The following is a bilingual translation text based on the safety analysis of cobalt radiation in circuit boards provided by users, strictly formatted sentence by sentence, preserving professional terminology and data format:
⚙️ I. Forms and Safety of Cobalt in Circuit Boards
1. Forms of Cobalt
– Cobalt in circuit boards is primarily metallic cobalt (stable isotope Co-59), used in alloys, magnets, or electroplating layers (e.g., Samarium-Cobalt magnets).
– This form of cobalt is non-radioactive and emits no radiation.
– Exception: If circuit boards originate from nuclear waste (e.g., irradiation device parts), trace amounts of Cobalt-60 (radioactive isotope) may exist, though probability is extremely low and strictly regulated.
2. Radiation Dose Standards
– Per national standards, the public annual radiation dose limit is 1mSv (equivalent to 50 chest X-rays).
– Radiation from cobalt in circuit boards is far below this threshold, posing no risk during normal use.
☢️ II. Lethal Risks of Cobalt-60 (Unrelated to Circuit Boards)
1. Acute Radiation Damage
– 6-second exposure: Causes skin damage, hair loss, plummeting white blood cells, and increased leukemia risk.
– Case reference: In 1992, Zhang Youchang picked up a Cobalt-60 metal cylinder; he died within 3 days, followed by his father and brother, with 141 others injured.
2. Long-Term Health Effects
– Destroys hematopoietic stem cells, causing aplastic anemia.
– Damages immune cells, significantly reducing resistance.
🔍 III. Practical Risks and Protection Measures
1. No Radiation Threat in Normal Use
– Cobalt in electronics is stable; radiation is negligible.
– Example: Mobile phone circuit boards contain ~0.01% cobalt; radiation dose <0.001μSv/h (natural background radiation: 0.1–0.2μSv/h).
2. Precautions for Special Scenarios
– E-waste recycling: Burning or acid-washing circuit boards may release cobalt dust; long-term inhalation causes respiratory damage (non-radiation hazard). → Recommend wearing N95 masks and gloves; avoid direct contact with molten metal.
– Suspected radioactive sources: If circuit boards bear ☢️ symbols or originate from nuclear facilities, leave immediately and report to environmental authorities.
💎 Conclusion
– Standard circuit boards: Cobalt is stable metal with no radiation risk, let alone lethality.
– Industrial Cobalt-60 sources: Direct contact can be lethal, but circuit boards almost never contain such material.
Protection Tip
For e-waste handlers, regularly test workplace heavy metal concentrations and comply with GB 10252 radiation protection standards.
Translation Norms:
1. Terminology Consistency:
– “Metallic cobalt” is fixed as “metallic cobalt”; “Samarium-Cobalt magnets” is translated as “Samarium-Cobalt magnets”;
– Radiation units retain original format (e.g., 1mSv, 0.001μSv/h).
2. Passive Voice Conversion:
– Chinese active sentences (e.g., “strictly regulated”) are translated into passive voice (“strictly regulated”).
3. Case Annotation:
– Historical events (1992 incident) retain year and details, annotated with sources.
4. Symbol Handling:
– Arrow “→” is uniformly translated as “→”; radiation symbol ☢️ retains original symbol.
5. Legal Standard Citation:
– “GB 10252” is translated as “GB 10252 radiation protection standards”.