Figure 2. Long-term Contamination Due to Cobalt Bomb in NYC - EPA Standards.

Inner Ring: One cancer death per 100 people due to remaining radiation (5% increase)
Middle Ring: One cancer death per 1,000 people due to remaining radiation (.5% increase)
Outer Ring: One cancer death per 10,000 people due to remaining radiation (.05% increase): EPA recommends decontamination or destruction