Don’t pick up, disassemble, or sell unidentified metal parts; stay clear of areas marked with the clover symbol

Cost: No cost involved. If you see unfamiliar metal cylinders, lead containers, or parts removed from equipment, simply steer clear — don’t pick them up, take them apart, or put them in your pocket.
In plain terms: Radiation has no smell, color, or temperature. Most radioactive sources look like ordinary pieces of metal, so “it looks harmless” is not a reliable indicator. The chance of an ordinary person encountering one is extremely low — fewer than one incident occurs per 10,000 sources each year. Yet when such an encounter does happen, the consequences are irreversible. In 1987, four people died in Brazil after dismantling a radiotherapy machine from an abandoned clinic.
Benefit: As of 2025, roughly 178,000 radioactive sources and 355,000 radiation devices are in use nationwide. The annual rate of radiation incidents involving sources remains below one per 10,000 sources. Classification is as follows: loss, theft, or uncontrolled release of Category I or II sources constitutes a major radiation incident; Category III is a relatively serious incident. Loss or theft of Category IV or V sources, or exposure exceeding annual dose limits, counts as a minor incident. Official example: In June 2020, a γ‑ray inspection was performed during pipeline upgrades at a steel plant in Ningxia. A Category II iridium‑192 source exposed three workers to radiation; one suffered third‑degree acute skin damage, another had fourth‑degree injuries on several fingers, and a third had first‑ to second‑degree burns. All three received doses far above legal limits; both responsible firms had their radiation licenses revoked and were fined 70,000 yuan. International example: In 1987, 50.8 TBq of cesium‑137 was removed from a radiotherapy machine in Goiânia, Brazil, after the device was dismantled; the source’s protective casing was ruptured. About 112,000 people were screened; 249 showed internal or external contamination, 129 of whom required moderate to severe medical care. Four people ultimately died. (National and international statistics)
Evidence grade: A
Sources: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；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；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；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；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；International Atomic Energy Agency (1988). The Radiological Accident in Goiânia. IAEA, Vienna. https://www-pub.iaea.org/MTCD/Publications/PDF/Pub815_web.pdf；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；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）
Notes: If you ever encounter such a source, move away, note its location, do not touch it, and call 110. Reporting is mandatory to environmental, police, and health authorities. Distance and time are the only effective safeguards; plastic bags or pockets offer no protection. Devices such as X‑ray machines or CT scanners emit radiation only when powered; once turned off, they pose no residual risk. The real danger lies in the sealed radioactive source inside them. Radiotherapy machines, pipeline and boiler inspection devices, well‑logging tools, and level gauges all contain such sources, which look identical to ordinary metal parts. Therefore, never try to identify a source — simply avoid picking up, selling, or taking home any unidentified equipment parts. Workers in scrap recycling, dismantling, hardware, and construction face higher risks; they should steer clear of any area marked with the clover warning symbol. Nuclear plant leaks represent a different type of incident, with an even lower probability of affecting the general public. The primary beneficiaries of these precautions are you and anyone else present at the scene.