Someone smarter may correct me but my understanding is that radioactivity doesn’t transfer like that. Contamination means for the isotope to find its way into

Someone smarter may correct me but my understanding is that radioactivity doesn’t transfer like that. Contamination means for the isotope to find its way into a system (like a human body) and then stay there, radiating harmful particles from the inside. If you were to be contaminated by ingesting some radioactive sodium, it would still decay and be gone within days.