the source. And their appearance is no different from an ordinary metal part. So don't count on recognizing a radioactive source; never take apart, sell or take home a piece of equipment of unknown origin. Cases of people unknowingly picking up a source have also happened in China. In May 2014, in a chemical park in Nanjing, an iridium-192 source was lost during flaw detection work at a factory. A warehouse keeper picked it up on his rounds and put it in his work-clothes pocket. He was later diagnosed with mild acute radiation sickness and acute radiation skin injury of the right leg, was treated in the hospital for a year, and several years later still walked with two crutches. Two other workers said they had seen it, and one of them, on the way to work, took it for a necklace, picked it up, looked at it and threw it away. The company that lost the source was Tianjin Hongdi Engineering Inspection Development Co., Ltd. (天津宏迪工程检测发展有限公司). No official accident bulletin on this was found. The picker's injuries are taken from a follow-up paper published by doctors at the Jiangsu Provincial CDC; the part where it was picked up and thrown away rests only on a China Environment News (《中国环境报》) reporter's account. People who work in scrap collection, dismantling, hardware and construction sites face much higher risk than others; if you see a cordoned area marked with the trefoil sign on a site, go around it. A nuclear power plant leak is a different kind of accident, and an ordinary person is even less likely to meet one. The beneficiary is mainly you and the family members at the scene with you.

Evidence grade

A : Specific numbers from meta-analyses, large cohorts or randomized trials; for law and policy, the statute or official text.

Sources

1. 生态环境部 (2025). 2024 中国生态环境状况公报. https://www.mee.gov.cn/ywgz/sthjjcgl/hjzljcypj/202506/t20250605_1120773.shtml
2. 国家核安全局 (2026). 2025 年我国核与辐射安全监管工作成效. https://nnsa.mee.gov.cn/tpxw/202601/t20260107_1140062.html
3. 生态环境部 (2021). 关于一起 γ 射线探伤作业违法违规造成辐射事故案件处理情况的通报. https://www.mee.gov.cn/xxgk2018/xxgk/xxgk06/202101/t20210121_818216.html
4. 国务院 (2019). 放射性同位素与射线装置安全和防护条例（2019 年修订，第三十四、四十二、六十八条）. https://www.mee.gov.cn/ywgz/fgbz/xzfg/201909/t20190918_734315.shtml
5. 环境保护部 (2009). 关于建立放射性同位素与射线装置辐射事故分级处理和报告制度的通知（辐射事故分级标准）. https://www.mee.gov.cn/gkml/zj/wj/200910/t20091022_172414.htm
6. International Atomic Energy Agency (1988). The Radiological Accident in Goiânia. IAEA, Vienna. https://www-pub.iaea.org/MTCD/Publications/PDF/Pub815_web.pdf
7. 王福如, 王进, 余宁乐, 等 (2019). 南京“5.7”放射源丢失事故受照者照后医学随访观察. 中华放射医学与防护杂志, 39(11), 859-863. https://doi.org/10.3760/cma.j.issn.0254-5098.2019.11.011
8. 中国环境报 (2014-05-15). 放射源丢失的48小时（徐小怗、邵艺、褚方樵、汤景茹）. http://nnsa.mee.gov.cn/ztzl/haqshmhsh/hjbzl/202406/P020240624472937009953.pdf（网页存档 https://web.archive.org/web/20261005044102/http://nnsa.mee.gov.cn/ztzl/haqshmhsh/hjbzl/202406/P020240624472937009953.pdf）

Translated from the Chinese original. Original book, section 1, tip 36. This section is about health and medicines. It is general information, not a substitute for a doctor’s diagnosis or prescription. Content may be out of date and rules differ by place. When you actually deal with an agency, a doctor or a court, follow what local officials, doctors and lawyers tell you. Disclaimer