|MadSci Network: Physics|
Generally your information is correct. I would think very little, if any, would be respirable from a scratch in the surface. You may produce some contamination however but I doubt there would be much to breath unless you specifically tried to inhale it. I am less sure about the chemical form of the americium as it relates to absoption in the gut. Basic radiation safety concerns with alpha emitters (like Am-241) is to limit their intake of any kind (ingestion, inhalation or injection) Even the small quantities of alpha emitters like that found in smoke detectors, as we learned from the alpha partical emitting Po-210 poisoning of the spy in England, can be harmful as it only takes a small amount inside the body. So care should always be taken with these materials.
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