Freefall in color by many folks.
Florence: DNA is a section of the cell we really don't want damaged. Radiation can cause three types of damage to DNA. Single strand break, dual strand break, and mutation.
Florence: Dual strand breaks and mutations usually can't be repaired. Given time, a cell can often fix a single strand break.
Florence: The key is time. The faster a cell reproduces, the more vulnerable it is to radiation.
Sam: Product opportunity. Atomic level duct tape for molecular repair. The tricky part will be finding someone with fingers small enough to apply it.