Half-life is not life-time. If you have a very high dose of I-131, 7% of that dose will still be around after a month, and 0.04% after 3-months. That might be e

Half-life is not life-time. If you have a very high dose of I-131, 7% of that dose will still be around after a month, and 0.04% after 3-months. That might be enough to still be very hazardous.